CRUISE REPORT: S04P
(Updated JUN 2018)







Highlights




                         Cruise Summary Information
               Section Designation:  S04P
Expedition designation (ExpoCodes):  320620180309
                  Chief Scientists:  Alison Macdonald / WHOI
                             Dates:  2018 MAR 09 - 2018 MAY 14 
                              Ship:  NATHANIEL B. PALMER
                     Ports of call:  Hobart,Tasmania - Punta Arenas, Chile

                                                    -59.6176
             Geographic Boundaries:  159.1537                      -73.499
                                                    -75.2905

                          Stations:  122
      Floats and drifters deployed:  18 Floats & 20 drifters deployed
    Moorings deployed or recovered:  0

                            Contact Information:

                             Alison M. Macdonald
              Senior Research Specialist • Physical Oceanography
                    Woods Hole Oceanographic Institution
           266 Woods Hole Rd. • MS# 21 • Woods Hole, MA 02543-1050
                             amacdonald@whoi.edu















Cruise Report for the 2018 Reoccupation of S04P
***********************************************


1.  GO-SHIP S04P 2018 HYDROGRAPHIC PROGRAM


Fig. 1.1: Cruise track of S04P 2018


The Pacific Ocean S04P repeat hydrographic line was reoccupied for the
US Global Ocean Carbon and Repeat Hydrography Program. Reoccupation of
the S04P transect occurred on the RVIB Nathaniel B Palmer from March
9, 2018 to May 14, 2018. The survey of S04P 2018 consisted of *CTDO*,
rosette, *LADCP*, *UVP*, water samples and underway measurements. The
ship departed from the port of Hobart on the island of Tasmania,
Australia and completed the cruise in the port of Punta Arenas, Chile.

A total of 122 stations were occupied with one CTDO/rosette/LADCP/UVP
package. 122 stations and 125 CTDO/rosette/LADCP/UVP casts including 2
test casts were performed. The stations were, for the most part, a
reoccupation of S04P 2011 and detailed in the following sections. 18
floats were deployed in total on S04P 2018 and detailed in the Float
Deployments section of the cruise report. 6 *SOCCOM* floats were
deployed on S04P 2018 and are detailed in the SOCCOM floats section of
the cruise report. 5 *FSU* floats were deployed on S04P 2018 and are
detailed in the FSU floats section of the cruise report. 5 *CSIRO*
floats were deployed on S04P 2018 and are detailed in the CSIRO floats
section of the cruise report. 2 EM-APEX floats were deployed on S04P
2018 and are detailed in the EM-APEX floats section of the cruise
report. 20 drifters were deployed on S04P 2018 and are detailed in the
Drifter Deployments section of the cruise report.

CTDO data and water samples were collected on each CTDO, rosette,
LADCP, and UVP cast, usually within 10 meters of the bottom. Water
samples were measured on board for salinity, dissolved oxygen,
nutrients, *DIC*, pH, total alkalinity and *CFCs*/*SF6*. Additional
water samples were collected and stored for shore analyses of Δ^15N
and Δ^18N, Δ^18O, *DOC*/*TDN*, 13C/14C, *POC*, *HPLC*, rare earth
elements, Neodymium, and noble gases.

A sea-going science team assembled from 20 different institutions
participated in the collection and analysis of this data set. The
programs, principal investigators, science team, responsibilities,
instrumentation, analysis and analytical methods are outlined in the
following cruise document.


1.1  Programs and Principal Investigators

Program                 | Affiliation        | Principal           | Email                    
                                             | Investigator        |
========================|====================|=====================|===========================
CTDO Data, Salinity,    | UCSD, SIO          | Susan Becker,       | sbecker@ucsd.edu,        
Nutrients, Dissolved O2 |                    | Jim Swift           | jswift@ucsd.edu          
------------------------+--------------------+---------------------+---------------------------
Total CO_2 (DIC)        | PMEL, AOML, NOAA   | Richard Feely,      | Richard.A.Feely@noaa.gov
                        |                    | Rik Wanninkhof      | Rik.Wanninkhof@noaa.gov  
------------------------+--------------------+---------------------+---------------------------
Underway Temperature,   | AOML, NOAA, ASC    | Rik Wanninkhof,     | Rik.Wanninkhof@noaa.gov 
Salinity, and pCO_2     |                    | ASC                 | admin@nbp.usap.gov       
------------------------+--------------------+---------------------+---------------------------
Total Alkalinity, pH    | UCSD               | Andrew Dickson      | adickson@ucsd.edu        
------------------------+--------------------+---------------------+---------------------------
SADCP                   | UH                 | Eric Firing         | efiring@soest.hawaii.edu 
------------------------+--------------------+---------------------+---------------------------
LADCP                   | LDEO               | Andreas Thurnherr   | ant@ldeo.columbia.edu    
------------------------+--------------------+---------------------+---------------------------
CFCs, SF6, N2O          | UW                 | Mark Warner         | warner@uw.edu            
------------------------+--------------------+---------------------+---------------------------
DOC, TDN                | UCSB               | Craig Carlson       | carlson@lifesci.ucsb.edu 
------------------------+--------------------+---------------------+---------------------------
C13 & C14               | WHOI, Princeton    | Ann McNichol,       | amcnichol@whoi.edu      
                        |                    | Robert Key          | key@princeton.edu        
------------------------+--------------------+---------------------+---------------------------
Transmissometry         | TAMU               | Wilf Gardner        | wgardner@ocean.tamu.edu  
------------------------+--------------------+---------------------+---------------------------
Fluorescence and        | U Maine            | Emmanuel Boss       | emmanuel.boss@maine.edu  
Backscatter (SOCCOM)    |                    |                     |                          
HPLC/POC                |                    |                     |                          
------------------------+--------------------+---------------------+---------------------------
UVP                     | U Alaska Fairbanks | Andrew McDonnell    | amcdonnell@alaska.edu    
------------------------+--------------------+---------------------+---------------------------
Nitrate Δ^15N and       | MPIC               | Gerald Haug,        | gerald.haug@mpic.de     
Δ^18N                   |                    | François Fripiat    | f.fripiat@mpic.de        
------------------------+--------------------+---------------------+---------------------------
REE                     | Oxford             | Yves Plancherel     | yves.plancherel@earth.ox 
                        |                    |                     | .ac.uk                   
------------------------+--------------------+---------------------+---------------------------
Noble Gases, ∆^18O      | OSU, SIO           | Nicholas Beaird,    | beairdn@oregonstate.edu 
                        |                    | Fiamma Straneo      | fstraneo@ucsd.edu        
------------------------+--------------------+---------------------+---------------------------
Neodymium               | Imperial College   | Tina van de Flierdt | tina.vandeflierdt@imperi 
                        | London             |                     | al.ac.uk                 
------------------------+--------------------+---------------------+---------------------------
Argo Floats             | FSU, CSIRO         | Kevin Speer,        | kspeer@fsu.edu,          
                        |                    | Steve Rintoul       | steve.rintoul@csiro.au   
------------------------+--------------------+---------------------+---------------------------
SOCCOM Floats           | UW, MBARI, UCSD,   | Steve Riser,        | riser@ocean.washington.edu 
                        | SIO                | Ken Johnson,        | johnson@mbari.org   
                        |                    | Lynne Talley        | ltalley@ucsd.edu         
------------------------+--------------------+---------------------+---------------------------
Surface Drifters        | NOAA, AOML         | Rick Lumpkin,       | rick.lumpkin@noaa.gov   
                        |                    | Shaun Dolk          | shaun.dolk@noaa.gov      
------------------------+--------------------+---------------------+---------------------------
EM-APEX Floats          | UW APL             | James Girton        | girton@apl.washington.edu
------------------------+--------------------+---------------------+---------------------------
Underway Bathymetry,    | ASC                | ASC                 | admin@nbp.usap.gov       
Meteorological Data     |                    |                     |                          



1.2  Science Team and Responsibilities

Duty                     | Name             | Affiliation | Email Address            
=========================|==================|=============|==========================
Chief Scientist          | Alison Macdonald | WHOI        | amacdonald@whoi.edu      
-------------------------+------------------+-------------+--------------------------
Co-Chief Scientist,      | Ellen Briggs     | UCSD        | ebriggs@ucsd.edu         
floats and drifters      |                  |             |                          
-------------------------+------------------+-------------+--------------------------
CTD Watchstander         | Ribanna Dittrich | U Edin.     | ribanna.dittrich@ed.ac.uk
-------------------------+------------------+-------------+--------------------------
CTD Watchstander         | Lauren Ferris    | W&M VIMS    | lnferris@vims.edu        
-------------------------+------------------+-------------+--------------------------
CTD Watchstander         | Taimoor Sohail   | ANU         | taimoor.sohail@anu.edu.au
-------------------------+------------------+-------------+--------------------------
CTD Watchstander, floats | Chanelle Cadot   | UW          | cadotc@uw.edu            
-------------------------+------------------+-------------+--------------------------
CTD Watchstander         | Bingkun Luo      | RSMAS       | LBK@rsmas.miami.edu      
-------------------------+------------------+-------------+--------------------------
CTD Watchstander         | Amir Barkhordary | RSMAS       | abarkhordary@rsmas.miami 
                         |                  |             | .edu                     
-------------------------+------------------+-------------+--------------------------
Nutrients, ODF           | Susan Becker     | UCSD ODF    | sbecker@ucsd.edu         
supervisor, SOCCOM       |                  |             |                          
floats                   |                  |             |                          
-------------------------+------------------+-------------+--------------------------
Nutrients                | John Ballard     | UCSD ODF    | jrballard@ucsd.edu       
-------------------------+------------------+-------------+--------------------------
CTDO Processing,         | Joseph Gum       | UCSD ODF    | jgum@ucsd.edu            
Database Management      |                  |             |                          
-------------------------+------------------+-------------+--------------------------
Salts, Rosette           | John Calderwood  | UCSD STS    | jcalderwood@ucsd.edu     
Maintenance              |                  |             |                          
-------------------------+------------------+-------------+--------------------------
Salts, Rosette           | Jeremiah Brower  | UCSD STS    | jjbrower@ucsd.edu        
Maintenance              |                  |             |                          
-------------------------+------------------+-------------+--------------------------
Dissolved O_2, Database  | Andrew Barna     | UCSD ODF    | abarna@ucsd.edu          
Management               |                  |             |                          
-------------------------+------------------+-------------+--------------------------
Dissolved O_2, CTDO      | Kenneth Jackson  | UCSD ODF    | k3jackson@ucsd.edu       
Processing               |                  |             |                          
-------------------------+------------------+-------------+--------------------------
SADCP, LADCP             | Manuel Gutierrez | UCSD        | mog002@ucsd.edu          
                         | Villaneuva       |             |                          
-------------------------+------------------+-------------+--------------------------
DIC, underway pCO2       | Andrew Collins   | PMEL        | andrew.collins@noaa.gov  
-------------------------+------------------+-------------+--------------------------
DIC, underway pCO2       | Patrick Mears    | AOML        | patrick.mears@noaa.gov   
-------------------------+------------------+-------------+--------------------------
CFCs, SF6, N2O           | Mark Warner      | UW          | warner@uw.edu            
-------------------------+------------------+-------------+--------------------------
CFCs, SF6, N2O           | Eugene Gorman    | LDEO        | egorman@ldeo.columbia.edu
-------------------------+------------------+-------------+--------------------------
CFCs, SF6, N2O student   | Max Rintoul      | ANU         | mrintoul23@gmail.com     
-------------------------+------------------+-------------+--------------------------
Total Alkalinity         | Manuel Belmonte  | UCSD        | mbelmonte@ucsd.edu       
-------------------------+------------------+-------------+--------------------------
Total Alkalinity         | Sarah Barnes     | UCSD        | sbarnes@ucsd.edu         
-------------------------+------------------+-------------+--------------------------
PH                       | May-linn Paulsen | UCSD        | mpaulsen@ucsd.edu        
-------------------------+------------------+-------------+--------------------------
DOC, TDN, Radio          | Cole Hansell     | UW          | cole.hansell926@gmail.com
Carbon                   |                  |             |                          
-------------------------+------------------+-------------+--------------------------
UVP                      | Rachel Lekanoff  | U Alaska    | rmlekanoff@alaska.edu    
-------------------------+------------------+-------------+--------------------------
Rare Earth Elements,     | Yves Plancherel  | Oxford      | yves.plancherel@earth.ox 
Barium, Noble Gases,     |                  |             | .ac.uk                   
Neodymium                |                  |             |                          
-------------------------+------------------+-------------+--------------------------
Marine Projects          | Ken Vicknair     | ASC         | mpc@nbp.usap.gov         
Coordinator              |                  |             |                          
-------------------------+------------------+-------------+--------------------------
Marine Lab Technician    | Jess Ackerman    | ASC         | mlt@nbp.usap.gov         
-------------------------+------------------+-------------+--------------------------
Marine Technician        | Jennie Mowatt    | ASC         | mt@nbp.usap.gov          
-------------------------+------------------+-------------+--------------------------
Marine Technician        | Tony D'Aoust     | ASC         | mt@nbp.usap.gov          
-------------------------+------------------+-------------+--------------------------
Electronic Technician    | Barry Bjork      | ASC         | et@nbp.usap.gov          
-------------------------+------------------+-------------+--------------------------
Network Administrator    | Chris Linden     | ASC         | admin@nbp.usap.gov       




2.  CRUISE NARRATIVE


2.1  Summary

The 2018 occupation of the GO-SHIP S04P hydrographic line (Figure 1.1)
measured the water column at 117 locations between Cape Adare
(70.45°S, 168.48°E) in the western Pacific sector of the Southern
Ocean to 73.48°W along a nominal 67°S between March 17 and May 9, 2018
(UTC, not including transits from/to ports, March 9-17 and May 9-15,
respectively). The track included 4 spurs to the south at
approximately 170°E, 170°W, 150°W and 103°W connecting to the GO-SHIP
P14S, P15S, P16S and P18S lines, respectively. There were two test
stations (green dots in Figure 1.1): one at the start of the cruise,
which sampled to ~1400 m (Station 901, 59.62°S, 159.16°E) and one,
which had no samples, but was used to re-lay the wire (Station 902,
67.56°S, 174.95°W). There were 3 aborted stations (red dots in Figure
1) that were not sampled at all (Station 9:  71.50°S, 170.00°W;
Station 104: 66.00°S, 103.00°W; Station 109: 67.50°S, 94.66°W)

The rosette instruments included dual CTDs, one with oxygen, a
secondary separate RINKO oxygen sensor, fluorometer, backscatter
fluorometer, tranmissometer, upward and downward looking LADCPs and an
underwater vision profiler (UVP) flow cytometer. There were also EM-
APEX, ALTO, biogeochemical, and Argo float deployments as well as GDP
drifter deployments carried out between 21 March and 22 April 2018
(173.5°E-129.5°W). Along with underway bathymetry, TSG and met data,
there was also underway sampling (S, O2, DIC, pH, TAlk, pCO2). Please
see individual sections for further detail.

After MOB (March 6th – 9th), the RVIB N.B. Palmer departed Hobart,
Australia on March 9th at 16:30 (local, 08:30 UTC) and steamed for 8
days before reaching the first station at 70.9°S, 168.5°E. A test cast
was done along the way.  Sampling began on March 17 and ended May 9
(UTC). The cruise track, originally based on the 2011 occupation,
turned out to be less than straightforward and it is the intention of
this narrative to explain the reasoning behind the complexity of the
2018 track.

Three words best describe the idiosyncrasies of the 2018 S04P
expedition: “weather”, “wire”, and “wonderment”.  The weather, which
not unexpectedly, caused delays, also determined many of the decisions
to change the planned track and/or direction. Sea state and ice
conditions, often forced by non-local winds, determined when and where
it was possible to put the rosette in and whether or not it was
possible to hold station. Our difficulties with the wire (see Chapter
3.5) either caused delays or spurred decisions to transit. While our
instrumentation performed, if not flawlessly, at least better than
might have been hoped for, on many occasions it was weather and wire
that turned what could have been simple situations into difficult
ones. But, then there was also the wonderment. Every time we headed
south the shear excitement of entering this southern ice-filled realm
(the first time, the second time, and yet again) brought an air of
expectation to all aboard. Our turns to south were morale boosters on
this; the longest of the GO-SHIP cruises. After succeeding at
fulfilling much of originally planned science and after many long
hours trying to fit the final needs of the science (to measure the
last boundary current and shelf) into the remaining time, the cruise
was abruptly cut short on May 9 (sta. 120) by a medical situation that
NSF deemed serious enough to require the ship to head with all due
speed to Punta Arenas. Although the order and choice of stations may
well cause frustration for data analysts well into the future, please
know that no turn or choice was made without care or forethought.


2.2  Narrative - In the Beginning

The 2018 occupation of the S04P line was scheduled for 67 DAS (Days at
Sea), 68 DAS including the dateline crossing, from March 9 2018
(Hobart, Tasmania, Australia) to May 14, 2018 (Punta Arenas, Chile)
(Figure 1.1). Like its 2011 predecessor, the cruise would take place
on the RVIB Nathaniel B. Palmer (NBP) a global-class vessel unique to
U.S. GO-SHIP in that, under charter to the U.S. National Science
Foundation, it is operated by the commercial entity, Edison-Chouest
Offshore (ECO).

The NSF’s U.S. Antarctic Program (USAP), through a contract with
Raytheon Polar Services whose personnel are Antarctic Support
Contractors (ASC), provides the pre-cruise and onboard support. All
pre-cruise planning, shipping management and onboard science is
supported by ASC. Every member of the science party (and ASC
personnel) underwent a rigorous USAP physical qualification prior to
joining the cruise, and while each science group was responsible for
their own shipping and customs, ASC/DAMCO (the shipping company used
by USAP) personnel facilitated and coordinated getting the shipments
to and from the ship in both ports.

The science parties arrived to meet the RVIB Nathaniel B. Palmer (NBP)
in Hobart, on March 6, 2018 to begin the mobilization (MOB) process of
loading the vessel, unpacking equipment, setting up the lab spaces and
training student personnel who would be carrying out a number of the
science activities. Arriving by the 6th was not made easy as weather,
which later became the driving factor in many cruise decisions, made
it difficult for a number of those coming from Europe and the U.S.
eastern seaboard where many thousands of flights were cancelled in the
early days of March due to two separate storms on either side of the
Atlantic. Nevertheless, we all eventually arrived. There had been the
intention for the chief and co-chief to tour the NBP the day before
(March 5th) the S04P MOB but the chief scientist was one of those
delayed by weather related flight cancellations, so the early walk-
through did not occur and March 6th was very busy and full of numerous
decisions.


2.3  The Spaces (i.e. Deck/Lab Plan)

The NBP cruise that took place prior to S04P had radiation sources so
there was concern about contamination of the lab and hold spaces.
However, numerous negative swipes of the decks, the container hold and
in particular the bio lab where the isotope samples would be prepped
gave the science party confidence that they could continue with the
initial layout plan It was decided to place two vans on the helo-deck
(ODF storage and the working CFC van) and one in the container hold
(DIC – hold would keep temperatures above freezing and allow easy
access to power if it were needed). This turned out to be a reasonable
decision as results from swabs that were sent away for more accurate
lab analysis were returned a couple of weeks later. Their results
showed that the only place that remained contaminated was inside the
previous cruise’s lab van, which sat in the container hold. In spite
of several swabs and swipes in the area, no tested location in the
container hold outside the interior of the contaminated van returned
positive results.

For S04P, the ODF team had full rein of the Hydro Lab for oxygen and
nutrient analysis and HPLC/POC sample prep. The rest of the onboard
measurements were done in Aft Dry Lab (Figure 2). These groups
included: TAlk (using the bench next to starboard bulkhead and half
the next one over); pH (using the backside of the TAlk interior bench
and half the next one over); DIC (using the backside of the pH bench
and half the next one over) leaving a corridor of generally unused
space on the interior (port) side of the Main Lab closest to the
passageway.  When necessary Δ15N/Δ18O isotopes in nitrate (N-isotopes)
used this space for prep and Δ18O secured their samples here while
they were warming to room temperature. DOC/radiocarbon used the
forward end of the Main Lab bulkhead bench behind the freezers for
prep and post-sampling work. N-isotopes used the -20 freezers in the
main lab. DOC used one of the -80 freezers. HPLC/POC used the other.
The Bio Lab was used as a clean space for stowage and sampling prep
for some of our sailing and non-sailing partners/ancillary
measurements (REE, Neodymium, Helium/noble gases, and Δ18O).  The
temperature controlled Salts Room was also in the Bio Lab. The CTD
Watch had full rein of the forward Dry Lab, and we all made use of the
computers in the E-Lab space across the passageway, which was also
used as the daily crossword space. The LADCP and UVP used the Aft Dry
Lab bench closest to the Baltic Room door so they could easily run
their data/recharging cables and used forward Dry Lab space for
working on their laptops. Floats and drifters were secured in the Wet
Lab. All in all there was ample space and some to spare for all
science stowage requirements and operations.


Fig. 2.1: S04P 2018 lab layout on the NBP according to the different
          groups measuring and sampling.


2.4  Shipping and MOB

While most of the S04P equipment showed up on the dock as scheduled
and was loaded on the first day of the MOB, there were a few issues.
In particular, there was trouble finding and tracking the SOCCOM and
APL floats and the GDP drifters, but it was managed. With the
tremendous efforts of Don Hill (from DAMCO) all equipment arrived at
the ship in time for pre-cruise prep and student training (the floats)
and before departure (the drifters). The NBP was loaded, science set
up, and equipment stowed in time for the scheduled departure. This
state of readiness was thanks in no small part to the efforts of the
MPC, K. Vicknair who worked tirelessly coordinating people and
logistics through constant emails and phone calls and lending his good
humor to distress in moments when the knots appeared too difficult to
untangle.

On March 7, those with the time followed up on an invitation to tour
the French research vessel Astrolabe, which was docked next to us at
Macquarie Wharf. On the evening of March 7th the NBP science parties
from both S04P and the cruise preceding S04P, as well as ASC and ECO
personnel were invited, along the crew of the French ship Astrolabe,
to a reception held by the Tasmanian Polar Network. This is a group of
local business people, academics and government officials with a
strong interest in supporting the collaboration amongst all those
exploring and living in Antarctica. It was a wonderful evening filled
with interesting conversation and discussion and even awards for the
youngest voyagers. The S04P science party was grateful for the
opportunity to have met all those who attended.

Overnight from the March 7 to 8 the ship moved from Macquarie Wharf
(easily accessible to the downtown hotels, restaurants, shopping and
oceanographic institutions) to Selfs Point fueling pier a few miles
away. All science personnel were asked to arrive at the ship on the
8th ready to stay onboard the night before we sailed. Most of the
science party arrived in cabs, some in rental vehicles. M. Rintoul (a
local and our CFC student) gave numerous rides and one or two hiked
the distance.  But, in the end everyone made it, and along with
continuing the setup, on the 8th and 9th the S04P science party gave
tours of the ship and in particular, the DIC, pH and TAlk setup, to
nearly 50 friends and Australian colleagues. Shortly before the NBP
sailed, there was an interview by a local newspaper. The chief and co-
chief scientists along with the float student (C. Cadot) answered
questions about the Palmer, Hobart, and GO-SHIP as well as the
international collaborative effort these long-line cruises entail.
The ship left a little earlier than the originally planned departure
(19:00) and was underway heading generally southeast by 16:30 (local).
The following sections of the narrative divide the cruise into the
various areas of the basins that were sampled divided by the transits
that took place in between.


2.5  The Transit South (Figure 1.1)

The preliminary cruise plan would take the NBP directly to the western
side of the Ross Sea off Cape Adare at 70.65°S, 168.07°E (between the
northern end of Borchgrevink Coast and western end of Pennell Coast).
Although S04P had clearance to sample within the Australian Economic
Exclusion Zone (EEZ), it had been decided not to apply for clearance
for the Commonwealth Marine Reserves (CMR). As most of the EEZ waters
surrounding Tasmania proper are also CMR, the ship track was chosen so
that once the NPB was first out of EEZ around Tasmania, underway
systems could be turned on and although it would travel through the
Australian EEZs around Macquarie Island it would not enter the CMR or
the New Zealand EEZ.

Not long after departure, the science party had their first weekly
abandon ship drill (where everyone tried on ECW gear and gumby suits)
and a general alarm drill the next day. However, on the afternoon of
the 9th the general alarm went off and it was not a drill, but rather
it was found out later that an electrical short that tripped the
alarm. It was good to know that the entire science party could get to
the muster station in short order when required.  From that point on
drills occurred every Tuesday at 12:30 (ship time). The following day
there were numerous orientation meetings for both USAP and ECO/Palmer,
and the students got a tour of the rosette.

While in transit (March 9 – 17) the MPC, MTs, co-chief and chief
scientist and ODF leads met to discuss over the side operations,
timing and definitions. We had a how to sample workshop for the
students with information on not just salts but also pH, TAlk and
finally radiocarbon. Before the start of actual sampling students were
chosen from both shifts to assist with TAlk, radiocarbon, and helium
sampling and to handle the Δ18O and N-isotope sampling.

On the March 10th the Captain decided to turn directly eastward
because the rough seas were causing large rolls on the southeasterly
heading. (The turn can be seen as a slight bend in the cruise track in
Figure 1.1). Although, the eastward turn bought the NBP a smoother
ride, it also brought the ship closer to Macquarie Island and into the
Australian EEZ. The ship never crossed into the CMR or New Zealand EEZ
on the eastern side of the island, and so it was not necessary to turn
off underway equipment or discontinue underway sampling and analysis
(see Chapter X). Some of the ship’s empty hazardous waste bins sitting
in metal frames on the deck took waves while in transit. Compressed
air was used to pop out the ones that had been deformed. Leak tests
showed that no leaks resulted from the temporary damage.   Science
talks were begun on this transit and the practice of having
presentations from the science party while in transit continued
throughout most of the cruise. The transit also saw the beginnings of
a continuous effort to update the station plan and track.

The ship moved 1 hour forward on the 11th and again on the 12th, and
had a Ground Hog’s Day repeat of March 13th (we did not change the day
after this regardless of whether or what direction we crossed the
Dateline). All hour changes, which were done at the discretion of
Captain Souza are listed in Table 1.


Table 2.1:  2018 S04P Ship Time Changes

       |         |         | Became  |          |  
Date   | Time    | Became  | Time    | Relation | Comment         
       | (local) | Date    | (local) | to UTC   |                 
=======|=========|=========|=========+==========|=================
3/9/18 |         |         |         | UTC+11   | Note: Hobart    
       |         |         |         |          | AEST UTC+10     
-------+---------+---------+---------+----------+-----------------
3/11/18| 22:00   | 3/11/18 | 23:00   | UTC+12   | Transit to      
       |         |         |         |          | Station 1       
-------+---------+---------+---------+----------+-----------------
3/12/18| 02:00   | 3/12/18 | 03:00   | UTC+13   | Transit to      
       |         |         |         |          | Station 1       
-------+---------+---------+---------+----------+-----------------
3/13/18| 24:00   | 3/13/18 | 00:00   | UTC-11   | Transit to      
       |         |         |         |          | Station 1       
-------+---------+---------+---------+----------+-----------------
3/14/18| 05:00   | 3/14/18 | 06:00   | UTC-10   | Transit to      
       |         |         |         |          | Station 1       
-------+---------+---------+---------+----------+-----------------
3/16/18| 09:00   | 3/16/18 | 10:00   | UTC-9    | Transit to      
       |         |         |         |          | Station 1       
-------+---------+---------+---------+----------+-----------------
4/8/18 | 13:00   | 4/8/18  | 14:00   | UTC-8    | Transit back to 
       |         |         |         |          | 67°S (Sta. 54)  
-------+---------+---------+---------+----------+-----------------
4/9/18 | 18:00   | 4/19/18 | 19:00   | UTC-7    | Transit back to 
       |         |         |         |          | 67°S (Sta. 54)  
-------+---------+---------+---------+----------+-----------------
4/29/18| 09:00   | 4/29/18 | 10:00   | UTC-6    | Transit to 103°W
       |         |         |         |          | (Sta. 98)       
-------+---------+---------+---------+----------+-----------------
5/10/18| 18:00   | 5/10/18 | 19:00   | UTC-5    | Transit to Punta
       |         |         |         |          | Arenas          
-------+---------+---------+---------+----------+-----------------
5/11/18| 09:00   | 5/11/18 | 10:00   | UTC-4    | Transit to Punta
       |         |         |         |          | Arenas          
-------+---------+---------+---------+----------+-----------------
5/12/18| 13:00   | 5/12/18 | 14:00   | UTC-3    | Transit to Punta
       |         |         |         |          | Arenas          
-------+---------+---------+---------+----------+-----------------
5/12/18| 13:00   | 5/12/18 | 14:00   | UTC-3    | Transit to Punta
       |         |         |         |          | Arenas          
——————————————————————————————————————————————————————————————————
Note: Ship time changes bore no relation to actual time zones 
      crossed by the ship.


2.6  The Test Cast

The original plan was for a test cast on the morning of March 11, but
the cast was delayed until the 13th due to rough weather/seas. It
began ~12:40 (local = UTC-9) and it took nearly 50 minutes to get the
bottles cocked and the rosette prepared the first time. Obviously this
improved with time and familiarity. On the test cast one student
deployed, another did the “bottom approach” and a third did the
recovery. Everybody was able to fire 6 bottles. After the test cast,
new cables were put on the transmissometer as the data appeared to be
very noisy. The LADCP cables also did not perform, and therefore
several Niskins were removed to allow access to instrumentation. The
issue turned out to be a faulty star cable (the cable that allows both
the upward and downward looking LADCPs to operate simultaneously).
Further information can be found in the LADCP section of this report.

The test cast (Station 901) helped sort out issues of timing and where
to get information – e.g. the pH/TAlk group wanted the salinity record
after a cast but the salinity record is not an automatic output of the
initial processing, nevertheless ODF was able to make this information
available online in short order. The cast also made it clear that
smoking could even on the smoking (waterfall) deck could be an issue.
This information was passed to the crew by the Chief Mate and was
rarely an issue for sampling again. It also became clear that there
was an inadequate supply of gloves and it was decided that only those
who absolutely had to wear them would. Originally it was thought that
it might be necessary move DOC up in the sampling order, but the DOC
and REE PIs (C. Carlson, Y. Plancherel) decided it was not necessary
for those going before them in the sampling to wear gloves as long as
they were careful not touch the Niskin nipples.

On the last day of transit, it was brought to the science parties’
attention that there were unspecified complaints about food from
unknown personnel and there was the issue arising of people hoarding
or wasting food, particularly fresh fruit. Emails were sent to ask
everyone to be more accepting and more aware that the ship was at the
beginning of a very long voyage with limited supplies. Similar
complaints arose at various times throughout the cruise and each was
followed up with a similar request from chief scientist and/or
caption.  There was little need for such behavior as throughout the
cruise the galley did an amazing job producing 4 hot meals a day
(breakfast, lunch, dinner and mid-rats). Certainly, the components of
the meals had less variety as the cruise progressed, but the fresh
lettuce lasted until Day 46, the apples and grapefruit lasted a couple
more weeks and there were still fresh avocados for the Taco Tuesday’s
guacamole on Day 61.

The weather picked up (NW 40 knot winds) the last day of this first
transit. Icebergs began to appear along the way, including a growler
with an Adélie penguin pack that dove in once they saw the ship go by.
The sight of ice, penguins, whales and seals remained a morale booster
through the long days of the voyage.


2.7  The Beginning of Sampling: 170°E  (P14S repeat) Line 
     (March 17–19, Stations 1– 8)


Fig: 2.2: 2018 S04P station locations in the vicinity of 170°E.
          Station numbers are labeled. Planned stations that were not
          executed due to ice are shown in red. See Figure 1 for transit
          tracks.

