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CRUISE REPORT: I08S_2007
(Updated JUL 2017)



Highlights

A.1.                      Cruise Summary Information

          WOCE section designation  I08S_2007
Expedition designation (ExpoCodes)  33RR20070204
                   Chief Scientist  Dr. James H.  Swift / SIO
                Co-chief Scientist  Dr. Annie Wong
                             Dates  4 FEB 2007 - 17 MAR 2007
                              Ship  R/V Revelle
                     Ports of call  Dunedin, New Zealand - Fremantle, Australia
                          Stations  88
                                               28°19.1'S
     Station geographic boundaries  84°33.0'E             95°0.05'E
                                               65°48.6'S

      Floats and drifters deployed  14 ARGO Floats Deployed
    Moorings deployed or recovered  0

                             Chief Scientists:

                             Dr. James H. Swift
   University of California, San Diego • Scripps Institution of Oceanography
            9500 Gilman Drive, MS 0214 • La Jolla, CA • 92093-0214
             jswift@ucsd.edu • ph 858-534-3387 • fax 858-534-7383
                               Dr Annie Wong
              School of Oceanography • University of Washington
                    Campus Box 355351 • Seattle, WA 98195
     awong@ocean.washington.edu • ph:  1-206-543-5156 • fax: 1-206-685-3354
  



Summary 

A hydrographic survey consisting of LADCP/CTD/rosette sections, bio-
optical casts, trace metals rosette sections, underway shipboard ADCP, 
ﬂoat deployments in the southern Indian Ocean was carried out in 
February and March 2007.  The R/V Revelle departed Dunedin, New Zealand 
on 4 February 2007.  A total of 88 stations were occupied.  88 
LADCP/CTD/Rosette casts, 39 Trace Metals Rosette casts, 25 bio-optical 
casts were made, and 14 ARGO ﬂoats were deployed from 15 February to 14 
March.  Water samples (up to 36) and CTD data were collected on each 

LADCP/CTD/rosette cast in most cases to within 10-20 meters of the 
bottom.  Salinity, dissolved oxygen and nutrient samples were analyzed 
for up to 36 water samples from each cast of the principal 
LADCP/CTD/rosette program.  Water samples were also measured for Total 
DIC, Total Alkalinity, CFCs and CDOM, and samples were collected for 
DOC, POC, Helium/Tritium, and C13.  Underway surface pCO2, temperature, 
conductivity, dissolved oxygen, ﬂuorometer, meteorological and 
multibeam acoustical bathymetric measurements were made.  The cruise 
ended in Fremantle, Australia on 17 March 2007.  


OFFICERS AND CREW 

                    Name                Position
                    ------------------  --------------
                    David Murline       Captain
                    Paul Mauricio       Chief Engineer
      
                    Robert Widdrington  1st Mate
                    Joe Ferris          2nd Mate
                    Favi Lochananonda   3rd Mate
      
                    Jack Healy          1st A/E
                    Michael Breen       2nd A/E
                    Ernie Juhasz        3rd A/E
      
                    Dax McTaggert       Senior Cook
                    Paul Porcincula     Cook
      
                    James Pearson       Boatswain
                    Mark Johnson        Electrician
      
                    Shon Bowden         A/B
                    Gary Curry          A/B
                    George Kennedy      A/B
      
                    Sean Mix            Oiler
                    Andrew Carter       Oiler
                    Phil Hogan          Oiler
                    Matthew Slater      Oiler
      
                    Buddy Carron        Wiper
      
                    Joe Martino         OS


SCIENCE PROGRAMS AND SCIENCE TEAM LEADERS 

CTDO/rosette/S/O2/nutrients/data processing
  Jim Swift, UCSD/SIO  (jswift@ucsd.edu; ph 858-534-3387; fx 858-534-7383)

Transmissometer
  Wilf Gardner, Texas A&M U (wgardner@ocean.tamu.edu; ph 979-845-7211)

Resident Technician Group
  Woody Sutherland, UCSD/SIO (restech@sdsioa.ucsd.edu; ph 858-543-1632

Shipboard Computer Group
  Frank Delahoyde, UCSD/SIO (frank@odf.ucsd.edu; ph 858-534-2751)

CO2 (alkalinity)
  Andrew Dickson, UCSD/SIO (adickson@ucsd.edu; ph 858-534-2990)

CO2 (DIC and underway pCO2)
  Dick Feely, PMEL/NOAA (Richard.A.Feely@noaa.gov; ph 206-526-6214)
  Chris Sabine, PMEL/NOAA (Chris.Sabine@noaa.gov; ph 206-526-4809)

DOC/DON
  Dennis Hansell, U Miami RSMS (dhansell@rsmas.miami.edu; ph 

CDOM
  Dave Siegel, U California Santa Barbara (davey@icess.ucsb.edu, 805-893-4547)
  Norm Nelson, U California Santa Barbara (norm@icess.ucsb.edu, 805-893-3202)
  Craig Carlson, U California Santa Barbara (carlson@lifesci.ucsb.edu, 805-
  893-2541)

13C/14C
  Ann McNichol, WHOI  (amcnichol@whoi.edu; ph 508-289-3394; fx 508-457-2183)
  Robert Key, Princeton (key@Princeton.EDU)

CFCs
  Bill Smethie, LDEO (bsmeth@ldeo.columbia.edu; ph 845-365-8566)
  John Bullister, PMEL/NOAA (John.L.Bullister@noaa.gov; ph 206-526-6741)
  
He/Tr
  Peter Schlosser, LDEO (peters@ldeo.columbia.edu; ph 845-365-8816; fx 914-
  365-8155)

ADCP/LADCP
  Eric Firing, U Hawaii (efiring@soest.hawaii.edu; ph 808-956-7894) 
  Andreas Thurnherr, LDEO (ant@ldeo.columbia.edu; ph 845-365-8816; fx 914-
  365-8157) 

Trace elements
  Chris Measures, U Hawaii (chrism@soest.hawaii.edu; ph 808-956-8693)
  Bill Landing, U Florida (landing@ocean.fsu.edu; ph 850-644-6037)

ARGO floats
  Stephen Riser, U of Washington (riser@ocean.washington.edu; ph 206-543-
  1187)

Aerosols
  Bill Landing, U Florida (landing@ocean.fsu.edu; ph 850-644-6037)



NARRATIVE 

We carried out Leg 1 of the R/V Roger Revelle "KNOX03RR" expedition for 
the US Global Ocean Carbon and Repeat Hydrography Program (contributions 
to both CLIVAR and IOCCP).  The leg, from Dunedin, New Zealand, to 
Fremantle, Australia, was a repeat of the WOCE line I8S, last carried 
out aboard R/V Knorr during December 1994.  

