Cruise Report for the 2022 Reoccupation of P02W
***********************************************


GO-SHIP P02 2022 Hydrographic Program
=====================================


Summary
-------

The Leg 1 2022 reoccupation of the GO-SHIP P02 hydrographic line,
RR2204 (Fig. 1) included 117 stations using a 36-bottle rosette: One
station (Sta 1, 21.000°N, 140.050°E) along the transit from Guam at
which core/bio [1] measurements were acquired between 1500/1000 m and
the surface in support of a GO-BGC Argo float deployment; A single
underway HPLC sample in support of a second float deployment (Sta 2,
26.670°N, 137.080°E); full water column core sampling at 12 stations
from 32.507°N, 133.030°E to 30.000°N, 134.860°E, and 103 stations
eastward along 30°N to 198.786°E. Biology samples were obtained
approximately every third station. In all, 10 GO-BGC floats were
deployed - all (except the underway Sta 2 float) were supported by
both core and bio sampling.

   [image]Black crosses - for P02W 2022 station locations; green
   crosses - stations that included bio-only bottles and/or casts,
   cyan asterisks - GO-BGC float deployments; purple dots - departure
   (Guam, Navy Base) and arrival (University of Hawaii Pier, Honolulu)
   ports; and blue shading - 1 minute Smith and Sandwell bathymetry.

The planned station spacing included very close spacing down the Japan
coast and across the region of the Kuroshio its large loop and
generally 30 nm spacing across the rest of the section. The delay at
the start and a limited allowed time in the Japan EEZ led to a reduced
number of stations in the west (9 vs. 15 coming south to 30°N, 23 vs.
33 in the Japan EEZ, and 46 vs. 59 west of 159°E where in 2022 30 nm
spacing was resumed). The planned 131 stations were reduced to 117,
but with fantastic weather and seas, Leg 1 finished only 1° west of
the original longitudinal goal.

The rosette instruments included dual CTDs, one with oxygen (SBE43), a
secondary separate RINKO oxygen sensor, fluorometer, transmissometer,
upward and downward-looking LADCPs an underwater vision profiler
(UVP), two upward-looking and one downward-looking Chi-POD. All 10
GO_BGC floats deployed had biochemical sensors. Along all transits,
including those in Japanese waters, continuous underway shipboard
multibeam bathymetry, TSG, met and pCO2 data were collected and a
flow-through cytometer was run. The SADCP ran continuously. The EK-80
ran during each cast. There was also discrete underway sampling three
times a day that included HPLC, POM, POC/N and DNA/RNA. Please see
individual sections for further detail.


Programs and Principal Investigators
------------------------------------

+---------------------------+---------------------------+---------------------------+---------------------------+
| Program                   | Affiliation               | Principal Investigator    | Email                     |
|===========================|===========================|===========================|===========================|
| BGC Floats                | *SIO*                     | Lynne Talley              | ltalley@ucsd.edu          |
+---------------------------+---------------------------+---------------------------+---------------------------+
| C13 & C14                 | *UW*, *WHOI*              | Rolf Sonnerup, Roberta    | rolf@uw.edu,              |
|                           |                           | Hansman                   | rhansman@whoi.edu         |
+---------------------------+---------------------------+---------------------------+---------------------------+
| *CFCs*, *SF6*             | *UT*                      | Dong-Ha Min               | dongha@austin.utexas.edu  |
+---------------------------+---------------------------+---------------------------+---------------------------+
| Chipods                   | *OSU*                     | Jonathan Nash             | nash@coas.oregonstate.edu |
+---------------------------+---------------------------+---------------------------+---------------------------+
| *CTDO* Data, Salinity,    | *UCSD*, *SIO*             | Susan Becker, Todd Martz  | sbecker@ucsd.edu,         |
| Nutrients, Dissolved O_2  |                           |                           | trmartz@ucsd.edu          |
+---------------------------+---------------------------+---------------------------+---------------------------+
| Underway pCO_2            | *PMEL*, *NOAA*            | Simone Alin               | simone.r.alin@noaa.gov    |
+---------------------------+---------------------------+---------------------------+---------------------------+
| *DOC*, *TDN*              | *RSMAS*                   | Dennis Hansell            | dhansell@rsmas.miami.edu  |
+---------------------------+---------------------------+---------------------------+---------------------------+
| Lowered *ADCP*            | *LDEO*                    | Andreas Thurnherr         | ant@ldeo.columbia.edu     |
+---------------------------+---------------------------+---------------------------+---------------------------+
| *POC*, *HPLC*             | *UCSD*                    | Adam Martiny              | amartiny@uci.edu          |
+---------------------------+---------------------------+---------------------------+---------------------------+
| Shipboard *ADCP*          | *UH*                      | Julia Hummon              | hummon@hawaii.edu         |
+---------------------------+---------------------------+---------------------------+---------------------------+
| Total Alkalinity, pH      | *SIO*                     | Andrew Dickson            | adickson@ucsd.edu         |
+---------------------------+---------------------------+---------------------------+---------------------------+
| Total CO_2 (DIC)          | *PMEL*, *NOAA*            | Richard Feely             | richard.a.feely@noaa.gov  |
+---------------------------+---------------------------+---------------------------+---------------------------+
| Transmissometer           | *UCI*, *OSU*              | Adam Martiny, Jason Graff | amartiny@uci.edu, jason.  |
|                           |                           |                           | graff@oregonstate.edu     |
+---------------------------+---------------------------+---------------------------+---------------------------+
| *UVP*-5                   | *UAF*                     | Andrew McDonnell          | amcdonnell@alaska.edu     |
+---------------------------+---------------------------+---------------------------+---------------------------+


Science Team and Responsibilities
---------------------------------

+---------------------------+---------------------------+---------------------------+---------------------------+
| Duty                      | Name                      | Affiliation               | Email Address             |
|===========================|===========================|===========================|===========================|
| Chief Scientist           | Alison Macdonald          | *WHOI*                    | amacdonald@whoi.edu       |
+---------------------------+---------------------------+---------------------------+---------------------------+
| Co-Chief Scientist        | Shuwen Tan                | *LDEO*                    | shuwent@ldeo.columbia.edu |
+---------------------------+---------------------------+---------------------------+---------------------------+
| CTD Watchstander          | Vic Dina                  | *RSMAS*                   | victoria.dina@rsmas.miam  |
|                           |                           |                           | i.edu                     |
+---------------------------+---------------------------+---------------------------+---------------------------+
| CTD Watchstander          | Lauren Moseley            | *LDEO*                    | laurenm@ldeo.columbia.edu |
+---------------------------+---------------------------+---------------------------+---------------------------+
| CTD Watchstander          | Mariana Aguirre Nunes     | *FSU*                     | ma20gn@fsu.edu            |
+---------------------------+---------------------------+---------------------------+---------------------------+
| CTD Watchstander          | Sophie Shapiro            | *UCSD*                    | soshapiro@ucsd.edu        |
+---------------------------+---------------------------+---------------------------+---------------------------+
| Nutrients, *ODF*          | Susan Becker              | *UCSD* *ODF*              | sbecker@ucsd.edu          |
| supervisor                |                           |                           |                           |
+---------------------------+---------------------------+---------------------------+---------------------------+
| Nutrients                 | Megan Roadman             | *UCSD* *ODF*              | mroadman@ucsd.edu         |
+---------------------------+---------------------------+---------------------------+---------------------------+
| CTDO Processing           | Aaron Mau                 | *UCSD* *ODF*              | ajmau@ucsd.edu            |
+---------------------------+---------------------------+---------------------------+---------------------------+
| Salts, ET, CTD/Rosette    | John Calderwood           | *UCSD* *SEG*              | jcalderwood@ucsd.edu      |
| Maintenance               |                           |                           |                           |
+---------------------------+---------------------------+---------------------------+---------------------------+
| Salts, Marine Technician  | Royhon Agostine           | *UCSD*                    | ragostine@ucsd.edu        |
+---------------------------+---------------------------+---------------------------+---------------------------+
| Marine Technician         | Josh Manger               | *UCSD*                    | jmanger@ucsd.edu          |
+---------------------------+---------------------------+---------------------------+---------------------------+
| CR Technician             | Nicholas Benz             | *UCSD*                    | nbenz@ucsd.edu            |
+---------------------------+---------------------------+---------------------------+---------------------------+
| Dissolved O_2, Database   | Andrew Barna              | *UCSD* *ODF*              | abarna@ucsd.edu           |
| Management                |                           |                           |                           |
+---------------------------+---------------------------+---------------------------+---------------------------+
| Dissolved O_2             | Elisa Aitoro              | *UCSD* *ODF*              | eaitoro@ucsd.edu          |
+---------------------------+---------------------------+---------------------------+---------------------------+
| LADCP                     | Kurtis Anstey             | *UVic*                    | kurtis.anstey@live.ca     |
+---------------------------+---------------------------+---------------------------+---------------------------+
| Bio/Genomics              | Adam Fagan                | *UCI*                     | afagan@uci.edu            |
+---------------------------+---------------------------+---------------------------+---------------------------+
| Bio/Imaging               | Star Dressler             | *UOG*                     | dresslerc@gotritons.uog.  |
|                           |                           |                           | edu                       |
+---------------------------+---------------------------+---------------------------+---------------------------+
| *UVP*-5                   | Stephanie O’Daly          | *UAF*                     | shodaly2@alaska.edu       |
+---------------------------+---------------------------+---------------------------+---------------------------+
| Total Alkalinity          | Sara Gray                 | *UCSD*                    | s5gray@ucsd.edu           |
+---------------------------+---------------------------+---------------------------+---------------------------+
| Total Alkalinity          | Daniela Nestory           | *UCSD*                    | dnestory@ucsd.edu         |
+---------------------------+---------------------------+---------------------------+---------------------------+
| pH                        | Brison Grey               | *U Miami*                 | bjg136@miami.edu          |
+---------------------------+---------------------------+---------------------------+---------------------------+
| pH                        | Albert Ortiz              | *RSMAS*                   | albert.ortiz@rsmas.miami  |
|                           |                           |                           | .edu                      |
+---------------------------+---------------------------+---------------------------+---------------------------+
| *DIC*                     | Dana Greeley              | *NOAA*                    | djgreel1@gmail.com        |
+---------------------------+---------------------------+---------------------------+---------------------------+
| *DIC*                     | Julian Herndon            | *NOAA*                    | julian.herndon@noaa.gov   |
+---------------------------+---------------------------+---------------------------+---------------------------+
| *CFCs*                    | David Cooper              | *UT*                      | davidcooper59@gmail.com   |
+---------------------------+---------------------------+---------------------------+---------------------------+
| *CFCs*                    | Carol Gonzalez            | *UT*                      | carolgonzalez@utexas.edu  |
+---------------------------+---------------------------+---------------------------+---------------------------+
| *CFCs*                    | Sidney Wayne              | *UCSD*                    | sidneyelisawayne@gmail.c  |
|                           |                           |                           | om                        |
+---------------------------+---------------------------+---------------------------+---------------------------+
| *DOC*                     | Abby Tinari               | *RSMAS*                   | a.tinari@umiami.edu       |
+---------------------------+---------------------------+---------------------------+---------------------------+

[1] Throughout “core” refers to the regular (GO-SHIP levels 1-2)
    sampling and “bio” refers to the biology sampling performed by the
    Bio GO-SHIP team. See Bio section of this report for the details
    on the bio sampling.


Cruise Narrative
================

The 2022 re-occupation of P02W along 30°N in the Pacific was defined
by a week-long delay, a quick start, a well-defined crossing of the
Kuroshio and then its large loop, deep western casts including the
Izu-Ogasawara Trench, and except for one post-Kuroshio wire re-
termination, supported by a nearly continuous spell of calm weather
and seas, no interruption to routine deployments and recoveries.
Technical difficulties were generally minimal and short lived.


Quarantine, Delay and Transit
-----------------------------

Most of the science party arrived in Guam by evening of April 9, glad
to have the 20+ hours of masked flying time over. One person was
unable to come due to a last-minute family emergency. A series of
fortunate events led us to an eager young marine biologist from the
University of Guam, who was willing to drop everything to join our Bio
GO-SHIP team in the P02 pilot project that would include both bio-only
casts and multiple underway measurements. We settled into quarantine
by noon on the 11th. Amazingly, we managed to get 90% of our assorted
multi-disciplinary/institutional/generational group to book rooms in
the same hotel. This has allowed us (our co-chief Shuwen Tan did all
the leg work) to set up group PCR testing prior to boarding without
the necessity of leaving the hotel.

Most of the pre-cruise logistical issues revolved around a lack of
cargo flights from Honolulu the week prior to our load. While most
were sorted out prior to the original departure date (April 22), part
of the CFC shipment was delayed until the day before our final
departure of April 30).

One item of note is that on one of the cruises out Guam earlier this
year a rosette was lost. However, after a thorough investigation and
the setting up of new protocols and safety features, we were confident
that our GO-SHIP 36-bottle rosette would not suffer the same fate.

While in quarantine we continued to follow the behavior of the
Kuroshio as this would affect our final station plan (Fig. 1). We held
daily virtual meetings with the students and held non-required all-
hands meetings (check in was required). Our student led GO-SHIP/GO-BGC
blog (can be accessed through either https://usgoship.ucsd.edu/blogs/
or https://www.go-bgc.org/expedition/north-pacific-2022/) and weekly
reports (https://usgoship.ucsd.edu/2022/04/16/weekly-reports-
from-2022-p02-leg-1/) were started.

   [image]The western end of the planned 2022 P02W track. Symbols
   represent station locations: Full-depth casts (red circles), with
   Bio 1000 m casts (red crosses), with GO-BGC float deployments (red
   “x”s). The green star represents the location of Station 11. Arrows
   represent the estimate of surface velocity from the Copernicus
   physical model for 5/07/22 12:00 UTC, the color shading indicates
   the amplitude of the surface velocity.

After 7 days in COVID quarantine (April 11-17), the science party
boarded the R/V Revelle for MOB (April 18-22) with the intention of
departing on April 22 at 16:00 (local, 10 hours ahead of UTC).
However, due to the ship’s inability to hire a key member of the
engineering department, the ship did not depart until 10:00 (local) on
April 30th. As we could not leave the ship, our time was well spent
setting up and for the students, learning about the equipment, waiting
and dealing with the shipment delays, creating a new bracket for the
ODF rosette so that the upward-looking LADCP could sit above the
bottles and not be crushed by the CAST-6 (Fig. 2), and decorating the
floats for schools which had adopted them. The R/V Revelle left the
dock at 10:00 (local) on April 30. Once out of the Navy Harbor, we
picked up two of our science party (who had not been able to gain
access to the Navy Base) via launch before heading out into open
waters.

   [image]Before (upper right) and after (upper left) views of the
   rosette illustrating the newly designed bracket (lower left panel)
   and it position protecting the rosette instrumentation as it docks
   with CAST-6 (lower right panel).

The Revelle then steamed for ~2 days before reaching the first “test”
station. It included 3 casts. The first, a dip to 20 m to fire all
bottles. ODF, DIC, and bio took water from this cast to keep their
equipment up and running over the 5-day transit. A second cast
included both core and bio sampling, and the third cast was a float
deployment. Because this station included samples analyzed and saved
in support of the GO-BGC float deployment it became Sta 1. It should
be noted however that this is not a full-depth station. After slowing
to deploy a second float while in international waters, sampling on
the regular line began on May 5 at 32.507°N, 133.03°E (Sta 3).


Station Spacing and Sampling Details
------------------------------------

The actual station spacing deviated from the planned spacing mainly
due to the 8-day delay in port (a protracted wait to hire a key crew
member), which then prematurely closed the requested window for
sampling within Japanese waters. The close spacing coming southeast
down the Japan slope was kept, but when not in steeply sloping
bathymetry or frontal regions - spacing was first increased to 40 nm
and then to 45 nm with one instance of 48 nm spacing. The slightly
closer spacing was based on the hope that an EEZ clearance extension
would be granted. The longer spacing occurred as the window of
opportunity closed. Having occupied a station (Sta 22, 30.000°N,
142.256°E) on the western side of the Izu-Ogasawara Trench and with no
extension in sight, the planned 6000 m station in the center of the
trench was cancelled in favor of a location on the eastern side (Sta
23, 30.000°N, 143.177 °E). News of an extension came after the Sta 23
cast, only a few hours prior to the end of the original clearance, at
which point spacing was reduced back to 35 nm. Still dealing with the
reduced days at sea due to the original delay, 35 nm spacing was
maintained until Sta 46 (30.000°N, 158.658°E), where upon it was
reduced to the standard 30 nm. The only change to this spacing
occurred at the Mercury Seamount (Sta 71-73, ~173.2°E) where the 2013
stations on either side were re-occupied and we included a shallow
station at the peak in between (Sta 72).

The Bio team took rosette samples at approximately every third station
on the line. At six stations (Sta: 1, 6, 11, 14, 17, and 20) in
western waters where casts were less than 5000 m deep, these samples
came from 12 rosette bottles (core sampling using the other 24).
Beginning at the first 6000 m station (Sta 23) and every third station
thereafter there was a separate 1000 m bio” cast, where 19 bottles
were tripped (at 1000 m, 500 m, 200 m, 150 m, 2x100 m, 75 m, 40 m, and
11 x5 m or the “surface”) for what became known as “standard bio”. On
the bio stations where floats were deployed (aka “float bio”), 20
bottles were tripped (at 1000 m, 500 m, 2x200 m, below the chlorophyll
max (according to the fluorometer), 2 x the chlorophyll max, above the
chlorophyll max, below the mixed layer, and 11 x 5 m or the
“surface”). The bio casts took a little less than an hour to go down
and up, and for the standard bio 20-30 minutes to sample and get back
in the water. They became quicker as we became more proficient at
sampling. Having the CTD watch assist was paramount to this efficiency
and a sample cop was absolutely necessary to avoid mistakes. Float bio
casts took 5-10 minutes longer because they were more complicated.

There were a total of 115 full water column casts that included CTD,
Bullister bottle, fluorometer, transmissometer, and upward & downward-
looking LADCP and Chi-PODS. The UVP ran for 114 of these. There were
33 separate bio-casts and another 6 casts (in waters less than 5000 m
deep) that included 12 bio-only bottles and 24 core bottles. These
combined casts required stricter use of water by both groups, but
worked well without adding the extra time to the stations for bio-
sampling and re-cocking & re-deployment of the rosette for a second
cast (a savings of about 1.5 hours). It should be noted however, that
including the bio-casts gave the other teams (particularly CFCS, DIC,
and pH/TAlk) more time to analyze their data which meant that for the
most part they were able to keep up if not full sampling on all 36
bottles, then at-least two-thirds sampling on every station.

Water samples (up to 36) were collected in 10 L Bullister bottles at
all stations providing water samples for CFCs/SF_6, Total DIC, Total
Alkalinity, pH, dissolved oxygen, nutrients, salinity, DOC,
\text{DI}^{13/14}C. There was also discrete underway sampling three
times a day that included HPLC, FCM, POM (POC, PON, POP, PCOD) and
genetics (DNA/RNA). Underway surface pCO_2, temperature, salinity,
dissolved oxygen, multi-beam bathymetry and meteorological
measurements were collected. XBTs provided upper water column
temperature profiles for calibration of the multi-beam on all days
that CTD casts were not performed. With few exceptions, casts were
made to within 10-12 m of the bottom. Note the exceptions are casts
that were purposely made to 3-6 m in calm waters.