The initial plan was to have the first station on the shelf in ~200 m
of water and have the ship move northward back toward the 67°S on a
line perpendicular to the shelf. Having received weather and ice
updates, on the 16th, the Captain believed it would be possible to
sail around the pack ice to where the 200 m station would be located in
more easily moved newer ice. However, this was not to be. Unable to
sail around because the wind was blowing new ice into the packed
multi-year on the shelf, hydrographic casts began well off the Cape
Adare shelf in 1400 m of water at 70. 90°S, 168.48°E (sta. 1) and
continued to the northeast from 168°E to 170°E toward the 67°S line
with the nominal 30 nm spacing (Figure 3). There were issues with the
altimeter on the first 3 stations resulting in the need to use LADCP
data to back out the bottom depth (see Chapter 22). On station 3, the
rosette made contact with the bottom and it was determined that
incorrect reprogramming caused the altimeter to begin reporting at 10
m above the bottom rather than at 200 m. Replacing what should have
been a 200-m-altimeter with the 100-m version from the NBP solved this
problem. The latter was used for the rest of the cruise with no
issues. On March 19, having completed Station 8 half way up the 170°E
line and waiting with the ship doing weather patterns for 12 hours, a
major storm threating a 5-day delay forced the decision to head
southeast to the southern end of the 170°W spur.


2.8  The 170°W (P15S repeat) Meridional Line 
     (March 21–23, Stations 9–17)


Fig. 2.3: 2018 S04P station locations in the vicinity of the 170°W and
          150°W meridional lines. Planned stations that were not executed 
          due to the combined forces of ice and wind are shown in red. 
          See Figure 1 for transit tracks.


The transit took approximately 1.75 days. Ice maps from SIO and
through the bridge had already suggested that the ship could not make
it to the planned start of the 170°W at 75.86°S (depth = 900 m)
(Figure 3, red crosses) given the time constraints on the cruise. In
turned out that, limited by freezing surface waters and swell, even
Station 9 at 71.5°S, 170°W was aborted. Observations on the 170°W line
began at 71°S (sta. 10, Figure 3 black crosses) and continued
northward with 0.5° (30 nm) spacing to 67.5°S (sta. 17) before the
ship transited back to the 170°E line to pick up at 67.62°S, 173.54°E
(sta. 18, 28.8 nm from sta. 8). On Station 12 the question of ship
roll came up. After discussion, the bridge was asked to make less use
of the Dynamic Positioning System (DPS) because although it allowed
position to be maintained, it was also the cause of the roll. As the
bridge said position could be maintained to within 0.1 nm in position
without DPS, it was decided not to use it while in sea state/weather
conditions similar to what was being seen at the moment. It was also
at this point that the chief scientist confirmed that there would be
no argument with any decision the bridge would make concerning station
position when it concerned safety.  This agreement first came into
play on Station 14 where there was an iceberg sitting on the planned
position.


2.9  The End of 170°E to the Zonal 67°S Line to 170.5°W 
     (March 24–29, Stations 18–30)

A 44 hour transit took the ship back to the nominally 170°E line at
173.54°E (sta. 18, Figure 3). As kinks had been found at the top of
the wire after Station 17, while transiting to Station 18, 24 m of
wire was cut and the wire was reterminated on March 24 (Table 2).
Sampling continued along the line (to sta. 27) until wire issues (the
lay of wire on the drum and a visually noticeable distortion of the
wire) appeared on Station 22. The details of these wire issues are
discussed in Chapter 3.5 and are not repeated here.  Suffice to say,
the net result of the issue for science was that it slowed casts, by
reducing winch speed and breaking the otherwise seamless downcasts,
requiring longer waits at bottle stops and eventually demanded an
attempt to unwind and rewind the wire in deeper water (sta. 902,
between stations 27 and 28). The rewinding was unsuccessful and was
followed by a decision to transit (after sta. 29, 67.00°S, 172.15°W)
to the southern end of the 150°W spur so as to use the underway time
to remove 935 m of wire (leaving 7652 m) and reterminate on March 30.


Table 2.2: 2018 S04P Timing of Reterminations

        |         |         | Became  |          |  
Date    | Time    | Became  | Time    | Relation | Comment         
        | (local) | Date    | (local) | to UTC   |                 
========|=========|=========|=========|==========|=================
3/9/18  |         |         |         | UTC+11   | Note: Hobart    
        |         |         |         |          | AEST UTC+10     
--------+---------+---------+---------+----------+-----------------
3/11/18 | 22:00   | 3/11/18 | 23:00   | UTC+12   | Transit to      
        |         |         |         |          | Station 1       
--------+---------+---------+---------+----------+-----------------
3/12/18 | 02:00   | 3/12/18 | 03:00   | UTC+13   | Transit to      
        |         |         |         |          | Station 1       
--------+---------+---------+---------+----------+-----------------
3/13/18 | 24:00   | 3/13/18 | 00:00   | UTC-11   | Transit to      
        |         |         |         |          | Station 1       
--------+---------+---------+---------+----------+-----------------
3/14/18 | 05:00   | 3/14/18 | 06:00   | UTC-10   | Transit to      
        |         |         |         |          | Station 1       
--------+---------+---------+---------+----------+-----------------
3/16/18 | 09:00   | 3/16/18 | 10:00   | UTC-9    | Transit to      
        |         |         |         |          | Station 1       
--------+---------+---------+---------+----------+-----------------
4/8/18  | 13:00   | 4/8/18  | 14:00   | UTC-8    | Transit back to 
        |         |         |         |          | 67°S (Sta. 54)  
--------+---------+---------+---------+----------+-----------------
4/9/18  | 18:00   | 4/19/18 | 19:00   | UTC-7    | Transit back to 
        |         |         |         |          | 67°S (Sta. 54)  
--------+---------+---------+---------+----------+-----------------
4/29/18 | 09:00   | 4/29/18 | 10:00   | UTC-6    | Transit to 103°W
        |         |         |         |          | (Sta. 98)       
--------+---------+---------+---------+----------+-----------------
5/10/18 | 18:00   | 5/10/18 | 19:00   | UTC-5    | Transit to Punta
        |         |         |         |          | Arenas          
--------+---------+---------+---------+----------+-----------------
5/11/18 | 09:00   | 5/11/18 | 10:00   | UTC-4    | Transit to Punta
        |         |         |         |          | Arenas          
--------+---------+---------+---------+----------+-----------------
5/12/18 | 13:00   | 5/12/18 | 14:00   | UTC-3    | Transit to Punta
        |         |         |         |          | Arenas          
--------+---------+---------+---------+----------+-----------------
5/12/18 | 13:00   | 5/12/18 | 14:00   | UTC-3    | Transit to Punta
        |         |         |         |          | Arenas          
--------+---------+---------+---------+----------+-----------------


2.10  The 150°W (P16S repeat) Meridional Line 
      (April 2–8, Stations 31–53, 75.29°S-67.5°S)

The transit south took 3.3 days (Figure 3, blue line). The first
station to be sampled on this line was Station 31, 75.287°S, 147.107°W
in 544 m of water surrounded by ice. However, having arrived this far
south and with leads in sight, it was decided head further onto the
shelf. The southernmost station on the 150°W line (sta. 32, 75.291,
147. 000°W) was done 285 m of water on the shelf. With closer spacing
on the shelf, stations were occupied every 0.5° (30 nm) up to 67.5°N
starting at Station 38 (75.0°S, 150°W).

The wire continued to be an issue and by April 3rd (sta. 37) the
discussion of the MPC and MTs with those onshore lead to the decision
to scrap the wire after the cruise. The thinking at the time was that
up to 1400 m of could be removed leaving ~7600 on the drum, which was
considered adequate as there were no stations expected with bottom
depths greater than 5000 m.

By Station 38, issues with the combination of drifting ice and wind
were causing major problems with maintaining station position.  It
should be noted that using the DPS in ice is not recommended as it can
literally push the ship and the rosette into ice. On Station 38 wind
and ice caused the ship to “miss” the planned position by nearly 0.5
nm by the time bridge decided they were setup on station. The decision
was made to attempt to set up on a position that would allow the ship
to drift back over the planned position by the time the rosette
reached the bottom. It was not clear that this tactic worked. Station
41, was started at 73.503°S, 149.935°W (1.3 nm to the west of
73.500°S, 150.000°W) and at the bottom the position was 73.514°S,
150.060°W, 1.3 nm to east of the planned position. However, there is
little that could be done about this. Station 43 was moved 7.5 nm
miles to the north to avoid an iceberg field. Station 44 was placed to
the east of a westward moving berg. During these period maneuvering of
the ship around icebergs, which were mostly picked up on radar and
through fields of smaller ice, but still significantly sized lumps,
was made more difficult by fog. Ship speeds through this region were
therefore quite slow.

Station 49 found the portions of the wire presenting for the first
time, but not the last, with strands that could be caused to separate
just by twisting the wire by hand, i.e. the outer armor was starting
to open and separate from the inner core.  The upper 552 m of the wire
were removed (Table 2) and the wire reterminated on April 7 on the
transit back to 67°S (between stations 53 and 54).  Just prior to
rosette going in on Station 50 the GPS signal was lost so the Seabird
SEASAVE software could get the NMEA information it needed to
initialize. The IT was able set up the secondary GPS system and the
rosette went on station 50 about 5 hours after it was supposed to
begin. From this point on the 150°W line went as expected and the
sampling continued up the line to 67.5°S (sta. 53), before the ship
began the 46.5 hour transit back to the 67°S line. On our way back to
the zonal line we passed the B30 iceberg and the field of smaller
icebergs accompanying it – again ship speeds were slowed by both the
ice field and fog.


2.11  The Continuation of the 67°S Line 
      (April 10–28, Stations 54–97, 168.88–105.16°W)

Sampling along 67°S continued beginning at 168.88°W (sta. 54, Figure
3) 43 nm from Station 30 finishing off the ~40 nm spacing we had been
maintaining since Station 27, when we lost time to the wire re-wind.
The winds began to rise on Station 56, but we managed to continue with
slow casts through Station 57 where every bottle after the bottom was
fired on the fly to get us out of the water more quickly. It was on
station 58 that the manner in which casts were being directed came
under question as the swell produced tension swings and it was
apparent that the winch speed was too high. Although it only took two
actual cast attempts, there was a delay of some 3 hours as
reassessments of the winds and swell occurred and much discussion
ensued on the dynamics of the cast. Eventually, the cast went in and
the MT was asked to try to go slower than the generally used 25 m/min.
Anything slower than 15 m/min, wasn’t possible given the winch
controls, but once it was realized that 15 to 17 m/min could be
maintained and 0 tensions usually avoided it became the norm on casts
when heave was an issue.

The enormous B30 iceberg that ship had passed on its transit back from
150°W, turned out to be sitting the planned position for Station 66.
As the iceberg was C-shaped and moving to the west (as the sampling
moved to the east), the ship stopped for Station 66 about 7.7 nm west
of the berg making the distance between stations 65 and 66 about 25
nm, which increased the spacing to station 67 to about 41 nm.  A dense
field of icebergs of every size and shape surrounded the B30 iceberg
and the ship at Station 66 so it was decided not to go through with
the planned drifter deployment. This last drifter deployment occurred
as we were underway to Station 67.

As the ship left station 66 and steamed north to avoid the bergs, the
wind picked up to 40-45 kts. It was too dangerous to try to maneuver
around the enormous field, so there was a 3-day weather delay (much of
the time with sustained winds of 40 kts and gusts to 50 kts, but also
large low frequency swell before the ship finally reached Station 67
on the eastern side of B30. Once the rosette got in the water on
Station 67, sampling continued with 30 nm spacing and only minor
issues (e.g. fog and ice slowing transits between stations, LADCP
star cable/junction box failure – see Chapter 22; concern about
northward moving ice flows for float deployments; oxygen pump
requiring replacement) until Station 79 when it was noticed that
although the wire was laying reasonably well on the drum and having no
conduction issue, the outer armor was beginning separate again.
Nevertheless, the floats went in without a hitch on Station 80 (no ice
in sight) and sampling continued through Station 87, when another
weather delay occurred.

Taking advantage of the break in a sampling, 302 m of wire were cut
(Table 2) and the wire was reterminated.  The rosette was back in the
water on Station 88 after about 17 hours later than originally
anticipated. It is apparent that even when the ship is not in a heart
of the storm that it is affected by low frequency signals, presumably
emanating from where the winds are stronger, that sometimes interfere
to reduce heave and sometimes interfere so as to enhance the heave.
For this reason, even when the local winds calm and the seas generally
lay down, there are still fairly regular larger swells that come
through. It is thought that it would help with getting the rosette in
the water more quickly after storms if the winch could go slower than
15 m/min. That being said stations 88-91 continued with slow descents
and with varying numbers of near surface bottles being tripped on the
fly, to reduce the chance of tension spikes on the way up. Note there
was discussion as to whether the spikes occurred on the stops or on
the acceleration after the stops. If the latter, it would again come
back to the idea of needing finer control of the winch speed. At this
point the wire again began having problems with winding on without
gaps, which in turn slowed upcasts. It is here that it should be
mentioned that a better view (or in fact any view) of the wire and
ocean for the winch operator so as to better time speed and
acceleration with the swell would have greatly eased operations. Also,
many times during this cruise casts were delayed because the direction
of swell relative to winds for ship positioning created the threat of
waves crashing into Baltic room to douse both the MT and the winch
operator and controls. The situation would be far less of an issue if
the operator and the controls were raised above the height of such
swell.

Before Station 93, the ship was issued a warning to divert due to
weather and seas. The decision was made to divert south to 68°S after
Station 93 (67.00°S, 111.21°W) so that sampling could continue (Figure
6). So once again, a long weather delay was averted by “running away.”
Station 94 was occupied at 67.5°S, and Stations 94-96 at 68°S. This
southward diversion tactic worked for just a few stations as wind
began to pickup on Station 95 (30-40 kt sustained winds and 50 kt
gust) where most of the bottles were tripped on the fly. After a
13-hour weather delay, on Station 96, there was a 2.5-hour down cast
to 4200 m and bottles in the top 500 m were tripped on the fly.

Station spacing was stretched to allow more time for the seas to calm
and to make up for 5 hours of the delay. To make up the other 8 hours
it was decided to transit directly to 70.5°S, 103°W from Station 97
and to cut the southernmost stations (1000m, 1500m, 2500m), on the
103°W line (Figure 5). This plan made sense because it was unlikely
the ship could have made it to the southernmost planned stations with
the remaining time due to ice, and even if it could have, it still
would not have reached the shelf.


2.12  The 103°W (P18 repeat) Meridional Line 
      (April 29–8, Stations 54–, 75.29°S-67.5°S)

The transit to the southern end of the 103°W line took only 14.5 hours
because it quickly became apparent that getting even as far as 70.5°S
would have taken more time than was available as the area was thick
with multi-year ice that had blown in to form solid pack. The short
transit allowed time for a required life boat drill for the crew (2
hours after Station 98) and the hope that perhaps the station spacing
on the zonal 67°S line could once again be reduced to 30 nm. The
opportunity was also taken to cut another 300.5 m of wire (Table 2),
removing the section that where the outer armor was opening up, and to
reterminate.

The southernmost station on this line was done in 4000 m of water on
Station 98 at 69.75°S, the next station was occupied 15 nm miles to
the north at 69.50°S, after which half degree (30 nm) station spacing
maintained until 67.5°S (Figure 5). Reaching even this station took
some effort as the ice was unforgiving and on more than one occasion
backing and ramming had to be used to make the path northward. As at
other stations surrounded by ice, although the seas were flat making
for excellent profiles, positions at the start of the stations
sometimes differed considerably from those at the end as the ship had
no choice but to drift with the ice and wind. Nevertheless, stations
continued along the meridional line without any major difficulties.

As the ship headed north and out of the ice the weather once again
became problematic and the 67°S station (104) was aborted due to
weather; not local weather – winds were only blowing 20 kts, but from
a storm that was producing intermittent 9-10 amplitude heaves. The
storm sitting to the north showed no intention of moving away, so the
ship once again diverted south and continued eastward along 67.5°S
until it was thought that weather would permit a move back to 67°S.
The station spacing was variably stretched further down the line to
make up for the 10 hour delay produced by the attempt to measure 67°S,
103°W position (sta. 104).


Fig. 2.4: 2018 S04P station locations in the vicinity of the 103°W
          meridional lines. Planned stations that were not executed due 
          to ice are shown in red. See Figure 1 for transit tracks.


2.13  The Eastern End of the S04P Line


Fig. 2.5: 2018 S04P station locations along the eastern end of the
          nominally 67°S line. Planned stations that were not executed 
          due to a medical situation are shown in red.

A couple of days of decent weather and slow downcasts to handle heave
ensued. After four stations at 67.5°S (105-108) and an attempt to
outrun a storm coming from northwest, Station 109 was aborted when the
wind picked up to 45 kts as the ship came onto station (Figure 6).
Forecasts had predicted the storm, but not its severity. Knowing that
spacing would have to be stretched once again and there was the
eventual need to return to the 67°S line, the position of Station 109
was changed to be 6 nm to ENE and it became Station 110, which in
spite of several intermediary assessments, took place after an 11.5
hour delay.

Stations continued with 40+ nm spacing and no particular issues until
Station 113, which was once again inflicted with stronger winds than
expected and resulted in a 13-hour weather delay. A couple of days
later there was yet another storm. This one turned out to be a major
event, which topped out with sustained 50+ kt winds, a gust at 80.2
kts and a weather pattern turn that sent everything flying and tipped
those off shift out of bed. Not wishing to repeat that roll the ship
continued westward into the wind some 40 nm away from the planned
station position and the final toll was a full day weather delay. In
the meantime, station spacing was stretched to 50-60 nm for the
remaining pre-slope/pre-boundary current section of 67°S line.

After the weather delay, the rosette went in the water on Station114
(the first station to the north of the 67°S line in preparation for
the coastal approach). Winch speeds were kept to the 15-17 m/min range
down to 800 m, after which accelerations were made as slowly as
possible carefully avoiding the periods of strong swell (heave).  It
was a long, but successful cast. It was around this time that it was
once again noted that the outer armor of the wire was beginning to
open up, so on the long transit between stations 117 and 118 another
300 m of wire was cut and the wire reterminated (Table 2). As the
weather continued to improve and promised to stay that way, hopes rose
for a successful completion of the cruise with the chance to resolve
the boundary current with 10 nm spacing and the slope to shelf region
with a perpendicular approach and 500 m jumps in bottom depths.

Unfortunately, this was not to be. After a coastal approach at the
eastern end of the line had been finalized and the timing agreed upon
by science, the MPC and Captain, and not long after Station 120 (the
last station prior to the 10 nm spacing) had gone in the water, a
medical situation arose causing a stop to science per NSF. Station 120
was completed and the ship proceeded transit to Punta Arenas with all
possible speed.


2.14  The Final Tally

A total of 117 of the 120 attempted stations were successfully
occupied producing CTD-O/rosette/fluorometer/transmissometer/LADCP/UVP
profiles. For a variety of reasons (See individual sections of this
report) of these 117 stations: 110 provided UVP results (no UVP on
stas. 4, 6,7-8, 45-47); 111 provided LADCP results (no LADCP on sta.
3, no upward looking on 6-7, no downward looking on 4, 5 and 117); for
2 stations (901 and 115) the FLBB was dark; and on 3 (stas. 1-3) the
altimeter failed. There were 3 aborted stations (9, 104 and 109).
With a few notable exceptions, casts were made to within 8-15 m of the
bottom. Water samples (up to 36) were collected in 10 L Bullister
style Niskin bottles at all stations providing water samples for
CFCs/SF6/NO2, Total DIC, TAlk, pH, dissolved oxygen, nutrients,
salinity, and on some stations for DOC, DI13/14C, HPLC, POC, Rare
Earth Elements (REE), neodymium, Helium/noble gases, Δ18O, and Nitrate
Δ15N/Δ18O. Underway surface pCO2, temperature, salinity, dissolved
oxygen, DIC, pH, TAlk, samples were measured, and multi-beam
bathymetry and meteorological measurements were collected during most
transits. Underway samples were not taken on the final transit to
Punta Arenas from Station 120. All other underway measurements ended
before entering at the Chilean EEZ at 09:13 (UTC) on May 10th. It
should be noted that clearance for sampling was requested and
eventually granted by the Chilean government. However, notice was not
given until the beginning of May when it was requested that a Chilean
observer be picked up on May 8. This action would have put end to
science, so the clearance was not used. A total of 18 floats (6 biogeo
–chemical, 2 EM-APEX, 5 Argo, 5 ALTO) floats were deployed for the
SOCCOM program, APL, FSU and CSIRO, respectively. 20 surface drifters
were deployed for the Global Drifter Program. The ship arrived in
Punta Arenas harbor on May 13th one day early due to the medial
situation, however as there was no place to tie up. Late in the
evening a place was found on the dolphin extension at the end of the
pier and on the 14th, cleared by customs science was allowed to go
onto dry land. Loading and unloading howver could not be done from
this pier and there was no promise of a place at the regular Prat Pier
until 16:30 on May 15th. On the 14th, one set of frozen samples was
picked up and the rosette was lifted by the crane from the winch
outside the Baltic Room to be placed on the deck for loading, but full
deMOB was planned for the 15th, finishing up with the container
offload on the 16th.

Although difficult to assess due to constantly changing plans, some
rough estimates can be made as to the overall success of the cruise.
Initially over the scheduled 67 DAS an ambitious 158 stations were
roughly sketched out covering ~4107 nm of track with nominally 30 nm
or less spacing along with another 1011 nm of transit (not including
the transit to/from the last stations). Including the planned 8 day
transit at the start, 5 day transit at the end, the 4.67 days of
transit between lines, and the extra day supplied by the Dateline
crossing this left 50.33 days, i.e. an average of 3.2 stations/day. On
the outside this sounds like a reasonable number, however it
overlooks: a) the average between station ship speed of the NBP = 9
kts and long transit speed of 10 kts, the slow progress of the ship in
older ice, and the 1-3 weather days occurring 4-5 days on average in
the Southern Ocean, particularly for an eastbound cruise.

The 2018 cruise managed 117 stations (74% of the planned stations), to
cover 3766 nm  (91.7%) of the planned track and had 2042 nm of transit
(twice that planned). However, there are a number caveats to these raw
numbers.

Although the intention was to get to 500 isobath on all the shelves
with 500 m jumps in bathymetry on the slope approaches, none of the
planned meridional lines did either.

The 2018 occupation did manage to do both on the 150°W line.

The inability of the 2018 cruise to do the same on the 170°E, 170°W
and 103°W lines had everything do with ice and lack the time to break
through it.

The inability of the 2018 cruise to do the same at the eastern end of
the line was due to the necessity of stopping the science due to the
medical situation.

The lack of time (as well as the ice extent itself and intensity of
storms) noted above was to some degree caused by the late departure
date resulting from ship scheduling conflicts. For example, one can
compare the extent of ice in Ross Basin in the middle of March to that
seen on April 2nd when the ship arrived at Station 31 (Figure 7).


Fig 2.6: Winch and between station speeds: upper left panel - time from 
         the time of start of cast to the time of end of cast divided by 
         the total distance from surface to bottom and back again; upper 
         right panel – same as left panel but removing the time necessary 
         for tripping bottles; lower left panel – time between casts 
         compared for distance from the first station, color shading 
         indicates latitude; lower right panel - time between casts 
         compared for station number, color shading indicates distance 
         between stations. Note that the cast used to re-lay the wire has 
         been relabeled as station 132.


There were a total of 6.5 days of obviously weather related delays and
no time that can clearly be described as a wire related delay.
However, it is difficult to measure the true impact of the weather or
the wire separately because more often than not bad weather not only
caused the inability to put the rosette in the water, it also caused
slow winch speeds, and worsened the state of the wire, which in turn
led to the need to cut and reterminate. Bad weather in the north, more
often than not combined with the need to reterminate, led to the
decisions to head south (i.e. the multiple transits). The time lost to
reterminations as well as weather was mitigated by the turns to the
south, but clearly the integrated length of these transits also had a
delaying effect. It should be noted that one advantage of the multiple
shorter transits, compared to the initial plan allowed the various
science groups to recoup and always be ready for full sampling of
upcoming stations. Also, the original plan which mimicked the 2011
westward transit from the southern end of 150°W line to the southern
end of the 170°W clearly would not have been possible given the ice
conditions found in March/April in 2018.

Have said this, the integrated effects of wire and weather can be
discussed in terms of the winch and ship speeds (Figure 8).  Beginning
with the time it took to complete casts (upper left panel). The
up/down average speed of casts on S04P was 36.1±5.1 m/min. There were
12 fast casts with average speeds greater than the mean plus the
standard deviation accounting for a time savings of about 7 hours.
There were 14 slow casts with average speeds less the mean minus the
standard deviation accounting for delays of ~13 hours. If one takes
the number of bottles tripped into account (assuming 45 seconds for
each bottle), the average winch speed was 41.3±5.8 m/min (upper right
panel). There were 18/15 fast/slow casts according to winch speed
accounting for a time savings/delay of 1/19 hours. So one could say
that slower than average winch speeds (caused by wire and weather/sea
state) offset by faster than average winch speeds produced a loss of
about 18 hours.


Fig 2.7: Ice concentration from satellite mapped by S. Escher at
         UCSD/SIO: a) ice concentration estimate for March 13, 2018; b) 
         ice concentration estimate for April 2, 2018.


The speed between casts can also be considered. Note, this is not
actually ship speed because it includes weather delays and anything
else that might have slowed the start or end of cast. Nevertheless,
for starters one can compare to what might have happened had there
been no delayed start or end of casts, and no weather, sea state or
ice delays. The original number for average ship speed between
stations supplied by the NBP was 9 kts. Over the 117 transits between
the first and last station, the mean speed between casts (vbc) was
7.7±2.4 kts (lower left and lower right panels).  The distance
weighted mean vbc was 8.0 kts. There were 43/74 transits that averaged
faster/slower than 9 kts. When distances are short however, one should
not expect to see the average speed approach such value. Considering
only the 69 transits (totaling 3637 nm) for which the average vbc was
less than 9 kts over distances greater than 10 nm, the total time used
was 626 hours. Had these between cast speeds occurred at 9 kts the
time used would have been 404 hours, suggesting that slow times
between casts (due to weather, sea state, ice, fog or technical
delays, but not slow winch speeds) accounted for a loss of 9.25 days.
Figure 5 also highlights the affect of ice at lower latitudes (lower
left panel) and the fact that longer distances between station did not
necessarily correlate with faster speeds, though very close stations
(~10 nm apart) did see slower speeds.

The 2018 S04P cruise presented a great many challenges. We would like
to thank the officers and crew of the RVIB N.B. Palmer who have done
an excellent job supporting S04P science. In particular, we wish to
thank the Captain and Mates on the bridge for their efforts to get us
where we needed to go and to keep us all safe in rough conditions. In
particular, we would like to thank the galley crew for the abundance
and quality of the food produced on this very long voyage. We also
wish to thank all the ASC personnel onboard (MPC, MTs, IT, ET) for
their constant assistance and sincere support throughout the cruise,
and give a special note thanks to our MPC for all his diligent efforts
to provide both science and the bridge with what was needed in all
situations. The successes of this expedition have been in no small
part due to efforts of all the ECO and ASC personnel: they have worked
with us every step of the way, to fix everything from the smallest
detail to the greatest problems, all the while speeding us along so
that we could sample as much of the full line as possible. Last but
not least we wish thank all those who sent us ice and weather reports
and up to date circulation information without which the choices we
made would not have been possible and far more time would have been
lost to delays and failed attempts to reach the most southern
positions. These include: S. Escher, S. Purkey and L. Talley
(SIO/UCSD), J. Girton (APL) and those at the Fleet Weather Center (San
Diego), SOPP Meteorology (McMurdo) and the National Ice Center.



3.  CTD AND ROSETTE SETUP

For S04P 2018 the new STS 36 place yellow rosette and bottles, built
in 2017, were used. These rosette and bottles was built before P06
2017, making this the second time this package has been deployed. The
bottles were made with new PVC, with new non-baked o-rings and
electro-polished steel springs. This represents a change from the
past, where on GO-SHIP cruises using ODF equipment before P06 2017
o-rings were baked for 3 days at 100°C at 1-3 Torr in a sweeper gas of
hydrogen. Springs were painted and Tygon tubing added to the ends to
prevent paint wearing away from bottle firing. As on P06 2017 no
sample contamination has been noticed by the change in o-rings and
springs. The package used on S04P 2018 weighs roughly 1350 lbs in air
without water, and 2200 lbs in air with water. The package used on
S04P 2018 weighs roughly 800 lbs in water. In addition to the standard
CTDO package on GO-SHIP cruises two LADCPs and one UVP were mounted on
the rosette. During the cruise we encountered numerous problems, most
notably the unravelling of the wire through the cruise resulting in
multiple re-terminations. We describe all of the above in more detail
in the sections below.


3.1  Underwater Sampling Package

CTDO/rosette/LADCP/UVP casts were performed with a package consisting
of a 36 bottle rosette frame, a 36-place carousel and 36 Bullister
style Niskin bottles with an absolute volume of 10.6L. Underwater
electronic components primarily consisted of a SeaBird Electronics
housing unit with Paroscientific pressure sensor with dual plumbed
lines where each line has a pump, temperature sensor, conductivity
sensor, and exhaust line. A SeaBird Electronics membrane oxygen sensor
was mounted on the "primary" line. A reference thermometer,
transmissometer, chlorophyll-a fluorometer and backscatter meter,
oxygen optode, and altimeter were also mounted on the rosette. LADCP
and UVP instruments were deployed with the CTD/rosette package and
their use is outlined in sections of this document specific to their
titled analysis.

CTD and cage were horizontally mounted at the bottom of the rosette
frame, located below the carousel for all stations. The temperature,
conductivity, dissolved oxygen, respective pumps and exhaust tubing
was mounted to the CTD and cage housing as recommended by SBE. The
reference temperature sensor was mounted between the primary and
secondary temperature sensors at the same level as the intake tubes
for the exhaust lines. The transmissometer was mounted horizontally on
the lower LADCP brace with hose clamps around both of its ends,
avoiding shiny metal or black tape inside that would introduce noise
in the signal. The fluorometer and backscatter meter, oxygen optode,
and altimeters were mounted vertically inside the bottom ring of the
rosette frames, with nothing obstructing their line of sight. The 150
KHz bi-directional Broadband LADCP (RDI) unit was mounted vertically
on the bottom side of the frame. The 300 KHz bi-directional Broadband
LADCP (RDI) unit was mounted vertically on the top side of the frame.
The LADCP battery pack was also mounted on the bottom of the frame.
The LADCP and LADCP battery pack were mounted next to each other at
the beginning of the cruise. If we imagine the LADCP being north on
the rosette, the LADCP battery was mounted west, the CTD mounted east,
and the UVP mounted south.