Loading commenced in Dunedin, New Zealand, on 31 January 2007.  The 
ship was left in fine condition by the previous science group.  Loading 
went smoothly, and a good relationship between science team and crew 
was already building.  We loaded three lab vans, cargo from three other 
containers, plus numerous other shipments.  SIO Shipboard Technical 
Support gets special kudos for providing four Resident Technicians to 
assist during loading - all of whom were friendly and helpful, not to 
mention very busy.  Chief Engineer Paul Mauricio and his team 
cheerfully set to work fixing the trace metal winch, which had been 
damaged in shipping.  After a "happy hour" for all hands at the 
Speight's brew pub, on Saturday evening, the ship left the dock Sunday, 
04 February 2007, at 1606 local time in good weather, Captain Dave 
Murline in command.  

The plan was to complete the first occupation of Indian Ocean transects 
for the US Global Ocean Carbon and Repeat Hydrography program, which 
contributes to both the CLIVAR Repeat Hydrography project and the 
International Ocean Carbon Coordination Project via decadal 
reoccupations of selected high-priority WOCE Hydrographic Program 
transects.  The science program followed or improved on the WOCE 
protocols, with enhanced measurements of ocean carbon parameters in 
particular, plus a trace metal sampling program.  Sampling and 
analytical work for temperature, salinity, dissolved oxygen, nutrients, 
a host of carbon-related parameters, CFCs, helium, tritium, radiocarbon, trace metals, and velocity were planned from surface-to-bottom at ca. 50 km intervals along ca. 95°E from Antarctica to Bangladesh, along with acquisition of data from a number of underway sampling systems, plus deployment of Argo floats.  

The cruise began with a long steam to the first station, located in one 
of the most remote reaches of the World Ocean, with the goal of 
carrying out the first station on the intended track as close to 
Antarctica as ice, weather, and the captain would permit.  We headed 
southwest across the 40s and 50s, making most westward progress south 
of 60°S, south of the strongest headwinds, swell, and opposing 
currents.  A further benefit was some westward currents and occasional 
following seas.  Hence we arrived somewhat ahead of schedule in the 
region where we hoped to make our close approach to Antarctica.  To 
approach the continental shelf break we required (1) working near the 
time of the local annual sea ice minimum (provided thanks to the ship 
schedulers), (2) useful satellite ice edge imagery and analyses (kindly 
provided for us real time by the Navy/NOAA Joint Ice Center), (3) 
navigational expertise (no problem with Captain Murline and his bridge 
staff in charge), and (4) a truly significant dose of good luck.  

We had been out of satellite communications (including email) for a few 
days, partly due to not being able to aim the ship's antenna low enough 
on the horizon to see geostationary satellites, and partly because SIO 
had to put together, ashore and at sea, the technical and business 
pieces to effect a transfer to an Indian Ocean satellite as we left 
behind the footprint of the Pacific one.  But just when we needed the 
connection to receive ice images, the satellite connection was 
reestablished, and updated ice images arrived.  One of the SIO grad 
students along, JJ Becker, works with SIO's Dave Sandwell, an expert in 
teasing out ocean bathymetry from satellite data.  JJ had along on his 
computer the latest bottom depth information.  Combined with the ice 
edge information, plus our operational limits, this influenced our plan 
to approach along 84 degrees, 35 minutes east longitude, in the western 
Davis Sea.  It turned out to be a good choice, and in hindsight perhaps 
was the only one which would have worked: As we proceeded south, the 
bottom beneath us rose, but meanwhile the ice was getting closer.  Just 
when Captain Murline said "no further" the real-time bathymetry data 
showed that we'd reached our goal of the 500 meter isobath.  

We lowered our instruments there for our first station, the late day 
sun illuminating the sea ice, with icebergs all about, in an embayment 
of open water, killer whales patrolling the ice edge for seals and 
penguins, seals on the ice not inclined to join them, soon into sunset 
with an aurora above.  Through the cold 25°F night we completed our 500 
meter station, then the 1200 meter station offshore of that, then the 
2000 meter station, and so on, being chased north by encroaching ice, 
yet in the process completing a rare Antarctic shelf-slope-basin 
transect from a non-ice-strengthened ship.  

We were not yet through our encounters with sea ice.  The ice images 
showed a tongue of sea ice spreading eastward from an nearby ice shelf, 
nearly across our planned path out from the Davis Sea to the 1994 I8S 
line.  Sure enough, on the way to station 7 and 8, sea ice provided an 
exciting moment, with parades of icebergs and myriad growlers about, 
causing a small detour.  

Three LADCPs were brought on the cruise, two newer 300kHz "workhorse" 
models (usually used in pairs), and one older "broadband" 150kHz 
instrument.  Testing uncovered problems with the originally intended 
LADCP pair, and there were also some data issues with the back-up unit.  
The 300kHz instruments typically only perform well in regions of high 
scattering (e.g. high latitudes, due to higher productivity overall) so 
the plan was to use the 300kHz instruments for most of the first leg, 
and switch to the 150kHz instrument when scattering levels dropped in 
the desert-like subtropical gyre.  One of the 300kHz instruments was an 
experimental model with higher power and was to be field-tested during 
this cruise.  That instrument was rendered moot until its bulkhead 
connector can be replaced (in Fremantle).  The remaining (more typical) 
300kHz instrument was used successfully until it started returning 
casts with incomplete data.  The cause was unknown.  We switched to the 
150kHz instrument for the duration of the cruise.  It was heavier than 
the 300kHz instrument, and its extra weight may have helped the rosette 
sink better, too.  

During some CTD casts early in the cruise very slow descent rates were 
needed to 1000-1500m because wire tension was very low, even in 
moderate to low sea states.  Since the rosette weighs ca. 1100 lbs.  in 
air, the reluctance to sink was puzzling.  Focus gradually centered on 
the Revelle's new CTD cable, which seemed to have a propensity to 
develop kinks under roll and load conditions which seemed significantly 
less severe than experienced, with fewer problems, on some other 
similar cruises.  Admittedly, we were working our way north through the 
50s, a tough area to work with a large rosette.  Still, our battle with 
cable kinks was perplexing because two years earlier we carried out a 
similar Southern Ocean transect (in the Pacific Ocean sector) from this 
ship with virtually the same equipment, and under occasionally trying 
sea conditions, but with few cable kink problems.  A working solution 
was elusive.  Finally we switched our rosette from the new CTD cable 
installed for this trip to the older CTD cable on the second winch, the 
cable used during the 2005 P16S cruise.  After that switch, CTD casts 
were completed without problems.  It thus seems plausible that the new 
cable had from its manufacture some intrinsic characteristic 
incompatible with our rosette operations in swell.  We did not know 
this with certainty, of course.  