The standard three-station schema was used to choose sampling depths.
These schema are designed to sample the full water column over a span
of the three stations (e.g. if the first station trips bottles at 600
m and 700 m, the next will sample 635 m and 735m, the third 665 m and
765, and the rotation begins again with the fourth sampling 600 m and
700 m). Near the bottom the schema were manually manipulated to avoid
gaps due to extremely flat or steeply sloped bathymetry. Particularly
near the bottom, it is not necessary to be overly concerned about
hitting these depths exactly so unless the wire out is significantly
different from the CTD depth, it can be used as the target. Closer to
the surface where bottle trips are more narrowly spaced, correcting
the target wire out to get the desired target depth can be beneficial
to the overall consistency, but being off by a meter or two at 100 m
is irrelevant. Surface bottle depth was defined by the res-tech on
duty who would bring the rosette up to the “surface” for the last
bottle trip. The goal is to cover the water column, not measure a
specific set of depths (Fig. 3).

   [image]Along-track bathymetry with P02 Leg 1 occupied stations
   1-117 (numbered vertical lines). Five panel section plot indicating
   depth in meters of each of the bottles tripped (blue crosses). Red
   circles indicate bottles with problems (misfires, leaking, etc).
   The pink vertical line indicates the longitude of the eastern edge
   of the Japanese EEZ. From top to bottom panels represent depth
   ranges 0 to <150 m, 150 to < 600 m, 600 to < 1500 m, 1500 to 3000
   m, and 3000 to 6000 m. (Image credit: Shuwen Tan).

For every deployment and recovery an entry from made in the UNOLS
E-logger
(https://www.unols.org/sites/default/files/R2R_EventLogger.pdf) that
included the transect (P02W), the station # (SSS), the cast number
(CC), the estimated depth from the Multibeam, the author id-name, and
a possible comment. The E-logger software provided the date/time &
position stamps. The event number that is made up of the UTC date
(YYYMMDD) and time (HHMM), and a 3-digit extension was assigned by the
software. For example: 20220608.1120.001 was the recovery of the Sta
117 cast on June 8th at 11:20 UTC. Had another operator on a different
cruise entered an event at the exact same time it would have been
given a different 3-digit extension. E-logger was used consistently
for the casts and for turning the EK-80 on and off during casts. There
are a few entries for the bio-underway samples, but these were not
maintained consistently. On the console log sheet, the event number
was written as MMDD.HHMM without the year or 3-digit extension
(neither of which changed over the course of the cruise).


Sampling and Analysis Challenges
--------------------------------

While the details of the lab and rosette issues are described and/or
listed in the individual sections of this report, a few of the most
notable are listed here.

Bullister 19 was a problem bottle. We found that it would trip but
then find a balance point so it would not close. Then after various
adjustments to the lanyard and raising it up, bottle 20 began
periodically catching 19’s lanyard, so that 20 would not close
properly. We made an effort to adjust so as to avoid large gaps over
the three-station schema rotation. Still, it was frustrating as these
two bottles tended to close at the oxygen minimum.

The only truly notable data gap was when CFCs got behind for one two-
day stint because of equipment failure (Sta 17-20 are missing CFC-11,
CFC-12, SF_6 and N_2O). There are two short gaps in the pCO_2 data set
that were caused by first equipment issues and secondly electrical
issues in the lab. Please see the pCO2 section for discussion of the
various water intakes on the *Revelle* and their associated
temperatures (that go into the pCO_2 numbers). There is one full cast
and 4 bio-casts where the transmissometer was purposely blacked out
for calibration purposes. We lost one cast of UVP data due to
corrosion and then a couple of others due to the battery’s inability
to handle both a bio cast and full cast in quick succession. Later
(after May 25) due to a software issue, the UVP data while still being
collected, could no longer be downloaded.

One particular misstep is noteworthy. In 2016, President Obama
increased by presidential proclamation the footprint of the
Papahanaumokuakea Marine National Monument to the seaward limit of the
EEZ. However, this change appears to have never been updated in the
current NOAA and Coast Pilot navigation charts used by the bridge or
our UCSD personnel assisting us with clearance requests and permit.
The net result was that while we thought we had closest point of
approach of 90 nm, we instead occupied 16 stations, took numerous
underway samples and other measurements and deployed float WMO#
5906516 within its boundaries. We were contacted by U.S. Fish &
Wildlife Service National Wildlife Refuge System Division of Refuge
Law Enforcement and after multiple conversations between them, Captain
Galiher and the acting UCSD Marine Superintendent Eric Buck, and
contact with the UCSD Port Captain Wes Hill, it was left as an
“educational opportunity”. The captain will follow-up to make sure
that this change and any others are updated into the charts they use.
The next occupation of P02W will have to acquire a permit for sampling
in this region. Such a permit should be possible as scientific
research is allowed, though whether there will be any restrictions we
cannot tell at this juncture.

The cruise ended in Honolulu, Hawaii on June 10th, 2011, where the
small amount deMOB activity occurred. All Leg 2 shipments also came
aboard, ready for stowing. While crew turnover occurred on the 10th,
most science party members stayed on the Revelle until June 11th for
cross-over discussions with the members of the Leg-2 science party who
were in quarantine in Honolulu and boarded on the 11th.


Acknowledgements
----------------

We would like to thank the officers and crew of the R/V *Revelle* who
have gone above and beyond to welcome us and support the science on
this expedition. They have worked with us every step of the way from
handling the repercussions of the 8-day delay in port to seeing us
through to the middle of the North Pacific with speed, alacrity and
accuracy. Their efforts have included:

* Not just driving the ship (big thank you to the Bridge – to Captain
  Heather, for her care in bringing us onto station, to our 2nd Mate
  and Navigator Trey for his smooth sailing into station (and apparent
  joy at receiving new positions), and to Henry – whoa! and just how
  close are you to our specified position? Was that 3.1 cm?)

* Great conversations on the bridge assisting us with our station plan
  and EEZ gymnastics, creating a “plankton” flag, your noontime
  reports to JCG, handling that misstep with a marine preserve and
  finding the quickest route home (thank you for our early morning
  chats, Trey and Captain Heather)

* Running our winch through all hours of the day and night, providing
  some enjoyable radio chatter (thank you Bob, Joey, Jake, Feivel and
  Gomez; Gomez thank you too for the fantastic blog post and inspired
  artwork)

* Feeding us outstanding cuisine – an amazing variety of soups, taco
  Tuesdays, Sunday dinners, always a vegetarian option or two or
  three, an array of birthday cakes, muffins and cookies, and crème
  brulée after our last full day of sampling – we can’t thank you
  enough Jay and Mark, and a great murmuring of thanks from the night-
  shift to Trey for bringing out 4 am delicacies.

* Burning those pesky insect-ridden float boxes (thank you Joe and
  Fievel), your care use of chemical products Joe and for everything
  else required after the winch work took over your labor force.

* Sorting out winch and wire challenges and fixing everything from the
  smallest detail to the greatest problems (the list is long here, big
  thank you to our res-techs Josh and Royhon, our Bosun Joe, our chief
  engineer Chance (love that bracket) and Harry as well as all the
  engineers for ship and equipment up and running).

* Thank you to our Chief Mate Michael for wonderful stories and sound
  advice and to all the other friendly faces in the passageways and
  mess: Daryl, Delvin, Jeffrey, Brian, Pete, and Bobby.

* Thanks to all of you from all of us for speeding us along so that we
  could sample the full line with minimal loss of data and have some
  fun while we were doing it.

We would also like to recognize the tremendous assistance we received
from Hannah Delapp at UCSD and Sasaki Eriko at MOFA with sorting out
the initial Japan clearance request (MSR), and then Hannah along with
Junko Nagahama at the State Dept for making the extension possible.
Lastly co-chief sci, Shuwen and chief sci, Alison would like to thank
Natalie Freeman (who, although chosen, was unable to sail as co-chief
for Leg 2) for her assistance with model output software and sending
us weather and current updates, as well as Andreas Thurnherr, chief
sci for Leg 2 for the fantastic pre-cruise discussion and
collaboration. Best of good fortune, calm winds and following seas to
Leg 2.


Preliminary Science Remarks
===========================


Kuroshio Large Meander
----------------------

Unlike 1994, 2004, and 2013 P02 occupations, the Kuroshio during the
occupation of leg 1 was in its Large Meander (LM) status rather than
in the mode where it takes a “straight” path following the coastline
of Japan. This LM event started at the beginning of 2018 and still
exists today (10th June 2022). This makes it the longest-lasting event
in the eight LM events that have taken place since 1950, i.e., at
least 4 years compared to a typical 1 to 2-year lifespan ([Qiu2021]).
We were able to visualize the Kuroshio LM live thanks to the Ship-
board ADCP (SADCP) UHDAS vector plots and sections that were updated
every 5 mins. Qiu and Chen (2021) suggest that the persistence of
Kuroshio LM is due to a constant feed of intense anticyclonic eddies
shed from the Subtropical Countercurrent. During the period of
Kuroshio-related occupation (May 4 to 7 UTC), an anti-cyclonic eddy
located west of the Kuroshio LM was recognized in the Copernicus model
data being sent to those on board (see Fig. 2 in the Narrative
Section). Stations 9-12 (May 6) sampled the northeastern edge of that
eddy (see Fig.1 and near the turn onto 30°N in Fig. 2). BGC-float was
deployed at Station 11 on May 6.

   [image]SADCP-based surface (29 m to 61 m average) current
   velocities (arrows) and temperature (colormap) during the period of
   May 3th-4th (during transit to Sta 3). Dark red arrows north of
   31.2°N and near 137°E indicate the warm and rapid Kuroshio and its
   deviation from the coastline. (Source: UHDAS 5-mins surface vector
   plot, University of Hawaii UHDAS system,
   https://currents.soest.hawaii.edu/uhdas_fromships.html)

   [image]SADCP-based surface (29 m to 61 m average) current
   velocities (arrows) and temperature (colormap) during the period of
   May 6th-7th (coming down the slope and turning eastward).


Rough Topography: Izu-Ogasawara Ridge and the Mercury Seamount
--------------------------------------------------------------

In addition to repeating the previously occupied WOCE/CLIVAR stations,
some stations in Leg-1 are intentionally adjusted to measure water
properties near rough topography (Fig. 3: 018, 019, 073 on top of
ridges/seamounts; 071, 072, 074 on the slopes). From LADCP data alone
(preliminary results from Kurtis Anstey and interpretation by Andreas
Thurnherr), we are excited to report prominent internal wave signals
and features in turbulent dissipation rates (\epsilon) that appear to
be associated with rough topography. The former can be visualized from
the periodic horizontal velocities throughout the water column (Fig.
4, 5). Large \epsilon are found above 1500 m at stations on top of
ridges/seamounts and bottom-intensified \epsilon are found on the
slope of the seamount (station 072).

   [image]Map of station locations over the western part of the Izu-
   Ogasawara Ridge overlaid on the SRTM 15 arcsecond bathymetry
   profiles of the turbulent kinetic energy dissipation rate
   ([Tozer2019]).

   [image]Map of station locations near the Mercury Seamount located
   northwest of the Hawaiian Ridge overlaid on the SRTM 15 arcsecond
   bathymetry profiles of the turbulent kinetic energy dissipation
   rate ([Tozer2019]).

   [image]

   [image]Horizontal velocities from LADCP measurements at the four
   stations (the 01 and 02 values after the station numbers enumerate
   the cast). (Image credit Shuwen Tan).


EK-80 Remarks
-------------

The Simrad EK-80 fisheries sonar
(https://www.simrad.online/ek80/ref_en/default.htm) has been turned on
during the deployment of both bio casts and core casts throughout the
cruise. Thanks to the real-time display, identifying and interpreting
interesting features has become a source of great interest for many in
the computer lab. Fascinating features including Kelvin-Helmholtz
billows (Fig. 6), internal waves at the thermocline, and internal
waves in the wake of the ship were identified, and other unidentified
phenomena were archived as screenshots. The EK-data from the cruise
will also be archived.

   [image]Simrad EK-80 monitor output (x-axis is time, y-axis is
   depth) during Station 38 which had two casts on 1430-2030 May 15
   (local time = UTC+11). The subpanels show results from different
   frequencies which translate into resolution of different depth
   ranges from left to right a) ES200 0-300, b) ES120 0-500, c) ES70 0
   -1000, d) ES38 0-3000 and e) ES18 0-bottom. (Image Credit: UCSD
   Shipboard Technical Services).


North Pacific Mode Water
------------------------

North Pacific Subtropical Mode Water (NPSTMW) is formed to the
east/south of Kuroshio/Kuroshio Extension in the late winter and early
spring. Subducted, it tends eastward, and like all mode waters is well
mixed and is therefore recognizable by its low potential vorticity
(see band of purple to blue colors centered at about 200 m in the
upper panels of Fig. 6). In the North Pacific, there is an Eastern
Subtropical Mode Water as well. With overlapping characteristics, the
two are distinguished as existing to the east and west of the date
line (180° longitude lies almost directly under the “o” in the title
word “Vorticity”). NPSTMW is only one of several mode waters formed in
the northwestern Pacific which is an area rich frontal zones and
meteorology conducive to mode water formation. Here one can see the
high PV in the region of the Kuroshio and its meander reaching down to
600-700 m. The latter is particularly strong in 2022 (upper panel, see
Section 1 above discussion the meander dynamics). In both years,
NPSTMW reaches to about 400 m, the expected depth of winter mixing
according to the literature, and as expected. These waters rise as
they cross the basin eastward. That said, the character of the NPSTMW
layer as well as the water above seem different in the two
occupations. While this may be an actual difference, it seems likely
that the low 2013 station spacing (even lower than in 2012) may be
playing a role in creating this apparent difference. Time of year may
also be a factor as the 2022 occupation began nearly a full month
later at a sensitive time of year for this water mass. We note that
radiocesium isotopes originating from the Fukushima Dai-ichi Power
Plants and measured on the 2013 occupation suggest that the NPSTMW at
161°E (~ 2700 km) is no more that 2 years old ([Yoshida2015]).

   [image]Potential Vorticity (units \text{10}^{-12} \text{m}^{-1}
   \text{s}^{-1}) sections for the upper thousand meters for 2022
   stations 3-117 (upper panel) and the station covering the same
   distance (6067 km) from the first station for the 2013 occupation
   (middle panel). The lower panel illustrates the 2022 stations
   included. (Image created using Web Ocean Data View 5.4.5, web
   server 28)

[Qiu2021] Qiu, B., and Chen, S. (2021). Revisit of the Occurrence of
          the Kuroshio Large Meander South of Japan. Journal of
          Physical Oceanography 51, 12, 3679-3694

[Tozer2019] Tozer, B, Sandwell, D. T., Smith, W. H. F., Olson, C.,
            Beale, J. R., & Wessel, P. (2019). Global bathymetry and
            topography at 15 arc sec: SRTM15+. Earth and Space
            Science, 6, 1847. https://doi.org/10.1029/2019EA000658

[Yoshida2015] Yoshida, S., A. M. Macdonald, S. R. Jayne, I. I. Rypina
              and K. O. Buesseler (2015) Observed eastward progression
              of the Fukushima 134Cs signal across the North Pacific,
              GRL, doi: 10.1002/2015GL065259.


CTD and Rosette Setup
=====================

For P02W-2022 a *SIO* *STS* 36-place yellow rosette and bottles were
used. The rosette was sent to Guam in early January, 2022. The rosette
and bottles were built before P06 2017, making this the thirteenth
time this package has been deployed. A steel bridle was added to the
top of the rosette to adapt to the winch head. The bottles were made
with new PVC, with new non-baked o-rings and electro-polished steel
springs. Springs within the Bullister-style Niskin bottles were
electropolished stainless steel. Bottle lanyards were made from
300-pound monofilament. No sample contamination has been noticed by
the change in o-rings and springs. The package used on P02W-2022
weighs roughly 1500 lbs in air without water and 2350 lbs in air with
water. The package used on P02W-2022 weighs roughly 950 lbs in water.
In addition to the standard *CTDO* package on GO-SHIP cruises three
chipods, two *LADCP*, and one *UVP* were mounted on the rosette.

During the cruise we encountered a handful of problems, most notably
noise between the primary and secondary CTD lines. We describe all of
the above in more detail in the sections below.


Underwater Sampling Package
---------------------------

CTDO/rosette/LADCP/UVP/chipod 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 10.6 L.
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, RINKO oxygen optode, transmissometer, chlorophyll-a
fluorometer, and altimeter were also mounted on the rosette. Chipod,
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 intakes for the
pumped temperature sensors. The transmissometer was mounted
horizontally on the lower LADCP brace with hose clamps, avoiding shiny
metal inside that would introduce noise in the signal. The hose clamps
for the transmissometer were covered in black electrical tape. The
oxygen optode, fluorometer, and altimeter were mounted vertically
inside the bottom ring of the rosette frames, with nothing obstructing
their line of sight. One 300 KHz bi-directional Broadband LADCP (RDI)
unit was mounted vertically on the bottom side of the frame. Another
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 near (90°) each other at the beginning of the
cruise. Imagining the now of the ship to be north, the LADCP battery
was mounted on the south side of the rosette, the up/down LADCPs were
on the west side, the UVP on the east, and CTD mounted to the north.