Equipment        | Model            | S/N          | Cal Date     | Stations   | Responsible 
                 |                  |              |              |            | Party       
=================|==================|==============|==============|============|=============
Rosette          | 36-place         | Yellow       | _            | 901-120    | *STS*/*ODF* 
-----------------+------------------+--------------+--------------+------------+-------------
CTD              | SBE9+            | 1281         | _            | 901-120    | *STS*/*ODF* 
-----------------+------------------+--------------+--------------+------------+-------------
Pressure Sensor  | Digiquartz       | 136428       | Dec 17, 2017 | 901-120    | *STS*/*ODF* 
-----------------+------------------+--------------+--------------+------------+-------------
Primary          | SBE3+            | 35844        | Jan 30, 2018 | 901-120    | *STS*/*ODF* 
Temperature      |                  |              |              |            |             
-----------------+------------------+--------------+--------------+------------+-------------
Primary          | SBE4C            | 44546        | Feb 8, 2018  | 901-120    | *STS*/*ODF* 
Conductivity     |                  |              |              |            |             
-----------------+------------------+--------------+--------------+------------+-------------
Primary Pump     | SBE5             | 54377        | _            | 901-12, 75 | *UCSD*      
-----------------+------------------+--------------+--------------+------------+-------------
Primary Pump     | SBE5             | 58691        | _            | 13-14      | *UCSD*      
-----------------+------------------+--------------+--------------+------------+-------------
Primary Pump     | SBE5             | 51646        | _            | 15-74      | *ASC*       
-----------------+------------------+--------------+--------------+------------+-------------
Primary Pump     | SBE5             | 58692        | _            | 76-120     | *UCSD*      
-----------------+------------------+--------------+--------------+------------+-------------
Secondary        | SBE3+            | 32309        | Jan 30, 2018 | 901-120    | *STS*/*ODF* 
Temperature      |                  |              |              |            |             
-----------------+------------------+--------------+--------------+------------+-------------
Secondary        | SBE4C            | 41880        | Feb 2, 2018  | 901-120    | *STS*/*ODF* 
Conductivity     |                  |              |              |            |             
-----------------+------------------+--------------+--------------+------------+-------------
Secondary Pump   | SBE5             | 54890        | _            | 901-14     | *UCSD*      
-----------------+------------------+--------------+--------------+------------+-------------
Secondary Pump   | SBE5             | 55644        | _            | 15-120     | *ASC*       
-----------------+------------------+--------------+--------------+------------+-------------
Transmissometer  | Cstar            | CST-1803DR   | Sep 16, 2016 | 901-120    | *TAMU*      
-----------------+------------------+--------------+--------------+------------+-------------
Fluorometer      | WetLabs          | FLBBRTD-3698 | Sep 23, 2014 | 901-120    | *U Maine*   
Chlorophyll and  |                  |              |              |            |             
Backscatter      |                  |              |              |            |             
-----------------+------------------+--------------+--------------+------------+-------------
Primary          | SBE43            | 430255       | Nov 22, 2017 | 901-120    | *ODF*       
Dissolved Oxygen |                  |              |              |            |             
-----------------+------------------+--------------+--------------+------------+-------------
RINKO Oxygen     | JFE Advantech    | 0296         | Apr 7, 2017  | 901-120    | *STS*/*ODF* 
Optode           | RINKO-III        |              |              |            |             
-----------------+------------------+--------------+--------------+------------+-------------
Reference        | SBE35            | 0035         | Feb 01, 2018 | 901-120    | *STS*/*ODF* 
Temperature      |                  |              |              |            |             
-----------------+------------------+--------------+--------------+------------+-------------
Carousel         | SBE32            | 1178         | _            | 901-120    | *STS*/*ODF* 
-----------------+------------------+--------------+--------------+------------+-------------
Altimeter        | Tritech LPA200   |              | _            | 901-1      | *UCSD*      
-----------------+------------------+--------------+--------------+------------+-------------
Altimeter        | Valeport 500     | 59116        | _            | 2-3        | *UCSD*      
-----------------+------------------+--------------+--------------+------------+-------------
Altimeter        | Valeport 500     | 51520        | _            | 4-120      | *ASC*       
-----------------+------------------+--------------+--------------+------------+-------------
Underwater       | Underwater       | 207          | _            | 901-120    | *U Alaska*  
Vision Profiler  | Vision Profiler  |              |              |            | Fairbanks   
5 HD (UVP)       | 5 HD             |              |              |            |             
-----------------+------------------+--------------+--------------+------------+-------------
DL LADCP         | 150 kHz Teledyne | 19394        | _            | 901-120    | *LDEO*      
                 | RDI WHM150       |              |              |            |             
-----------------+------------------+--------------+--------------+------------+-------------
UL LADCP         | 300 kHz Teledyne | 12734        | _            | 901-120    | *LDEO*      
                 | RDI WHM300       |              |              |            |             


3.2  Winch and Deployment

The DUSH5 baltic room winch deployment system was successfully used
for all stations. The rosette system was suspended from a UNOLS-
standard three-conductor 0.322" electro-mechanical sea cable. The sea
cable was terminated at the beginning of S04P 2018, and multiple times
afterwards.

The deck watch prepared the rosette 10-30 minutes prior to each cast.
The bottles were cocked and all valves, vents and lanyards were
checked for proper orientation. Any biofouling noted was cleaned off
the outsides of the rosette before the next cast, and the insides of
the bottles were checked for biofouling and sprayed down. LADCP
technician would check for LADCP battery charge, prepare instrument
for data acquisition and disconnect cables. The UVP battery was
monitored for charge and connectors were checked for fouling and
connectivity. Once stopped on station, the Marine Technician would
check the sea state prior to cast and decide if conditions were
acceptable for deployment. Recovering the package at the end of the
deployment was the reverse of launching. The Marine Technician would
perform a quick check and rinse of the rosette and block before
allowing samplers into the Baltic room. The block was rinsed with
water to remove ice that would form, preventing ice from landing on
heads or in samples.


3.3  Maintenance and Calibrations

During S04P 2018 routine maintenance was done to the rosette to ensure
quality of the science done. Actions taken included rinsing all
electrical instruments on the rosette down with fresh water after each
cast. Care was taken not to rinse the spigots and other parts of the
bottle that might be touched by samplers in order to not contaminate
the samples. After each cast salt water filled syringes were connected
to the plumbed lines to rinse the sensors between casts. Salt water
was used instead of fresh water due to the lower freezing point to
prevent it from freezing when exposed to the outside air. The rosette
was routinely examined for valves and o-ring leaks, which were
maintained as needed. SBE35RT temperature data was routinely
downloaded each day.


Fig. 3.1: Package sensor setup from top down, with the top of the
          picture as north.

Fig. 2.3: Package sensor setup from northwest, to show in order from
          left to right downward LADCP, transmissometer, altimeter,
          fluorometer and backscatter meter, and RINKO oxygen optode.

Fig. 2.4: Package sensor setup from south to show UVP, CTD, LADCP
          battery.


Every 20 stations, the transmissometer windows were cleaned and an on
deck blocked and un-blocked voltage readings were recorded prior to
the cast. The transmissometer was also calibrated before and after the
start and end science operations. The RINKO oxygen optode was also
taken off during transit to station 54 to perform a zero saturation
and full saturation calibration. The same calibration was performed at
the of the cruise during transit to Punta Arenas. Black tape was put
on the outside of the FLBB sensors to do a calibration "dark cast".
Dark casts were done at the beginning and end of the cruise to measure
pressure effects on the sensor. A dark cast was performed on casts
where depths reached at least 2000 meters, preferably average full
ocean depth for the cruise, and where previous profiles showed little
FLBB activity.


3.4  Problems

Some complications were overcome to complete CTDO/rosette/LADCP/UVP
station casts for S04P 2018. Throughout the cruise the primary and
secondary sensors would occasionally report a small spike in salinity
every 10-20 casts, at odds with the other line. This occasional spike
was small and intermittent, leading to the decision to allow the spike
to be removed in processing without further inspection of the CTD.
Storms caused casts to proceed slower than normal, limiting deployment
speed to 20 meters per minute for the first 1000 meters on some
stations during storms. Adverse weather conditions caused surface
bottles (nominal 5 meters) to be fired on the fly, instead of soaking
for 30 seconds. In rough weather more bottles would be fired on the
fly, ranging from the top two bottles to the extreme case of a whole
cast fired on the fly.

On station 2, cast 1 the primary line froze before entering the water.
The package was recovered, tepid salt water was run through the
plumbing, and the package was put in on cast 2 with no problems. On
station 3 the package touched the seafloor due to altimeter problems.
An estimated 20 meters of wire was paid out before stopping and
pulling the rosette back up, of which the tension did not change
appreciably after touching the bottom. The 20 meters of wire paid out
lead to a small increase in slack across 2700 meters of water. On
station 18, cast 1 the cast was canceled due to large wire tensions
and large variations in wire tensions early on in the cast. On station
58, cast 1 the cast was canceled due to large wire tensions and large
variations in wire tensions early on in the cast.

We were required to switch Niskin bottles on the rosette due to
leaking. On station 17 bottle 22 was observed to be leaking from the
bottom collar seam, prompting the replacement with a new bottle. On
stations 77 and 78 bottle 26 was observed to be leaking. Prior to
station 79 the bottle was inspected and a scratch was noticed across
the surface of the bottom collar. A bottle swap was attempted before
station 79, but during leak testing the replacement bottle was also
found to be leaking. The previous bottle was put back on with minor
sanding in order to keep to schedule for station 79. When the bottle
came up for sampling after station 79 and was still leaking, another
spare bottle that passed leak testing was found and placed on the
rosette. On station 80 bottle 26 did not leak. On station 111 bottle 9
was observed to leak from the bottom, and upon inspection scratches
were noticed. The bottom of bottle 9 was resurfaced and on station 112
the bottle 9 did not leak. When bottle 9 leaked on station 115, the
bottom end cap was replaced, and for the remainder of the cruise the
bottle did not leak.

During cocking and uncocking the rosette we had inner cap lanyards
snap at multiple times during the cruise. The lanyards were thought to
develop excessive wear due to the force required to cock the bottle,
where the lanyard would rub against the inner lower collar of the
bottle. The wear on the lanyards were thought to build up over 2
cruises, as few if any cap lanyards were replaced after P06 2017 or
before S04P 2018. At multiple points during the cruise the bottles
were checked for wear on the inner lanyards, and any suspicious
lanyards were replaced.


Fig. 3.4: Wear on an inner cap lanyard. This lanyard was cut and
          replaced before it snapped.


We had multiple problems with altimeters at the beginning. A Tritech
LPA 200 altimeter was initially installed at the beginning of the
cruise with range of 200 meters. The test cast did not reach full
ocean depth and so we did not have a chance to test the altimeter in
water. On the first station the altimeter did not lock in at all,
returning a 200 meter reading at all times. After navigating the
rosette to within an estimated 30 meters off the bottom with multibeam
reading, we stopped and started ascent. The Tritech altimeter was
taken off and replaced with a SIO Valeport altimeter with effective
range of 100 meters.

On station 2, cast 2 the Valeport altimeter also did not show a change
in reading. The package descended to a maximum pressure of 2011
decibars, where while soaking the rosette we saw a small dip in the
altimeter from ~100 meters to 94 meters. Post cast we decided that the
reading was real, and we simply stopped descending too early. On
station 3, cast 1 we continued past the multibeam depth, hoping the
altimeter would kick in while we proceeded at 20 meters per minute. At
some point the altimeter quickly dropped from ~100 meters to 1 meter
and then kicked back to ~100 meters, at which point the pressure and
the tension held constant while the winch continued to pay out at 20
meters per minute. The bottom bottle was fired, then the rosette was
pulled up, at which point the altimeter quickly changed from ~100 to
10, 20, 30 meters and rising until it reached 100 meters in less than
a minute. While not having the cables to interrogate the altimeter, it
is believed that the SIO Valeport altimeter was previously used on an
ROV, which would have been set to 0 to 10 meters instead of 0 to 100
meters. After station 3 an ASC Valeport altimeter was placed on the
rosette, which worked as expected in the 0 to 100 meter range for the
remainder of the cruise.

Post cruise, salt formation and corrosion was noticed on the Tritech
altimeter at the seams. This suggests that water leaked into the
altimeter during the first cast, shorting electronics and rendering
the altimeter inoperable. This interpretation is consistent with
recollections of previous failures of the Tritech altimeter due to
water seeping into the case. The altimeter was not opened up on the
ship and will be further inspected back in San Diego.


Fig. 3.5: Salt formation/extrusion at the seam of the Tritech
          altimeter where the seam pointed directly up.

Fig. 3.6: Corrosion formation at the seam of the Tritech altimeter
          where the altimeter rested.


We encountered multiple problems with SBE 5P pumps on this cruise. On
stations 10, 11, 12, and 14 we encountered situations where all
sensors on the primary line would suddenly show an offset and vastly
increased noise at depth on the downcast. This offset and noise would
disappear later on the upcast, within a few hundred meters of the
problem's starting depth. Triage included flushing the plumbed line
with fresh water at the surface for 30 minutes, swapping the pump
cable, and finally swapping the pump. On station 13 the cast proceeded
smoothly with no problems on the plumbed line with the new pump. On
station 14 the plumbed line with the new pump proceeded to show the
same symptoms as the previous pump. Both the second failed pump and
the pump on the working line were replaced with ASC SBE pumps as a
precautionary measure. Both pumps were judged to have failed within a
short period of time. Looking at the service logs from Seabird the
pumps were checked out, considered to not show problems, and sent back
out. A more extensive writeup has been written and will be sent to
Seabird alongside the pumps.


Fig. 3.7: First noted failure of the primary pump on the primary
          lines. Note the noise in the oxygen and salinity signal at 
          depth.

Fig. 3.8: The secondary sensors signal, note the oxygen signal is from
          the fouled primary line.


On station 74 the ASC pump on the primary line failed similarly to the
pump failures between stations 10 and 14. By mistake, a failed pump
was put on to replace the ASC pump, which showed the same failure as
it did before on station 75. A new SIO pump was put on before station
76 and was used for the rest of the cruise without problems. The pumps
on the secondary line worked well for the majority of the cruise, with
one odd failure on station 52. Thorough flushing of the pump after
station 52 was done, and subsequent casts showed no problems.

We encountered repeated biological fouling on multiple stations in the
latter half of the cruise. On multiple casts sea snot was found draped
on and in the package, on occasion getting inside the bottles. On two
casts we caught what looks like a jellyfish, once on a spring inside a
bottle and once on the lanyards. All biological fouling was removed
promptly and any sign of biological fouling prompted the checking of
bottles for inner fouling. While checking inside the bottles for
fouling some discoloration was noticed on a few of the springs. The
springs were removed and inspected, of which the discoloration was
found to be dried biological matter. Upon removing the matter the
springs were found to be rougher in those locations. It is not known
whether the springs were rougher to start due to imperfections in
electro-polishing, creating surfaces for the matter to stick onto, or
the biological matter created the roughness on the springs.
Regardless, all springs will be sent for polishing after the cruise.


3.5  Wire Situation

We re-terminated the .322 cable several times during the trip. The
first instance was to remove a kinked section. Subsequent re-
terminations were done after the marine techs removed questionable
sections of cable.

The kink(s) were probably caused by rough seas during deployment and
recovery of the rosette at the air/sea transition. They appeared
around the point on the cable that would be running on the
overboarding sheave as the rosette entered the water and during
periods of high seas and high winds.

The outermost layers of cable on the drum were not winding on to the
drum evenly and exhibited a ‘rumpled’ appearance as though the outer
layer of wire had been pushed back over the inner layer. Also, the
outer layer became more and more loosely wrapped about the core over
time.

It is unlikely that the new 36 place GO-SHIP rosette is the cause of
the ‘rumpling’, as a plausible means for the rosette and EverGrip
termination to pull the inner core or push back the outer layer of the
cable has not been proposed. However, the ‘unravelling’ of the outer
armor may be related to the net spin of the rosette, which in turn may
relate to the positions of the instrumentation mounted on it.

On previous legs aboard the Palmer, ODF has seen net negative
rotations (CCW?) from the ADCP data. Initially, the rosette spun the
same direction during both pay out and pay in. But, as the cruise
progressed, the absolute number of spins would decrease and the
direction of the spin would reverse on retrieval. Eventually, on pay
out the rosette would spin 10 to 20 times and on retrieval about the
same number in reverse; the net spin per cast would be about zero with
a slight bias toward negative spin totals.

On S04P (NBP18-02) the rosette’s spin was similar save for a reversal
in direction. The down cast showed positive spin counts, and
eventually the up cast showed negative counts. The net spin trended
toward zero and the number of spins towards low double digits.

If the cable’s outer armor is twisted in the direction corresponding
to a clockwise rotation of the rosette (viewed from above,) the outer
armor can loosen. Spun the opposite way, the outer armor would tighten
and the inner armor loosen. Assuming that the rosette induces a spin,
a clockwise rotation will see less opposition (inner armor winding
tight, outer armor loosening up) than ccw spin (outer armor
contracting while inner armor tries to expand.)

Sheaves, level wind, previous wire history (hysteresis) can also
contribute rotation. There may be some evidence in the ADCP record and
wire log to show that there is a contribution to spin correlated with
the rotation of the overboarding sheave when wire was trimmed back.

Arranging the instruments to accommodate the UVP and lower ADCP placed
the ADCP battery adjacent to the lower ADCP (each over 100lbs) and the
upper ADCP opposite the battery, with the UVP opposite the lower ADCP.
This created an imbalance the caused a slight tilt to the battery and
lower ADCP, and may have presented a skewed drag profile. Mirroring
the instrument arrangement could have shown if it affected spin, but
we were reluctant to disturb the instrumentation during the cruise. In
a future deployment with similar instruments, we could try that
mirrored arrangement or stand the CTD vertically and place the battery
in opposition to the ADCP.



4.  CTDO AND HYDROGRAPHIC ANALYSIS


PIs
   • Susan Becker
   • James Swift

Technicians
   • Joseph Gum
   • Kenneth Jackson


4.1  CTDO and Bottle Data Acquisition

The CTD data acquisition system consisted of an SBE-11+ (V2) deck unit
and a networked generic PC workstation running Windows 7. SBE SeaSave7
v.7.26.1.8 software was used for data acquisition and to close bottles
on the rosette.

CTD deployments were initiated by the console watch operators (CWO)
after the ship had stopped on station. The watch maintained CTD cast
logs for each attempted cast containing a description of each
deployment event. This cast log included the bottle scheme, any
phenomena, and any possible problems.

Once the deck watch had deployed the rosette, the winch operator would
lower it to 20 meters in good weather. In rougher weather, the winch
operator would lower the rosette to 25 or 30 meters. The CTD sensor
pumps were configured to start 10 seconds after the primary
conductivity cell reports salt water in the cell. The CWO checked the
CTD data for proper sensor operation, waited for sensors to stabilize
and the UVP to activate, and instructed the winch operator to bring
the package to the surface. The Marine Technician would signal to the
winch operator what was acceptable for rising to the surface. The
winch was then instructed to lower the package to the initial target
wire-out at no more than 60m/min after 100m depending on sea-cable
tension and the sea state.

The CWO monitored the progress of the deployment and quality of the
CTD data through interactive graphics and operational displays. The
altimeter channel, CTD pressure, wire-out and center multi-beam depth
were all monitored to determine the distance of the package from the
bottom. The winch would monitor altimeter readings, taking notice 100m
from the bottom and slowing quickly to a final stop 10m from the
bottom. The bottom of the CTD cast was usually to within 10-20 meters
of the bottom determined by altimeter data. For each up-cast, the
winch operator was directed to stop the winch at up to 36
predetermined sampling pressures. These standard depths were staggered
every station using 3 sampling schemes. The CTD CWO waited 30 seconds
prior to tripping sample bottles, to ensure package shed wake had
dissipated. An additional 15 seconds elapsed before moving to the next
consecutive trip depth, which allowed for the SBE35RT to record bottle
trip temperature averaged from 13 samples.

After the last bottle was closed, the CWO directed winch to recover
the rosette. Once the rosette was out of the water and on deck, the
CWO terminated the data acquisition, turned off the deck unit and
assisted with rosette sampling.

Additionally, the watch created a sample log for the deployment which
would be later used to record the depths bottles were tripped and
correspondence between rosette bottles and analytical samples drawn.

Normally the CTD sensors were rinsed after each station using a fresh
water tap connected to Tygon tubing. Syringes filled with salt water
was also used due to the higher freezing point, to prevent the fresh
water from freezing when exposed to the elements. The tubing was left
on the CTD between casts, with the temperature and conductivity
sensors immersed in fresh or salt water.

Each bottle on the rosette had a unique serial number, independent of
the bottle position on the rosette. Sampling for specific programs
were outlined on sample log sheets prior to cast recovery or at the
time of collection. The bottles and rosette were examined before
samples were drawn. Any abnormalities were noted on the sample log,
stored in the cruise database and reported in the APPENDIX.


4.2  CTDO Data Processing

Shipboard CTD data processing was performed after deployment using
SIO/ODF python CTD processing software v. 0.3. CTD acquisition data
were copied onto a OS X system, and then processed. CTD data at bottle
trips were extracted, and a 2-decibar down-cast pressure series
created. The pressure series data set was submitted for CTD data
distribution after corrections outlined in the following sections were
applied.

A total of 122 CTD stations were occupied including one test station.
A total of 125 CTDO/rosette/LADCP/UVP casts were completed. 122
standard CTDO/rosette/LADCP/UVP casts and one test cast completed with
a single 36-place (CTD #1281) rosette was used for all station/casts.

CTD data were examined at the completion of each deployment for clean
corrected sensor response and any calibration shifts. As bottle
salinity and oxygen results became available, they were used to refine
shipboard conductivity and oxygen sensor calibrations.

Temperature, salinity and dissolved O_2 comparisons were made between
down and up casts as well as between groups of adjacent deployments.
Vertical sections of measured and derived properties from sensor data
were checked for consistency.

A number of issues were encountered during S04P 2018 that directly
impacted CTD analysis. Issues that directly impacted bottle closures,
such as slipping guide rings, were detailed in the Underwater Sampling
Package section of this report. Temperature, conductivity and oxygen
analytical sensor issues are detailed in the following respective
sections.


4.3  Pressure Analysis

Laboratory calibrations of CTD pressure sensors were performed prior
to the cruise. Dates of laboratory calibration are recorded on the
underway sampling package table and calibration documents are provided
in the APPENDIX.

The Paroscientific Digiquartz pressure transducer S/N: 831-99677 was
calibrated on December 12th, 2017 at the SIO Calibration Facility. The
lab calibration coefficients provided on the calibration report were
used to convert frequencies to pressure. Initially SIO pressure lab
calibration slope and offsets coefficients were applied to cast data.
A shipboard calibration offset was applied to the converted pressures
during each cast. These offsets were determined by the pre and post-
cast on-deck pressure offsets. The pressure offsets were applied per
configuration cast sets.

• CTD Serial 1281-99677; Station Set 901 - 120


                             | Start P (dbar) | End P (dbar)
              ===============|================|=============
              Min            | -0.6           | -0.5        
              ---------------+----------------+-------------
              Max            | -0.0           | 0.8         
              ---------------+----------------+-------------
              Average        | 0.2            | 0.1         
              ---------------+----------------+-------------
              Applied Offset |                | -0.0539     


An offset of -0.0539 was applied to every cast performed by CTD 1281.
On-deck pressure reading for CTD 1281 varied from -0.6 to -0.0 dbar
before the casts, and -0.5 to 0.8 dbar after the casts. Before and
after average difference was 0.2 and 0.1 dbar respectively. The
overall average offset before and after cast was -0.0539 dbar.


4.4  Temperature Analysis

Laboratory calibrations of temperature sensors were performed prior to
the cruise at the SIO Calibration Facility. Dates of laboratory
calibration are recorded on the underway sampling package table and
calibration documents are provided in the APPENDIX.

The pre-cruise laboratory calibration coefficients were used to
convert SBE3plus frequencies to ITS-90 temperature. Additional
shipboard calibrations were performed to correct sensor bias. Two
independent metrics of calibration accuracy were used to determine
sensor bias. At each bottle closure, the primary and secondary
temperature were compared with each other and with a SBE35RT reference
temperature sensor.

The SBE35RT Digital Reversing Thermometer is an internally-recording
temperature sensor that operates independently of the CTD. The SBE35RT
was located equidistant between the two SBE3plus temperature sensors.
The SBE35RT is triggered by the SBE32 carousel in response to a bottle
closure. According to the manufacturer’s specifications, the typical
stability is 0.001°C/year. The SBE35RT was set to internally average
over a 15 second period.

A functioning SBE3plus sensor typically exhibit a consistent
predictable well modeled response. The response model is second order
with respect to pressure, a first order with respect to temperature
and a first order with respect to time. The functions used to apply
shipboard calibrations are as follows.

       T_{cor} = T + D_1 P_2 + D_2 P + D_3 T + \text{Offset}

                   T_{90} = T + tp_1 P + t_0

         T_{90} = T + a P_2 + b P + c T + \text{Offset}

Corrected temperature differences are shown in the following figures.


Fig. 4.1: SBE35RT-T1 by station (-0.002°C ≤ T1-T2 ≤ 0.002°C).

Fig. 4.2: Deep SBE35RT-T1 by station (Pressure ≥ 2000dbar).

Fig. 4.3: SBE35RT-T2 by station (-0.002°C ≤ T1-T2 ≤ 0.002°C).

Fig. 4.4: Deep SBE35RT-T2 by station (Pressure ≥ 2000dbar).

Fig. 4.5: T1-T2 by station (-0.002°C ≤ T1-T2 ≤ 0.002°C).

Fig. 4.6: Deep T1-T2 by station (Pressure ≥ 2000dbar).

Fig. 4.7: SBE35RT-T1 by pressure (-0.002°C ≤ T1-T2 ≤ 0.002°C).

Fig. 4.8: SBE35RT-T2 by pressure (-0.002°C ≤ T1-T2 ≤ 0.002°C).

Fig. 4.9: T1-T2 by pressure (-0.002°C ≤ T1-T2 ≤ 0.002°C).


The 95% confidence limits for the whole water column differences are
±0.0046°C for SBE35RT-T1, ±0.0043°C for SBE35RT-T2, and ±0.0026°C for
T1-T2. The 95% confidence limits for the deep temperature residuals
(where pressure ≥ 2000dbar) are ±0.00067°C for SBE35RT-T1,
±0.00066°C for SBE35RT-T2, and ±0.00059°C for T1-T2.

Minor complications impacted the temperature sensor data used for this
cruise.

   • Rough weather caused tripping on the fly for the surface bottle
     on many stations, leading to some surface SBE35RT averaging
     periods out of the water.

The resulting affected sections of data have been coded and documented
in the quality code APPENDIX.


4.5  Conductivity Analysis

Laboratory calibrations of conductivity sensors were performed prior
to the cruise at the SeaBird Calibration Facility. Dates of laboratory
calibration are recorded on the underway sampling package table and
calibration documents are provided in the APPENDIX.

The pre-cruise laboratory calibration coefficients were used to
convert SBE4C frequencies to mS/cm conductivity values. Additional
ship-board calibrations were performed to correct sensor bias.
Corrections for both pressure and temperature sensors were finalized
before analyzing conductivity differences. Two independent metrics of
calibration accuracy were examined. At each bottle closure, the
primary and secondary conductivity were compared with each other. Each
sensor was also compared to conductivity calculated from check sample
salinities using CTD pressure and temperature.

The differences between primary and secondary temperature sensors were
used as filtering criteria to reduce the contamination of conductivity
comparisons by package wake. The coherence of this relationship is
shown in the following figure.


Fig. 4.10: Coherence of conductivity differences as a function of
           temperature differences.


Uncorrected conductivity comparisons are shown in figures Uncorrected
CBottle - C1 by station (-0.002 mS/cm  BTLCOND-C1  0.002 mS/cm).
through Uncorrected C1-C2 by station (-0.002 mS/cm  C1-C2  0.002
mS/cm).


Fig. 4.11: Uncorrected C_Bottle - C1 by station (-0.002 mS/cm ≤
           BTLCOND-C1 ≤ 0.002 mS/cm).

Fig. 4.12: Uncorrected C_Bottle - C2 by station (-0.002 mS/cm ≤
           BTLCOND-C2 ≤ 0.002 mS/cm).

Fig. 4.13: Uncorrected C1-C2 by station (-0.002 mS/cm ≤ C1-C2 ≤
           0.002 mS/cm).


The residual conductivity differences after correction are shown in
figures Corrected CBottle - C1 by station (-0.002 mS/cm  BTLCOND-C1
0.002 mS/cm). through Corrected C1-C2 by conductivity (-0.002 mS/cm
C1-C2  0.002 mS/cm)..


Fig. 4.14: Corrected C_Bottle - C1 by station (-0.002 mS/cm ≤
           BTLCOND-C1 ≤ 0.002 mS/cm).

Fig. 4.15: Deep Corrected C_Bottle - C1 by station (Pressure >=
           2000dbar).

Fig. 4.16: Corrected C_Bottle - C2 by station (-0.002 mS/cm ≤
           BTLCOND-C2 ≤ 0.002 mS/cm).

Fig. 4.17: Deep Corrected C_Bottle - C2 by station (Pressure >=
           2000dbar).

Fig. 4.18: Corrected C1-C2 by station (-0.002 mS/cm ≤ C1-C2 ≤
           0.002 mS/cm).

Fig. 4.19: Deep Corrected C1-C2 by station (Pressure >= 2000dbar).

Fig. 4.20: Corrected C_Bottle - C1 by pressure (-0.002 mS/cm ≤
           BTLCOND-C1 ≤ 0.002 mS/cm).

Fig. 4.21: Corrected C_Bottle - C2 by pressure (-0.002 mS/cm ≤
           BTLCOND-C2 ≤ 0.002 mS/cm).

Fig. 4.22: Corrected C1-C2 by pressure (-0.002 mS/cm ≤ C1-C2 ≤
           0.002 mS/cm).

Fig. 4.23: Corrected C_Bottle - C1 by conductivity (-0.002 mS/cm ≤
           BTLCOND-C1 ≤ 0.002 mS/cm).

Fig. 4.24: Corrected C_Bottle - C2 by conductivity (-0.002 mS/cm ≤
           BTLCOND-C2 ≤ 0.002 mS/cm).

Fig. 4.25: Corrected C1-C2 by conductivity (-0.002 mS/cm ≤ C1-C2
           ≤ 0.002 mS/cm).


A functioning SBE4C sensor typically exhibit a predictable modeled
response. Offsets for each C sensor were determined using C_Bottle -
C_CTD differences in a deeper pressure range (500 or more dbars).
After conductivity offsets were applied to all casts, response to
pressure, temperature and conductivity were examined for each
conductivity sensor. The response model is second order with respect
to pressure, second order with respect to temperature, second order
with respect to conductivity and a first order with respect to time.
The functions used to apply shipboard calibrations are as follows.

Corrections made to all conductivity sensors are of the form:

   C_{cor} = C + cp_2 P^2 + cp_1 P + cc_1 C + \text{Offset}

The 95% confidence limits for the whole water column differences are
±0.0041 mS/cm for BTLCOND-C1, ±0.0045 mS/cm for BTLCOND-C2, and
±0.0027 mS/cm for C1-C2. The 95% confidence limits for the deep
temperature residuals (where pressure ≥ 2000dbar) are ±0.00155
mS/cm for BTLCOND-C1, ±0.00142 mS/cm for SBTLCOND-C2, and ±0.00086
mS/cm for C1-C2.

Salinity residuals after applying shipboard P/T/C corrections are
summarized in the following figures. Only CTD and bottle salinity data
with "acceptable" quality codes are included in the differences.
Quality codes and comments are published in the APPENDIX of this
report.


Fig. 4.26: Salinity residuals by station (-0.002 mPSU ≤ SALNTY-C1SAL
           ≤ 0.002 mPSU).

Fig. 4.27: Salinity residuals by pressure (-0.002 mPSU ≤ SALNTY-
           C1SAL ≤ 0.002 mPSU).

Fig. 4.28: Deep Salinity residuals by station (Pressure >= 2000dbar).


The 95% confidence limits for the whole water column differences are
±0.0054 PSU for salinity-C2SAL. The 95% confidence limits for the deep
salinity residuals (where pressure ≥ 2000dbar) are ±0.00188 PSU for
salinity-C2SAL.

A number of issues affected conductivity and calculated CTD salinities
during this cruise.

   • Bottle salinity analysis was complicated due to switching
     between two Autosals, leading to knock-on problems when
     attempting to calibrate conductivity against bottle salinity.

The resulting affected sections of data have been coded and documented
in the quality code APPENDIX.


4.6  CTD Dissolved Oxygen

Laboratory calibrations of the dissolved oxygen sensors were performed
prior to the cruise at the SBE calibration facility. Dates of
laboratory calibration are recorded on the underway sampling package
table and calibration documents are provided in the APPENDIX.