Late in the cruise we dealt with odd behavior from both the primary and 
back-up transmissometers.  This was finally tracked to a coincidence of 
faults in two cables, not the instruments.  

The rosette used on this cruise utilized Niskin-type "Bullister" 
bottles which delivered 10.4 liters of samples, up from 9-liters with 
the previous generation of ODF "Bullister" bottles.  We found that it 
was possible to sample nearly all samples from a single bottle, except 
for the occasional 4-liter POC samples.  

In addition to the usual cast of officers, crew, researchers, and 
graduate students, we had a three-person public outreach team along.  
In delving into the grit of oceanographic field work, they hoped to 
improve public understanding regarding how data that reflect the 
changing state of climate are collected.  They plan to produce a 
website, several articles, and multimedia features.  Their role on the 
ship was purposefully nebulous, something of a hybrid between research 
assistants and a media crew.  We integrated them into the science team 
by assigning them tasks that were, in their words, "difficult to ruin".  

Their project continues to evolve based on the materials they gather 
and the opportunities that arise.  They shadowed the scientists and 
shipboard technicians on their daily rounds, and were busy turning 
interviews into short articles and film clips about our research.  
Captain Murline helped considerably regarding coordinating the part of 
their work that provides a sense of the foundational support needed to 
run a cruise.  

We arrived dockside in Fremantle, Australia, the morning of 17 March, 
having completed not only all of the I8S line, with extension to the 
Antarctic continental shelf break, but also a few of the next leg's 
stations on the northern end.  The plan was for the ship to stay in 
Fremantle for about five days, then head back out to 95°E to resume 
northward on Leg 2 (called "I9N"), with Dr. Janet Sprintall (SIO) as 
chief scientist.  A handful of hardy souls in the I8S science team 
stayed on for Leg 2, and of course most of the mariners of R/V Roger 
Revelle remained aboard.  The I8S team enjoyed the satisfaction of a 
job Very Well Done.  Officers, crew, science team - it was as strong 
and harmonious a ship's company one can ever experience.  





CLIVAR I08S PRELIMINARY CRUISE REPORT 
(15 MARCH 2007) 

                                                                             Data Submitted by: 
                                        Shipboard Technical Support/Oceanographic Data Facility 
                                                            Scripps Institution of Oceanography 
                                                                       La Jolla, Ca. 92093-0214




INTRODUCTION 

A sea-going science team gathered from 8 oceanographic institutions 
participated on the cruise.  Several other science programs were supported 
with no dedicated cruise participant.  The science team and their 
responsibilities are listed below.  

________________________________________________________________________________________________
Duties                  Name              Affiliation            email 
----------------------  ----------------  ---------------------  -------------------------------
Chief Scientist         James H. Swift    UCSD/SIO               jswift@ucsd.edu 
Co-Chief Scientist      Annie Wong        UW                     awong@ocean.washington.edu 
Bottle Data/ODF TIC     Kristin Sanborn   UCSD/SIO/STS           ksanborn@ucsd.edu 
O2/Deck                 Jane Eert         IOS for UCSD/SIO/STS   tree@neovictorian.com 
Salinity/Deck           Chad Klinesteker  USCG for UCSD/SIO/STS  cklinesteker@uscg.mil 
O2/Deck                 David Langner     UCSD/SIO/STS           dlangner@ucsd.edu 
ET/Salinity/Deck Leader Rob Palomares     UCSD/SIO/STS           rpalomares@ucsd.edu 
Nutrients/Deck          Dan Schuller      UCSD/SIO/STS           dschuller@ucsd.edu 
Nutrients/Deck          Erik Quiroz       TAMU for UCSD/SIO/STS  erik@gergx.gerg.tamu.edu 
CTD Watchstander        J.J. Becker       UCSD                   jjbecker@ucsd.edu 
CTD Watchstander        Dion Putrasahan   UCSD                   dputrasa@ucsd.edu 
CTD Watchstander        David Ullman      U of Wisconsin         ullman@wisc.edu 
CTD/LADCP Watchstander  Lora VanUffelen   UCSD                   lvanuffe@ucsd.edu
LADCP                   Jules Hummon      UH                     hummon@hawaii.edu 
CFC                     David Wisegarver  NOAA/PMEL              David.Wisegarver@noaa.gov 
CFC                     Eric Wisegarver   NOAA/PMEL              Eric.Wisegarver@noaa.gov 
CFC                     David Cooper      NOAA/PMEL and LDEO     fleece@critter.net 
CDOM                    Norm Nelson       UCSB                   norm@icess.ucsd.edu 
CDOM                    Dave Menzies      UCSB                   davem@icess.ucsd.edu 
DIC                     Dana Greeley      NOAA/PMEL              Dana.Greeley.noaa.gov 
DOC/DON                 Charlie Farmer    RSMAS                  cfarmer@rsmas.miami.edu 
Helium/Tritium          Anthony Dachille  LDEO                   dachille@ldeo.columbia.edu 
PCO2                    Robert Castle     NOAA/PMEL              Robert.Castle.noaa.gov 
TALK                    George Anderson   UCSD/SIO               ganderson@ucsd.edu 
TALK                    Susan Alford      UCSD/SIO               sealford@ucsd.edu 
TM                      Chris Measures    UH                     chrism@soest.hawaii.edu 
TM                      Amir Hamidian     Otago                  ahamidian@chemistry.otago.ac.nz 
TM                      Maxime Grand      UH                     maxime@hawaii.edu 
TM                      Cliff Buck        FSU                    cbuck@ocean.fsu.edu 
TM                      William Hiscock   UH                     hiscock@hawaii.edu 
CTD, Data               Frank Delahoyde   UCSD/SIO/STS CR        fdelahoyde@ucsd.edu 
Computer Tech           Bud Hale          UCSD/SIO/STS CR        scg@rv-revelle.ucsd.edu 
Resident Tech           Gene Pillard      UCSD/SIO/STS           restech@rv-revelle.ucsd.edu 
Outreach                Pien Huang        Outreach               pien.huang@gmail.com 
Outreach                Cassandra Lopez   RSMAS                  CassandraSLopez@gmail.com 
Outreach                Daniel Park       Outreach               park.dan@gmail.com 
________________________________________________________________________________________________
Scientiﬁc Personnel I8S 



DESCRIPTION OF MEASUREMENT TECHNIQUES 


1.  CTD/HYDROGRAPHIC MEASUREMENTS PROGRAM 

The basic CTD/hydrographic measurements consisted of salinity, dissolved oxygen 
and nutrient measurements made from water samples taken on LADCP/CTD/rosette 
casts, plus pressure, temperature, salinity, dissolved oxygen, transmissometer 
and ﬂuorometer from CTD proﬁles. A total of 88 LADCP/CTD/rosette casts were 
made, usually to within 10-20m of the bottom. No major problems were encountered 
during the operation. The distribution of samples is illustrated in ﬁgures 1.0 
and 1.1.  
 