+------------------+------------------+------------------+------------------+------------------+------------------+
| Equipment        | Model            | S/N              | Cal Date         | Stations         | Group            |
|==================|==================|==================|==================|==================|==================|
| Rosette          | 36-place         | Yellow           | –                | 1-117            | *STS*/*ODF*      |
+------------------+------------------+------------------+------------------+------------------+------------------+
| CTD              | SBE9+            | 1281             | –                | 1-117            | *STS*/*ODF*      |
+------------------+------------------+------------------+------------------+------------------+------------------+
| Pressure Sensor  | Digiquartz       | 136428           | Dec 7, 2021      | 1-117            | *STS*/*ODF*      |
+------------------+------------------+------------------+------------------+------------------+------------------+
| Primary          | SBE3+            | 35046            | Mar 2, 2022      | 1-8              | *STS*/*ODF*      |
| Temperature      |                  |                  |                  |                  |                  |
+------------------+------------------+------------------+------------------+------------------+------------------+
| Primary          | SBE3+            | 34941            | Mar 9, 2022      | 9-40             | *STS*/*ODF*      |
| Temperature      |                  |                  |                  |                  |                  |
+------------------+------------------+------------------+------------------+------------------+------------------+
| Primary          | SBE3+            | 36049            | Mar 17, 2022     | 41-117           | *STS*/*ODF*      |
| Temperature      |                  |                  |                  |                  |                  |
+------------------+------------------+------------------+------------------+------------------+------------------+
| Primary          | SBE4C            | 43578            | Mar 22, 2022     | 1-117            | *STS*/*ODF*      |
| Conductivity     |                  |                  |                  |                  |                  |
+------------------+------------------+------------------+------------------+------------------+------------------+
| Primary Pump     | SBE5             | 51892            | –                | 1-41,51-117      | *UCSD*           |
+------------------+------------------+------------------+------------------+------------------+------------------+
| Primary Pump     | SBE5             | 53626            | –                | 41-50            | *UCSD*           |
+------------------+------------------+------------------+------------------+------------------+------------------+
| Secondary        | SBE3+            | 34941            | Mar 9, 2022      | 1-8              | *STS*/*ODF*      |
| Temperature      |                  |                  |                  |                  |                  |
+------------------+------------------+------------------+------------------+------------------+------------------+
| Secondary        | SBE3+            | 36018            | Mar 3, 2022      | 9-40             | *STS*/*ODF*      |
| Temperature      |                  |                  |                  |                  |                  |
+------------------+------------------+------------------+------------------+------------------+------------------+
| Secondary        | SBE3+            | 34138            | Mar 17, 2022     | 41-117           | *STS*/*ODF*      |
| Temperature      |                  |                  |                  |                  |                  |
+------------------+------------------+------------------+------------------+------------------+------------------+
| Secondary        | SBE4C            | 42569            | Mar 17, 2022     | 1-117            | *STS*/*ODF*      |
| Conductivity     |                  |                  |                  |                  |                  |
+------------------+------------------+------------------+------------------+------------------+------------------+
| Secondary Pump   | SBE5             | 51871            | –                | 1-42             | *UCSD*           |
+------------------+------------------+------------------+------------------+------------------+------------------+
| Secondary Pump   | SBE5             | 58692            | –                | 42-50            | *UCSD*           |
+------------------+------------------+------------------+------------------+------------------+------------------+
| Secondary Pump   | SBE5             | 53626            | –                | 51-117           | *UCSD*           |
+------------------+------------------+------------------+------------------+------------------+------------------+
| Transmissometer  | Cstar            | 1873DR           | Jan 5, 2022      | 1-117            | *TAMU*           |
+------------------+------------------+------------------+------------------+------------------+------------------+
| Fluorometer      | WetLabs ECO-FL-  | 4334             | –                | 1-117            | *STS*/*ODF*      |
| Chlorophyll      | RTD              |                  |                  |                  |                  |
+------------------+------------------+------------------+------------------+------------------+------------------+
| Dissolved Oxygen | SBE43            | 430060           | Mar 15, 2022     | 1-32             | *ODF*            |
+------------------+------------------+------------------+------------------+------------------+------------------+
| Dissolved Oxygen | SBE43            | 430185           | Mar 15, 2022     | 32-93            | *ODF*            |
+------------------+------------------+------------------+------------------+------------------+------------------+
| Dissolved Oxygen | SBE43            | 431508           | Oct 8, 2021      | 94-117           | *ODF*            |
+------------------+------------------+------------------+------------------+------------------+------------------+
| Oxygen Optode    | JFE Advantech    | 0296             | Apr 7, 2017      | 1-10             | *ODF*            |
|                  | Rinko-III        |                  |                  |                  |                  |
+------------------+------------------+------------------+------------------+------------------+------------------+
| Oxygen Optode    | JFE Advantech    | 0251             | Apr 7, 2017      | 11-117           | *ODF*            |
|                  | Rinko-III        |                  |                  |                  |                  |
+------------------+------------------+------------------+------------------+------------------+------------------+
| Reference        | SBE35            | 0105             | Mar 15, 2022     | 1-117            | *STS*/*ODF*      |
| Temperature      |                  |                  |                  |                  |                  |
+------------------+------------------+------------------+------------------+------------------+------------------+
| Carousel         | SBE32            | 1178             | –                | 1-117            | *STS*/*ODF*      |
+------------------+------------------+------------------+------------------+------------------+------------------+
| Altimeter        | Valeport 500     | 53821            | –                | 1-117            | *UCSD*           |
+------------------+------------------+------------------+------------------+------------------+------------------+
| UVP              | –                | 201              | –                | 1-117            | *UAF*            |
+------------------+------------------+------------------+------------------+------------------+------------------+
| Chipods          | Chipod           | 2014 Ti44-8      | –                | 1-117            | *OSU*            |
+------------------+------------------+------------------+------------------+------------------+------------------+
| Chipods          | Chipod           | 2013 TI44-12     | –                | 1-117            | *OSU*            |
+------------------+------------------+------------------+------------------+------------------+------------------+
| Chipods          | Chipod           | 2032 Ti44-15     | –                | 1-117            | *OSU*            |
+------------------+------------------+------------------+------------------+------------------+------------------+

   [image]Package sensor setup from south.

   [image]Package sensor setup from east.

   [image]Package sensor setup from north.

   [image]Package setup from southwest, from left to right: CTD cage,
   downward facing chipod, downward facing LADCP, transmissometer bar.

   [image]Package setup from southwest, from left to right:
   (Foreground) ECO fluorometer, UVP, RINKO, altimeter.

   [image]Package setup from west.

   [image]Package  setup from west, top view.


Winch and Deployment
--------------------

The CAST6 winch and deployment system was 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 with
an Evergrip (primary), Guy Grip (secondary), and set of Crosby Clips
(tertiary). No electrical issues occurred on P02W. There were
continuous issues with wire twist and had to “move up” the termination
3 times during the cruise.

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 outside of the rosette before the next cast, and the inside 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. Once stopped on station, the
Marine Technician would check the sea state prior to cast and decide
if conditions were acceptable for deployment. The rosette was moved
from the sampling bay out to the deck using the *Revelle’s* tugger-
driven cart. Once on deck, sea cable slack was pulled up by the winch
operator. CTD watch standers would then turn on the deckbox and begin
data acquistion, and the cast would begin. Recovering the package at
the end of the deployment was the reverse of launching. Once rolled
back into the sampling bay, a technician secured the cart to the deck
using additional ratchet straps. The carousel was rinsed and sensors
were cleaned (as described below) after every cast, and then samplers
were allowed to begin collecting water.


Maintenance and Calibrations
----------------------------

During P02W-2022 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 and adjusting hose clamps and guide rings as needed such that
lanyards had appropriate tension. 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,
syringes of fresh water were connected to the plumbed lines to rinse
the sensors and allow them to soak between casts. While in freezing
conditions, water was drained after rinse to avoid freezing in the
plumbing. Overhead heaters recently installed on the Thompson were run
while in freezing or near-freezing conditions. The rosette was
routinely examined for valve and o-ring leaks, which were maintained
as needed. SBE35RT temperature data was routinely downloaded each day.

Every 20 stations, the transmissometer windows were cleaned and on
deck blocked and un-blocked voltage readings were recorded prior to
the cast. The transmissometer was also calibrated before the start and
after the end of science operations.


Logs
----

In port: Preparation of the CTD and rosette was minimal as it had
nearly the same setup as A20 2021, which had just been completed. UVP
arrived in St. Thomas and was mounted opposite the ADCP. Downlooking
chipod mounting pole was swapped out to allow the sensor to be closer
to the leading edge of the rosette. Additional integrity checks on the
rosette, such as checking lanyard angles, o-ring and lanyard
replacement, and spigot movement waited until being underway to be
checked as lower priority tasks. We are using a new mounting system
for the downward looking LADCP which has the LADCP clamped facing
inward instead of outward, which will cause problems if we need to
change that LADCP in rough weather.

May 1, 2022

00101 - Test station to 20 m. Fired 36 bottles.

00102 - Test station to 1504 m. UVP turned on and voltage spikes were
confirmed as real. Bottle 6 misfired at console.

00201 - Float deployed. CTD cast abandoned to save time.

May 4, 2022

00301 - Shallow 160 m cast with only 10 bottles to fire. Up-facing
chipods were loose. Tightened hose clamps.

00401 - Bottle #2 o-ring broke on top vent upon recovery. Replaced.

May 5, 2022

00501 - No issues noted.

00601 - No issues noted.

00701 - No issues noted.

00801 - Primary temperature static to unrealistic value around 3150 m
during upcast. Swapped T1 with T2 and replaced bad sensor. Spigot pins
on bottles 6, 8 were bent and were straightened on recovery.

00901 - Alarms went off in computer lab approximately 5 minutes into
20 m soak. Deck box reading 1110, rather than normal 0110/0111.
Recovered CTD and checked external wiring.

00902 - Alarms went off prior to contact with the surface.
Reterminated end of cable upon recovery.

May 6, 2022

00903 - Alarms went off before reaching 20 m soak depth. Replaced sea
cable upon recovery. Covered new T2 sensor with dummy plug.

00904 - Restech checked deckbox connections in computer lab and
confirmed they were loose. Deployed with dummy on T2 to soak depth
with no alarms and continued to approx. 4200 m. Connected T2 upon
recovery and tested on deck.

01001 - Abnormal behavior on RINKO serial 0296, upcast and downcast do
not match each other or the SBE43. SBE35 hit cap on internal storage
and reference temperatures were not recorded. Replaced RINKO 0296 with
S/N 0251 following recovery.

May 7, 2022

01101 - UVP battery exploded. Cable changed out and other damaged
materials replaced. SBE35 hit cap on in ternal storage and references
temperatures were not recorded.

01201 - RINKO 0251 spiking to 0 V during both down and upcasts.
Replaced RINKO cable upon recovery. Data logging accidently ended
pematurely during recovery. Turned back on for on-deck pressure.

May 7, 2022

01301 - No issues noted, new RINKO cable solved spiking behavior.

01401 - No issues noted.

01501 - No issues noted.

May 8, 2022

01601 - No issues noted.

01701 - “Fire bottle” button pressed 37 times in SeaSave, final button
press at the surface.

01801 - No issues noted.

01901 - Paused approximately 100 m from seafloor waiting for restech
assistance.

May 9, 2022

02001 - No issues noted.

02101 - No issues noted.

02201 - No issues noted.

May 10, 2022

02301 - Bio cast. No issues noted.

02302 - No issues noted.

02401 - No issues noted.

02501 - No issues noted.

May 11, 2022

02601 - Bio cast. No issues noted.

02602 - UVP voltage was static or unresponsive beyond ~1500 m.

02701 - Restechs observed significant spinning during recoveries and
wrapped ~10 m of cable within the inside of the rosette to reduce
spinning.

02801 - Replaced o-ring on bottle 10 valve and used hose clamps to
secure slack cable to inside of rosette and away from lanyards.

May 12, 2022

02901 - Bio cast. Dark cast. Observed top caps of bottles 16 and 34
catching on lanyards of bottles 17 and 35, respectively. Lowered 16,
34, and raised 35. Replaced cracked spigot washer on bottle 9.

02902 - Tape left on transmissometer from dark cast. UVP voltage
static or unresponsive below ~1700 m. Confirmed to be a battery
problem associated with insufficient charge following bio casts.
Bottle 16 was too low and caught on rosette frame. Raised bottle 16.

03001 - No problems noted. UVP operational as normal.

03101 - Raised bottle 17 to reduce chance of catching on bottle 16.

May 13, 2022

03201 - Bio cast. Bio fouling event and recovered to clean off
sensors.

03202 - Bio cast. Primary and secondary CTD lines had noisy offsets
during soak period.

03203 - Primary and secondary CTD lines had noisy offsets during soak
period. Noticed significant noise and changes in SBE43 baseline during
upcast. Changed SBE43 sensor out when recovered. Reterminated winch
cable due to kink during recovery.

03301 - Primary and secondary CTD offsets improving. New SBE43 still
noisy, but no changes in baseline.

03401 - No issues noted.

May 14, 2022

03501 - Bio cast. No issues noted.

03502 - SBE43 a little noisy after 1200 m.

03601 - No issues noted.

03701 - Adjusted guide rings on bottles 2, 31.

May 15, 2022

03801 - Bio cast.

03802 - No issues noted.

03901 - No issues noted.

04001 - Primary and secondary offsets significantly noisy and spiky.
Recovered CTD and tested pumps. Replaced secondary temperature sensor.

04002 - Primary and secondary offsets still noisy. Recovered CTD,
tested pumps, and replaced primary temperature sensor.

04003 - Offsets still noisy at soak depth. Deployed regardless and
noise dissapated by 150 m depth. Noise may have been related to ship
heave and pycnocline depth.

May 16, 2022

04101 - Bio cast. Noisy soak.

04102 - Noisy soak. Replaced primary pump to attempt to remedy soak
noise.

04201 - Chipod 14-32 (top) had popped loose and flooded. Replaced with
14-36. Replaced secondary pump to attempt to remedy soak noise. Bottom
spring to cap connection broke on bottle 6. Crimped new line and
reattached cap prior to 04301.

04301 - No issues noted.

May 17, 2022

04401 - Bio cast. Crimp on bottom of bottle 6 failed. Reattached
spring with knot.

04402 - No issues noted.

04501 - Bottle 19 suspected of mistrip.

04601 - No issues noted.

May 18, 2022

04701 - Bio cast.

04702 - Valve o-ring broken on bottle 1.

04801 - Bottle 19 confirmed to be mistripping on 04501 and 04801.
Raised bottle 19 for better lanyard angle with carousel.

04901 - Bottle 19 fired. SBE43 noisy around 4000 m.

May 19, 2022

05001 - Bio cast. Soak is still noisy. Replaced primary pump.

05002 - Soak is still noisy. Replaced secondary pump.

05101 - Replaced o-rings on bottles 4, 6, 11, 12, 16, 20, 23, 26, 27.
RINKO was loose.

05201 - Primary and secondary offsets noisy and spiky up to 30 m.
Bottle 19 suspected of mistrip.

May 20, 2022

05301 - Bio cast. Bottles not fired sequentially.

05302 - No issues noted.

05401 - Bottle 19 came up empty. Changed out carousel latch. Raised
bottle 19 to highest position possible.

05501 - No issues noted.

May 21, 2022

05601 - Bio cast. Changed pump Y cable to attempt to improve
temperature and conductivity offsets.

05602 - No change in soak noise.

05701 - UVP suspected of slipping.

05801 - No issues noted.

05901 - Bio cast. No issues noted.

May 22, 2022

05902 - No issues noted.

06001 - No issues noted.

06101 - No issues noted.

06201 - Bio cast. Dark cast. Grease on vent of bottle 24 when
recovered.

May 23, 2022

06202 - No issues noted.

06301 - No issues noted.

06401 - Bottle 16 accidently fired at 1615 m while CTD was moving.

06501 - Bio cast. No issues noted.

06502 - No issues noted.

May 24, 2022

06601 - No issues noted.

06701 - No issues noted.

06801 - Bio cast. No issues noted.

06802 - No issues noted.

May 25, 2022

06901 - Bottle 16 came up empty. Lower cap caught on rosette frame.
Raised bottle 16 to ensure better closure.

07001 - Rinsed lower 600 m of winch wire upon rosette recovery.

07101 - Bio cast. No issues noted.

07102 - Biofouling event but sampling and CTD data look normal.

May 26, 2022

07201 - Spigot on niskin 33 replaced after sampling as it was
suspected of leaking when subsampled.

07301 - No issues noted.

07401 - Bio cast.

07402 - Spiky offsets in primary and secondary CTD lines during
downcast.

07501 - Lanyard of bottle 19 caught in top of bottle 20. Remade
lanyard.

May 27, 2022

07601 - No issues noted.

07701 - Bio cast. No issues noted.

07702 - No issues noted.

07801 - No issues noted.

07901 - No issues noted.

May 28, 2022

08001 - Bio cast. No issues noted.

08002 - Cast delayed 10 minutes due to personnel miscommunication.

08101 - Considerable difference between upcast and downcast in oxygen
sensors.

08201 - No issues noted.

May 29, 2022

08301 - Bio cast. No issues noted.

08302 - No issues noted.

08401 - Complaints of tightness on bottle 10 spigot. Replaced spigot
with no signs of problems in old o-rings.

08501 - Spiked in offsets between primary and secondary CTD sensors at
depths of 700 - 1240 m.

May 30, 2022

08601 - Bio cast. Spigot on bottle 13 was hard to depress and was
replaced after sampling.

08602 - No issues noted.

08701 - No issues noted.

08801 - No issues noted.

08901 - Bio cast. Replaced spigot on bottle 6. Offsets in primary and
secondary CTD sensors were noisy and spiky.

08902 - Bottle 24 not sealed upon recovery due to collision with top
bar. Lowered bottle 24 1/4” after sampling.

May 31, 2022

09001 - No issues noted.

09101 - No issues noted.

09201 - Bio cast. Dark cast. No issues noted.

09202 - No issues noted.

June 1, 2022

09301 - SBE43 noisy at depths exceeding 800 m. Changed SBE43 out when
recovered.

09401 - Bottle 19 lanyard caught in top of bottle 20. Remade lanyard.
Biofouling on bottles 10 - 13. New SBE43 still noisy at depth.

09501 - Bio cast. No issues noted.

09502 - SBE43 noisy at depths exceeding 800 m. Changed SBE43 cable out
when recovered.

09601 - No issues noted.

June 2, 2022

09701 - No issues noted.

09801 - Bio cast. Significant noise in CTD primary and secondary
sensors at soak depth.

09802 - Bottle 16 came up warm (8 degrees warmer than it should have),
suggesting mistrip. Raised bottle 16 and 17 to ensure bottle 16 closed
and did not get caught in lanyard of 17.

09901 - No issues noted.

June 3, 2022

10001 - No issues noted.

10101 - Bio cast. No issues noted.

10102 - SBE43 noisy after 800 m during downcast.

10201 - Bottle 30 accidently skipped, with bottle 31 fired at 30’s
intended depth.

June 4, 2022

10301 - No issues noted.

10401 - Bio cast. Offsets in primary and secondary CTD sensors became
very spiky at 500 m during upcast. Adjusted secondary pump height upon
recovery.

10402 - Adjusted heights and orientations on bottles 1, 4, 20.
Adjusted guide rings on 1, 31, and 33.

10501 - SBE43 is less noisy than rest of cruise.

10601 - No issues noted.

June 5, 2022

10701 - Bio cast. Added additional hoseclamp to primary pump tubing.

10702 - No issues noted.

10801 - No issues noted.

10901 - Bottle 19 lanyard caught in top of bottle 20. Remade lanyard
and adjusted rest of lanyard to ensure lanyard angled toward 18 when
fired, rather than 20. Many spikes in T and S sensor offsets in upper
120 m due to considerable ship heave.

No issues noted.

11001 - Bio cast. No issues noted.

11002 - No issues noted.

11101 - No issues noted.

11201 - No issues noted.

June 7, 2022

11301 - Bio cast. Dark cast. No issues noted.

11302 - No issues noted.

11401 - Bottle 13 leaking from bottom during sampling on deck. Changed
o-ring.

11501 - Bottle 19 lanyard caught in top of bottle 20. Remade lanyard
and further adjusted bottle 19 by lowering to original height.

11601 - Bio cast. No issues noted.

June 8, 2022

11602 - No issues noted.

11701 - No issues noted.


Sensor Problems
---------------

*T,C offsets*: During 20 m soak, sensor offsets in primary and
secondary lines (T2 - T1, C2 - C1) were noisy or spiky following
station 32. This was occasionally exacerbated by ship heave within a
steep density gradient.

*SBE43*: SBE43 O_2 was consistently noisy at depths of 800 m or
greater on downcasts and upcasts following station 32. This improved
around station 104, where the height of the secondary pump was
lowered.


CTDO and Hydrographic Analysis
==============================

PIs
   * Todd Martz (SIO)

   * Susan Becker (SIO)

Technicians
   * Aaron Mau (SIO)


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 10. SBE
SeaSave7 v.7.26.7.121 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 a CTD cast
log for each attempted cast containing a description of each
deployment event and any problems encountered.

Once the deck watch had deployed the rosette, the winch operator would
lower it to 20 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 instructed the winch operator to
bring the package to the surface in good weather or no more than 5
meters in high seas. The winch was then instructed to lower the
package to the initial target wire-out at no more than 60 m/min after
100 m depending on depth, 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 was directed to slow decent rate to 30 m/min 100 m
from the bottom, and 20 m/min 50 m 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 full upcast, the winch operator was
directed to stop the winch at up to 36 predetermined sampling
pressures. During upcasts specific to bio sampling, the winch operator
was directed to stop at up to 21 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 had shed its wake. 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
recorded the depths bottles were tripped and correspondence between
rosette bottles and analytical samples drawn.