The pre-cruise laboratory calibration coefficients were used to
convert SBE43 frequencies to µmol/kg oxygen values for acquisition
only. Additional shipboard fitting were performed to correct for the
sensors non-linear response. Corrections for pressure, temperature and
conductivity sensors were finalized before analyzing dissolved oxygen
data. The SBE43 sensor data were compared to dissolved O_2 check
samples taken at bottle stops by matching the down cast CTD data to
the up cast trip locations along isopycnal surfaces. CTD dissolved O_2
was then calculated using Clark Cell MPOD O_2 sensor response model
for Beckman/SensorMedics and SBE43 dissolved O_2 sensors. The residual
differences of bottle check value versus CTD dissolved O_2 values are
minimized by optimizing the SIO DO sensor response model coefficients
with a Levenberg-Marquardt non-linear least-squares fitting procedure.

The general form of the SIO DO sensor response model equation for
Clark cells follows Brown and Morrison [Millard82] and Owens [Owens85]
SIO models DO sensor secondary responses with lagged CTD data. In-situ
pressure and temperature are filtered to match the sensor responses.
Time constants for the pressure response (τ_p), a slow τ_{Tf}
and fast τ_{Ts} thermal response, package velocity τ_{dP},
thermal diffusion τ_{dT} and pressure hysteresis τ_h are fitting
parameters. Once determined for a given sensor, these time constants
typically remain constant for a cruise. The thermal diffusion term is
derived by low-pass filtering the difference between the fast response
T_s and slow response T_l temperatures. This term is intended to
correct non-linearity in sensor response introduced by inappropriate
analog thermal compensation. Package velocity is approximated by low-
pass filtering 1st-order pressure differences, and is intended to
correct flow-dependent response. Dissolved O_2 concentration is then
calculated:


O ml/l =
 2
             ph                                      dOc      dP
         C2 ————                  (C4t1+C5Ts+C7Pl+Ce ——— + C8 ——— + C9dT)
[C ·V  ·e   5000 + C ]·ƒsat(T,P)·e                   dt       dTt
  1  DO             3


Where:

• O_2 ml/l     Dissolved O_2 concentration in ml/l

• V_DO  Raw sensor output

• C_1   Sensor slope

• C_2   Hysteresis response coefficient

• C_3   Sensor offset

• f_sat ( T , P )|O2| saturation at T,P (ml/l)

• T     In-situ temperature (°C)

• P     In-situ pressure (decibars)

• P_h   Low-pass filtered hysteresis pressure (decibars)

• T_l   Long-response low-pass filtered temperature (°C)

• T_s   Short-response low-pass filtered temperature (°C)

• P_l   Low-pass filtered pressure (decibars)

• dO_c / dt     Sensor current gradient (¬µamps/sec)

• dP/dt Filtered package velocity (db/sec)

• dT    Low-pass filtered thermal diffusion estimate (T_s - T_l)

• C_4 - C_9     response coefficients

CTD dissolved O_2 residuals are shown in the following figures O2
residuals by station (-0.01 µmol/kg  OXYGEN-BTLOXY  0.01 µmol/kg).
through Deep O2 residuals by station (Pressure >= 2000dbar)..


fig. 4.29: O_2 residuals by station (-0.01 µmol/kg ≤ OXYGEN-BTLOXY
           ≤ 0.01 µmol/kg).

fig. 4.30: O_2 residuals by pressure (-0.01 µmol/kg ≤ OXYGEN-BTLOXY
           ≤ 0.01 µmol/kg).

fig. 4.31: Deep O_2 residuals by station (Pressure >= 2000dbar).

The second standard deviations of 3.62 (µmol/kg) for all dissolved
oxygen bottle data values and 1.15 (µmol/kg) for deep dissolved oxygen
values are only presented as general indicators of the goodness of
fit. CLIVAR GO-SHIP standards for CTD dissolved oxygen data are < 1%
accuracy against on board Winkler titrated dissolved O_2 lab
measurements.

A number of complications arose with the acquisition and processing of
CTD dissolved oxygen data.

   • Multiple stations had impacted SBE 43 oxygen data due to the
     pump not working leading to errant values. Values presented for
     those casts should all be considered as questionable.

   • RINKO oxygen optode data has been nominally calibrated and
     presented in the bottle data file and ctd data files. See RINKO
     Oxygen Optode section for more detail.

All compromised data signals were recorded and coded in the data
files. The bottle trip levels affected by the signals were coded and
are included in the bottle data comments section of the APPENDIX.

[Millard82] Millard, R. C., Jr., “CTD calibration and data
            processing techniques at WHOI using the practical salinity
            scale,” Proc. Int. STD Conference and Workshop, p. 19,
            Mar. Tech. Soc., La Jolla, Ca. (1982).

[Owens85] Owens, W. B. and Millard, R. C., Jr., “A new
          algorithm for CTD oxygen calibration,” Journ. of Am.
          Meteorological Soc., 15, p. 621 (1985).



5.  TRANSMISSOMETER


PI
   • Wilf Gardner (*TAMU*)

Cruise Technician
   • Joseph Gum

The following summarizes the air calibration and regular operation
procedures for the CST-1803DR transmissometer.


5.1  Air Calibration

   • Check that in air temperature and instrument temperature has
     been stable before starting calibration, and record air
     temperature

   • Connect transmissometer to a pigtail or CTD for air
     calibration, and power up

   • Remove protective red caps from windows

   • Rinse lenses with DI water and tap dry with lab wipes

   • Compare transmissometer readings with previous readings. If
     readings are substantially different, wash with slightly soapy
     water (2-3 drops of soap) or alcohol, then rinse with DI water
     and tap dry.

   • Repeat rinsing and wiping procedure until voltage stabilizes,
     then record voltage in log

   • Completely block light between two lenses, and record voltage

   • Check that air temperature, unblocked voltage, and blocked
     voltage have been recorded


Great care must be taken to clean the transmissometer windows and get
a stable reading in a couple of rinse and wipe cycles. The method used
on S04P 2018 involved folding a Kimwipe neatly into a small square 1/8
the starting size of the rectangle, with no creases or fingerprints on
the wiping surface. The lenses were rinsed with DI water then tapped
dry, taking care to hold the Kimwipe at the corners. A new Kimwipe was
then folded, soaked with ethanol or isopropyl alcohol, and then the
lenses were tapped, taking care to use one side of the Kimwipe per
lens. Each Kimwipe was discarded after one use to prevent
reintroducing contaminants onto the lenses. Following this method a
lens would have a reliable voltage in two to four cleanings.

One point of note is that a rinsing fluid of significantly different
temperature than the transmissometer seemed to cause the reading to
change by 0.1 to 0.3 volts. This forced the technician to wait for
some period of time until the voltage reading stabilized. This change
in reading might also be due to ship roll changing the atmosphere
temperature around the transmissometer.


5.2  Daily Operations

Before a cast the CTD watchstanders would remove the red caps and
rinse the windows with lightly soapy water, taking care to do this as
close as possible to the cast to prevent the windows from drying. This
was done to prevent bubbles from forming on the face of the windows.
Post the windows were rinsed with DI water and the red caps were
placed on the windows. At the end of the cruise the transmissometer
was rinsed with fresh water before packing.


5.3  Calibration Results


Table 5.1: Calibration results for Transmissometer

Date       | Time     | Blocked | Unblocked   | Unblocked | Air  | Remarks       
           |          | Value   | Value       | Value     | Temp |               
           |          | (Volts) | (Voltmeter) | (CTD)     |      |               
===========|==========|=========|=============|===========|======|===============
16-Sep-16  |          | 0.008   | 4.813       |           | 21.6 | Factory       
           |          |         |             |           |      | Calibration   
           |          |         |             |           |      | air           
-----------+----------+---------+-------------+-----------+------+---------------
16-Sep-16  |          |         | 4.699       |           | 21.4 | Factory       
           |          |         |             |           |      | Calibration   
           |          |         |             |           |      | water         
-----------+----------+---------+-------------+-----------+------+---------------
28-Apr-17  |          | 0.009   | 4.829       |           | 25   | TAMU Lab      
-----------+----------+---------+-------------+-----------+------+---------------
4-Dec-17   |          | 0.009   | 4.805       |           | 21   | TAMU Lab      
-----------+----------+---------+-------------+-----------+------+---------------
12-Mar-18  | 2200 UTC | 0.007   |             | 4.785     | 13.6 | Pre test cast 
-----------+----------+---------+-------------+-----------+------+---------------
16-Mar-18  | 0250 UTC | 0.006   |             | 4.795     | 9.6  | Pre-station 1 
           |          |         |             |           |      | - changed     
           |          |         |             |           |      | cables        
-----------+----------+---------+-------------+-----------+------+---------------
27-Mar-18  | 0231 UTC | 0.007   |             | 4.79      | 7.6  | Pre-station 23
-----------+----------+---------+-------------+-----------+------+---------------
4-Apr-18   | 0348 UTC | 0.007   |             | 4.78      | 4.7  | Pre-station 40
-----------+----------+---------+-------------+-----------+------+---------------
10-Apr-18  | 0239 UTC | 0.007   |             | 4.763     | 6    | Transit - Pre-
           |          |         |             |           |      | station 54    
-----------+----------+---------+-------------+-----------+------+---------------
15-Apr-18  | 0355 UTC | 0.007   |             | 4.777     | 24.2 | Transit -Pre- 
           |          |         |             |           |      | station 67 -  
           |          |         |             |           |      | heaters were  
           |          |         |             |           |      | on in transit 
-----------+----------+---------+-------------+-----------+------+---------------
24-Apr-18  | 2317 UTC | 0.007   |             | 4.768     | 8.9  | Pre-station 89
-----------+----------+---------+-------------+-----------+------+---------------
29-Apr-18  | 2010 UTC | 0.006   |             | 4.745     | 5.8  | Pre-station 99
           |          |         |             |           |      | - temps may   
           |          |         |             |           |      | not be uniform
           |          |         |             |           |      | due to water  
           |          |         |             |           |      | dump          
-----------+----------+---------+-------------+-----------+------+---------------
3-May-18   | 0530 UTC | 0.006   |             | 4.759     | 8.5  | Pre station   
           |          |         |             |           |      | 109           
-----------+----------+---------+-------------+-----------+------+---------------
9-May-18   | 1816 UTC | 0.007   |             | 4.762     | 27   | End of cruise 
           |          |         |             |           |      | - heaters were
           |          |         |             |           |      | on in transit 



6.  RINKO OXYGEN OPTODE



PIs
   • James Swift
   • Susan Becker

Analysts
   • John Ballard (Calibration)
   • Kenneth Jackson
   • Joseph Gum


ODF has been using a RINKO oxygen optode as a second dissolved oxygen
sensor on S04P 2018. The RINKO provides a redundant oxygen measurement
to the SBE43 that is not plumbed, avoiding problems with plumbed line
fouling. For S04P 2018 RINKO data has been fitted against bottle
oxygen data, and has been reported in data files as CTDRINKO.


6.1  Calibration


• Model: ARO-CAV
• Serial: 0296
• Factory calibration: April 10, 2017
• Film No: 164312BA
• Factory DO coefficients: see factory calibration sheet

A two point calibration was performed prior, during, and after
deployment on the 67 day repeat hydrography in the Southern Ocean.
These calibrations produced three sets of calibration coefficients (G
and H) to adjust factory calibration of dissolved oxygen raw voltage.
The calibrations also provided an assessment of foil degradation over
the course of the 125 station, 250-4800m, and -2 to -1.8 deg C
deployment.

As per manufacturer (JFE Advantech Co., Ltd.) recommendation, 100%
saturation points were obtained via bubbling ambient air in a stirred
beaker of tap water about 30 minutes, removing air stone, then
submersing the powered Rinko. Dissolved oxygen raw voltage (DOout),
atmospheric pressure, and solution temperature were recorded for
calculation of new oxygen sensor coefficients (G and H).

Zero point calibrations also followed general manufacturer
recommendations. A sodium sulfite solution (25g in 500mL deionized
water) was used for the pre-cruise calibration. For both the middle
and post-cruise calibrations, ultra pure nitrogen gas was flushed
through a plastic bag covering the sensor. Raw voltage (DOout),
atmospheric pressure, and solution or air temperature were recorded,
along with 100% saturation data, for calculation of coefficients (G
and H).

An external temperature probe (Measurement Specialties 4600; accuracy
+/-0.01 deg C) was used for middle and post-deployment calibrations.
Rinko temperature (factory coefficients) was used for pre-cruise
calibration. Mid-cruise comparison of Rinko temperature to 4600 probe
yielded a difference of -0.02 deg C.

Generally, the Rinko III sensor appears to have performed as expected
with no major problems or sharp drift throughout the deployment. An
SBE 43 dissolved oxygen sensor was deployed simultaneously. Both
oxygen sensor data sets were analyzed and quality controlled with
winkler bottle oxygen data.

                            | Date     | G       | H     
            ================|==========|=========|=======
            Pre-deployment  | 02/08/18 | -0.0327 | 1.0683
            ----------------+----------+---------+-------
            Mid-deployment  | 04/07/18 | -0.7339 | 1.0332
            ----------------+----------+---------+-------
            Post-deployment | 05/10/18 | -1.4941 | 1.0298



6.2  Analysis


RINKO data was acquired, converted from volts to oxygen saturation,
and then calculated for micromoles per kilogram. The resulting data
was then fitted using the same oxygen calibration and fitting routines
as for the SBE43. While the data in the deep looks acceptable, the
data in the first 200 meters is badly fitted resulting in large
erroneous values. More work will be needed to refine oxygen fitting,
and while values might be flagged with 2, all RINKO values should be
used with caution.



7.  SALINITY


PIs
   • Susan Becker
   • James Swift

Technicians
   • John Calderwood
   • Jeremiah Brower


7.1  Equipment and Techniques

Two Guildline Autosals located in salinity analysis room, an 8400B
(S/N 69-180) and an 8400A (S/N 57-396), were used for all salinity
measurements. Both were serviced prior to NBP18-02/S04P in San Diego
and sent with other equipment in January. The salinometer readings
were logged on a computer using a LabView program developed by Carl
Mattson. The Autosal water bath temperature was set to 21°C. The
laboratory’s temperature was set and maintained to 20°C. This is to
ensure stabilize reading values and improve accuracy. Salinity
analyses were performed after samples had equilibrated to laboratory
temperature range of 20-21°C, usually 8 hours after collection. The
salinometer was standardized for each group of samples analyzed (1 or
2 casts, up to 72 samples) using two bottles of standard seawater: one
at the beginning and end of each set of measurements. The salinometer
output was logged to a computer file. The software prompted the
analyst to flush the instrument’s cell and change samples when
appropriate. Between runs the water from the last standard was left in
the cell. For each calibration standard, the salinometer cell was
initially flushed 2 times before a set of conductivity ratio reading
was taken. For each sample, the salinometer cell was initially flushed
at least 2 times before a set of conductivity ratio readings were
taken.

IAPSO Standard Seawater Batch P-161 was used to standardize all casts.


7.2  Sampling and Data Processing

The salinity samples were collected in 200 ml Kimax high-alumina
borosilicate bottles that had been rinsed at least three times with
sample water prior to filling. The bottles were sealed with custom-
made plastic insert thimbles and Nalgene screw caps. This assembly
provides very low container dissolution and sample evaporation. Prior
to sample collection, inserts were inspected for proper fit and loose
inserts replaced to insure an airtight seal. Laboratory temperature
was also monitored electronically throughout the cruise. PSS-78
salinity [UNESCO1981] was calculated for each sample from the measured
conductivity ratios. The offset between the initial standard seawater
value and its reference value was applied to each sample. Then the
difference (if any) between the initial and final vials of standard
seawater was applied to each sample as a linear function of elapsed
run time. The corrected salinity data was then incorporated into the
cruise database.


7.3  Narrative

Autosal 69-180 was used to process samples from the first 16 stations.
Communication errors between Labview and Autosal 69-180 occurred
during processing of station 16’s samples, causing the Labview
software to lose connection with the Autosal. The LVasal software was
updated to version 1.35c, but communication errors continued. The
serial connection to the DGH board installed in the back of Autosal
69-180 had a wire work loose from its terminal block. Once the loose
wire was found and re-installed, the serial feed from 69-180 worked
correctly. Autosal 57-396 was used from station 18 to 120, and ended
the cruise in good working order.

Autosal 57-396, being a model 8400A, appeared to be more unstable with
its standard numbers between runs. On at least two occasions the
standard number changed more than 10 units when measuring a standard
for a single cast, with the casts on both sides of the impacted cast
having the same standard value. On those casts the data was flagged as
3 or 4 as deemed appropriate. Some bottles of IAPSO standard were also
suspected to be different from the stated value, requiring additional
standards to be open and run before starting analysis of the cast. It
is unclear whether the standards were bad, the autosal was reporting
erroneous values, or some combination of both.

Due to communication issues during handoff six bottles were not
sampled. Seven bottles were broken during sampling.


7.4  Standard Dial Experiment

To attempt corrections with the casts showing offsets in both salinity
values and standard dial values on Autosal 8400A S/N 57-396, an
experiment was run sampling IAPSO standard at different standard dial
values. At the end of the cruise 12 standards were run with different
standard dial values, where the values were chosen to constrain the
values seen during the cruise. The standards were run from 400 to 450
and back to 400 to see if there was a difference in turning the
standard dial versus standard dial down. Changing the standard dial
seemed to show a linear change in conductivity ratio. While no
standards were run as a standard, the value from the last autosal run
is presented as a measure of autosal stability. The values sampled are
presented below.


                 Std Value | Conductivity Ratio
                 ==========|===================
                 440       | 1.99976 (Last run)
                 ----------+-------------------
                 400       | 1.99947           
                 ----------+-------------------
                 410       | 1.99957           
                 ----------+-------------------
                 420       | 1.99965           
                 ----------+-------------------
                 430       | 1.99973           
                 ----------+-------------------
                 440       | 1.99978           
                 ----------+-------------------
                 450       | 1.99984           
                 ----------+-------------------
                 450       | 1.99991           
                 ----------+-------------------
                 440       | 1.99978           
                 ----------+-------------------
                 430       | 1.99971           
                 ----------+-------------------
                 420       | 1.99963           
                 ----------+-------------------
                 410       | 1.99954           
                 ----------+-------------------
                 400       | 1.99948           
                 
                 
The values were compared to the runs with offsets to see if a linear
offset would correct the data, such as station 93. Station 93 showed a
good shape in the profile, but offset from the profiles seen on
neighboring stations. Unfortunately, the offset did not entirely
correct the data, resulting in the deep salinity values lower and
outside the bounds of acceptable salinity than salinity values on
neighboring stations. It is unsure what else could have caused the
salinity value change. The impacted stations were still flagged as 4.

[UNESCO1981] UNESCO 1981. Background papers and
             supporting data on the Practical Salinity Scale, 1978.
             UNESCO Technical Papers in Marine Science, No. 37 144.



8.  NUTRIENTS


PIs
   • Susan Becker
   • James Swift

Technicians
   • Susan Becker
   • John Ballard


8.1  Summary of Analysis


• 4122 samples from 121 ctd stations

• The cruise started with new pump tubes and they were changed prior
  to stations 27, 54, and 87.

• 7 sets of nitrate, phosphate, and silicate Primary/Secondary
  standards were made up over the course of the cruise.

• 3 sets of Primary and 38 sets of Secondary nitrite standards were
  made up over the course of the cruise.

• The cadmium column efficiency was checked periodically and ranged
  between 97%-100%. A new column was put on if the efficiency fell
  below 97% or injected with air.


8.2  Equipment and Techniques

Nutrient analyses (phosphate, silicate, nitrate+nitrite, and nitrite)
were performed on a Seal Analytical continuous-flow AutoAnalyzer 3
(AA3). The methods used are described by Gordon et al [Gordon1992]
Hager et al. [Hager1972], and Atlas et al. [Atlas1971]. Details of
modification of analytical methods used in this cruise are also
compatible with the methods described in the nutrient section of the
GO-SHIP repeat hydrography manual (Hydes et al., 2010) [Hydes2010].


8.3  Nitrate/Nitrite Analysis

A modification of the Armstrong et al. (1967) [Armstrong1967]
procedure was used for the analysis of nitrate and nitrite. For
nitrate analysis, a seawater sample was passed through a cadmium
column where the nitrate was reduced to nitrite. This nitrite was then
diazotized with sulfanilamide and coupled with
N-(1-naphthyl)-ethylenediamine to form a red dye. The sample was then
passed through a 10mm flowcell and absorbance measured at 540nm. The
procedure was the same for the nitrite analysis but without the
cadmium column.

**REAGENTS**

Sulfanilamide
   Dissolve 10g sulfamilamide in 1.2N HCl and bring to 1 liter volume.
   Add 2 drops of 40% surfynol 465/485 surfactant. Store at room
   temperature in a dark poly bottle.

   Note: 40% Surfynol 465/485 is 20% 465 plus 20% 485 in DIW.

N-(1-Naphthyl)-ethylenediamine dihydrochloride (N-1-N)
   Dissolve 1g N-1-N in DIW, bring to 1 liter volume. Add 2 drops 40%
   surfynol 465/485 surfactant. Store at room temperature in a dark
   poly bottle. Discard if the solution turns dark reddish brown.

Imidazole Buffer
   Dissolve 13.6g imidazole in ~3.8 liters DIW. Stir for at least 30
   minutes to completely dissolve. Add 60 ml of CuSO4 + NH4Cl mix (see
   below). Add 4 drops 40% Surfynol 465/485 surfactant. Let sit
   overnight before proceeding. Using a calibrated pH meter, adjust to
   pH of 7.83-7.85 with 10% (1.2N) HCl (about 10 ml of acid, depending
   on exact strength). Bring final solution to 4L with DIW. Store at
   room temperature.

NH4Cl + CuSO4 mix
   Dissolve 2g cupric sulfate in DIW, bring to 100 m1 volume (2%).
   Dissolve 250g ammonium chloride in DIW, bring to l liter volume.
   Add 5ml of 2% CuSO4 solution to this NH4Cl stock. This should last
   many months.


8.4  Phosphate Analysis

Ortho-Phosphate was analyzed using a modification of the Bernhardt and
Wilhelms (1967) [Bernhardt1967] method. Acidified ammonium molybdate
was added to a seawater sample to produce phosphomolybdic acid, which
was then reduced to phosphomolybdous acid (a blue compound) following
the addition of dihydrazine sulfate. The sample was passed through a
10mm flowcell and absorbance measured at 820nm (880nm after station
59, see section on analytical problems for details).

**REAGENTS**

Ammonium Molybdate H2SO4 sol'n
   Pour 420 ml of DIW into a 2 liter Ehrlenmeyer flask or beaker,
   place this flask or beaker into an ice bath. SLOWLY add 330 ml of
   conc H2SO4. This solution gets VERY HOT!! Cool in the ice bath.
   Make up as much as necessary in the above proportions.

   Dissolve 27g ammonium molybdate in 250ml of DIW. Bring to 1 liter
   volume with the cooled sulfuric acid sol'n. Add 3 drops of 15% DDS
   surfactant. Store in a dark poly bottle.

Dihydrazine Sulfate
   Dissolve 6.4g dihydazine sulfate in DIW, bring to 1 liter volume
   and refrigerate.


8.5  Silicate Analysis

Silicate was analyzed using the basic method of Armstrong et al.
(1967). Acidified ammonium molybdate was added to a seawater sample to
produce silicomolybdic acid which was then reduced to silicomolybdous
acid (a blue compound) following the addition of stannous chloride.
The sample was passed through a 10mm flowcell and measured at 660nm.

**REAGENTS**

Tartaric Acid
   Dissolve 200g tartaric acid in DW and bring to 1 liter volume.
   Store at room temperature in a poly bottle.

Ammonium Molybdate
   Dissolve 10.8g Ammonium Molybdate Tetrahydrate in 1000ml dilute
   H2SO4. (Dilute H2SO4 = 2.8ml conc H2SO4  or 6.4ml of H2SO4 diluted
   for PO4 moly per liter DW) (dissolve powder, then add H2SO4) Add
   3-5 drops 15% SDS surfactant per liter of solution.

Stannous Chloride
   stock: (as needed)

   Dissolve 40g of stannous chloride in 100 ml 5N HCl. Refrigerate in
   a poly bottle.

   NOTE: Minimize oxygen introduction by swirling rather than shaking
   the solution. Discard if a white solution (oxychloride) forms.

   working: (every 24 hours) Bring 5 ml of stannous chloride stock to
   200 ml final volume with 1.2N HCl. Make up daily - refrigerate when
   not in use in a dark poly bottle.


8.6  Sampling

Nutrient samples were drawn into 40 ml polypropylene screw-capped
centrifuge tubes. The tubes and caps were cleaned with 10% HCl and
rinsed 2-3 times with sample before filling. Samples were analyzed
within 1-3 hours after sample collection, allowing sufficient time for
all samples to reach room temperature. The centrifuge tubes fit
directly onto the sampler.


8.7  Data Collection and Processing

Data collection and processing was done with the software (ACCE ver
6.10) provided with the instrument from Seal Analytical. After each
run, the charts were reviewed for any problems during the run, any
blank was subtracted, and final concentrations (micro moles/liter)
were calculated, based on a linear curve fit. Once the run was
reviewed and concentrations calculated a text file was created. That
text file was reviewed for possible problems and then converted to
another text file with only sample identifiers and nutrient
concentrations that was merged with other bottle data.


8.8  Standards and Glassware Calibration

Primary standards for silicate (Na2SiF6), nitrate (KNO3), nitrite
(NaNO2), and phosphate (KH2PO4) were obtained from Johnson Matthey
Chemical Co. and/or Fisher Scientific. The supplier reports purities
of >98%, 99.999%, 97%, and 99.999 respectively.

All glass volumetric flasks and pipettes were gravimetrically
calibrated prior to the cruise. The primary standards were dried and
weighed out to 0.1mg prior to the cruise. The exact weight was noted
for future reference. When primary standards were made, the flask
volume at 20C, the weight of the powder, and the temperature of the
solution were used to buoyancy-correct the weight, calculate the exact
concentration of the solution, and determine how much of the primary
was needed for the desired concentrations of secondary standard.
Primary and secondary standards were made up every 7-10days. The new
standards were compared to the old before use.

All the reagent solutions, primary and secondary standards were made
with fresh distilled deionized water (DIW).

Standardizations were performed at the beginning of each group of
analyses with working standards prepared every 10-12 hours from a
secondary. Working standards were made up in low nutrient seawater
(LNSW). One batch of LNSW was used on the cruise.  It was collected
and filtered prior to the cruise. The actual concentration of
nutrients in this water was empirically determined during the
standardization calculations.

The concentrations in micro-moles per liter of the working standards
used were:


               - | N+N   | PO_4 | SIL  | NO_2 | NH_4
                 | (uM)  | (uM) | (uM) | (uM) | (uM)
              ===|=======|======|======|======|=====
               0 |  0.0  | 0.0  | 0.0  | 0.0  | 0.0 
              ---+-------+------+------+------+-----
               3 | 15.50 | 1.2  |  60  | 0.50 | 2.0 
              ---+-------+------+------+------+-----
               5 | 31.00 | 2.4  | 120  | 1.00 | 4.0 
              ---+-------+------+------+------+-----
               7 | 46.50 | 3.6  | 180  | 1.50 | 6.0 



8.9  Quality Control

All final data was reported in micro-moles/kg. NO^3, PO_4, and NO_2
were reported to two decimals places and SIL to one. Accuracy is based
on the quality of the standards the levels are:


               NO^3 | 0.05 µM (micro moles/Liter)
               -----+-----------------------------
               PO_4 | 0.004 µM                   
               -----+-----------------------------
               SIL  | 2-4 µM                     
               -----+-----------------------------
               NO_2 | 0.05 µM                    


As is standard ODF practice, a deep calibration "check" sample was run
with each set of samples to estimate precision within the cruise. The
data are tabulated below.


             Parameter | Concentration (µm)  | stddev
             ----------+---------------------+-------
             NO^3      | 31.69               | 0.135 
             ----------+---------------------+-------
             PO_4      | 2.15                | 0.02  
             ----------+---------------------+-------
             SIL       | 98.1                | 0.5   


Reference materials for nutrients in seawater (RMNS) were also used as
a check sample run once a day. The RMNS preparation, verification, and
suggested protocol for use of the material are described by
[Aoyama2006] [Aoyama2007], [Aoyama2008] and Sato [Sato2010]. RMNS
batch CF was used on this cruise, with each bottle being used once or
twice before being discarded and a new one opened. Data are tabulated
below.


      Parameter | Concentration | stddev  | assigned conc
      ==========|===============|=========|==============
      -         | (µmol/l)      | -       | (µmol/l)     
      ----------+---------------+---------+--------------
      NO^3      | 44.68         | 0.17    | 44.46        
      ----------+---------------+---------+--------------
      PO_4      | 3.13          | 0.01    | 3.13         
      ----------+---------------+---------+--------------
      Sil       | 163.8         | 0.6     | 163.6        
      ----------+---------------+---------+--------------
      NO_2      | 0.09          | 0.01    | 0.07         




8.10  ANALYTICAL PROBLEMS

No major analytical problems.

   [image]

[Armstrong1967] Armstrong, F.A.J., Stearns, C.A., and
                Strickland, J.D.H., "The measurement of upwelling and
                subsequent biological processes by means of the
                Technicon Autoanalyzer and associated equipment,"
                Deep-Sea Research, 14, pp.381-389 (1967).

[Atlas1971] Atlas, E.L., Hager, S.W., Gordon, L.I., and
            Park, P.K., "A Practical Manual for Use of the Technicon
            AutoAnalyzer in Seawater Nutrient Analyses Revised,"
            Technical Report 215, Reference 71-22, p.49, Oregon State
            University, Department of Oceanography (1971).

[Aoyama2006] Aoyama, M., 2006: 2003 Intercomparison
             Exercise for Reference Material for Nutrients in Seawater
             in a Seawater Matrix, Technical Reports of the
             Meteorological Research Institute No.50, 91pp, Tsukuba,
             Japan.

[Aoyama2007] Aoyama, M., Susan B., Minhan, D., Hideshi,
             D., Louis, I. G., Kasai, H., Roger, K., Nurit, K., Doug,
             M., Murata, A., Nagai, N., Ogawa, H., Ota, H., Saito, H.,
             Saito, K., Shimizu, T., Takano, H., Tsuda, A., Yokouchi,
             K., and Agnes, Y. 2007. Recent Comparability of
             Oceanographic Nutrients Data: Results of a 2003
             Intercomparison Exercise Using Reference Materials.
             Analytical Sciences, 23: 1151-1154.

[Aoyama2008] Aoyama M., J. Barwell-Clarke, S. Becker, M.
             Blum, Braga E. S., S. C. Coverly,E. Czobik, I. Dahllof,
             M. H. Dai, G. O. Donnell, C. Engelke, G. C. Gong, Gi-Hoon
             Hong, D. J. Hydes, M. M. Jin, H. Kasai, R. Kerouel, Y.
             Kiyomono, M. Knockaert, N. Kress, K. A. Krogslund, M.
             Kumagai, S. Leterme, Yarong Li, S. Masuda, T. Miyao, T.
             Moutin, A. Murata, N. Nagai, G.Nausch, M. K. Ngirchechol,
             A. Nybakk, H. Ogawa, J. van Ooijen, H. Ota, J. M. Pan, C.
             Payne, O. Pierre-Duplessix, M. Pujo-Pay, T. Raabe, K.
             Saito, K. Sato, C. Schmidt, M. Schuett, T. M. Shammon, J.
             Sun, T. Tanhua, L. White, E.M.S. Woodward, P. Worsfold,
             P. Yeats, T. Yoshimura, A.Youenou, J. Z. Zhang, 2008:
             2006 Intercomparison Exercise for Reference Material for
             Nutrients in Seawater in a Seawater Matrix, Technical
             Reports of the Meteorological Research Institute No. 58,
             104pp.