Figure 1.0: Sample distribution, stations 1-50.  
Figure 1.1: Sample distribution, stations 50-88.  


1.1.  Water Sampling Package 

CTD/rosette casts were performed with a package consisting of a 36-
bottle rosette frame (SIO/STS), a 36-place carousel (SBE32) and 36 
10.5L Bullister bottles (SIO/STS).  Underwater electronic components 
consisted of a Sea-Bird Electronics SBE9plus CTD (SIO/STS #381) with 
dual pumps, dual temperature (SBE3plus), dual conductivity (SBE4), 
dissolved oxygen (SBE43), transmissometer (Wetlabs), ﬂuorometer, 
altimeter (Simrad) and LADCP (RDI).  

The CTD was mounted vertically in an SBE CTD cage attached to the 
bottom of the rosette frame and located to one side of the carousel.  
The SBE4 conductivity, SBE3plus temperature and SBE43 Dissolved oxygen 
sensors and their respective pumps and tubing were mounted vertically 
as recommended by SBE on a bracket adjacent to the CTD cage.  Pump 
exhausts were attached to the sensor bracket on the side opposite from 
the sensors and directed downward.  The transmissometer and ﬂuorometer 
were mounted horizontally along the bottom of the rosette frame.  The 
altimeter was mounted on the inside of the bottom frame ring.  The RDI 
LADCP was mounted vertically on one side of the frame between the 
bottles and the CTD.  Its battery pack was located on the opposite side 
of the frame, mounted on the bottom of the frame.  

The rosette system was suspended from a UNOLS-standard three-conductor 
0.322" electro-mechanical sea cable.  Three sea cable reterminations 
were made during I8S after casts 31/1, 32/1 and 33/2.  

The R/V Revelle's aft starboard-side Markey winch was used for casts 
1/1-33/2.  The forward starboard-side Markey winch was used for all 
subsequent casts (34/2-88/3).  The decision was made to move from the 
aft Markey winch to the forward one after noticing irregularities in 
the construction of the aft winch sea cable.  The forward winch 
sliprings were changed after cast 43/1.  

The deck watch prepared the rosette 10-15 minutes prior to each cast.  
The bottles were cocked and all valves, vents and lanyards were checked 
for proper orientation.  Once stopped on station, the rosette was moved 
out from the aft hanger to the deployment location under the squirt 
boom block using an air-powered cart and tracks.  The CTD was powered-
up and the data acquisition system in the computer lab started when 
directed by the deck watch leader.  The rosette was unstrapped from 
it's tiedown location on the cart.  Tag lines were threaded through the 
rosette frame and syringes were removed from the CTD intake ports.  The 
winch operator was directed by the deck watch leader to raise the 
package, the squirt boom and rosette were extended outboard and the 
package quickly lowered into the water.  The tag lines were removed and 
the package was lowered to 10 meters, by which time the sensor pumps 
had turned on.  The winch operator was then directed to bring the 
package back to the surface (0 winch wireout) and to begin the descent.  

Each rosette cast was lowered to within 10-20 meters of the bottom, 
using the altimeter, winch wireout, CTD depth and echosounder depth to 
determine the distance.  

During the up cast the winch operator was directed to stop the winch at 
each bottle trip depth.  The CTD console operator waited 30 seconds 
before tripping a bottle to insure the package wake had dissipated and 
the bottles were ﬂushed, then an additional 10 seconds after each 
bottle closure to insure that stable CTD comparison data had been 
acquired. 
 
Once a bottle had been closed, the deck watch leader was directed to haul 
in the package to the next bottle stop.  

Standard sampling depths were used throughout CLIVAR I8S.  These 
standard depths were staggered every station using 3 sampling schemes.  

Recovering the package at the end of the deployment was essentially the 
reverse of launching, with the additional use of poles and snap-hooks 
to attach tag lines.  The rosette was secured on the cart and moved 
into the aft hanger for sampling.  The bottles and rosette were 
examined before samples were taken, and anything unusual noted on the 
sample log.  

Each bottle on the rosette had a unique serial number.  This bottle 
identiﬁcation was maintained independently of the bottle position on 
the rosette,  which was used for sample identiﬁcation.  Three bottles 
were replaced on this leg and various parts of bottles were 
occasionally changed or repaired.  

Routine CTD maintenance included soaking the conductivity and DO 
sensors in fresh water between casts to maintain sensor stability and 
occasionally putting dilute Triton-X solution through the conductivity 
sensors to eliminate any accumulating bioﬁlms.  Rosette maintenance was 
performed on a regular basis.  O-rings were changed and lanyards 
repaired as necessary.  Bottle maintenance was performed each day to 
insure proper closure and sealing.  Valves were inspected for leaks and 
repaired or replaced as needed.  


1.2.  Underwater Electronics Packages 

CTD data were collected with a SBE9plus CTD (STS/ODF #381).  This 
instrument provided pressure, dual temperature (SBE3), dual 
conductivity (SBE4), dissolved oxygen (SBE43), CDOM ﬂuorometer 
(Wetlabs), transmissometer (Wetlabs) and altimeter (Simrad 807) 
channels.  The CTD supplied a standard SBE-format data stream at a data 
rate of 24 frames/second.  