The CTD sensors were rinsed after every cast using syringes of fresh
water connected to Tygon tubing. The tubing was left on the CTD
between casts, with the temperature and conductivity sensors immersed
in fresh 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.


CTDO Data Processing
--------------------

Shipboard CTD data processing was performed after deployment using
SIO/ODF CTD processing software “ctdcal” v. 0.1.3b. CTD acquisition
data were copied onto a OS X system, and then processed. CTD data at
bottle trips were extracted, and a 2-decibar downcast 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 117 CTD stations were occupied including one test station.
A total of 148 CTDO/rosette/LADCP/UVP/chipod casts were completed.

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
conductivity and oxygen sensor calibrations.

Temperature, salinity and, dissolved O_2 comparisons were made between
down and upcasts 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 P02W-2022 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.


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 lab calibration coefficients provided on the calibration report
were used to convert frequencies to pressure. Initial 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
cast.

CTD #1281:

+-----------------------------------+-----------------------------------+-----------------------------------+
|                                   | Start P (dbar)                    | End P (dbar)                      |
|===================================|===================================|===================================|
| Min                               | -0.16                             | -0.46                             |
+-----------------------------------+-----------------------------------+-----------------------------------+
| Max                               | 0.23                              | 0.13                              |
+-----------------------------------+-----------------------------------+-----------------------------------+
| Average                           | -0.04                             | -0.28                             |
+-----------------------------------+-----------------------------------+-----------------------------------+

On-deck pressure reading varied from -0.16 to 0.23 dbar before the
casts, and -0.46 to 0.13 dbar after the casts. The pressure offset
varied from -0.30 to 0.10, with a mean value of -0.24 dbar.


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 systematic 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 13 samples, approximately 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 and second-order with respect to temperature:

   T_{cor} = T + cp_2 P^2 + cp_1 P + ct_2 T^2 + ct_1 T + c_0

Fit coefficients are shown in the following tables.


Primary temperature (T1) coefficients.
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

+------------------+------------------+------------------+------------------+------------------+------------------+
| Station          | cp_2             | cp_1             | ct_2             | ct_1             | c_0              |
|==================|==================|==================|==================|==================|==================|
| 1-8              | 0.0              | -2.5655e-7       | 0.0              | 0.0              | 1.4204e-4        |
+------------------+------------------+------------------+------------------+------------------+------------------+
| 9-40             | 0.0              | -1.7576e-7       | 0.0              | 0.0              | 2.8372e-5        |
+------------------+------------------+------------------+------------------+------------------+------------------+
| 41-117           | -0.0             | -9.2544e-9       | 0.0              | 0.0              | 4.9377e-4        |
+------------------+------------------+------------------+------------------+------------------+------------------+


Secondary temperature (T2) coefficients.
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

+------------------+------------------+------------------+------------------+------------------+------------------+
| Station          | cp_2             | cp_1             | ct_2             | ct_1             | c_0              |
|==================|==================|==================|==================|==================|==================|
| 1-8              | 0.0              | -2.2795e-8       | 0.0              | 0.0              | -2.9018e-4       |
+------------------+------------------+------------------+------------------+------------------+------------------+
| 9-41             | 0.0              | -4.2754e-7       | 0.0              | 0.0              | 2.217e-4         |
+------------------+------------------+------------------+------------------+------------------+------------------+
| 42-117           | -1.4293e-11      | 2.0618e-7        | 0.0              | 0.0              | -7.9777e-6       |
+------------------+------------------+------------------+------------------+------------------+------------------+

Corrected temperature differences are shown in the following figures.

   [image]SBE35RT-T1 versus station.

   [image]Deep SBE35RT-T1 by station (Pressure \geq 2000dbar).

   [image]SBE35RT-T2 versus station.

   [image]Deep SBE35RT-T2 by station (Pressure \geq 2000dbar).

   [image]T1-T2 versus station.

   [image]Deep T1-T2 versus station (Pressure \geq 2000dbar).

   [image]SBE35RT-T1 versus pressure.

   [image]SBE35RT-T2 versus pressure.

   [image]T1-T2 versus pressure.

The 95% confidence limits for the mean low-gradient (values -0.002 °C
\leq T1-T2 \leq 0.002 °C) differences are ±0.00521 °C for SBE35RT-T1,
±0.00530 °C for SBE35RT-T2 and ±0.00129 °C for T1-T2. The 95%
confidence limits for the deep temperature residuals (where pressure
\geq 2000 dbar) are ±0.00062 °C for SBE35RT-T1, ±0.00072 °C for
SBE35RT-T2 and ±0.00067 °C for T1-T2.

Problems arose during the P02W-2022 cruise, prompting CTD temperature
sensors (SBE3) to be exchanged.
   * While deploying during station 9, cables to the deck box were
     loose. This was misdiagnosed as a sensor problem and was deployed
     without a secondary sensor on cast 4.

   * Differences in primary and secondary SBE3 were abnormally large
     during the pre-cast soak following station 32 and the sensors
     were exchanged during stations 40 and 41 to troubleshoot.

Minor complications impacted the reference temperature sensor (SBE35)
data.
   * Internal memory overflowed following station 9 and data was not
     captured during stations 10 and 11.

   * During casts designated for bio, many bottles were fired at the
     surface and sometimes were too fast (< 15 seconds) for a reading.

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


Conductivity Analysis
---------------------

Laboratory calibrations of conductivity sensors were performed prior
to the cruise at the Sea-Bird 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
shipboard 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 figures.

   [image]Coherence of conductivity differences as a function of
   temperature differences.

   [image]Corrected C_Bottle - C1 versus station.

   [image]Deep Corrected C_Bottle - C1 versus station (Pressure >=
   2000dbar).

   [image]Corrected C_Bottle - C2 versus station.

   [image]Deep Corrected C_Bottle - C2 versus station (Pressure >=
   2000dbar).

   [image]Corrected C1-C2 versus station.

   [image]Deep Corrected C1-C2 versus station (Pressure >= 2000dbar).

   [image]Corrected C_Bottle - C1 versus pressure.

   [image]Corrected C_Bottle - C2 versus pressure.

   [image]Corrected C1-C2 versus pressure.

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, and second-
order with respect to conductivity:

   C_{cor} = C + cp_2 P^2 + cp_1 P + ct_2 T^2 + ct_1 T + cc_2 C^2 +
   cc_1 C + \text{Offset}

Fit coefficients are shown in the following tables.


Primary conductivity (C1) coefficients.
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

+--------------+--------------+--------------+--------------+--------------+--------------+--------------+--------------+
| Station      | cp_2         | cp_1         | ct_2         | ct_1         | cc_2         | cc_1         | c_0          |
|==============|==============|==============|==============|==============|==============|==============|==============|
| 1-117        | 0.0          | 4.3091e-8    | 0.0          | 0.0          | 0.0          | 0.0          | -1.6721e-3   |
+--------------+--------------+--------------+--------------+--------------+--------------+--------------+--------------+


Secondary conductivity (C2) coefficients.
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

+--------------+--------------+--------------+--------------+--------------+--------------+--------------+--------------+
| Station      | cp_2         | cp_1         | ct_2         | ct_1         | cc_2         | cc_1         | c_0          |
|==============|==============|==============|==============|==============|==============|==============|==============|
| 1-117        | 0.0          | -2.3585e-7   | 0.0          | 0.0          | 0.0          | 0.0          | 4.6397e-3    |
+--------------+--------------+--------------+--------------+--------------+--------------+--------------+--------------+

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.

   [image]Salinity residuals versus station.

   [image]Deep Salinity residuals versus station (Pressure >=
   2000dbar).

   [image]Salinity residuals versus pressure.

The 95% confidence limits for the mean low-gradient (values -0.002 °C
\leq T1-T2 \leq 0.002 °C) differences are ±0.00521 °C for SBE35RT-T1,
±0.00530 °C for SBE35RT-T2 and ±0.00129 °C for T1-T2.

The 95% confidence limits for the mean low-gradient (values -0.002 ºC
\leq T1-T2 \leq 0.002 ºC) differences are ±0.00834 mPSU for salinity-
C1SAL, ±0.00659 mPSU for salinity-C2SAL and ±0.00358 mPSU for C1SAL-
C2SAL. The 95% confidence limits for the deep salinity residuals
(where pressure \geq 2000 dbar) are ±0.00225 mPSU for salinity-C1SAL,
±0.00179 mPSU for salinity-C2SAL and ±0.00178 mPSU for C1SAL-C2SAL.

Minimal issues affected conductivity and calculated CTD salinities
during this cruise.
   * Bottle stops in halocline may have had insufficient stop time
     during some casts, leading to low-biased measurements.

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


CTD Dissolved Oxygen (SBE43)
----------------------------

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. Corrections for hysteresis are applied following Sea-Bird
Application Note 64-3. The SBE43 sensor data were compared to
dissolved O_2 check samples taken at bottle stops by matching the
downcast CTD data to the upcast 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 PMEL DO sensor
response model coefficients using the BFGS non-linear least-squares
fitting procedure.

The general form of the PMEL DO sensor response model equation for
Clark cells follows Brown and Morrison [Mill82] and Owens [Owen85].
Dissolved O_2 concentration is then calculated:

   O_2 = S_{oc} \cdot (V + V_{\textrm{off}} + \tau_{20} \cdot e^{(D_1
   \cdot p + D_2 \cdot (T - 20))} \cdot dV/dt) \cdot O_{sat} \cdot
   e^{T_{cor} \cdot T} \cdot e^{[(E \cdot p) / (273.15 + T)]}

Where:

* V is oxygen voltage (V)

* D_1 and D_2 are (fixed) SBE calibration coefficients

* T is corrected CTD temperature (°C)

* p is corrected CTD pressure (dbar)

* dV/dt is the time-derivative of voltage (V/s)

* O_sat is oxygen saturation

* S_oc, V_off, \tau_20, T_cor, and E are fit coefficients

All stations were fit together to get an initial coefficient estimate.
Stations were then fit individually to refine the coefficients as the
membrane does not deform the same way with each cast. If the fit of
the individual cast had worse resdiuals than the group, they were
reverted to the original group fit coefficients.


SBE43 group fit coefficients. Coefficients were further refined station-by-station.
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

+------------------+------------------+------------------+------------------+------------------+------------------+
| Station          | S _oc            | V _off           | tau _20          | T _cor           | E                |
|==================|==================|==================|==================|==================|==================|
| 1-117            | 4.5239e-1        | -4.4878e-1       | 1.2000e+0        | 2.9469e-3        | 3.9203e-2        |
+------------------+------------------+------------------+------------------+------------------+------------------+

CTD dissolved O_2 residuals are shown in the following figures O2
residuals versus station. through Deep O2 residuals versus station
(Pressure >= 2000dbar)..

   [image]O_2 residuals versus station.

   [image]Deep O_2 residuals versus station (Pressure >= 2000dbar).

   [image]O_2 residuals versus pressure.

The 95% confidence limits of 1.67 (µmol/kg) for all acceptable (flag
2) dissolved oxygen bottle data values and 1.34 (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.

Issues arose with the acquisition and processing of CTD dissolved
oxygen data.
   * SBE43 data appeared noisy at depths exceeding 800 m following a
     biofouling event during station 32. Sensors were replaced at
     stations 32 and 94 in an attempt to alleviate the noise, which
     gradually dissapated by station 101.


CTD Dissolved Oxygen (RINKO)
----------------------------

A two-point calibration was performed prior and after deployment on
the rosette. These calibrations produced 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 90 stations. 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. Zero point calibrations also followed general
manufacturer recommendations, using a sodium sulfite solution (25g in
500mL deionized water). Dissolved oxygen raw voltage (DOout),
atmospheric pressure, and solution temperature were recorded for
calculation of new oxygen sensor coefficients (G and H).

Rinko temperature (factory coefficients) was used for pre-cruise
calibration. 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. RinkoIII data used as
primary oxygen for all stations (1-117), excluding stations 10-12 when
the RINKO cable needed to be changed.

RINKO data was acquired, converted from volts to oxygen saturation,
and then multipled by the oxygen solubility to find values in µmol/kg.
The resulting data were then fitted using the equations developed by
[Uchida08]:

   [O_2] = (V_0 / V_c - 1) / K_{sv}

   K_{sv} = c_0 + c_1 T + c_2 T^2, \hspace{6pt} V_0 = 1 + d_0 T,
   \hspace{6pt} V_c = d_1 + d_2 V_r

where:

* T is temperature (ºC)

* V_r is raw voltage (V)

* V_0 is voltage at zero O_2 (V)

* c_0, c_1, c_2, d_0, d_1, d_2 are calibration coefficients

Oxygen is further corrected for pressure effects:

   [O_2]_c = [O_2] (1 + c_p P / 1000) ^ {1/3}

where:

* P is pressure (dbar)

* c_p is pressure compensation coefficient

Lastly, salinity corrections are applied [GarciaGordon1992]:

   [O_2]_{sc} = [O_2]_c \exp[{S (B_0 + B_1 T_S + B_2 T_S^2 + B_3
   T_S^3) + C_0 S^2}]

where:

* T_S is scaled temperature (T_S = ln[(298.15 – T)/(273.15 + T)])

* B_0, B_1, B_2, B_3, C_0 are solubility coefficients

All stations excluding 10-12 were fit together to get an initial
coefficient estimate. Stations were then fit in groups of similar
profiles to get a further refined estimate. Individual casts were then
fit to remove the noticeable time drift in coefficients If the fit of
the individual cast had worse resdiuals than the group, they were
reverted to the original group fit coefficients.


Rinko group fit coefficients. Coefficients were further refined station-by-station.
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

+--------------+--------------+--------------+--------------+--------------+--------------+--------------+--------------+
| Station      | c_0          | c_1          | c_2          | d_0          | d_1          | d_2          | c_p          |
|==============|==============|==============|==============|==============|==============|==============|==============|
| 1-9          | 1.215e+0     | 1.5739e-2    | 8.2708e-5    | -1.5391e-3   | -9.9882e-2   | 3.1492e-1    | 8.507e-2     |
+--------------+--------------+--------------+--------------+--------------+--------------+--------------+--------------+
| 10-12        | -6.3699e+2   | 1.6180e+3    | 3.2984e+2    | -3.0743e+0   | -3.0791e-3   | -6.5677e-5   | 2.e-1        |
+--------------+--------------+--------------+--------------+--------------+--------------+--------------+--------------+
| 13-117       | 1.214e+0     | 1.8755e-2    | 4.1815e-5    | -6.8659e-5   | -9.1177e-2   | 3.2950e-1    | 8.6109e-2    |
+--------------+--------------+--------------+--------------+--------------+--------------+--------------+--------------+

CTD dissolved O_2 residuals are shown in the following figures.

   [image]O_2 residuals versus station.

   [image]Deep O_2 residuals versus station (Pressure >= 2000dbar).

   [image]O_2 residuals versus pressure.

The 95% confidence limits of 0.95 (µmol/kg) for all acceptable (flag
2) dissolved oxygen bottle data values and 0.58 (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.

Issues arose with the RINKO between stations 10-12. * During 10, the
RINKO upcast and downcast displayed abnormal voltages, prompting us to
exchange sensor serial 0296 for 0251. * During 11-12, the RINKO
voltage routinely spiked to 0. This was resolved by exchanging the
RINKO cable connecting it to the CTD. For these reasons, RINKO fit
coefficients during stations 10-12 are anomalous and SBE43 oxygen is
reported instead.


BIO Casts
---------

Throughout P02W-2022, 32 bio casts were taken prior to the full cast
for separate, large volumes of water for biological analyses. The
first bio cast was cast 1 at station 23. The last bio cast was cast 1
at station 116. Salinity and oxygen analyses were not performed during
these casts and therefore the CTD was not fit for those parameters.

   [image]CTD bottle values for temperature, salinity, oxygen, and
   fluorometer voltage plotted against CTD pressure across all bottle
   casts.

[Mill82] 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).

[Owen85] Owens, W. B. and Millard, R. C., Jr., “A new algorithm for
         CTD oxygen calibration,” Journ. of Am. Meteorological Soc.,
         15, p. 621 (1985).

[Uchida08] Uchida, H., Kawano, T., Kaneko, I., Fukasawa, M. “In Situ
           Calibration of Optode-Based Oxygen Sensors,” J. Atmos.
           Oceanic Technol., 2271-2281, (2008)

[GarciaGordon1992] García, H. E., and L. I. Gordon, 1992: Oxygen
                   solubility in sea- water: Better fitting equations.
                   Limnol. Oceanogr., 37, 1307– 1312.


Salinity
========

PIs
   * Todd Martz (SIO)

   * Susan Becker (SIO)

Technicians
   * John Calderwood (SIO)

   * Royhon Agostine (SIO)


Equipment and Techniques
------------------------

Two Guildline Autosals were on board and operational, SIO-owned 8400A
S/N 57-526 and 8400B S/N 69-180. S/N 57-526 was used for all salinity
measurements during this cruise. The salinity analysis was run in the
ship’s Climate Controlled Chamber, a refrigerator port and amidships
between the Computer Lab and Bioanalytical Lab. The chamber
temperature varied between about 21 and 25 degrees Celcius around 3
times each hour, with an average (based on measuring temperatures of
items in the chamber) of about 23°C.

IAPSO Standard Seawater Batch P-165 was used for all calibrations: K15
= 0.99986, salinity 34.994, expiration 2024-04-15. A LabView program
developed by Carl Mattson was used for monitoring temperatures,
logging data and prompting the operator. Salinity analyses were
performed after samples had equilibrated to laboratory temperature of
23°C, usually 8 hours or more after collection. Samples were placed
under fans to speed their acclimatization to the set room temperature.

The salinometer was standardized for each group of samples analyzed
(normally 1 or 2 casts, up to 72 samples) using two bottles of
standard seawater: one at the beginning and one at the end of each set
of measurements. For each calibration standard and sample reading, the
salinometer cell was initially flushed at least 2 times before a set
of conductivity ratio readings was recorded. Standardization
conductivity offsets did not exceed 0.00005 mS/cm for all casts.
Between runs the water from the last standard was left in the cell.


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 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 function of elapsed run time.
The corrected salinity data was then incorporated into the cruise
database.


Narrative
---------

3955 salinity samples were taken during P02W-2022, including 22
samples from test cast 00102. Due to ambient electrical noise, the
8400A Autosal was used over the 8400B Autosal for all samples and
practice. 8 samples were used for practice prior to arrival at the
test station and are not reported. One sample bottle (#2) was broken
and replaced during sampling, but the cast number was not recorded.
One sample bottle (#34) was broken and replaced during sampling of
cast 05701.

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


Nutrients
=========

Technicians
   * Susan Becker: Scripps Institution of Oceanography

   * Megan Roadman: Scripps Institution of Oceanography


Summary of Analysis
-------------------

* 3976 samples from 117 CTD stations

* The cruise started with new pump tubes and they were changed twice,
  before stations 039 and 082

* 6 sets of Primary/Secondary mixed standards and 3 sets of primary
  Nitrite standards were made up over the course of the cruise.

* The cadmium column efficiency was checked periodically and ranged
  between 85%-100%.


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
updated GO-SHIP repeat hydrography manual (Becker et al., 2019,
[Becker2019]).