[Bernhardt1967] Bernhardt, H., and  Wilhelms, A., "The
                continuous determination of low level iron, soluble
                phosphate and total phosphate with the AutoAnalyzer,"
                Technicon Symposia, I,pp.385-389 (1967).

[Gordon1992] Gordon, L.I., Jennings, J.C., Ross, A.A.,
             Krest, J.M., "A suggested Protocol for Continuous Flow
             Automated Analysis of Seawater Nutrients in the WOCE
             Hydrographic Program and the Joint Global Ocean Fluxes
             Study," Grp. Tech Rpt 92-1, OSU College of Oceanography
             Descr. Chem Oc. (1992).

[Hager1972] Hager, S.W.,  Atlas, E.L., Gordon L.I.,
            Mantyla, A.W., and Park, P.K., " A comparison at sea of
            manual and autoanalyzer analyses of phosphate, nitrate,
            and silicate ," Limnology and Oceanography, 17,pp.931-937
            (1972).

[Hydes2010] Hydes, D.J., Aoyama, M., Aminot, A., Bakker,
            K., Becker, S., Coverly, S., Daniel,A.,Dickson,A.G.,
            Grosso, O., Kerouel, R., Ooijen, J. van, Sato, K., Tanhua,
            T., Woodward, E.M.S., Zhang, J.Z., 2010. Determination of
            Dissolved Nutrients (N, P, Si) in Seawater with High
            Precision and Inter-Comparability Using Gas-Segmented
            Continuous Flow Analysers, In: GO-SHIP Repeat Hydrography
            Manual: A Collection of Expert Reports and Guidelines.
            IOCCP Report No. 14, ICPO Publication Series No 134.

[Kerouel1997] Kerouel, R., Aminot, A., “Fluorometric
              determination of ammonia in sea and estuarine waters by
              direct segmented flow analysis.” Marine Chemistry, vol
              57, no. 3-4, pp. 265-275, July 1997.

[Sato2010] Sato, K., Aoyama, M., Becker, S., 2010. RMNS as
           Calibration Standard Solution to Keep Comparability for
           Several Cruises in the World Ocean in 2000s. In: Aoyama,
           M., Dickson, A.G., Hydes, D.J., Murata, A., Oh, J.R.,
           Roose, P., Woodward, E.M.S., (Eds.), Comparability of
           nutrients in the world’s ocean. Tsukuba, JAPAN: MOTHER
           TANK, pp 43-56.



9.  OXYGEN ANALYSIS


PIs
   • Susan Becker
   • James Swift

Technicians
   • Andrew Barna
   • Kenneth Jackson


9.1  Equipment and Techniques

Dissolved oxygen analyses were performed with an SIO/ODF-designed
automated oxygen titrator using photometric end-point detection based
on the absorption of 365nm wavelength ultra-violet light. The
titration of the samples and the data logging were controlled by PC
LabView software. Thiosulfate was dispensed by a Dosimat 665 buret
driver fitted with a 1.0 ml burette. ODF used a whole-bottle modified-
Winkler titration following the technique of Carpenter [Carpenter1965]
with modifications by [Culberson1991] but with higher concentrations
of potassium iodate standard approximately 0.012N, and thiosulfate
solution approximately 55 gm/l. Pre-made liquid potassium iodate
standards were run every day of station work (approximately every 3-4
stations), unless changes were made to the system or reagents.
Reagent/distilled water blanks were determined with every
standardization or more often if a change in reagents required it to
account for presence of oxidizing or reducing agents.


9.2  Sampling and Data Processing

4138 oxygen measurements were made. Samples were collected for
dissolved oxygen analyses soon after the rosette was brought on board.
Using a silicone drawing tube, nominal 125ml volume-calibrated iodine
flasks were rinsed 3 times with minimal agitation, then filled and
allowed to overflow for at least 3 flask volumes. The sample drawing
temperatures were measured with an electronic resistance temperature
detector (RTD) embedded in the drawing tube. These temperatures were
used to calculate umol/kg concentrations, and as a diagnostic check of
bottle integrity. Reagents (MnCl_2 then NaI/NaOH) were added to fix
the oxygen before stoppering. The flasks were shaken twice (10-12
inversions) to assure thorough dispersion of the precipitate, once
immediately after drawing, and then again after about 30-40 minutes.

The samples were analyzed within 2-14 hours of collection, and the
data incorporated into the cruise database.

Thiosulfate normalities were calculated for each standardization and
corrected to 20°C. The 20°C normalities and the blanks were plotted
versus time and were reviewed for possible problems. The blanks and
thiosulfate normalities for each batch of thiosulfate were stable
enough that no smoothing was necessary.


9.3  Volumetric Calibration

Oxygen flask volumes were determined gravimetrically with degassed
deionized water to determine flask volumes at ODF's chemistry
laboratory. This is done once before using flasks for the first time
and periodically thereafter when a suspect volume is detected. The
volumetric flasks used in preparing standards were volume-calibrated
by the same method, as was the 10 ml Dosimat buret used to dispense
standard iodate solution.


9.4  Standards

Liquid potassium iodate standards were prepared in 6 liter batches and
bottled in sterile glass bottles at ODF's chemistry laboratory prior
to the expedition. The normality of the liquid standard was determined
by calculation from weight. The standard was supplied by Alfa Aesar
and has a reported purity of 99.4-100.4%. All other reagents were
"reagent grade" and were tested for levels of oxidizing and reducing
impurities prior to use.


9.5  Narrative

Setup occurred in Hobart, Tasmania, Australia from 2018-03-06 to
2018-03-09, the date of departure. The oxygen analysis rig was setup
and secured on the forward bench of the hydolab of the R/V Nathanial
B. Palmer (NBP). Initial reagent batches of approximately 4l were made
in port and the rig was checked out before departure.

During the week long transit from Tasmania to our first station off
Antarctica, samples were taken from the uncontaminated seawater system
every 4 hours in areas we had permission to sample in. These underway
samples were stored for batch analysis all at once. A test station
happened about midway though the transit, this was sampled and
analyzed by one of the oxygen technicians for practice. These data are
reported with the rest of the stations.

Station sampling and analysis went well, with only minor problems
encountered. Around station 78 it was noticed that the gain on the
detector box was almost at maximum, likely the cause of earlier high
"blocked" voltages. The UV pen lamp was replaced, resulting in a lower
needed gain. Additionally, the windows in the water bath were cleaned
which resulted in a further reduction in needed gain. A single sample
was lost due to the burette tip blocking the light path resulting in
no findable end point.

The trends in thiosulfate normality were analyzed at the end of
station work, three distinct trends were noticed. Batch 1 of
thiosulfate (station 1 to 56) was stable around a single value. Batch
2 had a period of drift (station 57 to 85), then was stable around a
value (station 86 to 120). The thiosulfate normality was smoothed
(linear regression) in these three regions and the concentrations
recalculated.

[Carpenter1965] Carpenter, J. H., “The Chesapeake Bay
                Institute technique for the Winkler dissolved oxygen
                method,” Limnology and Oceanography, 10, pp. 141-143
                (1965).

[Culberson1991] Culberson, C. H., Knapp, G., Stalcup,
                M., Williams, R. T., and Zemlyak, F., “A comparison of
                methods for the determination of dissolved oxygen in
                seawater,” Report WHPO 91-2, WOCE Hydrographic
                Programme Office (Aug 1991).


10.  DISSOLVED INORGANIC CARBON (DIC)


PIs
   • Richard A. Feely (*NOAA*/*PMEL*)
   • Rik Wanninkhof (*NOAA*/*AOML*)

Technicians
   • Andrew Collins (*UW*/*NOAA*/*PMEL*)
   • Patrick Mears (*U Miami*/*NOAA*/*AOML*)


10.1 Sample collection

Samples for DIC measurements were collected from Niskin bottles into
310 ml borosilicate glass flasks using silicone tubing according to
procedures outlined in the PICES Publication, Guide to Best Practices
for Ocean CO2 Measurements. The flasks were rinsed three times and
filled from the bottom with care not to entrain any bubbles,
overflowing by at least one-half volume. The sample tube was pinched
off and withdrawn, creating a 6 ml headspace, followed by addition of
0.12 ml of saturated HgCl2 solution in order to halt any biological
activity. The sample bottles were then sealed with glass stoppers
lightly covered with Apiezon-L grease and were stored at room
temperature for a maximum of 12 hours.


10.2  Equipment

DIC analysis was performed via coulometry using two analytical systems
(PMEL1 and PMEL2) simultaneously on the cruise. Each system consisted
of a coulometer (CM5015-O UIC Inc) coupled with a Dissolved Inorganic
Carbon Extractor (DICE). The DICE system was developed by Esa Peltola
and Denis Pierrot of NOAA/AOML and Dana Greeley of NOAA/PMEL to
modernize a carbon extractor called SOMMA (Johnson et al. 1985, 1987,
1993, and 1999; Johnson 1992).

The two DICE systems (PMEL 1 and PMEL 2) were set up in the dry lab
onboard the RVIB Nathaniel B. Palmer.


10.3  DIC Analysis

In coulometric analysis of DIC, all carbonate species are converted to
CO2 (gas) by addition of excess hydrogen ion (acid) to the seawater
sample, and the evolved CO2 gas is swept into the titration cell of
the coulometer with pure air or compressed nitrogen, where it reacts
quantitatively with a proprietary reagent based on ethanolamine to
generate hydrogen ions. In this process, the solution changes from
blue to colorless, triggering a current through the cell and causing
coulometrical generation of OH- ions at the anode. The OH- ions react
with the H+, and the solution turns blue again. A beam of light is
shone through the solution, and a photometric detector at the opposite
side of the cell senses the change in transmission. Once the percent
transmission reaches its original value, the coulometric titration is
stopped, and the amount of CO2 that enters the cell is determined by
integrating the total change during the titration.


10.4  DIC Calculation

Calculation of the amount of CO2 injected was according to the CO2
handbook [DOE1994]. The concentration of CO2 ([CO2]) in the samples
was determined according to:


                         (Counts - Blank * Run Time) * Kµmol/count
  [CO_2] = Cal. Factor * —————————————————————————————————————————
                            pipette volume * density of sample


where Cal. Factor is the calibration factor, Counts is the instrument
reading at the end of the analysis, Blank is the counts/minute
determined from blank runs performed at least once for each cell
solution, Run Time is the length of coulometric titration (in
minutes), and K is the conversion factor from counts to micromoles.

The instrument has a salinity sensor, but all DIC values were
recalculated to a molar weight (µmol/kg) using density obtained from
the CTD’s salinity. The DIC values were corrected for dilution due to
the addition of 0.12 ml of saturated HgCl_2 used for sample
preservation. The total water volume of the sample bottles was 305.55
ml (calibrated by Dana Greeley, PMEL). The correction factor used for
dilution was 1.0004. A correction was also applied for the offset from
the CRM. This additive correction was applied for each cell using the
CRM value obtained at the beginning of the cell. The average (± SD)
correction was 2.18 ± 1.31 µmol/kg for PMEL 1 and 5.32 ± 1.48 µmol/kg
for PMEL 2. The consistently low offset on PMEL 2 can likely be
explained by a slightly inaccurate pipette calibration. A post-cruise
calibration will be performed, which should confirm this.

The coulometer cell solution was replaced after 25 – 28 mg of carbon
was titrated, typically after 9 – 12 hours of continuous use. The
average (± SD) blanks for PMEL 1 and PMEL 2 were 17.73 ± 4.3 and 21.11
± 5.8 counts, respectively.


10.4  Calibration, Accuracy, and Precision

The stability of each coulometer cell solution was confirmed three
different ways.

1. Gas loops were run at the beginning of each cell;

2. CRM’s supplied by Dr. A. Dickson of SIO, were measured near the
   beginning; middle and end of each cell before sample analysis;

3. Duplicate samples from the same niskin were measured near the
   beginning; middle and end of each cell.

Each coulometer was calibrated by injecting aliquots of pure CO2
(99.999%) by means of an 8-port valve [Wilke1993] outfitted with two
calibrated sample loops of different sizes (~1ml and ~2ml). The
instruments were each separately calibrated at the beginning of each
cell with a minimum of two sets of these gas loop injections.

The accuracy of the DICE measurement is determined with the use of
standards (Certified Reference Materials (CRMs), consisting of
filtered and UV irradiated seawater) supplied by Dr. A. Dickson of
Scripps Institution of Oceanography (SIO). The CRM accuracy is
determined manometrically on land in San Diego and the DIC data
reported to the data base have been corrected to this batch ()#172)
CRM value. The CRM certified value for this batch is 2039.06 µmol/kg.

The precision of the two DICE systems can be demonstrated via the
replicate samples. Approximately 11.5% of the niskins sampled were
duplicates taken as a check of our precision. These replicate samples
were interspersed throughout the station analysis for quality
assurance and integrity of the coulometer cell solutions. The average
absolute difference from the mean of these replicates is 0.67 µmol/kg
- no major systematic differences between the replicates were
observed.

The pipette volume was determined by taking aliquots of distilled
water from volumes at known temperatures. The weights with the
appropriate densities were used to determine the volume of the
pipettes.

Table 1: PO6 Leg 2 Calibration data. Includes results up to station
#238 of a total of 250 stations. The additional stations should not
significantly change these reported values.


       |          |          |            |                | Std  | Avg rep.
UNIT   | L Loop   | S Loop   | Pipette    | Ave CRM1       | Dev  | diff.
=======|==========|==========|============|================|======|=========
PMEL 1 | 1.002553 | 1.006788 | 27.5905 ml | 2036.88, n=108 | 1.31 | 0.63    
-------+----------+----------+------------+----------------+------+---------
PMEL 2 | 1.004904 | 1.002426 | 26.4110 ml | 2033.74, n= 86 | 1.48 | 0.72    



10.6  Underway DIC Samples

Underway samples were collected from the flow thru system in the Hydro
Lab during transit. Discrete DIC samples were collected approximately
every 4 hours with duplicates every fifth sample. A total of 66
discrete DIC samples including duplicates were collected while
underway. The average difference for replicates of underway DIC
samples was 0.9 µmol/kg and the average standard deviation was 1.3.


10.7  Summary

The overall performance of the analytical equipment was good during
the cruise. At the time of submission, our data includes 13 samples
flagged as “questionable”, and 2 samples flagged as “bad”. In general,
questionable values seemed to result from drift in the coulometer
cell, which will be accounted for in post-cruise data quality control.

Including the duplicates, 3,905 samples were analyzed from 118 CTD
casts for DIC, yielding a value for approximately 84% of the niskins
tripped. The distribution of DIC with depth along the 2018 cruise
track can be seen in Figure 1, while differences in DIC distributions
observed between the 2011 and 2018 S04P occupations can be seen in
Figures 2 and 3. The DIC data reported to the database directly from
the ship are to be considered preliminary until a more thorough
quality assurance can be completed shore side.


Fig. 10.1: Distribution of dissolved inorganic carbon measured during
           the 2018 GO-SHIP S04P research expedition.

Fig. 10.2: Changes in the distributions of dissolved inorganic carbon
           in the upper 1000m measured during the 2018 S04P occupation
           compared to those measured during the 2011 S04P occupation.

Fig. 10.3: Changes in the distributions of dissolved inorganic carbon
           below 1000m measured during the 2018 S04P occupation compared 
           to those measured during the 2011 S04P occupation.



[DOE1994] DOE (U.S. Department of Energy). (1994). *Handbook
          of Methods for the Analysis of the Various Parameters of the
          Carbon Dioxide System in Seawater*. Version 2.0.
          ORNL/CDIAC-74. Ed. A. G. Dickson and C. Goyet. Carbon
          Dioxide Information Analysis Center, Oak Ridge National
          Laboratory, Oak Ridge, Tenn.

[Dickson2007] Dickson, A.G., Sabine, C.L. and Christian,
              J.R. (Eds.), (2007): *Guide to Best Practices for Ocean
              CO2 Measurements*. PICES Special Publication 3, 191 pp.

[Feely1998] Feely, R.A., R. Wanninkhof, H.B. Milburn, C.E.
            Cosca, M. Stapp, and P.P. Murphy (1998): *"A new automated
            underway system for making high precision pCO2
            measurements aboard research ships."* Anal. Chim. Acta,
            377, 185-191.

[Johnson1985] Johnson, K.M., A.E. King, and J. McN.
              Sieburth (1985): *"Coulometric DIC analyses for marine
              studies: An introduction."* Mar. Chem., 16, 61-82.

[Johnson1987] Johnson, K.M., P.J. Williams, L.
              Brandstrom, and J. McN. Sieburth (1987): *"Coulometric
              total carbon analysis for marine studies: Automation and
              calibration."* Mar. Chem., 21, 117-133.

[Johnson1992] Johnson, K.M. (1992): Operator's manual:
              *"Single operator multiparameter metabolic analyzer
              (SOMMA) for total carbon dioxide (CT) with coulometric
              detection."* Brookhaven National Laboratory, Brookhaven,
              N.Y., 70 pp.

[Johnson1993] Johnson, K.M., K.D. Wills, D.B. Butler,
              W.K. Johnson, and C.S. Wong (1993): *"Coulometric total
              carbon dioxide analysis for marine studies: Maximizing
              the performance of an automated continuous gas
              extraction system and coulometric detector."* Mar.
              Chem., 44, 167-189.

[Johnson1999] Johnson, K.M., Körtzinger, A.; Mintrop,
              L.; Duinker, J.C.; and Wallace, D.W.R. (1999).
              *Coulometric total carbon dioxide analysis for marine
              studies: Measurement and interna consistency of underway
              surface TCO2 concentrations.* Marine Chemistry
              67:123–44.

[Lewis1998] Lewis, E. and D. W. R. Wallace (1998) Program
            developed for CO2 system calculations. Oak Ridge, Oak
            Ridge National Laboratory.
            http://cdiac.ornl.gov/oceans/co2rprt.html

[Wilke1993] Wilke, R.J., D.W.R. Wallace, and K.M. Johnson
            (1993): "Water-based gravimetric method for the
            determination of gas loop volume." Anal. Chem. 65,
            2403-2406



11.  TOTAL ALKALINITY


PI
   • Andrew G. Dickson – Scripps Institution of Oceanography

Technicians
   • Manuel Belmonte
   • Sarah Barnes


11.1  Total Alkalinity

The total alkalinity of a sea water sample is defined as the number of
moles of hydrogen ion equivalent to the excess of proton acceptors
(bases formed from weak acids with a dissociation constant K ≤
10–4.5 at 25°C and zero ionic strength) over proton donors (acids with
K > 10–4.5) in 1 kilogram of sample.


11.2  Total Alkalinity Measurement System

Samples are dispensed using a Sample Delivery System (SDS) consisting
of a volumetric pipette, various relay valves, and two air pumps
controlled by LabVIEW 2012. Before filling the jacketed cell with a
new sample for analysis, the volumetric pipette is cleared of any
residual from the previous sample with the aforementioned air pumps.
The pipette is then rinsed with new sample and filled, allowing for
overflow and time for the sample temperature to equilibrate. The
sample bottle temperature is measured using a DirecTemp thermistor
probe inserted into the sample bottle and the volumetric pipette
temperature is measured using a DirecTemp surface probe placed
directly on the pipette. The LabVIEW program then calculates the
temperature of the sample dispensed. This calculated temperature is
used to convert the sample volume to mass for analysis.

Seawater samples are analyzed using an open cell two-stage titration
procedure using two 250 mL jacketed cells. One sample is undergoing
titration while the second is being prepared and equilibrating to 20°C
for analysis. The sample of seawater is first acidified to a pH
between 3.4 and 4.0 with a single aliquot of standardized hydrochloric
acid (~0.1 mol kg^-1 HCl in ~0.6 mol kg^-1 NaCl solution). The sample
is then stirred for five minutes while air is bubbled into the sample
at a rate of 200 scc/m to remove any liberated carbon dioxide gas. A
Metrohm 876 Dosimat Plus is used for all standardized hydrochloric
acid additions. After the five-minute period, the titration is
continued until a pH of about 3.0 has been reached. The progress of
the titration is monitored using a pH glass electrode/reference
electrode cell, and the total alkalinity is computed from the titrant
volume and e.m.f. measurements using a non-linear least-squares
approach [Dickson2007]. An Agilent 34970A Data Acquisition/Switch Unit
with a 34901A multiplexer is used to read the voltage measurements
from the electrode and monitor the temperatures from the sample, acid,
and room. The calculations for this procedure are performed
automatically using LabVIEW 2012.


11.3  Sample Collection

Samples for total alkalinity measurements were taken at all S04P
Stations (1-120). Two Niskin bottles at each station were sampled
twice for duplicate measurements. Using silicone tubing, the total
alkalinity samples were drawn from Niskin bottles into 250 mL Pyrex
bottles, making sure to rinse the bottles and Teflon sleeved glass
stoppers at least twice before the final filling. A headspace of
approximately 4.5 mL was removed and 0.05 mL of saturated mercuric
chloride solution was added to each sample for preservation. After
sampling was completed, each sample's temperature was equilibrated to
approximately 20°C using a Fischer Scientific Isotemp¬Æ  water bath.


11.4  Problems and Troubleshooting

The R/V IB Nathaniel B. Palmer is a fantastic research vessel. Our
electrodes only occasionally appeared to pick up larger than expected
interference from the lab's neighboring instruments or the ship
itself. While breaking through thick ice there was an increase in this
interference due to turbulence throughout the ship. Electrode plots
could show increased electrode sensitivity over time. However, enough
electrodes were brought on S04P so this never resulted in a bad
measurement. Any unusual measurements (poor electrode plot / profile
outlier) were always reran.

Near the start of S04P, low alkalinity values for reference material
titrations required a Metrohm 876 Dosimat Plus to be changed. This
changed the volume of acid being added to the titrations but due to
careful calibration of the Metrohm 876 Dosimat Plus's delivery volume
this did not affect the alkalinity titration's results.

Also near the start of S04P, Sample Delivery System B was changed due
to a suspected shift in the volume being delivered. SDS A delivers 1
mL more than SDS B, but again due to careful calibration of both
systems delivery volume this did not affect the alkalinity
measurements. Additionally, throughout the cruise there were minor SDS
glitches. Either the SDS would get stuck in a drawing command or
dispensing command or the temperature probes would produce an
obviously wrong temperature. Very few times did the system getting
stuck in drawing or dispensing command cause samples to be lost, and
erroneous temperatures were caught immediately. Furthermore, a leaky
valve was discovered and although no measurements were affected
because of the operators' quick responses, the valve was replaced to
prevent any future samples from being lost.


11.5  Quality Control

Dickson laboratory Certified Reference Material (CRM) Batch 172 was
used to determine the accuracy of the total alkalinity analyses on
S04P. The total alkalinity certified value for this batch is:

• Batch 172  2217.40 ± 0.7 µmol/kg (32;16)

The cited uncertainties represent the standard deviation. Figures in
parentheses are the number of analyses made (total number of analyses;
number of separate bottles analyzed).

At least one reference material was analyzed at every S04P station,
resulting in 455 reference material analyses. On S04P, the measured
total alkalinity value for each batch is:

• Batch 172 2216.34 ± 1.59  mol kg-1 (455) [mean ± std. dev. (n)]

Two Niskin bottles were sampled twice at every station for duplicate
analyses. The pooled standard deviation observed amongst duplicates
measured on S04P is:

• 1.07 µmol kg-1  (234)  [pooled std. dev. (n)] .

The total alkalinity measurements for each 2018 S04P station were
compared to measurements taken from the neighboring 2018 S04P
stations.

3502 total alkalinity values were submitted for S04P. The total
alkalinity of the entire transect is shown as sectional figures in the
attached Figures. Corrections have been made for Certified Reference
Material measurement comparison and also for the mercuric chloride
additions. The correct sample volume still needs to be verified on
land. Thus, the data submitted along with this report is to be
considered preliminary.

   [image]

Section of total alkalinity along S04P 67° S (stations 1 - 120 except
10-17, 31-53, and 98-103).

   [image]

Section of total alkalinity along S04P 170° W (stations 10-17).

   [image]

Section of total alkalinity along S04P 150° W (stations 31-53).

   [image]

Section of total alkalinity along S04P 103° W (stations 98-103).



12.  DISCRETE PH ANALYSES (TOTAL SCALE)


PI
   • Dr. Andrew Dickson

Technicians
   • May-Linn Paulsen


12.1  Sampling

Samples were collected in 250 mL Pyrex glass bottles and sealed using
Teflon-sleeved glass stoppers held in place by rubber bands. Each
bottle was rinsed two times and allowed to overflow by one additional
bottle volume. Prior to sealing, each sample was given a 1% headspace
and poisoned with 0.02% of the sample volume of saturated mercuric
chloride (HgCl2) using an Eppendorf repeating pipettor. Samples were
collected only from Niskin bottles that were also being sampled for
both total alkalinity and dissolved inorganic carbon in order to
completely characterize the carbon system. Additionally, two duplicate
samples were collected from all stations for quality control purposes.


12.2  Analysis

pH was measured spectrophotometrically on the total hydrogen scale
using an Agilent 8453 spectrophotometer and in accordance with the
methods outlined by Carter et al., 2013. [Carter2013]. A Kloehn V6
syringe pump was used to autonomously fill, mix, and dispense sample
through the custom 10cm flow-through jacketed cell. A Thermo NESLAB
RTE-7 recirculating water bath was used to maintain the cell
temperature at 25.0°C during analyses, and a YSI 4600 precision
thermometer and probe were used to monitor and record the temperature
of each sample immediately after the spectrophotometric measurements
were taken. The indicator meta-cresol purple (mCP) was used to measure
the absorbance of light measured at two different wavelengths (434 nm,
578 nm) corresponding to the maximum absorbance peaks for the acidic
and basic forms of the indicator dye. A baseline absorbance (Abase)
was also measured and subtracted from these wavelengths. The baseline
absorbance was determined by averaging the absorbances from 725-735nm.
The ratio of the absorbances was then used to calculate pH on the
total scale using the equations outlined in Liu et al., 2011
[Liu2011]. The salinity data used was obtained from the conductivity
sensor on the CTD. The salinity data was later corroborated by
shipboard measurements.


12.3  Reagents

The mCP indicator dye was made up to a concentration of approximately
2.0mM and a total ionic strength of 0.7 M. A total of 5 batches were
used during the cruise. The pHs of these batches was adjusted with 0.1
M solutions of HCl and NaOH (in 0.6 M NaCl background) to
approximately 7.85, measured with a pH meter calibrated with NBS
buffers. The indicator was obtained from Prof. Eric Achterberg at
GEOMAR-Helmholz Centre for Ocean Research (Kiel), and was purified
using the flash chromatography technique described by Patsavas et al.,
2013. [Patsavas2013].


12.4  Data Processing

An indicator dye is itself an acid-base system that can change the pH
of the seawater to which it is added. Therefore it is important to
estimate and correct for this perturbation to the seawater’s pH for
each batch of dye used during the cruise. To determine this
correction, multiple bottles from each station were measured twice,
once with a single addition of indicator dye and once with a double
addition of indicator dye. The measured absorbance ratio (R) and an
isosbestic absorbance (A_{\text{iso}}) were determined for each
measurement, where:


                          A_{578} - A_{base}
                      R = ——————————————————
                          A_{434} - A_{base}

and

                    A_{iso}} = A_{488} - A_{base}

The change in R for a given change in A_{iso}, ∆R/∆A_{iso}, was then 
plotted against the measured R-value for the normal amount of dye and 
fitted with a linear regression. From this fit the slope and y-intercept 
(b and a respectively) are determined by:

                        ∆R/∆A_{iso} = bR + a

From this the corrected ratio (R') corresponding to the measured
absorbance ratio if no indicator dye were present can be determined
by:

                      R' = R - A_{iso}(bR + a)


12.5  Problems and Troubleshooting

Many of the samples had high dissolved gas content and degassed when
brought to room temperature. This could be clearly seen in the
formation of bubbles inside the sealed sample bottles and in the
spectrophotometric pH system (Kloehn syringe pump, sample tubing, and
the 10-cm cell). Efforts were made to reduce bubble formation by
verifying all pump fittings were tight, and periodically flushing the
system with air or isopropanol, followed by thorough flushing with
junk seawater.

Bubbles also occasionally formed in the water bath that controls the
measurement temperature. In one instance, an extremely large bubble in
the tubing stopped the circulation of water around the 10-cm cell and
caused a sudden drop in temperature. This occurred as the room
temperature changed drastically (also observed in total alkalinity
temperature measurements), the reason for the room temperature change
is not known. This appeared to affect the pH of one sample, which
deviated from a typical profile and was flagged as questionable in the
preliminary data. Room temperature and water bath tubing was checked
periodically following this incident.

There were occasionally problems with the rubber bands slipping off
the bottle stoppers, potentially causing de-gassing of the samples
prior to the analysis, although the extent to which degassing could
have happened is not known. The rubber band slipping off would also
happen occasionally while the samples were temperature-equilibrating
in the water bath, and sometimes the stopper would pop off from the
sample expanding. The samples to which this happened did not appear to
have an anomalous pH when compared to deeper and shallower samples
from the same station.

One bottle broke prior to analysis, resulting in the loss of data for
one sample.

Our HgCl2 dispenser would sometimes partly clog due to the cold
temperatures in the Baltic Room causing the volume of HgCl2 dispensed
into some of the samples to vary slightly, although no effect on the
pH was detected. When this happened, the pipette tip was thoroughly
rinsed with de-ionized water.


12.6  Standardization/Results

The precision of the data was assessed from measurements of duplicate
analyses, replicate analyses (two successive measurements on one
bottle), certified reference materials (CRMs) from Batch 172 (provided
by Dr. Andrew Dickson, UCSD). CRMs were measured twice a day over the
course of the cruise.

The overall precision determined from duplicate analyses was ±0.0017
(n=207). The overall precision determined from replicate analyses was
±0.0027 (n=207). Additionally, 418 measurements were made on 112
bottles of Certified Reference Materials, which were found to have a
pH of 7.8306 ±0.002 (n=418) and a within-bottle standard deviation of
±0.0005 (n=103).

The precision statistics for P06W are:


            Duplicate precision   | ± 0.0017 (n=207)      
            ----------------------+-----------------------
            Replicate precision   | ± 0.0027 (n=207)      
            ----------------------+-----------------------
            B172                  | 7.8306 ± 0.002 (n=418)
            ----------------------+-----------------------
            B172 within-bottle SD | ± 0.0005 (n=103)      


3492 pH values were submitted for S04P 2018. Additional corrections
will need to be performed and these data should be considered
preliminary until a more thorough analysis of the data can take place
on shore. The preliminary pH of the entire transect is shown as a
section in Fig. 12.1.


Fig. 12.1: Section of pH on the total scale along S04P (all the
           stations along the 67 line, not including the south-ward
           excursions). The data were DIVA-gridded, and a few contours 
           are shown.



[Carter2013] Carter, B.R., Radich, J.A., Doyle, H.L., and
             Dickson, A.G., "An Automated Spectrometric System for
             Discrete and Underway Seawater pH Measurements,"
             Limnology and Oceanography: Methods, 2013.

[Liu2011] Liu, X., Patsavas, M.C., Byrne R.H., "Purification
          and Characterization of meta Cresol Purple for
          Spectrophotometric Seawater pH Measurements," Environmental
          Science and Technology, 2011.

[Patsavas2013] Patsavas, M.C., Byrne, R.H.,  and Liu X.
               "Purification of meta-cresol purple and cresol red by
               flash chromatography: Procedures for ensuring accurate
               spectrophotometric seawater pH measurements," Marine
               Chemistry, 2013.