Table 1.2.0: CLIVAR I8S Rosette Underwater Electronics.  
_______________________________________________________________________
Sea-Bird SBE32 36-place Carousel Water Sampler 
Sea-Bird SBE9plus CTD                          0381 
Paroscientiﬁc Digiquartz Pressure Sensor       S/N 58952 
Sea-Bird SBE11plus Deck Unit   
Sea-Bird SBE3plus Temperature Sensor           S/N 03P-4588 (Primary) 
Sea-Bird SBE3plus Temperature Sensor           S/N 03P-4226 (Secondary) 
Sea-Bird SBE4C Conductivity Sensor             S/N 04-3176 (Primary) 
Sea-Bird SBE4C Conductivity Sensor             S/N 04-3058 (Secondary) 
Sea-Bird SBE43 DO Sensor                       S/N 43-1129 
Sea-Bird SBE5 Pump                             S/N 05-4160 (Primary) 
Sea-Bird SBE5 Pump                             S/N 05-4377 (Secondary) 
Sea-Bird SBE35 Reference Temperature Sensor    S/N 35-0035 
Wetlabs CDOM Fluorometer                       S/N FLCDRTD-428 
Wetlabs CStar Transmissometer                  S/N CST-327DR 
Wetlabs CStar Transmissometer                  S/N CST-490DR 
Simrad 807 Altimeter                           S/N 4051 
RDI LADCPs   
_______________________________________________________________________


The CTD was outﬁtted with dual pumps.  Primary temperature, 
conductivity and dissolved oxygen were plumbed into one pump circuit 
and secondary temperature and conductivity into the other.  The sensors 
were deployed vertically.  The primary temperature and conductivity 
sensors (T1 #03P-4588 and C1 #04-3176) were used for reported CTD 
temperatures and conductivities on all casts except 50/2, where 
biofouling had rendered parts of the primary sensor record unusable.  
The secondary temperature and conductivity sensors were used as 
calibration checks for all other casts.  ASBE35RT reference temperature 
sensor was connected to the SBE32 carousel and recorded a temperature 
for each bottle closure.  These temperatures were used as additional 
CTD calibration checks.  

The SBE9plus CTD was connected to the SBE32 36-place carousel providing 
for single-conductor sea cable operation.  The sea cable armor was used 
for ground (return).  Power to the SBE9plus CTD (and sensors), SBE32 
carousel and Simrad 807 altimeter was provided through the sea cable 
from the SBE11plus deck unit in the main lab.  


1.3.  Navigation and Bathymetry Data Acquisition 

Navigation data were acquired at 1-second intervals from the ship's 
GP90 GPS receiver by a Linux system beginning February 13.  

Bathymetric data were logged from the Ship's Simrad EM120 multibeam 
echosounder system and merged with the navigation time series.  These 
depths were corrected using sound velocity proﬁles derived from CTD 
casts.  


1.4.  CTD Data Acquisition and Rosette Operation  

The CTD data acquisition system consisted of an SBE-11plus (V2) deck 
unit and three networked generic PC workstations running CentOS-4.4 
Linux.  Each PC workstation was conﬁgured with a color graphics 
display, keyboard, trackball and DVD+RW drive.  One of the systems also 
had 8 additional RS-232 ports via a Comtrol Rocketport PCI serial 
controller.  The systems were interconnected through a 1000BaseTX 
ethernet switch which was also connected to the ship's network.  These 
systems were available for real-time operational and CTD data displays, 
and provided for CTD and hydrographic data management and backup.  

One of the workstations was designated the CTD console and was 
connected to the CTD deck unit via RS-232.  The CTD console provided an 
interface and operational displays for controlling and monitoring a CTD 
deployment and closing bottles on the rosette.  Another of the 
workstations was designated the website and database server and 
maintained the hydrographic database for I8S.  All three systems were 
used to maintain redundant backups of the data.  

CTD deployments were initiated by the console watch after the ship had 
stopped on station.  The watch maintained a console operations log 
containing a description of each deployment, a record of every attempt 
to close a bottle and any pertinent comments.  The deployment and 
acquisition software presented a short dialog instructing the operator 
to turn on the deck unit, examine the on screen CTD data displays and 
to notify the deckwatch that this was accomplished.  

Once the deckwatch had deployed the rosette, the winch operator would 
lower it to 10 meters.  The CTD sensor pumps were conﬁgured with an 8 
second startup delay, and were usually on by this time.  The console 
operator checked the CTD data for proper sensor operation, waited an 
additional 60 seconds for sensors to stabilize, then instructed the 
winch operator to bring the package to the surface and descend to a 
target depth (wire-out).  The proﬁling rate was no more than 30m/min to 
50m, no more than 45m/min to 200m and no more than 60m/min deeper than 
200m depending on sea cable tension and the sea state.  

The progress of the deployment and CTD data quality were monitored 
through interactive graphics and operational displays.  Bottle trip 
locations were transcribed onto the console and sample logs.  The 
sample log would later be used as an inventory of samples drawn from 
the bottles.  The altimeter channel, CTD depth, winch wire-out and 
bathymetric depth were all monitored to determine the distance of the 
package from the bottom, usually allowing a safe approach to within 10-
20 meters.  

Bottles were closed on the up cast by operating an on-screen control.  
The winch operator was given a target wire-out for the bottle stop, 
proceeded to that depth and stopped.  Bottles were tripped at least 30 
seconds after stopping to allow the rosette wake to dissipate and the 
bottles to ﬂush.  The winch operator was instructed to proceed to the 
next bottle stop at least 10 seconds after closing bottles to insure 
that stable CTD data were associated with the trip and to allow the 
SBE35RT tertiary temperature sensor time to make a measurement.  

After the last bottle was closed, the console operator directed the 
deckwatch to bring the rosette on deck.  Once on deck, the console 
operator terminated the data acquisition, turned off the deck unit and 
assisted with rosette sampling.  


1.5.  CTD Data Processing 

Shipboard CTD data processing was performed automatically during each 
LADCP/CTD/Rosette deployment, and at the end of each Trace Metals 
rosette deployment using SIO/ODF CTD processing software.  The Trace 
Metals rosette contained its own CTD and carousel.  These data were 
acquired using SBE SeaSave software, then copied to a Linux workstation 
for further processing.  No shipboard calibration was done for Trace 
Metals rosette CTD data.  

Processing was performed during data acquisition for LADCP/CTD/Rosette 
deployments.  The raw CTD data were converted to engineering units, 
ﬁltered, response-corrected, calibrated and decimated to a more 
manageable 0.5 second time-series.  The laboratory calibrations for 
pressure, temperature and conductivity were applied at this time.  The 
0.5 second time-series data were used for real-time graphics during 
deployments, and were the source for CTD pressure and temperature 
associated with each rosette bottle.  Both the raw 24hz data and the 
0.5 second time-series were stored for subsequent processing.  During 
the deployment the data were backed up to another Linux workstation.  

Processing was performed after data acquisition for Trace Metals 
rosette deployments.  The raw CTD data and bottle trips acquired by SBE 
SeaSave on the Windows XP workstation were copied onto the Linux 
database and web server workstation, then processed to a 0.5 second time 
series and bottle trip values extracted.  