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 520nm. 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 CuSO_4 + NH_4Cl 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.

NH_4Cl + CuSO_4 mix
   Dissolve 2g cupric sulfate in DIW, bring to 100 m1 volume (2%).
   Dissolve 250g ammonium chloride in DIW, bring to 1l liter volume.
   Add 5ml of 2% CuSO_4 solution to this NH_4Cl stock. This should
   last many months.


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.

**REAGENTS**

Ammonium Molybdate H_2SO_4 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 H_2SO_4. 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.


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
   H_2SO_4. (Dilute H_2SO_4 = 2.8ml conc H_2SO_4  or 6.4ml of H_2SO_4
   diluted for PO_4 moly per liter DW) (dissolve powder, then add
   H_2SO_4) 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.


Sampling
--------

Nutrient samples were drawn into 30 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 4 hours after sample collection, allowing sufficient time for
all samples to reach room temperature. The centrifuge tubes fit
directly onto the sampler.


Data Collection and Processing
------------------------------

Data collection and processing was done with the software provided
with the instrument from Seal Analytical (AACE). 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.


Standards and Glassware Calibration
-----------------------------------

Primary standards for silicate (Na_2SiF_6), nitrate (KNO_3), nitrite
(NaNO_2), and phosphate (KH_2PO_4) 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. 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 12-16 hours from a
secondary. Working standards were made up in low nutrient seawater
(LNSW). Multiple batches of LNSW were used on the cruise. The first
batch of LNSW was treated in the lab. The water was re-circulated for
~8 hours through a 0.2 micron filter, passed a UV lamp and through a
second 0.2 micron filter. 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  |
|     | (uM)  | (uM)  | (uM)  | (uM)  |
|=====|=======|=======|=======|=======|
| 0   | 0.0   | 0.0   | 0.0   | 0.0   |
+-----+-------+-------+-------+-------+
| 3   | 15.50 | 1.2   | 60    | 0.50  |
+-----+-------+-------+-------+-------+
| 5   | 31.00 | 2.4   | 120   | 1.00  |
+-----+-------+-------+-------+-------+
| 7   | 46.50 | 3.6   | 180   | 1.50  |
+-----+-------+-------+-------+-------+


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                     |
+-------+-----------------------------+

Reference materials for nutrients in seawater (RMNS) were used as a
check sample run with every station. The RMNS preparation,
verification, and suggested protocol for use of the material are
described by [Aoyama2006] [Aoyama2007], [Aoyama2008], Sato [Sato2010]
and Becker et al. [Becker2019]. RMNS batch CM was used on this cruise,
with each bottle being used for all runs in one day before being
discarded and a new one opened. Data are tabulated below.

+-----------+---------------+---------+---------------+
| Parameter | Concentration | stddev  | assigned conc |
|===========|===============|=========|===============|
| -         | (µmol/kg)     | -       | (µmol/kg)     |
+-----------+---------------+---------+---------------+
| NO_3      | 33.16         | 0.13    | 33.2          |
+-----------+---------------+---------+---------------+
| PO_4      | 2.38          | 0.01    | 2.38          |
+-----------+---------------+---------+---------------+
| Sil       | 100.4         | 0.61    | 100.5         |
+-----------+---------------+---------+---------------+
| NO_2      | 0.019         | 0.008   | 0.02          |
+-----------+---------------+---------+---------------+


Analytical Problems
-------------------

There were issues with carryover and sensitivity on the phosphate
channel early in the cruise that were resolved over time. Similar
problems with Silicate were encountered for the last few stations. The
values of the reference material and the were used to monitor data
quality. Adjustments based on the values obtained for the references
material were made as necessary. The adjusted data for affected
stations was compared to adjacent stations and historical data during
the final QC checks.

[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.

[Becker2019] Becker, S., Aoyama M., Woodward M., Baaker, K., Covery,
             S., Mahaffey, C., Tanhua, T., “GO-SHIP Repeat Hydrography
             Nutrient Manual, 2019: The Precise and accurate
             determination of dissololved inorganic nutrients in
             seawater;Continuos Flow Analysis methods.  Ocean Best
             Practices, August 2019.

[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).

[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.


Oxygen Analysis
===============

PIs
   * Susan Becker (SIO)

   * James Swift (SIO)

Technicians
   * Andrew Barna (SIO)

   * Elisa Aitoro (SIO)


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 (~0.012 N), and thiosulfate solution (~55 g/L).

Pre-made liquid potassium iodate standards and reagent/distilled water
blanks were run every day (approximately every 3-4 stations), with
samples analysed within 24 hours of the last standard.


Sampling and Data Processing
----------------------------

A total of 3975 oxygen measurements were made, all but one of which
were niskin samples. Niskin samples were collected soon after the
rosette was secured on deck, either from fresh niskins or immediately
following CFC sampling.

Nominal 125 mL volume-calibrated biological oxygen demand (BOD) flasks
were rinsed 3 times with minimal agitation using a silicone draw tube,
then filled and allowed to overflow for at least 3 flask volumes,
ensuring no bubbles remained. Pickling reagents MnCl2 and NaI/NaOH (1
mL of each) were added via bottle-top dispensers to fix samples before
stoppering. Flasks were shaken twice (10-12 inversions) to assure
thorough dispersion of the precipitate - once immediately after
drawing and then again after 30-60 minutes.

Sample draw temperatures, measured with an electronic resistance
temperature detector (RTD) embedded in the draw tube, were used to
calculate umol/kg concentrations, and as a diagnostic check of bottle
integrity.

Niskin samples were analysed within 2-12 hours of collection, and the
data incorporated into the cruise database. Underway samples were
analysed within 96 hours of collection.

Thiosulfate normalities were calculated for each standardisation and
corrected to 20°C. The 20°C thiosulfate normalities and blanks were
plotted versus time and were reviewed for possible problems, and were
subsequently determined to be stable enough that no smoothing was
required.


Volumetric Calibration
----------------------

Oxygen flask volumes were determined gravimetrically with degassed
deionised 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 10
mL Dosimat buret used to dispense standard iodate solution was
calibrated using the same method.


Standards
---------

Liquid potassium iodate standards were prepared in 6 L 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 oxidising and reducing
impurities prior to use.


Narrative
---------

The oxygen analytical rig was setup in the main lab of the Revelle. As
a result of wanting to conserve DI water while in port, only 1L
batches of all reagents were made until the ship was underway.

No major analytical issues were encountered. A few high end points
occurred and were corrected for. The analytical computer would freeze
occasionally, but never while doing analysis.

The thiosulfate stability was considered in 3 batches and showed
remarkable stability throughout the entire cruise. No trends were
observed or corrected for.

An OSIL standard was run against the usual ODF working standard using
a hand pipetter. The agreement between the OSIL and the ODF standard
was just within the daily tolerance.

No data updates are expected.

[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
                deter mination of dissolved oxygen in seawater,” Repor
                t WHPO 91-2, WOCE Hydrographic Programme Office (Aug
                1991).


Total Alkalinity
================

PIs
   * Andrew G. Dickson (SIO)

Technicians
   * Daniela Nestory (SIO)

   * Sara Gray (SIO)


Total Alkalinity
----------------

The total alkalinity of sea water 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 < 10E-4.5 at
25°C and zero ionic strength) over proton donors (acids with K >
10E-4.5) in 1 kilogram of sample.


Total Alkalinity Measurement System
-----------------------------------

*Sample Delivery System:*

Samples are dispensed using a Sample Delivery System (SDS) which has
been calibrated for volume in the lab prior to the cruise. Its volume
is confirmed immediately before use at sea to ensure a consistent
volume will be delivered for each sample. The SDS consists of a
volumetric pipette, various relay valves, an air pump, and is
controlled by a program in LabVIEW 2012.

Before attaching a sample bottle to the SDS, the volumetric pipette is
cleared of any residual solution. The pipette is then rinsed and
filled with the sample. The sample overflows and time is allowed 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. These temperature measurements, along with
the bottle salinity, are used to convert the sample volume to mass for
analysis.

Samples are delivered into a 250-mL water-jacketed open cell for
titration analysis. While one sample is undergoing titration, a second
sample is prepared with the SDS and equilibrated to 20°C for analysis.

*Open-Cell Titration:*

The total alkalinity is measured through an open-cell titration with a
dilute hydrochloric acid titrant of known concentration. A Metrohm 876
Dosimat Plus is used for all standardized hydrochloric acid additions.

An initial aliquot of approximately 2.3-2.4 mL of standardized
hydrochloric acid (~0.1M HCl in ~0.6M NaCl solution) is first
delivered and the sample is stirred for 5 minutes while air is bubbled
into at a rate of 200 scc/m to remove any liberated carbon dioxide
gas.

After equilibration, ~19 aliquots of 0.035 ml are added. Between the
pH range of 3.5 to 3.0, 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]).

A Thermo Scientific Isotemp water bath is connected to the water-
jacketed open cell to maintain a cell temperature of approximately
20oC. 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.


Sample Collection
-----------------

Alkalinity samples are drawn using silicone tubing connected to the
Niskin bottles and collected into 250 mL Pyrex bottles. The sample
bottles and Teflon-sleeved glass stoppers were rinsed at least twice
before the final filling. A headspace of approximately 3 mL was
removed and 0.05 mL of saturated mercuric chloride solution was added
to each sample for preservation. The samples were equilibrated prior
to analysis at approximately 20°C using a Thermo Scientific Isotemp
water bath.

Samples for total alkalinity were taken at all stations during A22
(1-90). Except for a few instances, alkalinity samples were collected
from each niskin where DIC and pH were collected, to over-characterize
the CO2 system. The typical sample scheme of full collection on even-
numbered stations (36 niskin bottles) and partial collection (~8-20
bottles) on odd-numbered stations was followed.

In order to evaluate the reproducibility of the alkalinity system,
duplicate samples (two separate alkalinity bottles) were collected at
a minimum of 10% of total samples. For instance, when all 36 niskins
were sampled, 3 duplicate samples were collected for alkalinity. When
alkalinity sampled a partial cast, one or two duplicate samples were
collected.


Problems and Troubleshooting
----------------------------

There were no major analytical issues encountered.

At a few points during the cruise, the electrode was changed due to
signs of aging. Any affected samples were re-analyzed for accurate
values.


Quality Control
---------------

Certified Reference Material (CRMs) and duplicate samples (two bottles
collected from one niskin) were used to quality check the functioning
of the total alkalinity system throughout the cruise.

Dickson laboratory Certified Reference Material (CRM) Batches 188, 199
and 200 were used to determine the accuracy of the total alkalinity
analyses. The total alkalinity certified value for these batches are:

* Batch 188: 2264.96 ± 0.73 µmol/kg

* Batch 199 2202.75 ± 0.70 µmol/kg

* Batch 200 2186.43 ± 0.42 µmol/kg

The cited uncertainties represent the standard deviation.

A CRM sample was analyzed at a minimum frequency of once per every 20
runs, but more often once per every 15 runs. Because total alkalinity
is not affected by gas-exchange, brand new CRM bottles were reserved
for pH and DIC analysis. These pre-opened bottles were subsequently
used for alkalinity analysis.

242 reference material samples were analyzed on P02W.

The average measured total alkalinity value for each batch is:

* Batch 188: 2265.58 ± 1.54 µmol kg-1 (n = 35; 19)

* Batch 199 2202.88 ± 1.33 µmol/kg (n = 135, 80)

* Batch 200 2186.20 ± 1.10 µmol/kg (n = 93, 48)

Figures in parentheses are the number of analyses made (total number
of analyses; number of separate bottles analyzed).

Duplicate samples were also used to check the reproducibility of the
system. The absolute value of the mean offset between duplicate
samples and the standard deviation are given below.

Mean duplicate sample offset: 0.96 ± 0.90 µmol kg-1 (n = 230)

3036 total alkalinity values were submitted for P02W.

Further dilution corrections need to be applied to this data back
onshore, therefore, this data is to be considered preliminary.


Discrete pH Analyses (Total Scale)
==================================

PI
   * Dr. Andrew Dickson (SIO)

Technicians
   * Albert Ortiz (RSMAS)

   * Brison Grey (RSMAS)


Sampling
--------

Samples were collected in 250 mL Pyrex glass bottles and sealed using
grey butyl rubber stoppers held in place by aluminum-crimped caps.
Each bottle was rinsed two times and allowed to overflow by one half
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 (HgCl_2). 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, duplicate samples were collected from all
stations for quality control purposes.


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 Fisher
Isotemp 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 during the spectrophotometric measurements. Purified
meta-cresol purple (mCP) was the indicator 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 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 salinity
analysis conducted on board.


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 two batches were
used during A22. The pHs of these batches were adjusted with 0.1 mol
kg^-1 solutions of HCl and NaOH (in 0.6 mol kg^-1 NaCl background) to
approximately 7.80, measured with a pH meter calibrated with NBS
buffers. The indicator was obtained from Dr. Robert Byrne at the
University of Southern Florida and was purified using the flash
chromatography technique described by Patsavas et al., 2013.
[Patsavas2013].


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:

   R = \frac{A_{578} - A_{\text{base}}}{A_{434} - A_{\text{base}}}

and

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

The change in R for a given change in A_{\text{iso}}, \Delta R/\Delta
A_{\text{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:

   \Delta R/\Delta A_{\text{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_{\text{iso}} (bR + a)


Problems and Troubleshooting
----------------------------

During the beginning of the cruise, the tungsten lamp in the
spectrophotometer was replaced due to aging.

Around station 50, the sample cell was broken due to stress on the
cell body. The


Standardization/Results
-----------------------

The precision of the data was assessed from measurements of duplicate
analyses, replicate analyses (two successive measurements on one
bottle), and certified reference material (CRM) Batch 200 (provided by
Dr. Andrew Dickson, UCSD). two or three duplicates and one or two
replicate measurements were performed on every station when at least
twenty-four Niskins were sampled. If less than twenty-four Niskins
were sampled, only one or two duplicates and one replicate measurement
were performed. CRMs were measured at the beginning and ending of each
day.

The precision statistics for P02W are:

+----------------------------+--------------------------+
| Duplicate precision        | ± 0.0008 (n= 258)        |
+----------------------------+--------------------------+
| B200                       | 7.7991 ± 0.0014 (n= 58)  |
+----------------------------+--------------------------+

3035 pH values were submitted for P02W. 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.

[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.


Dissolved Inorganic Carbon (DIC)
================================

PI’s
   * Richard A. Feely (NOAA/PMEL)

   * Rik Wanninkhof (NOAA/AOML)

Technicians
   * Dana Greeley (NOAA/PMEL)

   * Julian Herndon (NOAA/PMEL)


Sample Collection
-----------------

Samples for *DIC* measurements were drawn (according to procedures
outlined in the PICES Special Publication, Guide to Best Practices for
Ocean CO_2 Measurements [Dickson2007]) from Bullister style niskin
bottles into ~310ml borosilicate glass flasks using platinum-cured
silicone tubing. The flasks were rinsed once 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 6ml headspace and 0.12 ml of saturated HgCl_2 solution was
added as a preservative. The sample bottles were then sealed with
glass stoppers lightly covered with Apiezon-L grease. DIC samples were
collected from a variety of depths with approximately 10% of these
samples taken as duplicates.


Equipment
---------

The analysis was done by coulometry with two analytical systems (PMEL1
and PMEL2) used simultaneously on the cruise. Each system consisted of
a coulometer (5015O 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 ([Johnson1985], [Johnson1987],
[Johnson1993], [Johnson1992], [Johnson1999]). The two DICE systems
were set up in a seagoing container modified for use as a shipboard
laboratory on the aft main working deck of the *RV Roger Revelle*.


DIC Analysis
------------

In coulometric analysis of DIC, all carbonate species are converted to
CO_2 by addition of excess hydrogen ion (acid) to the seawater sample,
and the evolved CO_2 is swept into the titration cell of the
coulometer with CO_2 free dry 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
coulometric 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 CO_2 that enters the cell is determined by
integrating the total change during the titration.


DIC Calculation
---------------

The amount of CO_2 injected was calculated according to the 2007 PICES
Special Publication. Each DICE instrument has a modified SBE45
salinity sensor, but all DIC values were recalculated to a molar
weight (µmol \text{kg}^{-1}) using density obtained from the CTD’s
salinity.

The DIC values were corrected for dilution resulting from the addition
of 0.12 ml of saturated HgCl_2 used for sample preservation. The
correction factor used for this dilution is 1.000397. A correction was
also applied for the offset from the Certified Reference Material
(CRM). This additive correction was applied for each cell using the
value of the CRM obtained at the beginning of the cell. The coulometer
cell solution was replaced after 24-28 mg of carbon was titrated,
typically after 10-12 hours of continuous use. The blanks (background
noise per cell) ranged from 12-50.


Calibration, Accuracy, and Precision
------------------------------------

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

1. Gas loops were always run at the beginning and usually at the end
   of each cell;

2. CRM’s supplied by Dr. A. Dickson of SIO, were measured near the
   beginning; and

3. Duplicate samples were run throughout the life of the cell
   solution.

Each coulometer was calibrated by injecting aliquots of pure CO_2
(99.999%), as a standard, 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; and when time allowed at the end of each cell to ensure no
drift during the life of the cell.

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 have
been corrected to batches 188 and 199 CRM values. Batch 188 was used
for the first 23 stations and batch 199 for the next 84, followed by
batch 200 for the final 9 stations. The CRM certified value for batch
188 is 2099.26 µmol \text{kg}^{-1} and for 199 is 2021.66 µmol
\text{kg}^{-1} and for 200 is 2022.46 µmol \text{kg}^{-1}. The summary
table below (table 1) lists information for the CRMs.

The precision of the two DICE systems can be demonstrated via the
replicate samples. Approximately 10% 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 0.82 µmol
\text{kg}^{-1}; No systematic differences between the replicates were
observed (table 2).


Instrument Repairs
------------------

We almost made it through the entire leg without any major equipment
problems. Early on, we had some sticky tubing in some drain valves,
but nothing that impacted the end data… Until station 95. What looked
like a simple leaky fitting turned out to be a bit more problematic.
It seems the rinsing of the pipette on DICE 2 was not completely
draining during the first two initial rinses. Thus, the extra rinse
from the pipette was ending up in the gas stripper and the pipette
calibration was way off. This was intermittent on stations 95 and 97
on system 2 and thus not noticed during the CRM run. And of course,
the gas loop calibration was unaffected by this as well. However, once
the data were plotted up it became readily apparent a fix was needed.
By simply adjusting the drain time of the pipette rinse cycle, we
patched it up until we had a bit of time between stations and sample
analysis. Before station 100, it was determined that the tubing in
pinch valve 1 had formed a small crack at the valve and Pneumatic Gas
was escaping enough to change the pipette drain time. By replacing the
tubing that fixed the issue and we were back in normal operation. It
appears we may have lost 2 stations worth of data. Some of it may be
salvageable, but until a more thorough shore side examination can be
done the data from those two stations will be flagged questionable (3)
or bad (4).


Summary
-------

The overall performance of the analytical equipment was good during
the cruise. As is standard operating procedure, the pipette
calibrations will need to be repeated upon return to shore. Both
systems ran with slightly higher than normal background noise (blanks)
than we are used to seeing. It is believed this extra noise is due to
the new bow thruster the Revelle had installed during the mid-life
refit and the need for all thrusters (Z-drive included) to be
calibrated so they work as a team. This extra instrument noise is
apparent while on station but not while the ship is underway. Further
supporting this belief, we had no extra background noise in Seattle or
while tied up at the pier while in Guam. Even with this additional
background noise, the overall precision and accuracy and comparison to
the 2013 P02 data set leads us to believe the systems were not
compromised by this higher blank. Including the duplicates, over 3,300
samples were analyzed for dissolved inorganic carbon. Therefore, DIC
analyzed over 75% of the niskins made available to us. 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.