13.  CHLOROFLUOROCARBON (CFC), SULFUR HEXAFLUORIDE (SF6), 
     AND NITROUS OXIDE (N2O)*


PI
   • Mark J. Warner, University of Washington
     (warner@u.washington.edu)

Co-PI
   • William Smethie, Columbia University – Lamont-Doherty Earth
     Observatory

Samplers and Analysts
   • Mark J. Warner, University of Washington
   • Eugene Gorman, Lamont-Doherty Earth Observatory
   • Max Rintoul, Australian National University

• Note that N2O measurements are a Level 3 measurement.  The
concentrations were measured on the same water samples collected for
the Level 1 CFC/SF6 measurements. The N2O analysis is still under
development. Please contact the PI for any use of these data.


13.1  Sample Collection

Samples for the analysis of dissolved CFC-11, CFC-12, SF6, and N2O
were collected from approximately 2460 of the Niskin water samples
during the expedition. When taken, water samples for CFC analysis were
the first samples drawn from the 10-liter bottles. Care was taken to
co-ordinate the sampling of CFCs with other samples to minimize the
time between the initial opening of each bottle and the completion of
sample drawing. In most cases, dissolved oxygen, dissolved inorganic
carbon, and pH samples (and 3He when sampled) were collected within
several minutes of the initial opening of each bottle. To minimize
contact with air, the CFC samples were collected from the Niskin
bottle petcock into 250-cc ground glass syringes through plastic 3-way
stopcocks. The syringes were stored in large ice chest in the
laboratory at 3.5° - 6°C until 30-45 minutes before analysis to reduce
the degassing and bubble formation in the sample. At that time, they
were transferred to a water bath at approximately 28°C in order to
increase the stripping efficiency.


13.2  Equipment and Technique

Concentrations of CFC-11, CFC-12, SF6, and N2O in air samples,
seawater and gas standards were measured by shipboard electron capture
gas chromatography (EC-GC). This system from the University of
Washington was located in a portable laboratory on the heli-deck.
Samples were introduced into the GC-EC via a purge and trap system.
Approximately 200-ml water samples were purged with nitrogen and the
compounds of interest were trapped on a Porapak Q/Carboxen
1000/Molecular Sieve 5A trap cooled by an immersion bath to -60°C.
During the purging of the sample (6 minutes at 220 ml min-1 flow), the
gas stream was stripped of any water vapor via a Nafion trap in line
with an ascarite/magnesium perchlorate dessicant tube prior to
transfer to the trap. The trap was isolated and heated by direct
resistance to 175°C. The desorbed contents of the trap were back-
flushed and transferred onto the analytical pre-columns. The first
precolumn was a 40-cm length of 1/8-in tubing packed with 80/100 mesh
Porasil B. This precolumn was used to separate the CFC-11 from the
other gases. The second pre-column was 13 cm of 1/8-in tubing packed
with 80/100 mesh molecular sieve 5A. This pre-column separated the N2O
from CFC-12 and SF6. Three analytical columns in three gas
chromatographs with electron capture detectors were used in the
analysis. CFC-11 was separated from other compounds by a long column
consisting of 36 cm of Porasil B and 150 cm of Carbograph 1AC
maintained at 90°C. CFC-12 and SF6 were analyzed using a column
consisting of 2.33 m of molecular sieve 5A and 1.5 m of Carbograph
1AC maintained at 80°C. The analytical column for N2O was 30 cm of
molecular sieve 5A in a 120°C oven. The carrier gas for this column
was instrumental grade P-5 gas (95% Ar / 5% CH4) that was directed
onto the second precolumn and into the third column for the N2O
analyses. All three detectors were run at 300°C.

The analytical system was calibrated frequently using a standard gas
of known gas composition. Gas sample loops of known volume were
thoroughly flushed with standard gas and injected into the system. The
temperature and pressure was recorded so that the amount of gas
injected could be calculated. The procedures used to transfer the
standard gas to the trap, precolumns, main chromatographic columns and
EC detectors were similar to those used for analyzing water samples.
Three sizes of gas sample loops were used. Multiple injections of
these loop volumes could be made to allow the system to be calibrated
over a relatively wide range of concentrations. Air samples and system
blanks (injections of loops of CFC-free gas) were injected and
analyzed in a similar manner. The typical analysis time for samples
was 740 sec.


13.3  Atmospheric Sampling

For atmospheric sampling, a ~100 meter length of 3/8-in OD Dekaron
tubing was run from the portable laboratory to the bow of the ship. A
flow of air was drawn through this line to the main laboratory using
an Air Cadet pump. The air was compressed in the pump, with the
downstream pressure held at ~1.5 atm. using a back-pressure regulator.
A tee allowed a flow (100 ml min-1) of the compressed air to be
directed to the gas sample valves of the CFC/SF6/N2O analytical
system, while the bulk flow of the air (>7 l min-1) was vented through
the back-pressure regulator. Air samples were generally analyzed when
the relative wind direction was within 50 degrees of the bow of the
ship to reduce the possibility of shipboard contamination. The pump
was run for approximately 30 minutes prior to analysis to insure that
the air inlet lines and pump were thoroughly flushed. The average
atmospheric concentrations determined during the cruise (from a sets
of 4 or 5 measurements analyzed when possible) were 224.0 +/- 2.9
parts per trillion (ppt) for CFC-11 (n=47), 504.7 +/- 4.7 ppt for
CFC-12 (N=47), 9.2 +/- 0.6 ppt for SF6 (N=28), and 325.1 +/- 2.6 parts
per billion for N2O (N=18). Note that a larger aliquot was required
for higher precision N2O analysis, and this higher aliquot resulted in
SF6 peak areas outside the range of the calibration curve used for
seawater samples. No air samples were collected after May 5th due to
the bow mast (and air inlet) becoming entirely ensconced in ice.


13.4  Summary

Concentrations of the CFCs in air, seawater samples and gas standards
are reported relative to the SIO98 calibration scale (Cunnold, et.
al., 2000) [Cunnold2000]. Concentrations in air and standard gas are
reported in units of mole fraction in dry gas, and are typically in
the parts per trillion (ppt) range for CFCs and SF6 and parts per
billion (ppb) for N2O. Dissolved CFC concentrations are given in units
of picomoles per kilogram seawater (pmol kg-1), SF6 in femtomoles per
kilogram seawater (fmol kg-1), and N2O in nanomoles per kilogram
seawater (nmol kg-1). CFC concentrations in air and seawater samples
were determined by fitting their chromatographic peak areas to multi-
point calibration curves, generated by injecting multiple sample loops
of gas from a working standard (UW WRS 32399) into the analytical
instrument. Full-range calibration curves were run at the beginning
and end of the cruise, as well as during long transits/weather delays
when possible. Single injections of a fixed volume of standard gas at
one atmosphere were run much more frequently (at intervals of 2 hours)
to monitor short-term changes in detector sensitivity. The SF6 peak
was often on a small bump on the baseline, resulting in a large
dependence of the peak area on the choice of endpoints for
integration. Estimated accuracy is +/- 3%. Estimated limit of
detection is 1 fmol kg-1 for CFC-11, 2 fmol kg-1 for CFC-12 and 0.05
fmol kg-1 for SF6.

The efficiency of the purging process was evaluated by re-stripping
water samples and comparing the residual concentrations to initial
values. These re-strip values were less than 1% for CFC-11 and
essentially zero for CFC-12 and SF6. For N2O, the re-strip values were
complicated by the apparent production of N2O within the re-stripped
sample within the sparging chamber for a subset of the samples. Based
on the re-strips of numerous samples where the stripper blank was low
and relatively constant, the mean values were approximately 5%.

On this expedition, based on the analysis of over 50 duplicate samples
(i.e two samples collected from the same Niskin), we estimate
precisions (1 standard deviation) of 0.67% or 0.0014 pmol kg-1
(whichever is greater) for dissolved CFC-11, 1.26% or 0.0023 pmol kg-1
for CFC-12 measurements, 0.032 fmol kg-1 or 3.5% for SF6, and 1.06% or
0.18 nmol kg-1 for N2O.


13.5  Analytical Difficulties

The major analytical challenge for this voyage was the sensitivity of
the electron capture detector used for the measurement of SF6 and
CFC-12 to changes in atmospheric pressure. The peak area of an
injection of one large sample loop of the increased by approximately
4% per decrease of 1 mb in atmospheric pressure. In addition the
baseline shifted upwards and was very sensitive to the motion of the
ship. At atmospheric pressures below 970 mb, the broad plateau on
which the SF6 peak eluted became a broad peak with the SF6 peak on the
downslope. In rough seas, it was difficult to separate the smaller SF6
peaks from the broader peaks associated with the ship roll. For most
of the analyses during these periods, any peak within a time window
(74 to 80 sec) was identified as SF6 with endpoints manually chosen.
In most of these instances, the reported low-level SF6 concentrations
are flagged as questionable (flag 3).

[Cunnold2000] Prinn, R. G., Weiss, R.F., Fraser, P.J.,
              Simmonds, P.G., Cunnold, D.M., Alyea, F.N., O'Doherty,
              S., Salameh, P., Miller, B.R., Huang, J., Wang, R.H.J.,
              Hartley, D.E., Harth, C., Steele, L.P., Sturrock, G.,
              Midgley,  P.M., McCulloch, A., 2000.  A history of
              chemically and radiatively important gases in air
              deduced from ALE/GAGE/AGAGE.  Journal of Geophysical
              Research, 105, 17,751-17,792


13.6  Surface Saturations of the Dissolved Gases


Analyst
   • Max Rintoul

The O2, CFC-11, CFC-12, SF6, and N2O concentration values obtained
from the surface bottles were used to calculate the surface saturation
of each gas.


Fig. 13.1: Surface saturations of O2, CFC-11, CFC-12, SF6 and N2O.


Of all gases measured, only N2O was consistently supersaturated
(saturation > 100%) at the ocean’s surface (Figure above). The other
gases were primarily slightly undersaturated, with O2 consistently
being the closest to saturation. The CFC-12 saturations were similar
to, but displayed less variance than, the CFC-11 saturations, while
the much greater variance in SF6 values makes comparisons between the
saturations of SF6, CFC-11 and CFC-12 difficult. The marked difference
in the variation of O2 and the other gases likely stems from the
different technique used to measure the O2 concentrations.


Fig. 13.2: Simple model of gas fluxes into and out of the mixed layer.


The observed gas saturations can be explained by considering a simple
model of mixed layer of the surface ocean (Figure above). At the
surface of this layer, gas exchange occurs between the atmosphere and
the ocean. If this exchange was the only process affecting the
saturation of gases in the surface ocean, over time the system would
approach thermodynamic equilibrium, with all gases having saturations
of 100%. The deviation of the saturation values from 100% likely
results from a gas flux occurring along the mixed layers lower
boundary driven by mixing and upwelling. The concentration of CFC-11,
CFC-12, SF6 and O2 decline exponentially with depth (Figure below) and
hence the water introduced along the lower boundary of the mixed layer
is undersaturated, resulting in the entire layer becoming slightly
undersaturated with respect to these gases.


Fig: 13.3: Idealised concentration profiles of various gases with
           depth.

   Upwelling of deeper waters into the mixed layer also accounts for
   the observed supersaturation of N2O. Unlike CFC-11, CFC-12, SF6 and
   O2, N2O is produced in the ocean by nitrogen fixers, with such
   production occurring beyond the mixed layer. In areas and times of
   high productivity, such as the Southern Ocean in summer, N2O is
   rapidly consumed as it is a source of bioavailable nitrogen,
   however beyond the photic zone primary production decreases
   dramatically, allowing N2O concentrations to build up and for the
   water below the mixed layer to become supersaturated. The mixing of
   this supersaturated water into the mixed layer is likely
   responsible for the observed supersaturation of the surface.

   At greater depths N2O production also diminishes, resulting in the
   concentration profile shown in the figure immediately above.

   The gas saturations calculated for stations 35-40 lend further
   credence to the theory that upwelling and mixing have a notable
   impact on gas saturation values in the surface ocean. These
   stations were performed in areas of relatively thick sea ice which
   would prevent gas exchange occurring between the surface ocean and
   atmosphere. If upwelling and mixing continues to occur it would be
   expected that the gas saturations of CFC-11, CFC-12, SF6 and O2
   would be lower than in the open ocean, while N2O would be higher.
   While this is observed most strongly between stations 35 to 40, the
   O2 saturation in particular was also noticeably lower between
   stations 10 to 14 and 98 to 100. These stations were conducted in
   regions of high, but not complete, ice cover in which gas exchange
   between the ocean and atmosphere continued to occur, albeit at a
   reduced rate. A similar trend was also observed in the open ocean
   stations 68 and 70. As there was nothing limiting gas exchange
   between the surface ocean and atmosphere in these locations, this
   may indicate a region of stronger upwelling or the presence of a
   shallower mixed layer.

   The higher saturation of O2 is likely a result of photosynthesis
   occurring within the mixed layer. This would also help explain the
   low oxygen saturation at ice bound stations, as the limited light
   filtering though the ice would limit primary production. The
   difference in saturations between CFCs, SF6 and O2 may be further
   enhanced by the different gas saturations below the mixed layer.
   The production of CFCs and SF6 began fairly recently and so these
   gases unlikely to have become as pervasive below the mixed layer as
   O2, which has been present for a significantly greater period of
   time. As a result, the O2 saturation of the ocean below the mixed
   layer is likely greater than the saturation of either CFCs or SF6,
   hence mixing and upwelling of deeper water would cause a smaller
   decrease in the surface saturation of O2 than it would on the other
   gases. As CFC production preceded SF6 production, it might be
   expected that the CFC saturation values would be greater than those
   of SF6, however the variation in the calculated SF6 surface
   saturations prevents this assertion from being made with any
   confidence.



14.  NITRATE Δ^15N AND Δ^18O


PIs
   • Gerald Haug (Max-Planck Institute of Chemistry)
   • François Fripiat (Max-Planck Institute of Chemistry)

Samplers
   • Taimoor Sohail
   • Bingkun Luo

Samples for Nitrate Δ15N and Δ18N were taken by the CTD-watch (Taimoor
Sohail and Bingkun Luo) for Haug and Fripiat. A total of 1896 30 ml
plastic bottles were used to collect 20 ml samples according to the
protocol provided.

• The sample bottles came stored in annotated postal boxes
  (31x21.5x7 cm); with the annotation corresponding to the labels of
  the bottles inside; e.g. MPI 2016 Haug SO 01970 to 03866.

• The container with the empty sample bottles and documentation was
  kept in the forward bio-lab. Usually before the return of the CTD to
  the deck, but sometimes afterward, the 36 bottle plastic rack was
  filled with the empty bottles.

• Seawater was taken directly from the Niskin bottles. Sample
  bottles were rinsed 3 times with seawater from the Niskin prior to
  sampling. Each 30 ml sample bottle was filled with approximately 20
  ml of seawater.

• After 36 bottles were filled they were placed in their
  corresponding postal boxes and placed directly in the dark in a
  -20°C freezer.

• The sample ID’s, Niskin bottle numbers and date were recorded on
  the log sheet provided. After all sampling was complete this log
  sheet was converted to the electronic version, also provided.

The original sample plan asked for 52 stations x 36 bottles sampling
every third station. Assuming 30 nm spacing (except near boundaries)
this would provide ~90 nm spacing. As station spacings were increased
over the course of the cruise due to weather delays, the sampling
resolution was increased, first to 2:3:2 from station 54, and then to
every station from station 105 till the end of the transect at station
120.

Note that Bottles 3814 to 3866 were not sampled as the ship diverted
to Punta Arenas for a medical emergency.


Table 14.1: List of sample boxes and corresponding stations sampled. 
            Latitude and longitude ranges correspond to the first and 
            last station sampled in that box, respectively.

            Box | ID    | ID   | Stations | Latitude    | Longitude   
                | Start | End  |          |             |
            ====|=======|======|==========|=============|=============
            1   | 1970  | 2023 | 1 - 4    | -70.4507 to | 168.4729 to 
                |       |      |          | -69.6653    | 169.9072    
            ----+-------+------+----------+-------------+-------------
            2   | 2024  | 2077 | 4 - 11   | -69.6653 to | 169.9072 to 
                |       |      |          | -70.496     | -170.0017   
            ----+-------+------+----------+-------------+-------------
            3   | 2078  | 2131 | 11 - 14  | -70.496 to  | -170.0017 to
                |       |      |          | -69.0064    | -170.0002   
            ----+-------+------+----------+-------------+-------------
            4   | 2132  | 2185 | 14 - 20  | -69.0064 to | -170.0002 to
                |       |      |          | -67.0023    | 175.5832    
            ----+-------+------+----------+-------------+-------------
            5   | 2186  | 2239 | 20 - 23  | -67.0023 to | 175.5832 to 
                |       |      |          | -66.999     | 179.4227    
            ----+-------+------+----------+-------------+-------------
            6   | 2240  | 2293 | 23 - 29  | -66.999 to  | 179.4227 to 
                |       |      |          | -66.9997    | -172.1528   
            ----+-------+------+----------+-------------+-------------
            7   | 2294  | 2347 | 29 - 35  | -66.9997 to | -172.1528 to
                |       |      |          | -75.2647    | -147.4598   
            ----+-------+------+----------+-------------+-------------
            8   | 2348  | 2401 | 35 - 38  | -75.2647 to | -147.4598 to
                |       |      |          | -74.9995    | -150.1162   
            ----+-------+------+----------+-------------+-------------
            9   | 2402  | 2455 | 38 - 44  | -74.9995 to | -150.1162 to
                |       |      |          | -71.9904    | -149.9658   
            ----+-------+------+----------+-------------+-------------
            10  | 2456  | 2509 | 44 - 47  | -71.9904 to | -149.9658 to
                |       |      |          | -70.5       | -149.9987   
            ----+-------+------+----------+-------------+-------------
            11  | 2510  | 2563 | 47 - 54  | -70.5 to    | -149.9987 to
                |       |      |          | -67.0001    | -168.8821   
            ----+-------+------+----------+-------------+-------------
            12  | 2564  | 2617 | 54 - 56  | -67.0001 to | -168.8821 to
                |       |      |          | -67.0002    | -166.1342   
            ----+-------+------+----------+-------------+-------------
            13  | 2618  | 2671 | 56 - 61  | -67.0002 to | -166.1342 to
                |       |      |          | -66.9995    | -159.2655   
            ----+-------+------+----------+-------------+-------------
            14  | 2672  | 2725 | 61 - 64  | -66.9995 to | -159.2655 to
                |       |      |          | -66.9983    | -155.1439   
            ----+-------+------+----------+-------------+-------------
            15  | 2726  | 2779 | 64 - 69  | -66.9983 to | -155.1439 to
                |       |      |          | -67.0002    | -147.685    
            ----+-------+------+----------+-------------+-------------
            16  | 2780  | 2833 | 69 - 71  | -67.0002 to | -147.685 to 
                |       |      |          | -66.9995    | -144.6988   
            ----+-------+------+----------+-------------+-------------
            17  | 2834  | 2887 | 71 - 76  | -66.9995 to | -144.6988 to
                |       |      |          | -66.9987    | -138.2009   
            ----+-------+------+----------+-------------+-------------
            18  | 2888  | 2941 | 76 - 79  | -66.9987 to | -138.2009 to
                |       |      |          | -67.0013    | -134.3021   
            ----+-------+------+----------+-------------+-------------
            19  | 2942  | 2995 | 79-84    | -67.0013 to | -134.3021 to
                |       |      |          | -67.0001    | -126.0023   
            ----+-------+------+----------+-------------+-------------
            20  | 2996  | 3049 | 84-86    | -67.0001 to | -126.0023 to
                |       |      |          | -67.0014    | -122.7131   
            ----+-------+------+----------+-------------+-------------
            21  | 3050  | 3103 | 86-91    | -67.0014 to | -122.7131 to
                |       |      |          | -67.0011    | -114.4999   
            ----+-------+------+----------+-------------+-------------
            22  | 3104  | 3157 | 91-93    | -67.0011 to | -114.4999 to
                |       |      |          | -67.001     | -111.2144   
            ----+-------+------+----------+-------------+-------------
            23  | 3158  | 3211 | 93-97    | -67.001 to  | -111.2144 to
                |       |      |          | -68.0023    | -105.1588   
            ----+-------+------+----------+-------------+-------------
            24  | 3212  | 3265 | 97-98    | -68.0023 to | -105.1588 to
                |       |      |          | -69.7477    | -102.9768   
            ----+-------+------+----------+-------------+-------------
            25  | 3266  | 3319 | 98-102   | -69.7477 to | -102.9768 to
                |       |      |          | -67.9997    | -102.9985   
            ----+-------+------+----------+-------------+-------------
            26  | 3320  | 3373 | 102-105  | -67.9997 to | -102.9985 to
                |       |      |          | -67.4996    | -101.3294   
            ----+-------+------+----------+-------------+-------------
            27  | 3374  | 3427 | 105-107  | -67.4996 to | -101.3294 to
                |       |      |          | -67.5012    | -98.0007    
            ----+-------+------+----------+-------------+-------------
            28  | 3428  | 3481 | 107-108  | -67.5012 to | -98.0007 to 
                |       |      |          | -67.4994    | -96.3293    
            ----+-------+------+----------+-------------+-------------
            29  | 3482  | 3535 | 108-111  | -67.4994 to | -96.3293 to 
                |       |      |          | -67.3004    | -92.9992    
            ----+-------+------+----------+-------------+-------------
            30  | 3536  | 3589 | 111-113  | -67.3004 to | -92.9992 to 
                |       |      |          | -67.0996    | -89.6713    
            ----+-------+------+----------+-------------+-------------
            31  | 3590  | 3643 | 113-116  | -67.0996 to | -89.6713 to 
                |       |      |          | -67.0004    | -83.4641    
            ----+-------+------+----------+-------------+-------------
            32  | 3644  | 3697 | 116-117  | -67.0004 to | -83.4641 to 
                |       |      |          | -66.54143   | -80.58336   
            ----+-------+------+----------+-------------+-------------
            33  | 3698  | 3751 | 117-119  | -66.5414 to | -80.5833 to 
                |       |      |          | -66.4194    | -75.5959    
            ----+-------+------+----------+-------------+-------------
            34  | 3752  | 3805 | 119-120  | -66.4194 to | -75.5959 to 
                |       |      |          | -66.3597    | -73.2998    
            ----+-------+------+----------+-------------+-------------
            35  | 3806  | 3859 | 120      | -66.3597    | -73.2998    
            ----+-------+------+----------+-------------+-------------
            36  | 3860  | 3866 | --       | --          | --          




15.  DISSOLVED ORGANIC CARBON AND TOTAL DISSOLVED NITROGEN


PI
   • Craig Carlson (UCSB)

Technician
   • Cole Hansell

On-Shore Technicians
   • Keri Opalk
   • Elisa Halewood

Support
   NSF


15.1  Project Goals

The goal of the DOM project is to evaluate dissolved organic carbon
(DOC)) concentrations along the S04P zonal transect (67°S to 75°S &
168°E to 70°W).


15.2  Sampling

Over the course of the S04P cruise, DOC was sampled at every other
station (with few exceptions where multiple stations in a row were
sampled for DOC), in alignment with the full profile casts of DIC,
Alkalinity, and pH. DOC was sampled at 64 stations of the total 120
stations. At the start of the cruise, DOC sampled 30 unique Niskins
ranging the full depth of the water column, with a single duplicate
randomly selected for a total of 31 samples collected per cast.
Starting at station 12, when it was established we would be skipping
stations inaccessible due to ice, DOC sampled 31 unique Niskins with a
single duplicate randomly selected for a total of 32 samples collected
per cast. At station 102, when further weather delays substantially
reduced the total number of expected stations, DOC sampled all 36
Niskins with a single duplicate randomly selected for a total of 37
samples collected per cast. In total 2052 individual DOC samples were
collected.

DOC samples were passed through an inline filter holding a combusted
GF/F filter attached directly to the Niskin for samples from the upper
500 m of each cast. This filtering was done to eliminate particles
larger than 0.7 µm from the sample. Samples from deeper depths were
not filtered. Previous work has demonstrated that there is no
resolvable difference between filtered and unfiltered samples in
waters below the upper 500 m at the µmol kg-1¬†resolution.

To avoid contamination, gloves were used when handling all sampling
equipment and clean lab surfaces were used for processing samples.
After each station, all equipment used for sampling was rinsed with
10% hydrochloric acid and soaked in DI water in preparation for the
next station.

All samples were rinsed 3 times with about 5 mL of seawater and
collected into 40 mL glass EPA vials. Sample vials were prepared for
this cruise by soaking in 10% hydrochloric acid, followed by a 3 times
rinse with DI water. The vials were then combusted at 450°C for 4
hours to remove any organic matter. Vial caps were cleaned by soaking
in DI water overnight, followed by a 3 times rinse with DI water and
left out to dry.

Samples were fixed with 50 µL of 4N hydrochloric acid and stored
upright at -1.5°C on board. Samples were never frozen. Samples were
shipped back to UCSB for analysis via high temperature combustion on
Shimadzu TOC-V or TOC L analyzers.

Sampling goals for this cruise were to continue high resolution, long
term monitoring of DOC distribution throughout the water column, in
order to help better understand biogeochemical cycling in global
oceans.


15.3  Standard Operating Procedure for DOC Analyses- Carlson Lab UCSB

DOC samples will be analyzed via high temperature combustion using a
Shimadzu TOC-V or Shimadzu TOC-L at an in shore based laboratory at
the University of California, Santa Barbara. The operating conditions
of the Shimadzu TOC-V have been slightly modified from the
manufacturer's model system. The condensation coil has been removed
and the headspace of an internal water trap was reduced to minimize
the system's dead space. The combustion tube contains 0.5 cm Pt
pillows placed on top of Pt alumina beads to improve peak shape and to
reduce alteration of combustion matrix throughout the run. CO_2 free
carrier gas is produced with a Whatman® gas generator [Carlson2010].
Samples are drawn into a 5 ml injection syringe and acidified with 2M
HCL (1.5%) and sparged for 1.5 minutes with CO2 free gas. Three to
five replicate 100 µl of sample are injected into a combustion tube
heated to 680°C. The resulting gas stream is passed through several
water and halide traps, including an added magnesium perchlorate trap.
The CO2 in the carrier gas is analyzed with a non-dispersive infrared
detector and the resulting peak area is integrated with Shimadzu
chromatographic software. Injections continue until the at least three
injections meet the specified range of a SD of 0.1 area counts, CV
≤ 2% or best 3 of 5 injections.

Extensive conditioning of the combustion tube with repeated injections
of low carbon water (LCW) and deep seawater is essential to minimize
the machine blanks. After conditioning, the system blank is assessed
with UV oxidized low carbon water. The system response is standardized
daily with a four-point calibration curve of potassium hydrogen
phthalate solution in LCW. All samples are systematically referenced
against low carbon water and deep Sargasso Sea (2600 m) or Santa
Barbara Channel (400 m) reference waters and surface Sargasso Sea or
Santa Barbara Channel sea water every 6 – 8 analyses [Hansell1998].
The standard deviation of the deep and surface references analyzed
throughout a run generally have a coefficient of variation ranging
between 1-3% over the 3-7 independent analyses (number of references
depends on size of the run). Daily reference waters were calibrated
with DOC CRM provided by D. Hansell (University of Miami;
[Hansell2005]).


15.4  DOC calculation

            average sample area - average machine blank area
      µMC = ————————————————————————————————————————————————
                         slope of std curve


15.5  Standard Operating Procedure for TDN analyses- Carlson Lab UCSB

TDN samples were analyzed via high temperature combustion using a
Shimadzu TOC-V with attached Shimadzu TNM1 unit at an in-shore based
laboratory at the University of California, Santa Barbara. The
operating conditions of the Shimadzu TOC-V were slightly modified from
the manufacturer's model system. The condensation coil was removed and
the headspace of an internal water trap was reduced to minimize the
system's dead space. The combustion tube contained 0.5 cm Pt pillows
placed on top of Pt alumina beads to improve peak shape and to reduce
alteration of combustion matrix throughout the run. Carrier gas was
produced with a Whatman® gas generator [Carlson2010] and ozone was
generated by the TNM1 unit at 0.5L/min flow rate. Three to five
replicate 100 µl of sample were injected at 130mL/min flow rate into
the combustion tube heated to 680°C, where the TN in the sample was
converted to nitric oxide (NO). The resulting gas stream was passed
through an electronic dehumidifier. The dried NO gas then reacted with
ozone producing an excited chemiluminescence NO_2 species [Walsh1989]
and the fluorescence signal was detected with a Shimadzu TNMI
chemiluminescence detector. The resulting peak area was integrated
with Shimadzu chromatographic software. Injections continue until at
least three injections meet the specified range of a SD of 0.1 area
counts, CV ≤2% or best 3 of 5 injections.

Extensive conditioning of the combustion tube with repeated injections
of low nitrogen water and deep seawater was essential to minimize the
machine blanks. After conditioning, the system blank was assessed with
UV oxidized low nitrogen water. The system response was standardized
daily with a four-point calibration curve of potassium nitrate
solution in blank water. All samples were systematically referenced
against low nitrogen water and deep Sargasso Sea reference waters
(2600 m) and surface Sargasso Sea water every 6 – 8 analyses
[Hansell1998]. Daily reference waters were calibrated with deep CRM
provided by D. Hansell (University of Miami; [Hansell2005]).

Dissolved organic nitrogen (DON) concentrations are calculated as the
difference between TDN and DIN. Samples with less than 10 µmol/kg DIN
are most reliable estimates of DON.


15.6  TDN calculation

            average sample area - average machine blank area
      µMN = ————————————————————————————————————————————————
                         slope of std curve


[Carlson2010] Carlson, C. A., D. A. Hansell, N. B.
              Nelson, D. A. Siegel, W. M. Smethie, S. Khatiwala, M. M.
              Meyers and E. Halewood 2010. Dissolved organic carbon
              export and subsequent remineralization in the
              mesopelagic and bathypelagic realms of the North
              Atlantic basin. Deep Sea Research II, 57: 1433-1445.

[Hansell1998] Hansell, D.A. and C.A. Carlson 1998. Deep
              ocean gradients in the concentration of dissolved
              organic carbon. Nature, 395: 263-266.

[Hansell2005] Hansell, D.A. 2005  Dissolved Organic
              Carbon Reference Material Program.  EOS, 35:318-319.

[Walsh1989] Walsh, T.W., 1989.  Total dissolved nitrogen
            in seawater: a new high-temperature combustion method and
            a comparison with photo-oxidation. Mar. Chem., 26:295-311.


16.  CARBON ISOTOPES IN SEAWATER (14/13C)


PI
   • Ann McNichol (WHOI)
   • Robert Key (Princeton)

Technician
   • Cole Hansell
   • Ribanna Dittrich
   • Chanelle Cadot


16.1  Project Goals

In the upper water column, the goal is to adequately measure the
distribution to estimate the penetration of bomb-produced 14C and
quantify the 13C decrease due to the influx of anthropogenic CO2.
While the vast majority of bomb-14C will be confined to the upper
1000m of the water column, we are also looking to document the
penetration of bomb-produced 14C in abyssal waters near deep water
formation regions.


16.2  Sampling

A total of 502 samples were collected from 20 stations along the S04P
transect (67°S -75°S & 168°E to 70°W). The North-South transects of
168°E -174°E, 170°W, 150°W, 103°W were prioritized in sampling due to
their proximity to the continental shelf (See figure for the
visualized station plan). The East-West approach of 70°W was planned
to be sampled, however due to a medical emergency NSF advised for an
immediate departure to Punta Arenas resulting in unexecuted stations
along this approach. 12 stations sampled 31 of 36 Niskin bottles with
a focus on deep abyssal water, while 5 available Niskins in the upper
water column were skipped. A random duplicate was taken at these 12
stations. The other 9 stations sampled 18 of 36 Niskins, where only
the top 1500-2000m of the water column was sampled.