At the completion of a deployment a sequence of processing steps were 
performed automatically.  The 0.5 second time-series data were checked for 
consistency, clean sensor response and calibration shifts.  A 2 decibar 
pressure-series was then generated from the down cast.  Both the 2 decibar 
pressure-series and 0.5 second time-series data were made available for 
downloading, plotting and reporting on the shipboard cruise website. 

LADCP/CTD/Rosette CTD data were routinely examined for sensor 
problems, calibration shifts and deployment or operational problems. The 
primary and secondary temperature sensors (SBE 3) were compared to each 
other and to the SBE35 temperature sensor. CTD conductivity sensors (SBE 4) 
were compared and calibrated by examining differences between CTD and 
check-sample conductivity values. The CTD dissolved oxygen sensor data 
were calibrated to check-sample data. Additional TS and theta-O2 
comparisons were made between down and up casts as well as with 
adjacent deployments. Vertical sections were made of the various 
properties derived from sensor data and checked for consistency. 

Few CTD acquisition and processing problems were encountered during 
I8S.  A clogged bleeder valve in the primary pump circuit led to 
aborting cast 29/1 at 100M, then redeploying after cleaning the valve.  
The cast was not renamed.  Wire problems (resulting in reterminations) 
were apparent in the downcasts of 31/1, 32/1 and 33/2 and were ﬁltered 
out.  Slipring problems on 43/1 were evident on the upcast and were 
ﬁltered out.  Bioﬁlm artifacts contaminated the downcasts on 29/1 and 
50/2.  29/1 was ﬁltered, the upcast was used for 50/2.  The ﬂuorometer 
endcap covers were left on for 2/1, 3/1 and 4/1.  A ﬂuorometer dark 
cast was made for 12/1.  The transmissometer was changed on 69/1, then 
changed back on 83/1.  

A total of 88 casts were made using the 36-place LADCP/CTD rosette, and 
39 using the 12-place Trace Metals rosette.  


1.6.  CTD Sensor Laboratory Calibrations 

Laboratory calibrations of the CTD pressure, temperature, conductivity 
and dissolved oxygen sensors were performed prior to CLIVAR I8S.  The 
calibration dates are listed in table 1.6.0.  


Table 1.6.0: CLIVAR I8S CTD sensor laboratory calibrations.  
_________________________________________________________________________
                                              Calibration     Calibration 
Sensor                              S/N       Date            Facility 
----------------------------------  --------  --------------  -----------
Paroscientific Digiquartz Pressure  58952     17-December-06  SIO/ODF 
Sea-Bird SBE3plus T1 Temperature    03P-4588  14-December-06  SBE 
Sea-Bird SBE3plus T2 Temperature    03P-4226  14-December-06  SBE 
Sea-Bird SBE4C C1 Conductivity      04-3176   30-November-06  SBE 
Sea-Bird SBE4C C2 Conductivity      04-3058   30-November-06  SBE 
Sea-Bird SBE43 Dissolved Oxygen     43-1129   N/A             N/A 
_________________________________________________________________________


1.7.  CTD Shipboard Calibration Procedures 

CTD #381 was used for all LADCP/CTD rosette casts on I8S.  The CTD was 
deployed with all sensors and pumps aligned vertically, as recommended 
by SBE.  The primary temperature and conductivity sensors (T1 & C1) 
were used for all reported CTD data on all casts except 50/2, the 
secondary sensors (T2 & C2) serving as calibration checks.  The SBE35RT 
Digital Reversing Thermometer (S/N 3528706-0035) served as an 
independent calibration check for T1 and T2.  In-situ salinity and 
dissolved O2 check samples collected during each cast were used to 
calibrate the conductivity and dissolved O2 sensors.  

The variability of the environment that was observed on many of the 
deployments made sensor and check sample comparisons somewhat 
problematic.  An independent metric of variability was inferred from 
comparing primary and secondary temperature data.  This metric was used 
to ﬁlter check sample comparisons for calibration purposes.  


1.7.1.  CTD Pressure 

The Paroscientiﬁc Digiquartz pressure transducer (S/N 58952) was 
calibrated in December 2006 at the SIO/ODF Calibration Facility.  
Calibration coefficients derived from the calibration were applied to 
raw pressures during each cast.  Residual pressure offsets (the 
difference between the ﬁrst and last submerged pressures) were examined 
to check for calibration shifts.  All were < 0.7db, and the sensor 
exhibited < 0.3 db offset shift over the period of use.  No additional 
adjustments were made to the calculated pressures.  


1.7.2.  CTD Temperature 

A single primary temperature sensor (T1 SBE 3, S/N 03P-4588) and 
secondary sensor (T2 SBE 3, S/N 03P-4226) served the entire cruise.  
Calibration coefficients derived from the pre-cruise calibrations were 
applied to raw primary and secondary temperatures during each cast.  
The SBE35RT Digital Reversing Thermometer is an internally-recording 
temperature sensor that operates independently of the CTD.  It 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 on I8S was set to internally average over 
approximately one ship roll period (8 seconds).  It was located 
equidistant between T1 and T2 with the sensing element aligned in a 
plane with the T1 and T2 sensing elements.  

Two independent metrics of calibration accuracy were examined.  The primary 
and secondary temperatures were compared at each bottle closure, and the 
SBE35RT temperatures were compared to primary and secondary temperatures 
at each bottle closure.  These comparisons showed all three temperatures 
to be within ±0.001°C with the SBE35RT between T1 and T2, so T1 and T2 were 
both corrected to the SBE35RT.  No sensor drift was evident and only one 
sensor (T2) exhibited any secondary responses (to pressure).  The residual 
differences after correction are shown in ﬁgures 1.7.2.0 and 1.7.2.1.  


Figure 1.7.2.0: T1-T2 by station (P>1000db).  
Figure 1.7.2.1: SBE35RT-T1 by  station (P>1000db).  


1.7.3.  CTD Conductivity 

A single primary conductivity sensor (SBE 4, S/N 04-3176) and secondary 
conductivity sensor (SBE 4, S/N 04-3058) served the entire cruise.  
Conductivity sensor calibration coefficients derived from the pre-cruise 
calibrations were applied to raw primary and secondary conductivities.  

Comparisons between the primary and secondary sensors and between each 
of the sensors to check sample conductivities (calculated from bottle 
salinities) were used to derive conductivity corrections.  To reduce 
the contamination of the comparisons by package wake, differences 
between primary and secondary temperature sensors were used as a metric 
of variability and used to qualify the comparisons.  The coherence of 
this relationship is illustrated in ﬁgure 1.7.3.0.  


Figure 1.7.3.0: C1-C2 byT1-T2, all points.  