Calibration data during this cruise:

+-----------------+-----------+------+-----------+-----------+------+-----------+
| CRM Info        | PMEL1                        | PMEL2                        |
+-----------------+-----------+------+-----------+-----------+------+-----------+
| Batch - Cert.   | Ave       | N    | Std Dev   | Ave       | N    | Std Dev   |
|=================|===========|======|===========|===========|======|===========|
| 188 - 2099.26   | 2098.97   | 19   | 1.52      | 2097.68   | 21   | 2.01      |
+-----------------+-----------+------+-----------+-----------+------+-----------+
| 199 - 2021.66   | 2021.01   | 47   | 1.32      | 2020.31   | 45   | 1.35      |
+-----------------+-----------+------+-----------+-----------+------+-----------+
| 200 - 2022.46   | 2022.10   | 5    | 0.66      | 2022.50   | 5    | 0.87      |
+-----------------+-----------+------+-----------+-----------+------+-----------+

+----------+-------------------------------+------------------+------------+
| SYSTEM   | Average Gas Loop Cal Factor   | Pipette Volume   | Observed   |
|==========|===============================|==================|============|
| PMEL1    | 1.00547                       | 27.571 ml        | 0.77       |
+----------+-------------------------------+------------------+------------+
| PMEL2    | 1.00340                       | 26.363 ml        | 0.87       |
+----------+-------------------------------+------------------+------------+

[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.

[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.

[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


Dissolved Organic Carbon and Total Dissolved Nitrogen
=====================================================

PI
   * Dennis Hansell (U Miami)

Technician
   * Abby Tinari (U Miami)

Analysts
   * Lillian Custals

Support
   NSF


Project Goals
-------------

The goal of the DOM project is to evaluate dissolved organic carbon
(DOC) and total dissolved nitrogen (TDN) concentrations along the P02W
zonal transect.


Sampling
--------

DOC profiles were taken from approximately every two out of three
stations from 26 of 36 niskin bottles ranging the full depth of the
water column (80 of 117 stations; 2012 DOC/TDN samples). All samples
collected above 250 meters were filtered through an inline filter
holding a combusted GF/F filter attached directly to the niskin. This
was done to eliminate particles larger than 0.7 µm from the sample. To
reduce contamination by the filter or filter holder, a new filter and
holder was used for every station. All samples were rinsed 3 times
with about 5 mL of seawater and collected into combusted 40 mL glass
EPA vials. Samples were fixed with 100 µL of 4M Hydrochloric acid and
stored at room temperature on board. Samples were shipped back to
University of Miami for analysis via high temperature combustion on
Shimadzu TOC-V or TOC L analyzers.

Sample vials were prepared before the cruise by combustion at 450°C
for 12 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.

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.


Standard Operating Procedure for DOC analyses – Hansell Lab U Miami
-------------------------------------------------------------------

DOC samples will be analyzed via high temperature combustion using a
Shimadzu TOC-V or Shimadzu TOC-L at an inshore based laboratory at the
University of Miami. 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 pillow 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 CO_2 free gas. Three to five replicate 100 µL of sample are
injected into a combustion tube headed to 680°C. The resulting gas
stream is passed through several water and halide traps, including an
added magnesium perchlorate trap. The CO_2 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 at least three injections meet the specified
range of a SD of 0.1 area counts, CV \leq 2% or best 3 of 5
injections.

Extensive conditioning of the combustion tube with repeated injection
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) reference
waters and surface Sargasso Sea water every 6 – 8 analyses ([Hansell
1998]_). 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 the size of the run). Daily references waters
were calibrated with DOC CRM provided by D. Hansell (University of
Miami; ([Hansell 2005]_)).


DOC Calculation
~~~~~~~~~~~~~~~

   \mu\text{MC} = \frac{\text{average sample area} - \text{average
   machine blank area}}{\text{slope of std curve}}


Standard Operating Procedure for TDN analyses – Hansell Lab U Miami
-------------------------------------------------------------------

TDN samples were analyzed via high temperature combustion using
Shimadzu TOC-V with attached Shimadzu TNMI unit at an inshore based
laboratory at the University of Miami. 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 resuce alteration of
combustion matrix throughout the run. Carrier gas was produced with a
Whatman® gas generator ([Carlson2010]) and ozone was generated by the
TNMI unite at 0.5L/min flow rate. Three to five replicate 100 µL of
sample were injected at 130 mL/min flow rate into the combustion tube
headed 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 \leq 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 ever 6-8 analyses
([Hansell1998]). Daily references waters were calibrated with deep CRM
provided by D. Hansell (University of Miami; [Hansell2005])).


TDN calculation
~~~~~~~~~~~~~~~

   \mu\text{MN} = \frac{\text{average sample area} - \text{average
   machine blank area}}{\text{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.


Carbon Isotopes in Seawater (14/13C)
====================================

PI
   * Roberta Hansman (WHOI)

   * Rolf Sonnerup (UW)

Technician
   * Abby Tinari (U Miami)

A total of 544 samples were collected from stations collected along
the P02W transect. 32 samples (full casts) were taken from 15 of the
117 stations, 24 samples (bio casts) were taken from a separate 2 of
the 117 stations and 16 stations (partial casts) were taken from a
separate 1 of the 117 stations. Station spacing was closer (every 3
stations) towards the beginning of the transect then spread out to
every 8 stations in the middle of the transect. Station locations
followed previous P02 occupations. Samples were collected in 500 mL
airtight glass bottles. Using silicone tubing, the flasks were rinsed
3 times with seawater. 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 100 µL of saturate mercuric chloride
solution was added to the sample. To avoid contamination, 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 stored in AMS crates in the ship’s dry
laboratory. Samples were shipped to WHOI for analysis.

The radiocarbon/DIC content of the seawater (\delta^14C) is measured
by extracting the inorganic carbon as CO_2 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 ^14C using established
procedures modified for AMS applications. The ^13C/^12C of the CO_2
extracted from seawater is measured relative to the ^13C/^12C of a
CO_2 gas standard calibrated to the PDB standard using and isotope
radio mass spectrometer (IRMS) at NOSAMS.


CFC, SF_6, and N_2O
===================

PIs
   * Dong-Ha Min (UT)

Analysts
   * David Cooper (UT)

   * Carol Gonzalez (UT)

   * Sidney Wayne (UCSD)

Samples for the analyses of the dissolved chlorofluorocarbons (CFCs,
freons) F11 and F12, sulfur hexafluoride (SF_6) and nitrous oxide
(N_2O) were collected and analyzed during RR2204. Seawater samples
were taken from all casts, with full profiles generally taken from
alternating casts and strategically determined bottles sampled from
the remaining casts. These measurements are complemented by periodic
measurements of air samples.

Seawater samples were drawn from 10 liter Niskin bottles. Samples for
CFC and SF_6 were the first samples drawn, taking care to check the
integrity of the sample and coordinate the sampling analysts to
minimize any time between the initial opening of each bottle and the
completion of sample drawing. To minimize contact with air, the CFC
samples were drawn directly through the stopcocks of the Niskin
bottles into 250 ml precision glass syringes. Syringes were rinsed and
filled via three-way plastic stopcocks. The syringes were subsequently
held at 0-5 degrees C until 30 minutes before being analyzed. At that
time, the syringe was placed in a bath of surface seawater heated at
approximately 28 °C.

For atmospheric sampling, a ~90 m length of 3/8” OD Dekaron tubing was
run from the main lab to the bow of the ship. A flow of air was drawn
through this line into 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 backpressure regulator. A tee allowed a flow (100
ml min-1) of the compressed air to be directed to the gas sample valve
of the CFC analytical system, while the bulk flow of the air (>7 l
min-1) was vented through the backpressure regulator. Analysis of bow
air was performed at several locations along the cruise track.
Approximately five measurements were made at each location to increase
the precision. Atmospheric data were not submitted to the database,
but were found to be in excellent agreement with current global
databases.

Concentrations of CFC-1l, CFC-12, SF_6 and N_2O in air samples,
seawater samples and gas standards were measured by shipboard electron
capture gas chromatography (ECD-GC) using techniques described by
[Bullister2008]. This method has been modified with the addition of an
extra ECD to accommodate N_2O analysis. For seawater analyses, water
was transferred from a glass syringe to a glass sparging chamber (~200
ml). The dissolved gases in the seawater sample were extracted by
passing a supply of CFC-free purge gas through the sparging chamber
for a period of 6 minutes at 120 - 140 ml/min. Water vapor was removed
from the purge gas by passage through a Nafion drier, backed up by a
18 cm long, 3/8” diameter glass tube packed with the desiccant
magnesium perchlorate. This tube also contained a short length of
Ascarite to remove carbon dioxide, a potential interferent in N_2O
analysis. The sample gases were concentrated on a cold-trap consisting
of a 1/16” OD stainless steel tube with a ~5 cm section packed tightly
with Porapak Q (60-80 mesh), a 22 cm section packed with Carboxen 1004
and a 2.5 cm section packed with molecular sieve MS5A. A neslab
cryocool was used to cool the trap, to below -50°C. After 6 minutes of
purging, the trap was isolated, and it was heated electrically to
~150°C. The sample gases held in the trap were then injected onto a
precolumn (~60 cm of 1/8” O.D. stainless steel tubing packed with
80-100 mesh Porasil B, held at 80°C) for the initial separation of
CFC-12 and CFC-11 from later eluting peaks. After the F12 had passed
from the pre-column through the second pre-column (22 cm of 1/8” O.D.
Stainless steel tubing packed with Molecular Sieve 5A, 100/120 mesh)
and into the analytical column #1 (~170 cm of 1/8” OD stainless steel
tubing packed with MS5A and held at 80°C) the outflow from the first
precolumn was diverted to the second analytical column (~150 cm 1/8”
OD stainless steel tubing packed with Carbograph 1AC, 80-100 mesh,
held at 80°C). After F11 had passed through the first precolumn, the
flow was diverted to a third analytical column (1/8” stainless steel
tube with 30cm Molecular Sieve 5A, 60/80 mesh) for N_2O analysis. The
first pre-column was then backflushed and vented. The first two
analytical columns and precolumn 1 were held isothermal at 80 degrees
C in an Agilent (HP) 6890N gas chromatograph with two electron capture
detectors (250°C). The third analytical column and second pre-column
were held at 160C in a Shimadzu GC-8A gas chromatogram. The ECD in the
Shimadzu was held at 250°C.

The analytical system was calibrated using a blended standard gas
(seawater ratio, PMEL 464568), with available further reference to a
second atmospheric ratio standard. 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, precolumn, main chromatographic column,
and EC detector were similar to those used for analyzing water
samples. Four 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
seawater, air, standard or blank samples was ~12 minutes.
Concentrations of the CFCs in air, seawater samples, and gas standards
are reported relative to the SIO98 calibration scale (e.g.
[Bullister2010]). Concentrations in air and standard gas are reported
in units of mole fraction CFC in dry gas, and are typically in the
parts per trillion (ppt) range. Dissolved CFC concentrations are given
in units of picomoles per kilogram seawater (pmol 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 (PMEL cylinder 464568) into the analytical instrument. The
response of the detector to the range of moles of CFC passing through
the detector remained relatively constant during the cruise. Full-and
partial-range calibration curves were run several times during the
cruise. Single injections of a fixed volume of standard gas at one
atmosphere were run much more frequently (at intervals of ~90 minutes)
to monitor short-term changes in detector sensitivity.

The purging efficiency of the stripper was estimated by re-purging a
water sample in the upper concentration range and measuring the
residual signal. At a flow rate of 120 cc/min for 6 minutes, the
purging efficiency for SF_6 and F12 was greater than 99% and the
efficiency for F11 was about 99%. The purging efficiency for N_2O was
about 95%, but subject to some degree of variability due to changes in
flow rate and purging temperature. Although correction is made for
this variability, N_2O data from stations 1-22 were rather more
compromised than subsequent data.

Results of 3234 seawater samples are reported from 113 of the 117
stations, with stations 17-20 omitted due to system problems.
Duplicates were taken from 90 stations to estimate precision and
variability. Low-level samples were selected from deep samples and
higher level (surface) samples were mostly taken from the upper water
column. From the higher level samples, we calculate the average
deviation to be less than 1.0% from the mean of the pairs for F12, F11
and N_2O measurements, and 2.0% from the mean for SF_6 measurements.
Deviation from the mean of pairs from deeper samples averaged less
than 5% (or 0.01 pM) from the mean for F12 and F11 and approximately
10% for SF_6. Due to the exceedingly low levels of SF_6 present in
deeper water, accurate estimates of precision are not possible. A
small number of additional water samples had anomalous SF_6 or CFC
concentrations relative to adjacent samples. These samples occurred
sporadically during the cruise, were not clearly associated with other
features in the water column (e.g., anomalous dissolved oxygen,
salinity, or temperature features) and are omitted from the reported
data.

[Bullister2010] Bullister, J.L. and T. Tanhua. 2010. Sampling and
                Measurement of Chlorofluorocarbons and Sulfur
                Hexafluoride in Seawater. In: The GO-SHIP Repeat
                Hydrography Manual: A Collection of Expert Reports and
                Guidelines. IOCCP Report No. 14, ICPO Publication
                series No. 134, Version 1.

[Bullister2008] Bullister, J.L. and D.P. Wisegarver. 2008. The
                shipboard analysis of trace levels of sulfur
                hexafluoride, chlorofluorocarbon-11 and
                chlorofluorocarbon-12 in seawater. Deep-Sea Res. I, v.
                55, pp. 1063-1074.


LADCP
=====

PI
   * Dr. Andreas Thurnherr (LDEO)

Cruise Participant
   * Kurtis Anstey (University of Victoria)


Data Acquisition and QC
-----------------------

To collect full-depth profiles of horizontal and vertical ocean
velocities, two acoustic Doppler current profilers (ADCPs), one facing
upward (uplooker, UL) and the other downward (downlooker, DL), as well
as a DeepSea Power & Light rechargeable 48V battery and cables, were
installed on the conductivity, temperature, depth (CTD) system
rosette. The lowered ADCP (LADCP) system was provided by the Lamont-
Doherty Earth Observatory (LDEO). The LADCP system is self-contained,
requiring on-deck cable connections via a five-wire star-cable to
charge the battery and communicate. Each end of the star-cable had a
short extension cable attached to mitigate wear. The battery charger
was affixed to an elevated power box in the hanger, with an extension
power cable run into the wet lab to be plugged in near to the hanger
door. Installed on the bench were the LADCP data acquisition computer,
a Mac Mini, and a bench-top power supply for the ADCPs.

While cruising the LADCP system in the hanger was left connected to
the (unpowered) battery charger, as well as to two deck cables leading
to the data acquisition computer and the bench-top power supply. The
male plug of the (disconnected) adapter cable between the battery and
the LADCP star-cable was dummied. While the deck cables in the wet lab
were permanently connected to the acquisition computer with RS232-to-
USB adapters, the corresponding power supply was turned on and off
with a toggle adapter. With this setup there is no voltage to any of
the LADCP cables on the rosette.

A few minutes before rosette deployment, the battery was disconnected
from the charger and connected to the LADCP system via the extension
power / star-cable. The male plug of the battery charger cable was
dummied. To begin data acquisition, the instruments were woken up by
the acquisition computer by checking storage contents, data from the
previous cast deleted from the built-in memory cards, and the
instruments programmed to start pinging. The two deck cables were
disconnected from the two star-cable extensions. The deck cables and
star-cable extension connectors were dummied, and the latter secured
to the rosette frame with velcro straps to avoid excessive motion
during the cast. The CTD operator and/or res-tech were notified that
the LADCP system was ready for deployment. Deployment information was
recorded on LADCP log sheets, either when the data acquisition was
started or once the CTD system had entered the water.

Upon recovery, the velcro straps securing the dummied star-cable
extensions were removed, as well as the dummies, the cable ends rinsed
with fresh water, and the star-cable extensions connected to the deck
cables (also un-dummied). Using the acquisition computer, LADCP data
acquisition was stopped by initiating the data download. The bench top
power supply was activated, the LADCP battery disconnected from the
adapter cable on the rosette, the male end of the battery adapter
cable on the rosette with two exposed pins now carrying 48V (from the
bench-top power supplies) dummied, and the battery cable attached to
the (still unpowered) battery charger cable. Power was applied to the
battery charger via an accessible power toggle switch below the
charger, and the time noted on the LADCP log sheet.

After data from the cast had finished downloading (about 20 minutes
for deep casts), the bench top power supply was deactivated with the
bench power toggle switch. The new data files (one for each the UL and
DL) were roughly quality-checked by integrating the measured vertical
velocities in time, yielding estimates for the maximum depth (zmax)
and the end depth (zend) of the profile, and these values recorded on
the log sheet. Once the battery was fully charged (usually about an
hour after charging was initiated, as indicated by the charger LED
status) the charger was disconnected from power, and the time noted on
the log sheet. At this stage, the LADCP system was ready for the next
cast.

Communication between the acquisition computer and the LADCP system
was handled by Thurnherr’s custom acquisition software (acquire2),
implemented as a set of UNIX shell commands designed to minimize the
possibility of operator error. Primary commands are:

*Ldir*: Lists the status of the LADCP memory, including number of
files, file size, etc.

*Lstart*: Wakes the instruments, lists their memory contents, clears
the memory (after operator confirmation), and instructs the
instruments to begin pinging by uploading command files. CTD station
and cast number must be provided by the operator, as the LADCP files
use an independent numbering scheme.

*Ldownload*: Interrupts the running data acquisition, downloads data,
and backs up data files.

*Lcheck*: Integrates the measured vertical velocities from both the UL
and DL to estimate zmax and zend, which are displayed with other
useful profile statistics before data files are backed up, again.

*Lreset*: Resets the LADCP system after swapping instruments or in
case of communications issues.

After each cast, data were quality-checked with an initial processing
run of both horizontal and vertical velocities. CTD .cnv data were
obtained from the ship’s shared drive and processed into 1 and 6 Hz
formats. These were used with LADCP_w (vertical velocity) and LDEO_IX
(horizontal velocity) processing software to produce diagnostic logs,
figures, and post-processed data files. Additionally, LADCP data
quality was continuously monitored via horizontal velocity section
plots (Figure 1), useful for identifying large-scale data
inconsistencies. A written assessment, diagnostics, and figures were
sent to Thurnherr’s lab in Lamont via rsync. A more comprehensive
post-cruise data quality-check will be carried out by Thurnherr in his
lab before submission of the combined leg 1 and 2 data to the
archives.