Fig. 16.1: An updated station plot for 14C sampling along the S04P
           cruise. Red rectangles represent full profile casts, where 31
           Niskins were sampled. Green triangles represent stations where 
           only the upper water column (1500-2000m) was sampled. Stations 
           crossed out in red represent stations that were originally 
           planned to be sampled but were cancelled for varying reasons.


Samples were collected in 500 mL airtight glass bottles. The first
50mL was used to rinse the tygon tubing. Then the flasks were rinsed 2
times with seawater from the specified Niskin. While keeping the
tubing at the bottom of the flask, the flask was filled and flushed by
allowing it to overflow 1.5 times its volume. Once the sample was
taken, about 10 mL of water was removed to create a headspace and 120
µL of 50% saturated mercuric chloride solution was added to the
sample. To avoid contamination, nitrile gloves were used when handling
all sampling equipment and plastic bags were used to cover any surface
where sampling or processing occurred.

After each sample was taken, the glass stoppers and ground glass joint
were dried and Apiezon-M grease was applied to ensure an airtight
seal. Stoppers were secured with a large rubber band wrapped around
the entire bottle. Samples were secured in AMS crates inside an
onboard walk-in cooler set at 10°C. Samples were shipped to WHOI for
analysis.

The radiocarbon/DIC content of the seawater (DI14C) is measured by
extracting the inorganic carbon as CO2 gas, converting the gas to
graphite and then counting the number of 14C atoms in the sample
directly using an accelerated mass spectrometer (AMS).

Radiocarbon values will be reported as Δ14C using established
procedures modified for AMS applications. The 13C/12C of the CO2
extracted from seawater is measured relative to the 13C/12C of a CO2
gas standard calibrated to the PDB standard using and isotope radio
mass spectrometer (IRMS) at NOSAMS.



17.  MICROBIAL REMINERALIZATION


PI
   • Craig Carlson (UCSB)

Technician
   • Cole Hansell

On-Shore Technicians
   • Keri Opalk
   • Elisa Halewood

Support
   NSF


17.1  Project Goals

To observe surface microbes utilization/transformation of carbon that
is available to them over a long duration of time by measuring
microbial growth and total organic carbon (TOC).


17.2  Sampling

Four microbial remineralization experiments were conducted over the
course of the S04P zonal transect (67-75°S & 168°E to 70°W).
Collection locations were selected based on spatial and timing
separation. At each collection site, 9L of surface water were
collected from an underway line. 4.5L were filtered using a Georig
142mm filter holding a 0.22µm filter into a designated 8L carboy.
Using a Georig 142mm filter holding a 1.2 µm filter, 1.5L were
filtered into a separately designated 8L carboy. The 0.22µm and 1.2µm
filtered waters were combined and mixed well. 2L were dispensed into a
2L biotainer. Using a positive pressure system, where filtered air
displaces the water in the bottle, eighteen 40mL combusted EPA glass
vials were filled to serve as parallels to test for bottle effect
within the incubation containers (2L biotainers). The remaining 4L of
mixed filtered water were equally dispensed into two 2L biotainers.
Incubations were stored in a dark, -1.5°C walk in cooler. Duplicate
TOC samples were taken from each biotainer, and 3 of 18 parallel vials
were sacrificed at 6 separate timepoints (T-0, T-3, T-7, T-14, T-21,
T-28). Duplicate flow cytrometry (FCM) samples were taken from each
biotainer, with a duplicate also taken from the 3rd parallel vial
(only at overlapping TOC collection points), at 12 separate timepoints
(T-0, T-1, T-2, T-3, T-4, T-5, T-6, T-7, T-10, T-14, T-21, T-28; where
bold represents overlapping collection points with TOC collection)
(See table for sampling scheme).


Table 17.1: Sampling scheme for microbial remineralization experiments. 
            Duplicates are denoted by xx and triplicates are denoted by 
            xxx. Rows marked with * represent timepoints where both FCM 
            and TOC measurements were taken.

Time   | Parallel | FCM- 3rd | TOC- Bio- | TOC- Bio- | FCM- Bio- | FCM- Bio-
(days) | TOC vial | TOC vial | tainer A  | tainer B  | tainer A  | tainer B 
=======|==========|==========|===========|===========|===========|==========
T-0*   | xxx      | xx       | xx        | xx        | xx        | xx       
-------+----------+----------+-----------+-----------+-----------+----------
T-1    |          |          |           |           | xx        | xx       
-------+----------+----------+-----------+-----------+-----------+----------
T-2    |          |          |           |           | xx        | xx       
-------+----------+----------+-----------+-----------+-----------+----------
T-3*   | xxx      | xx       | xx        | xx        | xx        | xx       
-------+----------+----------+-----------+-----------+-----------+----------
T-4    |          |          |           |           | xx        | xx       
-------+----------+----------+-----------+-----------+-----------+----------
T-5    |          |          |           |           | xx        | xx       
-------+----------+----------+-----------+-----------+-----------+----------
T-6    |          |          |           |           | xx        | xx       
-------+----------+----------+-----------+-----------+-----------+----------
T-7*   | xxx      | xx       | xx        | xx        | xx        | xx       
-------+----------+----------+-----------+-----------+-----------+----------
T-10   |          |          |           |           | xx        | xx       
-------+----------+----------+-----------+-----------+-----------+----------
T-14*  | xxx      | xx       | xx        | xx        | xx        | xx       
-------+----------+----------+-----------+-----------+-----------+----------
T-21*  | xxx      | xx       | xx        | xx        | xx        | xx       
-------+----------+----------+-----------+-----------+-----------+----------
T-28*  | xxx      | xx       | xx        | xx        | xx        | xx       


Sampling scheme for microbial remineralization experiments. Duplicates
are denoted by xx and triplicates are denoted by xxx. Yellow boxes
represent timepoints where both FCM and TOC measurements were taken.

TOC samples were collected in 40mL EPA vials from each 2L biotainer
using a positive pressure system. TOC samples were fixed with 50 µL of
4N hydrochloric acid and stored upright at -1.5°C on board. TOC
samples were never frozen.

FCM samples were initially collected in 14mL falcon tubes from each 2L
biotainer using a positive pressure system. Under a fume hood, 50µL of
8% Paraformaldehyde was added to 2mL cryovials followed by 1.95mL of
sample water which were dispensed from the falcon tubes into the
cryovials. FCM samples were mixed and stored at room temperature for
30 minutes before being stored in a -80°C freezer.

To avoid contamination, nitrile gloves were used when handling all
sampling equipment and clean lab surfaces were used for processing
samples. Prior to each experiment, all equipment used for sampling was
rinsed with 10% hydrochloric acid and rinsed with DI water. Containers
used for collecting, storing, and transporting sample seawater were
rinsed 3 times with sample water prior to use (8L carboys, 2L
biotainers, 14mL falcon tubes). TOC samples were rinsed 3 times with
about 5 mL of seawater.

EPA glass vials were prepared for this cruise by soaking in 10%
hydrochloric acid, followed by a 3 times rinse with DI water. The
vials were then combusted at 450°C for 4 hours to remove any organic
matter. Vial caps were cleaned by soaking in DI water overnight,
followed by a 3 times rinse with DI water and left out to dry.

TOC samples were shipped back to UCSB for analysis via high
temperature combustion on Shimadzu TOC-V or TOC L analyzers. FCM
samples were shipped back to UCSB for analysis.




18.  Δ18O ISOTOPES


PIs
   • Lynne Talley (SIO)
   • Nicholas Beaird (OSU)
   • Fiamma Straneo (SIO)
   • Yves Plancherel (Oxford)

Samplers
   • Lauren Ferris
   • Amir Barkhordary

Samples for Δ18O were taken by the CTD watch for Talley. A total of XX
poly-seal screw cap vials were used to collect XX ml samples according
to the protocol provided.

• The empty sample vials were stored in annotated boxes (i.e. “Box
  2”) within a metal cabinet in the Bio Lab. A paper copy of the Δ18O
  sample log was kept in the forward Dry Lab, and an electronic copy
  of the sample log was maintained in the “Science” drive of the
  ship’s network.

• Before return of the CTD Rosette to deck, sample vials (5 to 10
  per cast) were prepared with tape labels, around the circumference
  of the vial, with the station number and sample number (i.e.
  “Station 36, Bottle 109”). The “Bottle number” on the label is the
  Δ18O sample number, not the Niskin bottle # or intended depth. The
  prepared vials were placed in the provided foam holder. The bottle
  numbers to be used on the cast were written into the sample log.

• For each sample, the Niskin bottle # was obtained from a sample
  cop who read them from the previously prepared sample log (ii).
  Seawater was taken directly from the Niskin bottles as described:

  - Retrieve the empty vial from the foam holder. Unscrew the cap
    from the vial. Fill the vial with seawater from the identified
    bottle on the rosette. Re-cap, shake the vial, uncap, and empty
    the seawater onto the cap to rinse.

  - Fill the vial nearly to the top (not overflowing but nearly
    full).

  - Tighten the cap and place the vial back into the foam holder.

• After sampling, the foam rack with filled samples was taken back
  to the Bio Lab, where sample vials were dried with paper towels and
  allowed to come to ambient room temperature. After warming, the caps
  were re-tightened and wrapped with vinyl electrical tape (around the
  neck of the vial) to prevent loosening.

• The samples were documented in the paper and identical electronic
  Δ18O sample logs with the following information: Sample, Station,
  Cast, Niskin, UTC Date (i.e. “Bottle 111, Station 36, Cast 1, Niskin
  26, 03 Apr 2018”).

The sampling plan focused on five shelf-ward excursions from the 67S
line (below).


Fig. 18.1: The sampling plan for d18O on S04P 2018.


Some of these meridional sections were truncated before reaching the
shelf due to ice and weather conditions and a medical situation. The
table below summarizes the sampling.

Excur- | Stn | ΔO18  | ΔO18 | LAT    | LON     | Date      | Depth 
sion   |     | Start | End  |        |         |           |  (m)
=======|=====|=======|======|========|=========|===========|=======
A      | 1   | 1     | 10   | -70.45 | 168.47  | 17-Mar-18 | 1391.5
-------+-----+-------+------+--------+---------+-----------+-------
A      | 2   | 11    | 20   | -70.36 | 168.63  | 17-Mar-18 | 1993.1
-------+-----+-------+------+--------+---------+-----------+-------
A      | 4   | 21    | 30   | -69.67 | 169.91  | 17-Mar-18 | 2744.7
-------+-----+-------+------+--------+---------+-----------+-------
A      | 6   | 31    | 40   | -68.81 | 171.39  | 18-Mar-18 | 3167.7
-------+-----+-------+------+--------+---------+-----------+-------
A      | 8   | 41    | 48   | -68.01 | 172.82  | 18-Mar-18 | 3128.7
-------+-----+-------+------+--------+---------+-----------+-------
B      | 10  | 49    | 58   | -71.01 | -170    | 21-Mar-18 | 3995.8
-------+-----+-------+------+--------+---------+-----------+-------
B      | 11  | 59    | 68   | -70.5  | -170    | 22-Mar-18 | 4032.5
-------+-----+-------+------+--------+---------+-----------+-------
B      | 13  | 69    | 78   | -69.5  | -170    | 22-Mar-18 | 4183.4
-------+-----+-------+------+--------+---------+-----------+-------
B      | 15  | 79    | 88   | -68.5  | -170    | 23-Mar-18 | 4139.9
-------+-----+-------+------+--------+---------+-----------+-------
C      | 31  | 89    | 94   | -75.28 | -147.1  | 2-Apr-18  | 543.3 
-------+-----+-------+------+--------+---------+-----------+-------
C      | 32  | 95    | 98   | -75.29 | -147    | 2-Apr-18  | 285.7 
-------+-----+-------+------+--------+---------+-----------+-------
C      | 34  | 99    | 107  | -75.26 | -147.28 | 2-Apr-18  | 2047.3
-------+-----+-------+------+--------+---------+-----------+-------
C      | 36  | 108   | 116  | -75.21 | -148.19 | 3-Apr-18  | 3403.5
-------+-----+-------+------+--------+---------+-----------+-------
C      | 38  | 117   | 125  | -75    | -150.12 | 3-Apr-18  | 3749.1
-------+-----+-------+------+--------+---------+-----------+-------
C      | 40  | 126   | 134  | -74.02 | -150.11 | 4-Apr-18  | 4030  
-------+-----+-------+------+--------+---------+-----------+-------
C      | 42  | 135   | 142  | -73.02 | -150.05 | 5-Apr-18  | 4141.4
-------+-----+-------+------+--------+---------+-----------+-------
C      | 44  | 143   | 150  | -71.99 | -149.97 | 5-Apr-18  | 4188.5
-------+-----+-------+------+--------+---------+-----------+-------
C      | 46  | 151   | 158  | -71    | -150    | 6-Apr-18  | 4263  
-------+-----+-------+------+--------+---------+-----------+-------
C      | 50  | 159   | 167  | -69    | -150    | 7-Apr-18  | 4362.6
-------+-----+-------+------+--------+---------+-----------+-------
C      | 68  | 168   | 176  | -67    | -149.36 | 17-Apr-18 | 4443.6
-------+-----+-------+------+--------+---------+-----------+-------
D      | 99  | 177   | 185  | -69.5  | -102.92 | 30-Apr-18 | 4081.6
-------+-----+-------+------+--------+---------+-----------+-------
D      | 100 | 186   | 194  | -68.96 | -103    | 30-Apr-18 | 4068.1
-------+-----+-------+------+--------+---------+-----------+-------
D      | 102 | 195   | 203  | -68    | -103    | 1-May-18  | 4485.7
-------+-----+-------+------+--------+---------+-----------+-------
E      | 117 | 204   | 212  | -66.9  | -80.97  | 7-May-18  | 4188.7
-------+-----+-------+------+--------+---------+-----------+-------
E      | 118 | 213   | 220  | -66.8  | -78.48  | 8-May-18  | 4019.8
-------+-----+-------+------+--------+---------+-----------+-------
E      | 119 | 221   | 229  | -66.7  | -75.99  | 8-May-18  | 3217.7
-------+-----+-------+------+--------+---------+-----------+-------
E      | 120 | 230   | 269  | -66.6  | -73.5   | 9-May-18  | 3647.6
-------+-----+-------+------+--------+---------+-----------+-------




19.  RARE EARTH ELEMENTS (REEs)


PI
   • Yves Plancherel

Sampler
   • Yves Plancherel

A total of 945 REEs samples were taken from 50 stations (Figure 1)
during S04P making this section one of the most heavily sampled REEs
section ever sampled to date (with P18-2016). This REEs sample set
also constitutes the first transect in the Pacific sector of the
Southern Ocean and the first sections across the Ross Sea, increasing
the total number of REE samples from that area by a factor >10. The
southernmost station occupied was station 31, in the eastern Ross Sea.
Vertical resolution varied slightly from station to station,
especially for shelf stations, but for typical stations comprise 21
samples, oscillating between odd and even Niskin bottles, with more
samples taken near the top, the bottom and in the oxygen minimum.


Fig. 19.1: Station location for REE, neodymium isotopes and noble
           gases. The first number in parenthesis in the legend shows the
           number of station, the second number is the average number of
           samples per station. The IODP core sites that the eNd samples 
           taken here are meant to support are shown in dark green.


19.1  Sampling

Samples were drawn from Niskins with acid-cleaned (3M HCl) 60ml PP
syringes and 1/4" acid-cleaned silicone tubing equiped with a PP Luer
slip syringe fitting. New syringes and filters were used for every 4-5
samples to reduce cross-contamination and due to syringe
deterioration. After flushing the tubing for a few seconds, a ~30ml
aliquot was taken into the syringe. The plunger was then fully opened
and the syringe was shaken before ejecting 25ml from the syringe. A
0.45um PP Whatman Puradisc filter was connected to the syringe and the
remaining 5ml were used to sample-rinse the filter. After this
systematic sample rinse, 60ml were drawn into the syringe and syringe-
filtered into prelabelled acid-cleaned 60ml LDPE bottles. Bottles were
dried with a Kimwipe and the stopper sealed with Parafilm. All samples
were then stored in Ziploc bags in the dark.

To minimize contamination, all sampling material was kept in plastic
bags until sampling and nitrile gloves were worn at all times when
manipulating REE equipment. Samples were collected either directly
after Alkalinity or after DOC. The lab workbench was covered in
plastic, which was cleaned regularly with DI water and a Kimwipe.
Anything left on the counter was stored in a plastic bag, which was
taped to the wall and tied shut, opened only to access content.




20.  NEODYMIUM ISOTOPES (eNd)


PI
   • Tina van de Flierdt

Sampler
   • Yves Plancherel

A total of 15 eNd samples were taken, from 9 stations (Figure 1), all
of them as close to the continental shelf as possible, in the Ross
Sea. The goal of these samples is to support interpretation of IODP
cores taken on the Ross Sea shelf 2 months prior to SO4P and help
constrain eNd variability of Ross Sea Bottom Water. Samples were taken
from the bottom-most Niskin bottle, the top most, or close to the
oxygen minimum.


Fig. 20.1: Station location for REE, neodymium isotopes and noble
           gases. The first number in parenthesis in the legend shows the
           number of station, the second number is the average number of
           samples per station. The IODP core sites that the eNd samples 
           taken here are meant to support are shown in dark green.


20.1  Sampling

eNd samples were collected last, or from dedicated Niskin bottles.
Silicone tubing was connected to the Niskin and fitted with an Acropak
0.22um cartridge filter. Air was first purged from the line and the
filter and the filter was then flushed with sample for about 20
seconds. Two filter cartridges were used: one for “shallow” samples
and one for “deep samples”. The samples were collected in 4L acid-
cleaned cubitainers. Upon collection, which took less than 10 minutes
per sample, the cubitainers where sealed with parafilm and stored in
the dark at room temperature.




21.  NOBLE GASES


PI
   • Nicholas Beaird
   • Fiamma Straneo

Samplers
   • Yves Plancherel
   • Lauren Ferris
   • Bingkun Luo

A total of 482 noble gases samples were taken, from 34 stations
(Figure 1). This is ~200 fewer than the previous occupation of SO4P
2011. Typically, 15 samples were taken from each station, but this
number varies somewhat depending on station location.


Fig. 21.1: Station location for REE, neodymium isotopes and noble
           gases. The first number in parenthesis in the legend shows the
           number of station, the second number is the average number of
           samples per station. The IODP core sites that the eNd samples 
           taken here are meant to support are shown in dark green.


21.1  Sampling

The copper tube used was 5/8” dehydrated refrigeration copper tubing
from Cambridge-Lee Industries Inc., supplied in 50ft rolls. All rolls
were kept in their shipping boxes and stored in the air-conditioned
and low humidity bio-analytical lab in order to limit corrosion and
exposure risk.

The copper tubes were rolled out and cut into 30” sections less than
1.5 hours before sampling. Each tube sections was flattened slightly
with the Pana press so that after sampling and sealing (cold welding),
each sample could be re-rounded in order to create a small headspace
allowing for expansion of the seawater after warming.

Copper tubes were connected to the Niskins using Tygon tubing fitted
with a small silicon tubing adaptor at the nipple end. Tubing is
attached to both ends of the copper tube, with the inlet tube coming
in the bottom of the copper tube and outlet at the top. Water was
drawn through the copper tube while knocking the tube with a thumper
to remove bubbles from the inside of the tubes. After all bubbles had
been cleared, the 2 plastic clamps were closed and the Tygon
disconnected from the Niskin (closing the outlet clamp first).
Hydraulic jaws operating at 9000 psi supplied with 80 psi of
compressed air from the ship’s air line, were used to cold-weld the
copper tubes shut. Immediately after sealing, the tubes were re-
rounded with the Pana press to create the expansion space. All samples
were then rinsed with fresh water, dried with a paper towel, wrapped
in bubble wrap and stored at room temperature in Bio-Analytical Lab.




22.  LADCP


PI
   • Dr. Andreas Thurnherr

Cruise Participants
   • Manuel Othon Gutierrez Villaneuva
   • Rachel Lekanoff

Full depth Lowered Acoustic Doppler Current Profiler (LADCP)
velocities were sampled on every CTD station by Manuel Othon Gutierrez
Villanueva (MOGV) and Rachel Lekanoff (RL). MOGV performed the on-
board preliminary Quality Control (QC) and processing of each cast
using the LDEO_IX routines for MATLAB. After the processing, the
processed files and plots were sent for inspection to Andreas
Thurnherr and Bruce Huber at Lamont-Doherty Earth Observatory (LDEO).


22.1  LADCP Configuration

Two ADCP instruments were affixed to the Rosette using custom
brackets: the Upward Looking (UL) instrument was mounted above the
Niskin bottle 14 and the Downward Looking (DL) instrument was mounted
below the Niskin bottles 04 and 06. A rechargeable battery was also
installed in the Rosette below the bottles 31-33 to supply power to
both instruments during the full length of the cast.

The UL instrument used in this cruise was a 300 kHz Teledyne RDI
WHM300 (sn: 12734). The DL instrument was a 150 kHz Teledyne RDI
WHM150 (sn: 19394). The two instruments were configured to record
velocity data at 8 m bin with staggered pinging to avoid previous ping
contamination. The battery was a DeepSea Power & Light SB-48V/18A (sn:
01283).

A magnetometer was installed inside the UL instrument to provide an
independent source of pitch, roll and heading measurements. These data
will be used for post-processing the on-board processed casts. The
magnetometer started (stopped) taking measurements once the
rechargeable battery was connected (disconnected) from both
instruments. A Teledyne RDI star cable was installed to connect both
instruments to the battery and deck/communication cables using three
extension cables.

While the Rosette was in the Baltic Room (BR) resting between
stations, two deck (communication) serial cables extended from the dry
lab to the BR. The serial cables connected to a MacMini Desktop
computer in the dry lab using a USB Serial Port Adapter. A power
supply was connected to one of the deck cables in the dry lab to
provide additional power while the data were being downloaded from the
instruments. The power supply was disconnected once the data download
finished and was not used when programming the ADCPs before each cast.
Between casts a second cable connected the battery on the Rosette to
the battery charger located in the Aft Dry Lab. Once the data download
was complete, the battery was fully charged. The battery voltage was
measured before each cast and before charge. The MacMini Desktop
computer was synced to the ship’s clock server via the ship network
system.


Problems and Setup Warnings
---------------------------

• Test Cast 901: UL (DL) instrument was programmed as the master
  (slave) instrument. Configuration changed to DL (UL) as the master
  (slave) instrument after this cast. Star cable failed, unable to
  connect to both instruments after the cast. Star cable replaced by a
  spare.

• CTD Station 002: CTD pumps stopped working when they froze.
  Rosette was brought back on deck and pumps were allowed to warm
  while the ADCPs continued to sample. Rosette was re-deployed once
  the pumps had unfrozen.

• CTD Station 003: Data download from ADCPs failed. Star cable
  failed. Raw files were individually downloaded from each instrument
  bypassing the star cable, i.e. connecting the deck cables directly
  to each instrument. The star cable was not replaced due to the short
  transit between stations.

• CTD Station 004: Only the UL instrument was programmed. Data were
  downloaded without using the star cable.

• CTD Station 005: Only the UL instrument was programmed. Data were
  downloaded without using the star cable. Star cable was replaced by
  a spare after data were downloaded.

• CTD Station 006: Only the DL instrument was programmed.

• CTD Station 007: Only the DL instrument was programmed.

• CTD Station 008: Both instruments were programmed.

• CTD Station 009: Cast aborted due to bad weather. Station
  cancelled.

• CTD Station 016: One extension cable burnt and lost a dummy plug.
  Extension cable was replaced and data was downloaded successfully.

• CTD Station 020: Battery charger did not fully charge the battery
  before the cast. Nevertheless, the battery in the Rosette had enough
  voltage to last the full cast.

• CTD Station 023: MacMini clock desynched from ship’s server. The
  computer’s clock was synced again.

• CTD Station 031: No BT data available.

• CTD Station 050: Charger was not able to charge battery. Faulty
  extension cable from the battery charger was replaced.

• CTD Station 058: Station cancelled due to bad weather.

• CTD Station 066: Cast was done before planned position due to
  icebergs drifting towards the ship.

• CTD Station 095: During the upcast, winch was stopped to avoid ice
  floes. CTD wire was badly angled under the ship.

• CTD Station 098: After the cast, computer was not able to connect
  to instruments. USB Serial adapter was swapped by a spare. Data
  download was successful.

• CTD Station 104: Cast aborted at 146 m due to ship’s heave causing
  large tension spikes.

• CTD Station 117: Problems while connecting to both instruments
  before the cast. Only the UL instrument was programmed. USB serial
  adapter had problems but was disconnected and connected to the
  computer. Communications were fine afterwards.


22.3  Data Processing and Quality Processing

The DL ADCP data from the DL instrument had a bad orientation switch
during the entire S04P cruise, reporting its orientation as upward
facing. After the data were downloaded, MOGV corrected the raw
orientation data from the DL instrument using the perl-based editPD0
utility from Thurnherr’s ADCP Acquire Tools. Once the raw file was
corrected, the correct zmax (maximum depth) and zend (end depth)
values were recalculated with the mkProfile tool and logged in on the
corresponding LADCP cast sheet.

MOGV processed the ADCP data from both instruments daily using the
MATLAB-based LDEO IX Processing software. Additional data were
obtained from the os38nb Shipboard ADCP (SADCP) processed using UH DAS
software. To obtain the final velocity profile Conductivity,
Temperature and Depth (CTD) 1 Hz raw data were used. LDEO IX plots and
log files included processing warnings such as GPS issues, large
compass deviations and/or large shear-inverse solution differences.
Plots and files were individually inspected for signs of anomalies
such as Rosette rotation, tilt, biased shear, agreement between the
unconstrained LADCP velocities and ADCP data, beam strength and range,
bin residuals and quality of Bottom Track (BT) data and Rosette
position relatively to ship’s position. Processed files and plots of
each cast were emailed to Andreas Thurnherr and Bruce Huber on daily
basis. Raw data (CTD, LADCP and SADCP) were sent to Andreas Thurnherr
when suspicious profiles were detected.

Figure 1 shows the preliminary velocity results: zonal (U) and
meridional (V) for the 4 southward transects. In general, maximum
values reached ~0.5 m/s. Relatively strong northward flows are found
on the 103o W leg. Also, a bottom intensified northward flow was
observed near the shelf break on the 175o E transect. Figure 2 shows
the U and V velocity components and along the main track. Mid-depth
and near-bottom intensified northward flows (0.40 m/s) were observed.

Available for download at  http://www.ldeo.columbia.edu/LADCP

fig. 22.1: Zonal (U) and meridional (V) velocity transects for the
           south-north legs along 175E. Colored markers indicate CTD 
           station position and open black markers show the position of 
           the southernmost station along the transect.

fig. 22.2: Zonal (U) and meridional (V) velocity transects for the
           south-north legs along 170W. Colored markers indicate CTD 
           station position and open black markers show the position of 
           the southernmost station along the transect.

fig. 22.3: Zonal (U) and meridional (V) velocity transects for the
           south-north legs along 150W. Colored markers indicate CTD 
           station position and open black markers show the position of 
           the southernmost station along the transect.

fig. 22.4: Zonal (U) and meridional (V) velocity transects for the
           south-north legs along 103W. Colored markers indicate CTD 
           station position and open black markers show the position of 
           the southernmost station along the transect.

fig. 22.5: Along track Zonal (U) and meridional (V) velocity transects
           for the west-east main track. Colored markers indicate CTD 
           station position and open black markers indicate the position 
           of the southernmost station in each transect (right panel).

fig. 22.6: Map showing the S04P cruise track. Black line indicates the
           coastline.




23.  UNDERWATER VISION PROFILER 5 HD (UVP)


PI
   • Andrew McDonnell

Cruise Participant
   • Rachel Lekanoff


23.1  System Configuration and Sampling

The Underwater Vision Profiler 5 (UVP5) HD serial number 207 was
programmed, mounted on the rosette, and charged. The UVP5 is outfitted
with a High Definition 4 Mp camera with an acquisition frequency of up
to 20 Hz. This optical imaging device obtains in situ concentrations
and images of marine particles and plankton throughout the water
column, capturing objects sized ~100 µm to several cm in diameter. The
camera of the UVP5 HD is different from the previous non-HD version,
but the operations are identical for both. The instrument and data
processing are described in Picheral et al., 2010 [Picheral2010]. A
typical station had high particle abundance in the upper few hundred
meters of the water column and just above the seafloor. Some stations
had secondary maxima of particle concentrations between 500 and 1000
m.


23.2  Figures

Fig. 23.1: Examples of preliminary profiles at station 77. Plots show
           particle concentration in size bins (top) and total large
           particulate matter (LPM) abundance, mean grey level 
           (brightness) of LPM, and equivalent spherical diameter (ESD) 
           (middle), and temperature of camera, Peltier temperature, 
           angle of instrument, battery voltage, and temperature of 
           motherboard (bottom). All are plotted against depth (meters).

Fig. 23.2: Examples of particle and plankton images captured by the
           UVP5HD and processed by custom software. The scale bar 
           indicates 2 millimeters. Station number, image number for that 
           cast, and depth at which the image was captured are also given 
           in the image.


23.3  Problems

Station 2 is missing due to operator error. At stations 4, 6, 7, and 8
the UVP5 was not turned on due to the lithium ion battery not
charging. After some troubleshooting, it was determined that the
charging unit inside the UVP5 deck box had been disconnected either by
shipping agents or Australian customs agents. After reconnecting the
charger, the UVP5 battery was able to charge and then operated as
expected. At stations 45, 46, and 47, the UVP5 was kept off due to
problems with the UVP5 software. The manufacturer of the UVP5,
Hydroptic, was consulted for assistance with troubleshooting. Their
instructions included accessing the UVP5 via remote desktop connection
and removing the password from the UVP5’s Hydroptic account. After
following their instructions, the UVP5 successfully acquired data and
was able to communicate with the custom Hydroptic laptop for
downloading and processing data.


23.4  Reference

[Picheral2010] Picheral, M., Guidi, L., Stemmann, L.,
               Karl, D.M., Iddaoud, G., Gorsky, G., 2010. The
               Underwater Vision Profiler 5: An advanced instrument
               for high spatial resolution studies of particle size
               spectra and zooplankton. Limnol. Ocean. Methods 8,
               462–473.




24.  FLOAT DEPLOYMENTS


Cruise Participant Leads
   • Ellen Briggs
   • Chanelle Cadot

During 2018 S04P a total of 18 profiling floats were deployed, which
were part of several programs: 6 SOCCOM biogeochemical, 5 FSU MRV
ALTO, 5 CSIRO Argo, and 2 APL EM-APEX profiling floats. There was an
effort to co-deploy floats from the different programs at the same
coordinates particularly for the SOCCOM and FSU floats.

Ellen Briggs and Chanelle Cadot were responsible for overseeing all
float deployments as well as recording and communicating the
deployment details to the various PIs of the programs. The ASC marine
technician on watch was the lead for the actual deployment of the
floats and all back deck operations. The CTD watchstanders assisted
with float preparation and deployment when available. Rick Rupan (UW)
prepared and tested all of the applicable profiling floats during the
port call in Hobart, Australia prior to departure on 2018 S04P.

In typical operation, profiling floats descend to 2000 m and collect
data as they ascend to the surface. Onboard measurements include
temperature, salinity and pressure for all the float varieties and
additional velocity measurement for the EM-APEX floats and additional
biogeochemical measurements for the SOCCOM floats. Data from the 2000
m to surface profile are then sent to shore via satellite, using an
antenna located at the top of the float. The floats then descend to a
parking depth of 1000 m and drift for a programmable length of time
(typically 10 days) with the ocean currents at this depth and then
repeat the cycle by again heading down to 2000 m and collecting data
on the ascent back to the surface.

In the following, the specific deployment details of each float
program are discussed.