One of the sensors (C2) exhibited a secondary pressure response.  
Otherwise the sensors tracked within ±0.001mS/cm the entire cruise 
exhibiting no drift.  The uncorrected comparison between the primary 
and secondary sensors is shown in ﬁgure 1.7.3.1, and between C1 and the 
bottle conductivities in 1.7.3.2.  


Figure 1.7.3.1: Uncorrected C1 and C2 conductivity differences by cast 
                (-0.005°C≤T1-T2≤0.005°C).  
Figure 1.7.3.2: Uncorrected C1 residual differences from bottle 
                conductivities by cast (-0.005°C≤T1-T2≤0.005°C).  


The comparison of the primary and secondary conductivity sensors by cast 
after applying shipboard corrections is summarized in ﬁgure 1.7.3.3.  


Figure 1.7.3.3: Corrected C1 and C2 conductivity differences by cast 
                (-0.001°C≤T1-T2≤0.001°C).  


Salinity residuals after applying shipboard T1/C1 corrections are 
summarized in ﬁgure 1.7.3.4, 1.7.3.5, 1.7.3.6 and 1.7.3.7.  


Figure 1.7.3.4: Corrected C1 and C2 salinity differences by cast (P>0db) 
Figure 1.7.3.5: salinity residuals by cast (P>0db).  
Figure 1.7.3.6: Corrected C1 and C2 salinity differences by cast (P>1000db) 
Figure 1.7.3.7: salinity residuals by cast (P>1000db).  


Figures 1.7.3.6 and 1.7.3.7 represent estimates of the salinity 
accuracy of CLIVAR I8S.  The 95% conﬁdence limits are ±0.00072 PSU 
relative to C1, and ±0.00147 PSU relative to the bottle salts.  


1.7.4.  CTD Dissolved Oxygen 

A single SBE43 dissolved O2 (DO) sensor was used during this cruise 
(S/N 43-1129).  The sensor was plumbed into the primary T1/C1 pump 
circuit after C1.  

The DO sensors were calibrated to dissolved O2 check samples at bottle 
stops by calculating CTD dissolved O2 then minimizing the residuals 
using a non-linear least-squares ﬁtting procedure.  The ﬁtting 
procedure determined the calibration coefficients for the sensor model 
conversion equation, and was accomplished in stages.  The time 
constants for the exponential terms in the model were ﬁrst determined 
for each sensor.  These time constants are sensor-speciﬁc but 
applicable to an entire cruise.  Next, casts were ﬁt individually to 
check sample data.  The resulting calibration coefficients were then 
smoothed and held constant during a reﬁt to determine sensor slope and 
offset.  

Standard and blank values for bottle oxygen data were smoothed and the 
bottle oxygen recalculated prior to the ﬁnal ﬁtting of CTD oxygen.  

The residuals are shown in ﬁgures 1.7.4.0-1.7.4.2.  


Figure 1.7.4.0: O2 residuals by cast (all points).  
Figure 1.7.4.1: O2 residuals by pressure (all points).
Figure 1.7.4.2: O2 residuals by cast (-0.005°C≤T1-T2≤0.005°C).  


The standard deviations of 2.93 uM/kg for all oxygens and 0.86 uM/kg 
for low-gradient oxygens are only presented as general indicators of 
goodness of ﬁt.  ODF makes no claims regarding the precision or 
accuracy of CTD dissolved O2 data.  

The general form of the ODF O2 conversion equation for Clark cells 
follows Brown and Morrison [Brow78]and Millard [Mill82], [Owen85].  
ODF models membrane and sensor temperatures with lagged CTD 
temperatures and a lagged thermal gradient.  In-situ pressure and 
temperature are ﬁltered to match the sensor response.  Time-constants 
for the pressure response τp, two temperature responses τTs and τTf, 
and thermal gradient response τdT are ﬁtting parameters.  The thermal 
gradient term is derived by low-pass ﬁltering the difference between the 
fast response (Tf)and slow response (Ts)temperatures.  This term is 
SBE43-speciﬁc and corrects a non-linearity introduced by analog thermal 
compensation in the sensor.  The Oc gradient, dOc/dt, is approximated 
by low-pass ﬁltering 1st-order Oc differences.  This gradient term 
attempts to correct for reduction of species other than O2 at the 
sensor cathode.  The time-constant for this ﬁlter, τog, is a ﬁtting 
parameter.  Dissolved O2 concentration is then calculated: 

                                                                
                               (c3Pl+c4Tf+c5T8+c6(dOc/dt)+c7dT)  
O2ml/l=[c1Oc + c2]•fsat(S,T,P)•e                                     (1.7.4.0)

where: 

O2ml/l      = Dissolved O2 concentration in ml/l;
Oc          = Sensor current (µamps);
fsat(S,T,P) = O2 saturation concentration at S,T,P (ml/l);
S           = Salinity at O2 response-time (PSUs);
T           = Temperature at O2 response-time (°C);
P           = Pressure at O2 response-time (decibars);
Pl          = Low-pass ﬁltered pressure (decibars);
Tf          = Fast low-pass ﬁltered temperature (°C);
Ts          = Slow low-pass ﬁltered temperature (°C);
dOc/dt      = Sensor current gradient (µamps/secs);
dT          = low-pass ﬁltered thermal gradient (Tf -Ts).  


1.8.  Bottle Sampling 

At the end of each rosette deployment water samples were drawn from the 
bottles in the following order: 

  • CFCs 
  • He3 
  • O2 
  • Dissolved Inorganic Carbon (DIC) 
  • Total Alkalinity 
  • C13 and C14 
  • Dissolved Organic Carbon (DOC) 
  • Tritium 
  • Nutrients 
  • CDOM 
  • PIC/POC 
  • Salinity 

The correspondence between individual sample containers and the rosette 
bottle position (1-36) from which the sample was drawn was recorded on 
the sample log for the cast.  This log also included any comments or 
anomalous conditions noted about the rosette and bottles.  One member 
of the sampling team was designated the sample cop, whose sole 
responsibility was to maintain this log and insure that sampling 
progressed in the proper drawing order.  

Normal sampling practice included opening the drain valve and then the 
air vent on the bottle, indicating an air leak if water escaped.  This 
observation together with other diagnostic comments (e.g., "lanyard 
caught in lid", "valve left open") that might later prove useful in 
determining sample integrity were routinely noted on the sample log.  
Drawing oxygen samples also involved taking the sample draw temperature 
from the bottle.  The temperature was noted on the sample log and was 
sometimes useful in determining leaking or mis-tripped bottles.  