Instrumentation
---------------

Two 300kHz Teledyne RDI Workhorse Monitor ADCPs (WHM300HZ) were used
at the beginning of the cruise, a primary/DL (S/N 3441) and
secondary/UL (S/N 150), working well. The secondary is synced to the
primary to follow a staggered ping rate of 1.3 and 1.6 seconds,
designed to mitigate acoustic reflection depth issues. The UL made use
of the Teledyne RDI WM15 surface-/bottom-tracking command, while the
DL did not, though the use of this command is arbitrary for the
purposes of bottom-tracking during this cruise. Data quality for the
duration of the cruise is generally good, with typically negligible
issues associated with the following events:

Upon recovery at station 029 the UL would not respond to the
*Ldownload* prompt. A full reset procedure – including software checks
(Lreset), complete cable reconfiguration, and a power assessment – was
conducted and it was determined that the issue was the UL, itself. The
instrument was replaced with a spare LADCP of the same model (S/N
754), after which system operations returned to normal. The entire
system configuration was refastened to the rosette, the battery reset
in its tray, and again tested positive for operation. UL data were
lost for this cast, and DL data appear to end deep during the upcast
(5530.2 m) but is otherwise fine according to initial quality checks.
The new UL and original DL were used for the duration of the cruise.

During the first half of the cruise, the battery was twice temporarily
removed during CTD troubleshooting, without issue (stations 009 and
028).

For some of the deepest casts (> 6000 m, stations 027, 031), the
seabed would be at the edge of the DL bottom-tracking range, causing
erroneous values for seabed depth when using Lcheck. Despite this, the
processing software could correctly determine seabed depth from the
data.

At station 046, the *Lstart* command was given with the deck and star-
cable extensions connected in a ‘crossed’ configuration, so that the
DL was detected as the UL, and vice versa, and the WM15 commands were
leading to a failed start. Before the cause was identified, the LADCP
WM15 commands were disabled for both instruments, and so the true UL
(which usually runs with WM15 enabled) was cast with WM15 disabled.
Upon recovery, inspection of the data revealed the cause, and the data
files were revised to reflect the correct DL and UL configuration. The
initial data quality-checks suggest that the data are fine.

In the second half of the cruise, the installed battery began to show
extended charging times and low voltage, particularly after combined
bio- and deep-casts. When it began to no longer reach ‘trickle-charge’
(~80%) between casts, it was deemed unusable and swapped for a spare
battery. Another spare was strapped to the deck near the rosette
staging area for emergency access. The replacement battery continued
to work optimally for the duration of the cruise. However, despite
reaching full charge consistently and quickly between casts, the
voltage of the replacement did appear to be slowly falling during the
last few stations.

A cabling adjustment before station 071 placed a bulk of coiled CTD
wire adjacent to the UL, potentially problematic for the ADCP’s
magnetic components, but does not appear to have affected data
quality.

Attempting to account for a lack of scatterers in the deep regions of
the latter half of the cruise, the command files for both the DL and
UL were adjusted (station 080) for larger depth bins (8 m changed to
10 m), less blanking distance (first bin changed to 4m), and lower
ambiguity velocity (4 m/s changed to 2.5 m/s). The introduction of
these adjustments may have led to the detection of cast intermittent
wake effects, manifesting as a region of poor vertical velocity data
around 3400 m, from the DL. After a further adjustment of the DL by
45° CCW (station 093), the issue was no longer detected, and profile
quality is good for the remainder of the cruise.


Preliminary results
-------------------

Though not yet fully QC’d or processed, the horizontal and vertical
velocity data show signs of expected mean currents (e.g. Kuroshio),
regional eddies, and low-frequency (likely near-inertial, based on
qualitative vertical wavelength), highly energetic internal waves near
slope, and over seamount, topography.

From vertical velocities, an estimate of vertical kinetic energy
(VKE), and therefore turbulent dissipation (\epsilon_VKE) can be made
for each station profile. However, as there are both DL and UL data
contributing to the vertical velocity profile, averaging to determine
\epsilon_VKE can be performed at different points in the process.
Determining VKE from the final combined DL and UL vertical velocity
profile results in ‘combination \epsilon_VKE’, while first determining
VKE from the individual DL and UL profiles and then combining the VKE
profiles results in ‘DL & UL \epsilon_VKE’. From the combined method,
dissipation appears to increase near the surface and topography
(Figure 2, upper), notably so near slopes and seamounts, exceeding
\text{10}^{-9} W \text{kg}^{-1} in some cases. Away from topography,
dissipation can recede to background values less than \text{10}^{-11}
W \text{kg}^{-1}. By comparison, the latter method results in
generally higher values of \epsilon_VKE (Figure 2, lower), with less
obvious features near topography and additional data gaps.
Statistically, these assumptions are confirmed (Figure 3) – the
combined method has a greater range of intensity, while the latter
method trends toward its mean, higher than that of the combined
method. The correlation between the two methods results is good, but
there is an obvious difference at an r-value of 0.82. Further analysis
will be required to decide which method is most appropriate.


Figures
-------

   [image]Figure 1. Zonal (upper) and meridional (lower) velocity
   sections for GO-SHIP P2 leg 1. Horizontal velocity data were
   smoothed for vertical scales < 50 m, to filter instrument noise,
   and are constrained by time- and GPS-synchronised CTD, SADCP, and
   bottom-tracking data by LDEO_IX software. Station profiles are
   shown as vertical dotted gray lines, zero-velocity contours as thin
   grey lines, and dot-dashed black lines are neutral density contours
   ([Jackett1997]), labelled right (units of kg \text{m}^{-3}).
   Interpolated data were blanked linearly between stations, near the
   seabed, with bathymetry determined from ETOPO1 global relief data
   ([NOAA2009]). There is evidence of regional mean currents, eddies,
   and internal wave activity near topography.

   [image]Figure 2. Section plots of combination \epsilon_VKE (upper)
   and DL & UL \epsilon_VKE (lower). Interpolated data were blanked
   linearly between stations, near the seabed, with bathymetry
   determined from ETOPO1 global relief data ([NOAA2009]). There is
   evidence of enhanced dissipation near the surface and topography.
   The averaging method in the upper panel better resolves these
   features.

   [image]Figure 3. Statistics for combination \epsilon_VKE and DL &
   UL \epsilon_VKE averaging methods. The former method has a greater
   range of intensities, while the later trends towards its greater
   mean. The two methods are correlated at r = 0.82.

[Jackett1997] Jackett, David R., Trevor J. McDougall, 1997: A Neutral
              Density Variable for the World’s Oceans. J. Phys.
              Oceanogr., 27, 237–263. doi:
              10.1175/1520-0485(1997)0272.0.CO;2

[NOAA2009] NOAA National Geophysical Data Center. 2009: ETOPO1 1 Arc-
           Minute Global Relief Model. NOAA National Centers for
           Environmental Information. Accessed May 25, 2022.


BIO GO-SHIP
===========

PIs
   * Adam Martiny (UCI)

Samplers
   * Adam Fagan (UCI)

   * Star Dressler (UOG)

   * Stephanie O’Daly (UAF)


Genetics
--------

Genetics samples were collected approximately at 0600, 1200, and 2000
local time from the uncontaminated underway seawater system and pre-
filtered (30 µm mesh) (88 stations). Samples were also collected using
the CTD at 5m, 100m, 200m, and 1000m (39 stations). If the CTD
collection coincided with one of the standard collection times, it
would take that slot, otherwise the CTD cast would be a fourth
collection period. In total, 285 samples were collected (129 with the
underway and 156 with the CTD). Up to 8L of seawater was collected
into a plastic cubitainer and filtered immediately after collection.
Water was filtered through a Sterivex 0.22 µm filter using a
peristaltic pump at a low speed. Once all water is pumped through the
Sterivex cartridge, one end is sealed with Crito-seal putty. 1620 µL
of sterile lysis buffer is pipetted into the filter cartridge and the
other end is sealed with a luer-lok cap. The filter is placed in a
separate Ziplok bag and preserved frozen at -80°C until shipment to
the Adam Martiny lab at UC Irvine for further analysis. Final
filtration volume was recorded for all samples. Gloves were worn
during all steps, and were also used by all samplers at the rosette.

Prior to the cruise, all silicone tubing, Omnifit caps and cubitainers
were cleaned in soapy water, 10% HCL, and Milli-Q water. Weekly, the
tubing and Omnifit caps were soaked in a 10% bleach solution over four
hours and rinsed with Milli-Q water. Between sample collections, the
tubing and sample container were rinsed 3x with Milli-Q water.


Particulate Organic Matter
--------------------------

Particulate organic matter (POM) samples were collected for
particulate organic carbon (POC), nitrogen (PON), phosphorous (POP)
and particulate chemical oxygen demand (PCOD). POM samples were
collected approximately at 0600, 1200, and 2000 local time from the
uncontaminated underway seawater system and pre-filtered (30 µm mesh)
(88 stations). Samples were also collected using the CTD at 5m (39
stations). In total, 1068 samples were collected (717 with the
underway and 351 with the CTD). If the CTD collection coincided with
one of the standard collection times, it would take that slot,
otherwise the CTD cast would be a fourth collection period. In total,
127 stations were sampled (underway and CTD). Each sample passed
through a GF/F filter (nominal pore size 0.7 µm). An aspirator pump
was used to pull water through the filters at a vacuum setting of
-0.06 to -0.08 MPa. Nine carboys were filled with 3-8L of water
(volume biomass-dependent) and designated as follows: 3x POP, 3x
POC/PON, 3x PCOD. POP filters were rinsed with 5mL of 0.017M Na_2SO_4
to remove traces of dissolved organic phosphorous at the end of
filtration. PCOD filters were rinsed with 5ml of Milli-Q water to
remove excess salt at the end of filtration. Filters were folded and
stored frozen at -80°C in pre-combusted foil squares.

All carboys were rinsed 3x with sample water before collection. GF/F
filters and foil squares were precombusted at 500°C for 4.5 hours.
Prior to the cruise, all silicone tubing, filter holders, and carboys
were cleaned in soapy water, 10% HCL, and Milli-Q water. All filters
will be shipped frozen and analyzed by the Martiny lab at UC Irvine.
Gloves were used for all steps mentioned above.


Small Volume Particulate Organic Carbon/Nitrogen
------------------------------------------------

Small volume particulate organic carbon/ nitrogen (POC/N) samples were
collected approximately at 0600, 1200, and 2000 local time from the
uncontaminated underway seawater system and pre-filtered (30 µm mesh)
(16 stations). Samples were also collected using the CTD ranging from
200m to 5m (8 stations). In total, 104 samples were collected (48 with
the underway and 56 with the CTD). If the CTD collection coincided
with one of the standard collection times, it would take that slot,
otherwise the CTD cast would be a fourth collection period. In total,
24 stations were sampled (underway and CTD).

Three samples of 0.5 - 2L of water were collected when using the
underway and six samples of approximately 2L with one replicate at a
random depth were collected using the CTD during a float deployment.
Samples were stored in a HPDE bottle rinsed 3x with DI and sample
water before being filtered onto 25mm GF/F filters using a vacuum pump
set at 100mmHg. 1L of sampled water is re-filtered onto a new GF/F to
create a blank for the underway. For CTD collection a wet blank is
created by stacking two filters, filtering 1L of filtered sample water
and using the bottom filter as a blank. Filters were folded and stored
frozen at -80°C in pre-combusted foil squares. Small volume POC/N were
collected to compare to POC/N samples described above in order to
compare across methods. Sample bottles and funnels were rinsed with DI
3x after each sample period.


HPLC Pigments
-------------

*HPLC* samples were collected approximately at 0600, 1200, and 2000
local time from the uncontaminated underway seawater system and pre-
filtered (30 µm mesh) (83 stations). Samples were also collected using
the CTD ranging from 200m to 5m (42 stations). In total, 259 samples
were collected (101 with the underway and 158 with the CTD). If the
CTD collection coincided with one of the standard collection times, it
would take that slot, otherwise the CTD cast would be a fourth
collection period. In total, 125 stations were sampled (underway and
CTD).

One to two samples were collected when using the underway and three to
six samples with one replicate at a random depth using the CTD
depending if there was a float deployment (three samples with no float
deployment). Samples were stored in a HPDE bottle rinsed 3x with DI
and sample water before being filtered onto 25mm GF/F filters using a
vacuum pump set at 100mmHg. Filters were folded twice and stored
frozen at -80°C in 1ml cryovials. Sample bottles and funnels were
rinsed with DI 3x after each sample period.

NASA requires 10% of samples to be duplicates, resulting in two sample
being taken, rather than one during underway sampling.


FCM
---

HPLC samples were collected approximately at 0600, 1200, and 2000
local time from the uncontaminated underway seawater system and pre-
filtered (30 µm mesh) (83 stations). Samples were also collected using
the CTD ranging from 1000m to 5m (42 stations). In total, 419 samples
were collected (83 with the underway and 336 with the CTD). If the CTD
collection coincided with one of the standard collection times, it
would take that slot, otherwise the CTD cast would be a fourth
collection period. In total, 125 stations were sampled (underway and
CTD).

Single samples were collected when using the underway and eight
samples at unique depths were collected using the CTD. Samples were
collected in a 50ml tinted falcon tube, with 1.8ml being extracted and
put into a 2ml cryovial. In a fumehood, 18 µL of a preservation
mixture (50/50 of 25% Glutaraldehyde and 2% Kolliphor) are added to
the sample. The sample is inverted several times and allowed to sit
for 10 minutes. After the 10 minutes the samples are flash frozen in
liquid nitrogen and finally stored in a -80°C freezer.


Underwater Vision Profiler 5 HD (UVP)
=====================================

PI
   * Andrew McDonnell (University of Alaska, Fairbanks)

Cruise Participant
   * Stephanie O’Daly (Lead, Ph.D. Student, University of Alaska,
     Fairbanks)

   * Kurtis Anstey (Secondary, M.S. Student University of Victoria)


System Configuration and Sampling
---------------------------------

The Underwater Vision Profiler 5 (UVP5) HD (High Definition) serial
number 201 was programmed, mounted on the rosette, and charged. This
instrument is owned by Emmanuel Boss at University of Maine. 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 [Picheral2010]. Depth
trigger mode was used throughout the entirety of the cruise,
programmed to turn on at 15 m with a maximum depth of 6000 m. A 20 m
soak for one minute was used throughout the cruise.


Problems
--------

On station 011 cast 01, the UVP voltage read 0 on deck after the CTD
was powered on. The voltage came up to a non-zero number when the
rosette hit the water, but it didn’t appear that the UVP turned on
during the one-minute soak at 20 meters. After the cast, corrosion was
found between the power shunt and the 1m power cable extension
indicating seawater intrusion. No data was collected on this cast.
Those parts were swapped out for spares and this problem did not occur
again. A reading of 0 volts on the deck indicates that a good seal has
not been made between the power shunt and the 1 m power cable
extension. If this is found again in the future the power shunt should
be inspected and replaced on the 1 m power cable extension.
Additionally, we started drying and greasing the power shunt before
application before every cast as instructed by the instrument
manufacturers. Cans of compressed air can be used to dry the shunt or
the ship’s air compressors.

Once we left the Japanese EEZ and Bio Casts started happening
separately from core casts we started having other issues with the
UVP. On station 026 cast 02 the UVP did not save all of the associated
metadata files that allow us to process the particle size
distributions. On station 027 cast 01 the UVP shut off at 1100m on the
downcast. Then on station 029 cast 02 the UVP did not save all of the
associated metadata files again. I believe these issues are due to the
limited charging time after the Bio Casts before the full casts. We
started dummying up the UVP for bio casts and only running it for the
full casts and these issues did not occur for the rest of the cruise.

The last and most consequential issue we ran into with the UVP on this
cruise occurred after station 057 cast 01. We were able to download
and delete the data from the UVP for this station, but when I tried to
perform a light test the UVP did not respond to any commands. I
swapped out all associated cabling for spares and the deck box for a
spare deck box and this did not establish good deck communication with
the UVP. After discussing with the manufacturers, we decided the issue
is likely a bad Sea Data bulkhead connector. I continued running the
UVP for every core cast and it appeared to turn on based on the CTD
voltage and by visual inspection of the lights at the surface for the
rest of the cruise. I was never able to establish communication with
the instrument again and therefore was not able to download data.
Based on my calculations there should be enough space on the internal
memory card for the rest of Leg 1 and Leg 2 of P02 if the particle
concentrations are similar to the first 57 stations. When the internal
memory card is full the instrument will not turn on anymore. The
instrument will be run until this occurs, if at all, on Leg 2. Then
the instrument will be sent to the manufacturers for maintenance who
will open the bulkhead and hopefully download the data from the
remaining stations.


General Particle Patterns
-------------------------

Near Japan, we see medium particle abundance overall with a surface
and subsurface particle abundance maximum. A deep nephloid layer is
not present and with there is a medium mean particle size increases
with depth (Fig. 1). In the Kuroshio current, we see low particle
abundance at the surface and subsurface with a very strong deep
nephloid layer (high particle abundance) reaching 500 m above the
seafloor (Fig. 2). Off the Japanese continental shelf, we see a strong
surface particle abundance maximum at around 100m with a large average
particle size and a subsurface particle maximum at around 400 m with
low average particle size, and low particle abundances down the
seafloor (Fig. 3). At the off-shelf stations, we see lower particle
abundances with moderate surface and subsurface particle abundance
maximum and no deep nephloid layer (Fig. 4).


Future Data Analysis
--------------------

Total image count gathered during the cruise from the first 57
stations was 585,700 images. A combination of machine learning and
manual validation will be used to sort images using the Ecotaxa
database. Images will be sorted into various zooplankton taxa and
detrital categories. Zooplankton categories will include crustacea
(including copepods and krill), gelatinous (larvacean, jellyfish,
salps), and rhizaria. Examples of these images are shown in Fig. 5.


Figures
-------

   [image]

Fig. 1:  Examples of preliminary profiles at station 4. Plots show
total large particulate matter (LPM) abundance, mean grey level
(brightness) of LPM, and equivalent spherical diameter (ESD) (right)
and particle concentration in size bins (left) both plotted against
depth (meters). Near Japan, we see medium particle abundance overall
with a surface and subsurface particle abundance maximum. A deep
nephloid layer is not present and with there is a medium mean particle
size increases with depth.

   [image]

Fig. 2:  Examples of preliminary profiles at station 10. Plots show
total large particulate matter (LPM) abundance, mean grey level
(brightness) of LPM, and equivalent spherical diameter (ESD) (right)
and particle concentration in size bins (left) both plotted against
depth (meters). In the Kuroshio current, we see low particle abundance
at the surface and subsurface with a very strong deep nephloid layer
(high particle abundance) reaching 500 m above the seafloor.

   [image]

Fig. 3:  Examples of preliminary profiles at station 20. Plots show
total large particulate matter (LPM) abundance, mean grey level
(brightness) of LPM, and equivalent spherical diameter (ESD) (right)
and particle concentration in size bins (left) both plotted against
depth (meters). Off the Japanese continental shelf, we see a strong
surface particle abundance maximum at around 100m with large average
particle size and a subsurface particle maximum at around 400 m with
low average particle size, and low particle abundances down the
seafloor.

   [image]

Fig. 4:  Examples of preliminary profiles at station 51. Plots show
total large particulate matter (LPM) abundance, mean grey level
(brightness) of LPM, and equivalent spherical diameter (ESD) (right)
and particle concentration in size bins (left) both plotted against
depth (meters). At the off-shelf stations, we see lower particle
abundances with moderate surface and subsurface particle abundance
maximum and no deep nephloid layer.

   [image]Fig. 5: 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.

[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.


Underway pCO_2
==============

PIs
   * Simone Alin (NOAA/PMEL)

Technicians
   * Julian Herndon (UW/NOAA/PMEL)

   * Andrew Collins (UW/NOAA/PMEL)

With assistance from Mr. Nick Benz (SIO-STS) to identify and clarify
the source of MET data supplied by the ship; Mr. Royhon Agostine (SIO-
STS) and Mr. Jake Pate (SIO-Revelle) to locate and identify the
various scientific seawater supply systems aboard.