24.1  SOCCOM floats

PIs
   • Steve Riser
   • Ken Johnson
   • Lynne Talley

Six biogeochemical floats have been deployed, as part of the “Southern
Ocean Carbon and Climate Observations and Modeling” project (SOCCOM).
SOCCOM is a U.S. project sponsored by NSF that focuses on carbon and
climate in the Southern Ocean. Its goal is to deepen our knowledge of
the processes that regulate the carbon export in the Southern Ocean.
Its goal is to deepen our knowledge of the processes that regulate the
carbon export in the Southern Ocean in addition to expanding the
existing observing system for heat and freshwater (i.e. Argo floats).
So far, SOCCOM has 111 active floats, and the data are available to
the public at http://soccom.princeton.edu/content/float-data. The
floats are equipped with CTD, oxygen (Anderaa optode 4330), nitrate
(MBARI/ISUS), FLBB bio-optical (Wetlabs) and pH (Deep-Sea DuraFET)
sensors. Data acquisition is made available through Iridium Satellite
communication and GPS. The SOCCOM floats deployed on 2018 S04P are
also equipped with ice avoidance software to prevent the float from
colliding with sea ice at the surface. If the float measures colder
than -1.79°C in the upper 30 m the float immediately descends to park
depth and continues its normal cycle until it reads 2 consecutive
measurements greater than -1.79°C near the surface at which point the
float will surface and transmit its stored data via satellite.

Before the deployment of each float, the fluorometer/backscatter and
the NO3- sensors were carefully cleaned using DI water, pre-moistened
lens wipes, and lens paper. The deployments occurred after the
completion of the CTD station that was chosen to be the closest to the
planned deployment location and had a bottom depth greater than 2500m
and no sea ice present (not including icebergs) or an upper water
column temperature greater than -1.7°C. After the CTD cast, the ship
steamed approximately 1 nm away from the station location and then
slowed to 1 knot for the float deployment. The floats were deployed by
stringing a line through the stability ring of the float and slowly
lowering the float over the side of the ship timing the release of the
line with the swell. Each deployment occurred on the starboard side,
stern, while the ship was steaming at 1 knot.

Samples for HPLC and POC analyses were taken from the Niskin bottles,
tripped as duplicates, at the surface and at the depth corresponding
to the chlorophyll maximum. These samples were filtered shipboard and
will be sent to the U.S., where NASA (HPLC) and UCSB (POC) groups will
perform the analyses. Full-depth samples of other ocean properties
(salts, pH, DIC, nitrate, oxygen) were collected and analyzed by the
different groups on board, as part of a validation process of the
floats’ sensors. In particular, pH samples were collected and analyzed
by personnel from SIO, Dickson lab; DIC samples by personnel from AOML
and PMEL; oxygen, nitrate and salinity samples by the ODF group at
SIO.

5 of the 6 floats have reported their first profiles and their sensors
are working well. Float 12768 was deployed under conditions of slushy
ice at the surface and it is likely that the ice avoidance software
was activated, thus keeping the float from surfacing and transmitting
its data. It is likely this float will stay under ice cycling until
next austral Spring when the ice melts and the float can surface to
transmit its stored data.

As part of an outreach initiative, the SOCCOM project also partners
with teachers and classrooms across the country through a program
called ‘Adopt-a-Float’ to engage elementary to secondary aged students
with lead scientists on the significance of the Southern Ocean and
climate change research. As part of the program, selected schools are
given the opportunity to name a profiling float, follow its
deployment, and later track the float as it collects biogeochemical
observations. The 6 SOCCOM floats on 2018 S04P were decorated with
drawings depicting their given name and the deployments were
documented with pictures, videos, and blogposts to be shared with the
schools that adopted the float.

The float ID, location, date, station number, and depth of the float
deployments are indicated in the table below along with the
Adopt-a-Float program name and communication confirmation. An asterisk
marks the SOCCOM floats that were co-deployed with floats from other
programs.


Table 24.1: Summary of the deployment details of the six SOCCOM floats

Float  | Lat     | Lon      | Date    | Stn | Depth | Adopt a      | Confirm 
 ID    |         |          | (UTC)   |     |       | Float Name   | (Y/N)   
=======|=========|==========|=========|=====|=======|==============|=========
12768* | -71.01  | -170.002 | 3/21/18 | 10  | 4000  | Floating     | N       
       |         |          | 19:50   |     |       | Falcon       |         
-------+---------+----------+---------+-----+-------+--------------+---------
12398* | -67.617 | 173.521  | 3/25/18 | 18  | 3470  | MVESuperSeal | Y       
       |         |          | 22:17   |     |       |              |         
-------+---------+----------+---------+-----+-------+--------------+---------
12701* | -66.998 | -173.67  | 3/29/18 | 28  | 3650  | Thunderbird- | Y       
       |         |          | 07:22   |     |       | Martlet      |         
-------+---------+----------+---------+-----+-------+--------------+---------
12758  | -69     | -150.011 | 4/7/18  | 50  | 4362  | Tidal Wave   | Y       
       |         |          | 18:12   |     |       |              |  
-------+---------+----------+---------+-----+-------+--------------+---------
12754  | -66.997 | -149.283 | 4/17/18 | 68  | 4443  | Griffin-     | Y       
       |         |          | 21:35   |     |       | Eagle        |         
-------+---------+----------+---------+-----+-------+--------------+---------
12787* | -66.999 | -129.469 | 4/22/18 | 82  | 4362  | Southern     | Y       
       |         |          | 04:42   |     |       | Ocean Spy    |         
       |         |          |         |     |       | (SOS)        |         



24.2  FSU floats

PI
   • Kevin Speer

5 MRV ALTO profiling floats from FSU were deployed on 2018 S04P. These
floats have the core Argo temperature, salinity, and pressure sensors.

Prior to deployment, the FSU floats needed to be activated by swiping
a magnet in the ‘activation region’ on the float indicated by a reset
sticker. The floats were enclosed in bio-degradable cardboard boxes
and there was a small window through which the activation region could
be accessed. Plastic covered the box, deployment harness, and water
release mechanism. To activate a FSU float it was first brought
outside and secured in the best unobstructed location for sending a
signal to be picked up by satellite. A hole was then cut in the outer
plastic covering the window in the cardboard box. Then the reset
sticker was located and the provided magnet was placed on the sticker
and deliberately swiped. Tape was then used to repair the hole in the
plastic and the float remained outside for 24 hours or until
communication was received on land via satellite. Once the float was
activated, there were 5 days until the float embarked on deployment
mode unless it was re-activated by an additional magnet swipe.

Several problems were encountered while trying to activate these
floats. First, the activation region was not properly positioned in
the window provided in the cardboard box. The reset sticker was well
out of sight and half under support cardboard that could not easily be
moved and in some cases needed to be cut away. One of the floats had
rotated which required cutting a much larger hole in the cardboard box
to rotate the float to expose the activation region. Another float
(11036) did not activate after numerous attempts so the float was
fully removed from the box and swiped by the magnet in a much larger
area not indicated by the reset sticker which finally did the trick.
Being the Southern Ocean the weather was too extreme some days to
reasonably access the floats outside and carry them up and down icy
stairs. It was too cold for the tape to adhere to the plastic outer
covering and precipitation did penetrate through to the box. Despite
all of these problems all of the floats were properly activated in the
end.

These floats were deployed in their original bio-degradable cardboard
boxes (with the outer plastic covering removed) in order to reduce the
possibility of incurring any damage to the float during deployment.
Two bands of soluble PVA tape were placed around the box, in order to
hold it together. Four straps were attached around the box, connected
to a water release mechanism (a metal cylinder) at the bottom and with
four trailing loops on the top. The deployment line was slipped
through the trailing loops at the top, and then secured on the other
end to a cleat. The water release mechanism failed to release (likely
because the water was too cold) during the deployment of the first 2
floats after more than 5 minutes of soaking so it was decided for the
remaining floats to instead cut one strap of the harness to allow the
float, still inside the box, to slide free from the harness and drift
away from the ship. Float 11036 had to be completely removed from its
box in order to be activated, as outlined above, so it was deployed by
stringing a line through its deployment collar and lowering it over
the side of the ship.

Deployments were done after the completion of the CTD station nearest
to the requested deployment location, immediately after the ship had
turned, and begun its course to the next station and had reached a
speed of approximately 1 knot. Deployment details including float ID,
location, date, station, depth, and communication confirmation are
listed in the Table below. An asterisk marks the FSU floats that were
co-deployed with floats from other programs.


Table 24.2: Summary of the deployment details of the five FSU MRV ALTO 
            floats

Float  | Lat     | Lon      | Date          | Stn | Depth | Confirm
ID     |         |          | (UTC)         |     |       | (Y/N)  
=======|=========|==========|===============|=====|=======|========
11038* | -71.001 | -170.002 | 3/21/18 20:07 | 10  | 4000  | Y      
-------+---------+----------+---------------+-----+-------+--------
11035* | -67.617 | 173.534  | 3/25/18 22:08 | 18  | 3470  | Y      
-------+---------+----------+---------------+-----+-------+--------
11037* | -67.617 | 173.528  | 3/25/18 22:13 | 18  | 3470  | Y      
-------+---------+----------+---------------+-----+-------+--------
11039* | -66.999 | -173.812 | 3/29/18 07:16 | 28  | 3650  | Y      
-------+---------+----------+---------------+-----+-------+--------
11036  | -67     | -160.643 | 4/12/18 14:56 | 60  | 4070  | Y      



24.3  CSIRO floats

PI
   • Steve Rintoul

5 Argo profiling floats from CSIRO were deployed during 2018 S04P, and
have the core Argo temperature, salinity, and pressure sensors. These
floats were intended to be deployed in their original bio-degradable
cardboard boxes that were secured with a connected to a water release
mechanism (a metal cylinder) at the bottom. Due to failure of similar
water release mechanisms on the first 2 FSU floats it was decided to
deploy the CSIRO floats without the harness and box. The floats were
removed from their boxes, and a deployment line strung through the
stability ring of the float was used to gently lower the float into
the water in time with the swell at the stern, starboard side of the
ship.

Deployments were done after the completion of the CTD station nearest
to the requested deployment location, immediately after the ship had
turned, and begun its course to the next station and had reached a
speed of approximately 1 knot. Deployment details including float ID,
location, date, station, depth, and communication confirmation are
listed in the Table below.


Table 24.3: Summary of the deployment details of the five CSIRO floats

Float | Lat     | Lon      | Date (UTC)    | Stn | Depth | Confirm
ID    |         |          |               |     |       | (Y/N)
======|=========|==========|===============|=====|=======|========
8148  | -67.003 | 175.57   | 3/26/18 11:22 | 20  | 3085  | Y      
------+---------+----------+---------------+-----+-------+--------
8149  | -67     | -179.293 | 3/27/18 13:58 | 24  | 3616  | Y      
------+---------+----------+---------------+-----+-------+--------
8150  | -67     | -168.882 | 4/10/18 16:13 | 54  | 3438  | Y      
------+---------+----------+---------------+-----+-------+--------
8151  | -67.006 | -163.384 | 4/12/18 09:00 | 58  | 3980  | Y      
------+---------+----------+---------------+-----+-------+--------
8152  | -66.998 | -156.517 | 4/13/18 12:04 | 63  | 3957  | Y      



24.4  EM-APEX floats

PI
   • James B. Girton

2 EM-APEX floats that collect profiles of velocity, temperature,
salinity, and pressure were deployed on 2018 S04P. These floats also
include an ice guard, which consists of a carbon-fiber pole that
reaches 20 cm above the CTD allowing for measurements close to the ice
and a custom collar that allows the float to rotate through the water
column.

Prior to deployment the floats were prepared by replacing the pressure
fit electrode caps and pre-filling the bladder with water by dunking
the float cowling in a bucket of water. The starboard side mid-ship
A-frame was used to deploy the float. A harness fitted with a pin was
adjusted to the center of gravity of the float so it could be lifted
horizontally and not damage its rotation collar. The float was then
lifted and lowered over the side of the ship using the A-frame until
the float reached the water surface. A line attached to the pin was
then pulled to release the float from the harness and the harness and
pin were recovered. The ship then slowly accelerated in the opposing
direction of the float until the float was clear of the ship. The
floats were deployed without any problems via the mid-ship starboard
A-frame, but it should be noted that the stern A-frame may have been a
more preferable option on the RVIB NB Palmer, depending on the sea
state, to deploy the float further away from the ship.

Both deployments were carried out immediately after the CTD cast at
the specified location without changing ship position. The floats were
both successfully deployed, with no issues. Float ID, date, time,
location of the deployment, CTD cast associated with the deployments,
depth, and float communication confirmation are reported in the Table
below. An asterisk marks the EM-APEX floats that were co-deployed with
floats from other programs.


Table 24.4: Summary of the deployment details of the two EM-APEX floats

Float | Lat     | Lon      | Date (UTC)    | Stn | Depth | Confirm
ID    |         |          |               |     |       | (Y/N)
======|=========|==========|===============|=====|=======|========
6624  | -66.999 | -131.261 | 4/21/18 19:55 | 81  | 4556  | Y      
------+---------+----------+---------------+-----+-------+--------
6479* | -67     | -129.504 | 4/22/18 04:23 | 82  | 4362  | Y      




25.  DRIFTER DEPLOYMENTS


PI
   • Rick Lumpkin (*AOML*)
   • Shaun Dolk (*AOML*)

20 drifters were deployed on S04P 2018 for the Global Drifter Program.
Alison Macdonald and Ellen Briggs oversaw the deployment of the
drifters and the CTD watchstanders of each shift and the UVP student
carried out the deployment. Secondary assistance was provided by ASC
Marine Technicians.

The deployments occurred after the completion of the CTD cast at the
station that was closest to the planned deployment location. Two
drifters were deployed at each location within 30 seconds of each
other after achieving a minimum ship speed of 1 knot. The simple
deployment process involved: (1) removing the plastic wrapping from
the drifter; (2) carrying the drifter to the back or O1 deck; (3)
deploying the drifter off the stern on starboard side, after reaching
at least 1 knot ship speed; (4) recording the deployment details
including drifter ID, time, latitude, and longitude. Ellen Briggs,
Chanelle Cadot or Alison Macdonald sent the deployment details to
Shaun Dolk at AOML. The Table below lists the details for each
deployment.


Table 25.1: Deployment details for the 20 drifters

Drifter ID | Date (UTC)    | Lat     | Lon      | Stn       | Depth
===========+===============+=========+==========+===========+======
65333790   | 3/27/18 07:12 | -67     | -179.427 | 23        | 3696 
-----------+---------------+---------+----------+-----------+------
65334790   | 3/27/18 07:12 | -67     | -179.427 | 23        | 3696 
-----------+---------------+---------+----------+-----------+------
65253040   | 3/28/18 04:22 | -67     | -176.732 | 26        | 4059 
-----------+---------------+---------+----------+-----------+------
65252010   | 3/28/18 04:22 | -67     | -176.732 | 26        | 4059 
-----------+---------------+---------+----------+-----------+------
65253050   | 3/29/18 07:12 | -67     | -173.816 | 28        | 3650 
-----------+---------------+---------+----------+-----------+------
65253020   | 3/29/18 07:12 | -67     | -173.816 | 28        | 3650 
-----------+---------------+---------+----------+-----------+------
65250050   | 3/30/18 00:35 | -67     | -170.51  | 30        | 3383 
-----------+---------------+---------+----------+-----------+------
65250040   | 3/30/18 00:35 | -67     | -170.51  | 30        | 3383 
-----------+---------------+---------+----------+-----------+------
65336420   | 4/10/18 22:54 | -67     | -167.501 | 55        | 3521 
-----------+---------------+---------+----------+-----------+------
65333780   | 4/10/18 22:54 | -67     | -167.501 | 55        | 3521 
-----------+---------------+---------+----------+-----------+------
65336530   | 4/11/18 12:19 | -67     | -164.736 | 57        | 3802 
-----------+---------------+---------+----------+-----------+------
65250070   | 4/11/18 12:19 | -67     | -164.736 | 57        | 3802 
-----------+---------------+---------+----------+-----------+------
65334530   | 4/12/18 07:49 | -67     | -162.025 | 59        | 4079 
-----------+---------------+---------+----------+-----------+------
65333890   | 4/12/18 07:49 | -67     | -162.025 | 59        | 4079 
-----------+---------------+---------+----------+-----------+------
65251020   | 4/12/18 12:07 | -67     | -159.26  | 61        | 4283 
-----------+---------------+---------+----------+-----------+------
65336570   | 4/12/18 22:09 | -67     | -159.26  | 61        | 4283 
-----------+---------------+---------+----------+-----------+------
65251010   | 4/13/18 12:07 | -66.997 | -156.516 | 63        | 3958 
-----------+---------------+---------+----------+-----------+------
65252060   | 4/13/18 12:07 | -66.997 | -156.516 | 63        | 3958 
-----------+---------------+---------+----------+-----------+------
65336560   | 4/16/18 09:02 | -67.058 | -150.967 | before 67 | 4406 
-----------+---------------+---------+----------+-----------+------
65335480   | 4/16/18 09:02 | -67.058 | -150.967 | before 67 | 4406 




26.  Student Statements


26.1  Ribanna Dittrich

My name is Ribanna Dittrich and I am Ph.D. student at the University
of Edinburgh. My Ph.D. is about dissolved organic matter at the West
Antarctic Peninsula which is why I was absolutely thrilled to hear
about the opportunity to go down to Antarctica as part of the GO-SHIP
team and potentially conduct some experiments on board the ship.

I am now a CTD watchstander for the day shift aka the dinner club. Our
team consists of Lauren, Taimoor and myself and for the night shift,
there are Chanelle, Bingkun and Amir. Together, we have been
responsible for the safe deployments of all CTD casts (120 in total).
The cruise has been a very exciting experience for me. The people are
wonderful and good fun to work with which is important on such a long
cruise. We got to experience the Southern Ocean in all its glory:
Rough and stormy seas that kept us from doing science on the one hand,
and wonderful, indescribable landscapes of sea ice and icebergs with
penguins, seals and humpback whales on the other hand. The routine
work as a CTD watchstander consists of preparing the CTD rosette for
deployment and deploying it from the CTD console – we are in direct
contact with the winch controller and the marine tech and observe all
sensors and the tension on the wire on screens so that we can
interfere if necessary. We are in constant communication with the
marine tech so that we can make quick decisions if conditions change.
After the CTD comes back onboard, different samples are taken for
different parameters to be measured. My sampling jobs are either for
alkalinity or radiocarbon, depending on who needs me. Within our
shift, we have a well-working rotation system so that none of us ever
gets bored of doing the same task over and over again. So every now
and then one of us also happens to be the sample cop – making sure
that everyone fills the correct sampling bottle from the correct
Niskin bottle in the correct order. But we also get to help out the
techs when adjustments need to be made to the Niskin bottles, or the
wire needs to be cut. Overall, this is a great experience which showed
my once more how important and valuable observational data is for
oceanographic research, especially down here in the Southern Ocean.


26.2  Taimoor Sohail

My name is Taimoor Sohail and I am a PhD candidate in Earth Sciences
at The Australian National University. I primarily conduct modelling
studies of the Southern Ocean, so I never expected to be on a research
cruise conducting observational fieldwork! I applied to be part of the
S04P leg of the GO-SHIP project with the hopes of learning more about
the work and processes that go behind observational work. Little did I
know, that innocuous application would result in a life-changing
experience with the best ship-mates I could ask for.

I was accepted to be a CTD Watchstander and, with much trepidation,
embarked on a 69 day journey from Hobart to Punta Arenas. I was placed
with two other watchstanders in the day shift, Lauren and Ribanna, and
found that we were fast friends. As the ship ventured South to
Antarctica, we settled into our various roles. The responsibilities of
a watchstander are large (that’s why there’s three of us!). We prepare
the rosette for deployment, fire Niskin bottles as the rosette rises
from the depths, and help to collect seawater samples for analysis.
With 120 stations completed over the course of the cruise, needless to
say we got good at our jobs. I also got a crash course in Ocean Data
View, an invaluable tool for biological and chemical oceanographers,
from the Co-Chief scientist, Ellen, and learned a lot about ensuring
high-quality observational data from our in-house data analyst,
Joseph. Overall, I gained a unique insight into how observational data
is collected, how it is ensured the data is accurate, and finally how
it can be interpreted. As an ocean modeller, this knowledge forms a
critical part of my understanding, and will hopefully pave the way for
future research connections.

This experience was much more than an avenue for professional growth.
During the course of the trip, we saw scores of Adelie and Emperor
penguins, crushed through feet of sea ice, and saw seals and pods of
whales. Through this shared experience, I got to know my fellow ship-
mates and formed life-long friendships. Being in one of the most
remote places in the world, I gained a broader perspective on life and
realised just how untameable nature can be. The S04P GO-SHIP Cruise
has been a life-changing experience in more ways than one, and I can’t
wait to come back to Antarctica and do it all over again!


26.3  Lauren Newell Ferris


Fig. 26.1: Wrestling on a survival suit before joining marine
           technician Tony in the Baltic Room for a CTD cast. (Photo by 
           MOG Villanueva)

My name is Lauren Ferris and I am a PhD student in physical
oceanography. When I first talked to Alison (chief-scientist) half a
year ago, I felt incredibly lucky to be given this opportunity. Now
into 60+ days at sea in the Southern Ocean, I can say that I never
imagined that I would learn so much on GO-SHIP S04P. I am a CTD
watchstander on the day shift with Ribanna and Taimoor. Together with
the night shift (Chanelle, Bingkun, and Amir), we were responsible for
120 CTD casts. My favorite part of this experience was being part of
the “full stack” of this process (to use a programming term). It
entailed working closely with the marine technicians, winch operators,
data analyst, and chief scientists. Each one of them had a different
perspective on the CTD operations and a unique angle on the cast.

A cast begins with stringing up the Niskin bottles and their closing
valves, cleaning optical sensors, turning on winch data feed and
switching off Multi-beam bathymetric logging (since it would be a bit
of a nightmare to analyze hours of bathymetry data in the same spot).
The day shift (aka “Dinner Club) has a system. Ribanna strings bottles
separately (since she is lightning-fast) and Taimoor and I “tag-team”
for efficiency. Casts take 4-8 hours, depending on sea state. The
winch operates more slowly during rough weather to avoid tension
spikes and artificial overturns due to ship heave. It also operates
more slowly during deep casts due to the immense tension of having
more than 4500m of heavy metal wire in the ocean. During the cast, we
communicate with the day shift marine technician (Tony) and winch
operators (Lauro, Louie, Domingo) to relay depths and deliberate about
weather considerations. When the CTD is recovered, sampling begins!
All of the watchstanders take salt samples. I sample for helium,
oxygen isotopes, and alkalinity. Ribanna does radiocarbon and
alkalinity. Taimoor does nitrogen isotopes and alkalinity. There is
also “sample cop” who is effectively an air traffic controller,
directing samplers to Niskin bottles and ensuring that properties are
sampled in the correct order (i.e. CFCs, then helium, then oxygen,
then inorganic carbon species, organic carbon species, etc.). The
Dinner Club rotates through sampling jobs to make sure that every cast
stays interesting.

Perhaps my favorite part of S04P was being trapped on a ship with
unbelievably knowledgeable scientists, technicians, and crewmembers.
Tony taught us about “wire forensics”, after which both the marine
technicians (Tony and Jennie) led us through removing hundreds of
meters of worn winch wire. (The wire used for S04P had some
interesting issues that resulted in us having to remove wire on a
fairly regular basis). Electronics technician Barry was always up for
me barging into his shop asking for an explanation about what he was
currently fixing. Data analyst Joseph taught me how to inspect and
replace Niskin bottles, and about the extensive process of
scrutinizing reference-quality hydrographic data. Ellen taught us
Ocean Data View and Alison provided advice on incorporating bathymetry
into data analysis. I also learned from the ECO crew, who were kind
about my affinity to spend hours on end (while off-shift, of course)
on the bridge. As an ocean engineer by training, I have been quite
excited about the infrastructure and operation of the ship. The
crewmembers told me about iceberg avoidance, selecting a course
through sea ice, the ship’s dynamic positioning system, and maritime
industry, etc.

More than anything, I have gained an appreciation for the difficulty
of collecting and scrutinizing hydrographic data in an environment
such as the Southern Ocean. Prior to this cruise, it was simple for me
to write a quick script to search through a few gigabytes of CTD data,
derive a few physical parameters, and automatically plot them….
without ever considering the laborious and exhaustive process of
acquiring reference-quality data! In particular, with the frequent and
intense storms that we experienced on S04P, I have also learned that
the ocean doesn’t always cooperate with the science goals. As I am in
the planning stage of my PhD research, this is a critical lesson that
I will take home with me and incorporate into both my project and
professional career.


26.4  Bingkun Luo

My name is Bingkun Luo and I am a Ph.D. student from RSMAS/Meteorology
and Physical Oceanography Program at University of Miami. I am a CTD
watch stander on the night shift with Chanelle and Amir. Thanks for
Alison and Ellen give me this opportunity to participate this 67-days
cruise. I think this cruise is awesome! We did 120 CTD casts and
collected lots of samples!

I am a night shift person. It is very quiet at night and I enjoy the
peaceful night to let me concentrate on all of the things. During the
sample, I was responsible for the weather maps, Nitrate Δ15N and Δ18O,
Helium and salt. Thanks for two students MATLAB code from another
cruise (Natalie Freeman and Seth Travis). We developed the new version
S04P code based on them. The code was very efficiently to plot the
ship path and forecast stations on the weather map. What's more,
Taimoor also wrote a Python code to format the input files. That's
nice! The Δ18O is very easy to sample since the bottle is already
cleaned before and the bottle is very small. For the Helium, I enjoy
the music of "bang bang bang" to remove the bubbles from the tube. It
is very interesting to sample Helium. We need to press or copper the
tube after collecting sample. At the beginning I failed, I almost
wasted 50% of the tube! But after Yves told me how to do it correctly,
I did it with more patience! Then the success rate with the copper is
100%! These samples are going to help our community learn all sorts of
interesting things about the interaction of the cryosphere and the
ocean. It is my pleasure to make contributions to them! After all of
the samples finished, we need to collect salt bottles together. I
usually did it very quickly and try to finish all of it as soon as
possible, but it will make some problems and make the result not
accurate. Thanks to ODF's instruction, I know that I should have more
patience to collect salt samples. After that, Alison told us that the
result was much better than before. I am very proud of it! I think the
most important knowledge that I learned is the patience!

When the storms approaching, our ship moves to south. It is so
beautiful in South Pole! The big iceberg, the penguins, seals, whales
are wonderful! This is the first time I see this kind of animals out
of TV and Seaquarium!

All of the cruise members and scientists are very kind, I have made
lots of friends from this cruise. Thanks for this opportunity and I
think it refreshes my mind about the ocean and research! AWESOME!


26.6  Chanelle Cadot

My name is Chanelle Cadot, and I am an undergraduate studying
Oceanography at the University of Washington. I work as a student
technician at the UW Argo Float Lab, and our lab builds SOCCOM floats.
Argo floats are autonomous sensor platforms that are deployed
throughout the worlds’ oceans and measure salinity, temperature, and
depth. SOCCOM floats are part of the Southern Ocean Carbon Climate
Observation and Modeling project, and they are outfitted with
additional biogeochemical sensors to measure nitrate, pH, chlorophyll,
and oxygen. I have worked with these instruments in the lab, but I
have never had the opportunity to take part of their deployments. When
I found out that I would be going on the S04P research cruise to be a
CTD watch stander and help oversee float deployments, I was ecstatic.

There were 6 SOCCOM floats from our lab on the cruise, but there were
18 floats in all from a total of 4 different institutions. Each
institution had a different variation of a float, so they all had
varying deployment procedures. My job was to make sure that all the
floats were ready to go, and that they were deployed according to
their protocol. Once the float was deployed, I would then contact the
various PI’s to give them all the information regarding the deployment
information of their floats. Of course, not everything always went
exactly according to plan. For example, 10 of the floats had these
deployment harnesses that were operated with a water-soluble release
mechanism. The idea is that you dunk the release mechanism in the
water, and upon contact with the water, it dissolves and the float is
released into the water. This works great in warm water, but when we
tried it in the Southern Ocean, the release mechanism froze and would
not dissolve. We were able to improvise other methods to deploy these
floats, which was a good lesson in trouble shooting.

Another issue we ran into was activating the 5 MRV floats. This
process involved hauling these floats outside, securing them to the
side, activating them with a magnet swipe, and getting confirmation
that they sent a message. This proved to be challenging sometimes
because the activation had to happen during a certain window prior to
deployment, but sometimes we got unexpected weather delays. There were
also days where we couldn’t go outside to do this because of weather
conditions, so we had to be strategic about the timing of the magnet
swipe. We also had trouble with a few of the floats with actually
activating them. The magnet swipe was over a magnetic relay switch,
which is denoted on the outside of the float with a “reset” sticker.
It was sometimes hard to reach the reset sticker with the surrounding
cardboard box that the float was in, so finally the PI overseeing
those floats told me to conduct a magnet “dance” rather than a magnet
swipe. The magnet dance was a fancy way of saying to make sure that
the magnet traveled around a broad swath of the float in case the
magnetic relay is offset from the reset sticker. Once the magnet dance
was suggested, we were usually able to activate the floats pretty
easily. Sometimes it would be frustrating when we couldn’t get a float
activated or it wasn’t sending a message, but overall it was
satisfying to problem solve and finally get it to work.

I’m probably biased, but my favorite deployments were the SOCCOM
floats. The SOCCOM program also has an outreach program called
Adopt-a-Float, which is where classrooms across the country can pick a
float and name it. The students then follow the float deployment and
study the data profiles that the float produces once it is in the
ocean. All of the SOCCOM floats on board were “adopted”, so we had fun
decorating the floats according to their given names. I then took lots
of pictures of the floats before and during deployment to send back
for the students. The SOCCOM stations were also interesting because we
did special CTD casts for these stations. We fired extra bottles on
the rosette at the surface and at the chlorophyll maximum. There was
also a lot of sampling that occurred on these stations. This is
because data obtained from the casts at SOCCOM stations are used to
validate the data of the float’s profiles to ensure that the sensors
on the floats are measuring reasonable values.

I could go on and on about the float deployments, but my other job on
the cruise was to be a CTD watch stander. This meant that I helped
oversee the CTD console as the CTD did a cast and then I participated
in the sampling when the CTD was back on deck. I usually helped out
with the Radiocarbon, alkalinity, and salts sampling. Radiocarbon was
interesting because it had this whole post sampling procedure that
required greasing and sealing the stoppers to the sample bottles. I
liked being a CTD watch stander because you get to be really involved
with all the science. You’re there watching the cast itself and seeing
the profile of the cast. You’re also helping out with the sampling and
sometimes overseeing the sampling as a “sample cop”.

Overall, this cruise was an incredible experience, and I feel
fortunate to have been able to be a part of it.


Fig  26.2: I’m standing with one of the SOCCOM floats shortly before
           its deployment.




CCHDO Data Processing Notes

Data History

• File Online  Carolina Berys
s04p_2018.pdf (download) #ece08
Date: 2018-06-01
Current Status: unprocessed

• File Online  Carolina Berys
320620180309_ct1.zip (download) #05018
Date: 2018-06-01
Current Status: unprocessed

• File Online  Carolina Berys
320620180309_hy1.csv (download) #bb9b8
Date: 2018-06-01
Current Status: unprocessed

• File Submission  Joseph Gum
320620180309_hy1.csv (download) #bb9b8
Date: 2018-05-20
Current Status: unprocessed
Notes
S04P 2018 Preliminary Cruise Data

• File Submission  Joseph Gum
320620180309_ct1.zip (download) #05018
Date: 2018-05-20
Current Status: unprocessed
Notes
S04P 2018 Preliminary Cruise Data

• File Submission  Joseph Gum
s04p_2018.pdf (download) #ece08
Date: 2018-05-20
Current Status: unprocessed
Notes
S04P 2018 Preliminary Cruise Data