The partial pressure of carbon dioxide (pCO_2) in the surface ocean
was measured throughout the cruise track of this cruise with a General
Oceanics 8050 pCO_2 Measuring System. Uncontaminated seawater was
continuously passed (~1.7-2.1 L/min) through a chamber where the
seawater concentration of dissolved CO_2 was equilibrated with an
overlaying headspace gas. The CO_2 mole fraction of this headspace gas
(xCO_2) was measured every two minutes via a non-dispersive infrared
analyzer (LiCor 7000) for 60 consecutive measurements. At the end of
these 60 discrete measurements, a set of five standard gases was
analyzed; four of these standards have known CO_2 concentrations
certified by the NOAA Earth Science Research Laboratory (ESRL) ranging
from ~300 to ~900 ppm CO_2 (see Table 1). The fifth standard is a tank
of 99.9995% ultra-high purity nitrogen gas, used as a baseline 0%
CO_2. Following the measurements of standard gases, six consecutive
measurements of atmospheric xCO_2 were made of air supplied through
tubing fastened to the ships forward jack staff. Twice a day, the
infrared analyzer was zeroed and spanned using the nitrogen gas and
the highest concentration CO_2 standard (911.41 ppm). In addition to
measurements of seawater xCO_2, atmospheric xCO_2, and standard gases,
other variables were monitored to evaluate system performance (e.g.
gas and water flow rates, pump speeds, equilibrator pressures, etc.).
For more detail on the general design and operation of this underway
pCO_2 system, see [Pierrot2009].

In coordination with Mr. John Ballard (ODF-SIO) and before departing
from Guam, the pCO_2 system received maintenance by Andrew Collins and
Julian Herndon. We replaced the Nafion tubes, replumbed the ATM and
EQU return lines (which were found to have been plumbed backwards),
replaced the vent flow meter and added a filter upstream of it to help
prolong its useful life, disassembled and cleaned the water flow meter
which was stuck due to corrosion and salt build up inside the impeller
housing. The run routine was adjusted as described above and all the
gas and water flows were adjusted. The standard gases onboard were
replaced with certified standards from ESRL; the existing standards
had been sourced from Praxair. The Resident Technicians onboard used
bleach to clean/sanitize the scientific seawater system after we
departed Guam and prior to the pCO_2 system being turned on. Model and
serial numbers for the pCO_2 instrument components and ancillary
instruments have been recorded in a separate Excel file and will
reported as part of the metadata that will accompany the
final/processed pCO_2 data submission. This pCO_2 system does not have
a Druck or other external barometer installed in the dry box to
measure the pressure in the LiCor cell. The primary equilibrator in
this pCO_2 system is an older, non-jacketed equilibrator built using a
clear plastic filter housing.


Notes on seawater source and data:
----------------------------------

The pCO_2 system on this cruise was installed in the Hydrolab. The R/V
*Revelle* has three separate but related sources of uncontaminated
underway seawater. The first (#1) is fairly typical of her AGOR-24
sister ships like the R/V *Brown* and the R/V *Thompson* with an
intake at the bow that feeds all the labs. The second (#2) is sourced
from the engine room sea-chest and is plumbed into the rest of the
ship via a “T” in the system in the Hydrolab. This system has a
baffle/diaphragm pump to supply intake water for biologists concerned
about damage to the organisms by the centrifugal pump used for system
#1. This (system #1) is the system that was used on this cruise. The
residence time of water in the engine room sea-chest is believed, by
the Chief Engineer, to be less than a minute given the large volume of
water taken from it to cool the engines. There is no antifouling
system installed in this engine room sea-chest. The third (#3) system
is an isolated/standalone flow-through at the bow, but separate from
#1 at the bow. System #3 has a TSG45 and SBE38, downstream and
upstream respectively, of the centrifugal pump. System #3 takes water
in at the bow thruster and dumps it out over the side a few feet away.
This was an installation done in drydock to get around the
modifications associated with installing the new bow thruster during
the mid-life refurbishment. The result is that the intake seawater
temperature for system #1 and #2 comes from the independent system #3.
Salinity can be sourced either from system #3 or a separate TSG45
installed in the Hydrolab that is fed by either system #1 or #2.
System #1 (bow intake) does NOT have its own intake temperature probe.
System #2 (engine room sea-chest) does NOT have an intake temperature
probe. The pCO_2 system in the Hydrolab received water from system #2,
intake temperature from system #3 and salinity data from the TSG45 in
the Hydrolab, which measured salinity (along with temperature) of the
source water from the sea-chest once it reached the Hydrolab. The
pCO_2 received water from a “T” before the sea-chest water was de-
bubbled and subsequently fed to the TSG45. To facilitate data
processing and future troubleshooting of the *Revelle* pCO_2 system,
the column headings for data in the pCO_2 files sourced from the ship
are identified in Table 2. Serial numbers and additional details for
the instruments in table #2 are in a separate Excel file and will be
reported as part of the metadata for pCO_2 data submitted for this
cruise.


Table 1: Standard gases for P02W 2022 cruise UW pCO_2 system.
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

+-----------------------------------+-----------------------------------+-----------------------------------+
| Standard                          | Concentration (ppm)               | Tank Serial Numbers               |
|===================================|===================================|===================================|
| 1                                 | 0.0                               | Praxair 5.0 Ultra High Purity N2  |
+-----------------------------------+-----------------------------------+-----------------------------------+
| 2                                 | 283.42                            | LL55868                           |
+-----------------------------------+-----------------------------------+-----------------------------------+
| 3                                 | 399.51                            | LL127199                          |
+-----------------------------------+-----------------------------------+-----------------------------------+
| 4                                 | 539.97                            | LL127204                          |
+-----------------------------------+-----------------------------------+-----------------------------------+
| 5                                 | 911.41                            | LL127176                          |
+-----------------------------------+-----------------------------------+-----------------------------------+


Table 2: pCO_2 system ship supplied data column headers for P02W 2022 cruise, Leg 1.  MWL = mean water level.
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

+---------------------------+---------------------------+---------------------------+---------------------------+
| Column Header             | Instrument                | System                    | Location                  |
|===========================|===========================|===========================|===========================|
| TSGF1                     | SW flow meter             | 3                         | Bow                       |
+---------------------------+---------------------------+---------------------------+---------------------------+
| TSGT2                     | TSG45 temperature         | 2 and 3                   | Hydrolab                  |
+---------------------------+---------------------------+---------------------------+---------------------------+
| TSGS2                     | TSG45 salinity            | 2 and 3                   | Hydrolab                  |
+---------------------------+---------------------------+---------------------------+---------------------------+
| TSGF2                     | SW flow meter to TSG45    | 2 and 3                   | Hydrolab                  |
+---------------------------+---------------------------+---------------------------+---------------------------+
| PCO2F                     | SW flow meter to pCO_2    | 2 and 3                   | Hydrolab                  |
+---------------------------+---------------------------+---------------------------+---------------------------+
| SST                       | SBE 38 temperature        | 3                         | Bow                       |
+---------------------------+---------------------------+---------------------------+---------------------------+
| AT                        | RM Young temperature      | MET                       | 56’ above MWL*            |
+---------------------------+---------------------------+---------------------------+---------------------------+
| BP                        | RM Young barometer        | MET                       | 56’ above MWL*            |
+---------------------------+---------------------------+---------------------------+---------------------------+
| HDG                       | Konsberg GPS              |                           |                           |
+---------------------------+---------------------------+---------------------------+---------------------------+
| SOG                       | Speed over ground         |                           |                           |
+---------------------------+---------------------------+---------------------------+---------------------------+

While the raw data is not reported here, it has been collected and
will be analyzed using MATLAB® routines developed by Dr. Denis Pierrot
of the Atlantic Oceanographic and Meteorological Lab in Miami, FL.
Measurements of gas standards were generally within 1% of their
certified value throughout the duration of the cruise. During Leg 1
there were two separate, short periods where the instrument was not
recording data. The first time was as a result of a Windows 10
initiated update that restarted the computer and the second was the
result of a loss of power due to a heavy load on the circuit used at
the time. In response, additional Windows updates were delayed until
after the date of arrival in Hawaii, where an update will be run
manually prior to Leg 2 to avoid a repeat situation. The power loss
has been addressed by changing the pCO_2 instrument power source to
the ship’s clean power supplied by the UPS in the Main Lab.

The data from the pCO_2 system that is included as part of the ships
data supplied by the onboard Resident Technicians to the Chief
Scientist is xCO_2 (not pCO_2) that has not been processed or
evaluated for QA/QC and as such should be considered preliminary.

[Pierrot2009] Pierrot, D., Neill, C., Sullivan, K., Castle, R.,
              Wanninkof, R.W., Lüger, H., Johannessen, T., Olsen, A.,
              Feely, R.A., Cosca, C.E.; 2009. Recommendations for
              autonomous underway pCO2 measuring systems and data-
              reduction routines. Deep-Sea Research II 56 (2009)
              512–522


Chipods
=======

PI
   * Jonathan Nash (OSU)


Overview
--------

Chipods are instrument packages that measure turbulence and mixing in
the ocean. Specifically, they are used to compute turbulent
diffusivity of heat (K) which is inferred from measuring dissipation
rate of temperature variance (\chi) from a shipboard CTD. Chipods are
self-contained, robust and record temperature and derivative signals
from FP07 thermistors at 100 Hz; they also record sensor motion at the
same sampling rate. Details of the measurement and our methods for
processing \chi can be found in [Moum_and_Nash2009]. In an effort to
expand our global coverage of deep ocean turbulence measurements, the
ocean mixing group at Oregon State University has supported chipod
measurements on all of the major global repeat hydrography cruises
since December 2013.


System Configuration and Sampling
---------------------------------

Three chipods were mounted on the rosette to measure temperature (T),
its time derivative (dT/dt), and x and z (horizontal and vertical)
accelerations at a sampling rate of 100 Hz. Two chipods were oriented
such that their sensors pointed upward. The third one was pointed
downward.

The up-looking sensors were positioned higher than the Niskin bottles
on the rosette in order to avoid measuring turbulence generated by
flow around the rosette and/or its wake while its profiling speed
oscillates as a result of swell-induced ship-heave. The down-looking
sensors were positioned as far from the frame as possible and as close
to the leading edge of the rosette during descent as possible to avoid
measuring turbulence generated by the rosette frame and lowered ADCP.

The chipods were turned on by connecting the sensors to the pressure
case at the beginning of the cruise. They continuously recorded data
until the end of the leg. Only one issue occurred with the chipods
following the recovery of cast 04201. The sensor tip (14-32) had
popped out of the holder and water had gotten inside. The tip and
holder were replaced (14-36) on recovery.

   [image]

Upward-looking chipod sensors attached to the rosette.

   [image]

Downward-looking chipod sensor attached to the rosette.

   [image]Highly sensitive temperature probe, which is sampled at
   100Hz.

+------------------+--------------------+-----------------+-------------------------+
| Logger Board SN  | Pressure Case SN   | Up/Down Looker  | Cast Used               |
|==================|====================|=================|=========================|
| 2013             | Ti 44-12           | Up              | 1-117                   |
+------------------+--------------------+-----------------+-------------------------+
| 2032             | Ti 44-15           | Up              | 1-117                   |
+------------------+--------------------+-----------------+-------------------------+
| 2014             | Ti 44-08           | Down            | 1-117                   |
+------------------+--------------------+-----------------+-------------------------+

[Moum_and_Nash2009] Moum, J., and J. Nash, Mixing Measurements on an
                    Equatorial Ocean Mooring, Journal of Atmospheric
                    and Oceanic Technology, 26(2), 317–336, 2009


Float Deployments
=================

A total of 10 *GO-BGC* Argo floats were deployed during the 2022 P02W
research cruise The GO-BGC floats measure temperature, salinity,
pressure, O_2, NO_3, pH, and bio-optics.


GO-BGC Argo Floats
------------------

PIs
   * Kenneth Johnson (MBARI)

   * Lynne Talley (UCSD/SIO)

   * Susan Wijffels (WHOI)

   * Curtis Deutsch (Princeton)

   * Steven Riser (UW)

   * Jorge Sarmiento (Princeton)

Shipboard personnel
   * Lauren Moseley (Columbia/LDEO)

   * Shuwen Tan (Columbia/LDEO)

10 biogeochemical (BGC) Argo floats were deployed on P02W as part of
the Global Ocean Biogeochemistry (GO-BGC) program (https://go-
bgc.org), which is funded by NSF Award OCE-1946578. GO-BGC contributes
to international and US BGC-Argo, and all floats conform to Argo
mission requirements. BGC-Argo floats will help to resolve seasonal
cycles of many key properties relevant to global biogeochemical
processes.

All floats deployed were UW-modified Teledyne Webb Apex floats
equipped with SBE41-CP CTDs, O_2, NO_3, pH, and FLBB bio-optical
sensors. The floats for the P02 cruise were provided by the UW float
lab (S. Riser Argo lab).

At sea, CTD watchstander Lauren Moseley and co-chief scientist Shuwen
Tan were in charge of deployments. Before each deployment, they
carefully cleaned the NO_3 and FLBB bio-optical sensors. Each sensor
was rinsed with DI water, wiped/dabbed with lens wipes, rinsed with DI
water again, then wiped/dabbed with lens paper. The floats were set to
self-activate, so sensor cleaning was the only pre-deployment
preparation required. Floats were deployed from the aft stern as the
ship steamed slowly away from the CTD station. Floats were lifted over
the stern, then carefully lowered into the water with a slip-line
strung through the deployment collar of the float. Deployments were
completed by Lauren Moseley (deployments #1 and #10), Shuwen Tan
(deployments #2 and #7), Sophie Shapiro (deployment #3), Mariana
Aguirre Nunes (deployments #4, #6, and #8), and Vic Dina (deployments
#5 and #9), with assistance from the ResTechs on watch (Royhon
Agostine and Josh Manger, SIO). All deployments were clean with no
tangling or hangups of the slip-line.

All floats operate on a standard Argo profiling 10-day cycle. After an
initial test dive, the floats descend to a parking depth of 1000 m,
and then drift for 10 days with the ocean currents. After 10 days, the
floats dive to 2000 m and then ascend to the surface, during which
data are measured and saved. The data are then sent to shore via
Iridium Satellite communication. All of the floats began reporting
data immediately and the sensors are operating well. All data is
publicly available via the GO-BGC data portals and the Argo GDAC.

All deployments occurred at “full” carbon stations so that all GO-SHIP
carbon parameters were analyzed for each depth sampled (34 depths from
surface to 10 m off bottom). Additionally, duplicate bottles were
tripped at the surface (~5 m) and at the depth of the chlorophyll
maximum to allow for the addition of *POC* and *HPLC* sampling at
these stations. POC and HPLC samples were collected and filtered by
the Bio team (Star Dressler and Adam Fagan) and will be sent frozen
for analysis at NASA for HPLC and SIO/UCSD for POC.

All floats were adopted by different schools and organizations in the
US as part of the Adopt-a-float program (https://www.go-
bgc.org/outreach/adopt-a-float). Names and images provided by the
adoptees were skillfully drawn onto the floats by P02W science and
crew party members. Each class received the details their deployment
via posts to the GO-BGC expeditions webpage by onshore personnel
George Matsumoto (MBARI). Together with their teachers, the students
will follow the float data, which can be easily downloaded and plotted
from the website.


Float deployments.
^^^^^^^^^^^^^^^^^^

+------------------+------------------+------------------+------------------+------------------+------------------+
| Deployment       | WMO              | Lat              | Lon              | Date and Time    | CTD Station      |
|                  |                  |                  |                  | (UTC)            |                  |
|==================|==================|==================|==================|==================|==================|
| 1                | 5906519          | 21.00            | 140.05           | 05/01/2022 23:25 | 1                |
+------------------+------------------+------------------+------------------+------------------+------------------+
| 2                | 5906513          | 26.67            | 136.68           | 05/03/2022 07:39 | 2                |
+------------------+------------------+------------------+------------------+------------------+------------------+
| 3                | 5906510          | 30.54            | 134.46           | 05/06/2022 20:12 | 11               |
+------------------+------------------+------------------+------------------+------------------+------------------+
| 4                | 5906511          | 30.00            | 138.37           | 05/08/2022 11:57 | 15               |
+------------------+------------------+------------------+------------------+------------------+------------------+
| 5                | 5906522          | 30.00            | 143.18           | 05/10/2022 07:06 | 23               |
+------------------+------------------+------------------+------------------+------------------+------------------+
| 6                | 5906518          | 30.00            | 151.25           | 05/14/2022 09:33 | 35               |
+------------------+------------------+------------------+------------------+------------------+------------------+
| 7                | 5906515          | 30.00            | 161.07           | 05/19/2022 08:43 | 50               |
+------------------+------------------+------------------+------------------+------------------+------------------+
| 8                | 5906512          | 30.00            | 169.72           | 05/24/2022 03:00 | 65               |
+------------------+------------------+------------------+------------------+------------------+------------------+
| 9                | 5906516          | 30.00            | 179.17           | 05/29/2022 08:53 | 83               |
+------------------+------------------+------------------+------------------+------------------+------------------+
| 10               | 5906521          | 30.00            | -170.45          | 06/03/2022 16:08 | 101              |
+------------------+------------------+------------------+------------------+------------------+------------------+


Student Statements
==================

U.S. GO-SHIP thanks all of the students who participated on the cruise
for their important contribution to collection of this essential
global ocean data set, used as the benchmark for accuracy of all other
deep ocean observing systems. The training opportunity for students
and leadership is an important part of US GO-SHIP’s mission. We are
committed to do so in a fair, cooperative and professional
environment, ensuring an inclusive, safe and productive climate at
sea. We thank the students for their honest reflections on their
experiences that are included in this section. We have reached out to
those who expressed concerns and are taking issues raised seriously,
by working to address and prevent these issues from occurring in the
future. We also thank them for their feedback in the anonymous post-
cruise survey, which we are using to continue to improve our program.
This will include ongoing education for all members of our community
to create a more inclusive environment.


Kurtis Anstey
-------------

As a soon-to-defend MSc student in ocean physics, I should have had
ample experience at sea, by this point. However, due to the
restrictions of pursuing a graduate degree during COVID, the research
cruises I was scheduled for were either cancelled or the roster
reduced to ‘essential’ – graduate students not included! This is fair,
but also very inconvenient when working towards a career in
observational physical oceanography. Leg 1 of line P-2, for GO-SHIP in
2022, offered me the experience I needed, and more. Much of my
research deals with velocity data obtained from acoustic Doppler
current profilers (ADCP), and up to this point I had only dealt with
the software and data. As the focus of my position onboard, I operated
and performed QC for the lowered ADCP instruments, of which there were
two attached to the rosette. Working directly with the instruments
provides an understanding that you just don’t get at your desk.
Additionally, I gained experience as the off-shift operator for the
Underwater Vision Profiler (UVP), and assisting with CTD watch
procedures, sampling, and deployment/recovery of the rosette. Not to
mention the immersion of eight weeks of ship-life, in general. The
scientists and crew were kind and incredibly helpful, and there was no
shortage of fun to be found between processing and casts. And the food
was ‘chef’s kiss’! The hands-on experience gained from this research
cruise more than makes up for the gap in my education, and I feel I
now have the practical knowledge to move confidently into a career in
physical oceanography.