Once individual samples had been drawn and properly prepared, they were 
distributed for analysis.  Oxygen, nutrient and salinity analyses were 
performed on computer-assisted (PC) analytical equipment networked to 
the data processing computer for centralized data management.  


1.9.  Bottle Data Processing 

Water samples collected and properties analyzed shipboard were 
centrally managed in a relational database (PostgreSQL-8.0.8) running 
on a Linux system.  A web service (OpenAcs-5.2.3 and AOL Server-4.0.10) 
front-end provided ship-wide access to CTD and water sample data.  Web-
based facilities included on-demand arbitrary property-property plots 
and vertical sections as well as data uploads and downloads.  

The sample log (and any diagnostic comments) was entered into the 
database once sampling was completed.  Quality ﬂags associated with 
sampled properties were set to indicate that the property had been 
sampled, and sample container identiﬁcations were noted where 
applicable (e.g., oxygen ﬂask number).  

Analytical results were provided on a regular basis by the various 
analytical groups and incorporated into the database.  These results 
included a quality code associated with each measured value and 
followed the coding scheme developed for the World Ocean Circulation 
Experiment (WOCE) Hydrographic Programme (WHP) [Joyc94].  

Various consistency checks and detailed examination of the data 
continued throughout the cruise.  


1.10.  Salinity Analysis 

Equipment and Techniques 

Two Guildline Autosal 8400A salinometers (S/N 57-396, 53-503) located 
in the hydro lab, were used for salinity measurements.  57-396 was used 
for casts 1/1-47/1 and 50/1-88/3, 53-503 for casts 48/1-49/2.  These 
salinometers were modiﬁed by SIO/STS to provide an interface for 
computer-aided measurement.  The water bath temperature was set and 
maintained at a value near the laboratory air temperature (24°C).  

The salinity analyses were performed after samples had equilibrated to 
laboratory temperature, usually within 6-8 hours after collection.  The 
salinometers were standardized for each group of analyses (usually 1-2 
casts, up to ~75 samples) using at least two fresh vials of standard 
seawater per group.  Salinometer measurements were made by computer, 
the analyst prompted by the software to change samples and ﬂush.  


Sampling and Data Processing 

A total of 3306 salinity measurements were made (429 for Trace Metals) 
and approximately 180 vials of standard seawater (IAPSO SSW) were used.  

Salinity samples were drawn into 200 ml Kimax high-alumina borosilicate 
bottles, which were rinsed three times with sample prior to ﬁlling.  
The bottles were sealed with custom-made plastic insert thimbles and 
Nalgene screwcaps.  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 air tight seal.  The draw time and equilibration time were 
logged for all casts.  Laboratory temperatures were logged at the 
beginning and end of each run.  

PSS-78 salinity [UNES81] was calculated for each sample from the 
measured conductivity ratios.  The difference (if any) between the 
initial vial of standard water and the next one run as an unknown was 
applied as a linear function of elapsed run time to the data.  The 
corrected salinity data were then incorporated into the cruise 
database.  

The estimated accuracy of bottle salinities run at sea is usually 
better than ±0.002 PSU relative to the particular standard seawater 
batch used.  The 95% conﬁdence limit for residual differences between 
the bottle salinities and calibrated CTD salinity relative to SSW batch 
P-147 was ±0.0145 PSU for all salinities, and ±0.0015 PSU for 
salinities deeper than 1000db.  


Laboratory Temperature 

The temperature in the salinometer laboratory varied from 21 to 25.4°C, 
during the cruise, except for the period stated above when room 
temperature was 25 to 27°C.  (The air temperature thermometer had been 
moved and was not monitoring appropriate room temperature in the 
vicinity of the autosal.  The air temperature change during any 
particular run varied from -1.0 to +0.9°C.  


Standards 

IAPSO Standard Seawater Batch P-147 was used to standardize all casts.  


1.11.  Oxygen Analysis 

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 
software.  Thiosulfate was dispensed by a Dosimat 665 buret driver 
ﬁtted with a 1.0 ml buret.  ODF used a whole-bottle modiﬁed-Winkler 
titration following the technique of Carpenter [Carp65] with 
modiﬁcations by Culberson et al.  [Culb91], but with higher 
concentrations of potassium iodate standard (˜0.012N) and thiosulfate 
solution (˜55 gm/l).  Pre-made liquid potassium iodate standards were 
run every day (approximately every 2-4 stations), unless changes were 
made to the system or reagents.  Reagent/distilled water blanks were 
determined every day or more often if a change in reagents required it 
to account for presence of oxidizing or reducing agents.  


Sampling and Data Processing 

2917 oxygen measurements were made.  Samples were collected for 
dissolved oxygen analyses soon after the rosette was brought on board.  
Using a Tygon and silicone drawing tube, nominal 125ml volume-
calibrated iodine ﬂasks were rinsed 3 times with minimal agitation, 
then ﬁlled and allowed to overﬂow for at least 3 ﬂask volumes.  The 
sample drawing temperatures were measured with an electronic resistance 
temperature detector (RTD) embedded in the drawing tube.  These 
temperatures were used to calculate uM/kg concentrations, and as a 
diagnostic check of bottle integrity.  Reagents (MnCl2 then NaI/NaOH) 
were added to ﬁx the oxygen before stoppering.  The ﬂasks were shaken 
twice (10-12 inversions) to assure thorough dispersion of the 
precipitate, once immediately after drawing, and then again after about 
20 minutes.  

The samples were analyzed within 1-4 hours of collection, and the data 
incorporated into the cruise database.  

Thiosulfate normalities were calculated from each standardization and 
corrected to 20°C.  The 20°C normalities and the blanks were plotted 
versus time and were reviewed for possible problems.  The blanks and 
thiosulfate normalities for each batch of thiosulfate were smoothed 
(linear ﬁts) in two groups during the cruise and the oxygen values 
recalculated.  


Volumetric Calibration 

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


Standards 

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


1.12.  Nutrient Analysis 

Equipment and Techniques 

Nutrient analyses (phosphate, silicate, nitrate and nitrite) were 
performed on an ODF-modiﬁed 4-channel Technicon AutoAnalyzer II, 
generally within one to two hours after sample collection.  

The methods used are described by Gordon et al. [Gord92].  The analog 
outputs from each of the four colorimeter channels were digitized and 
logged automatically by computer (PC) at 2-second intervals.  

Silicate was analyzed using the technique of Armstrong et al. [Arms67].  
An acidic solution of 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.  Tartaric acid was also added to impede PO4 color 
development.  The sample was passed through a 15mm ﬂowcell and the 
absorbence measured at 660nm.  

A modiﬁcation of the Armstrong et al. [Arms67] procedure was used for 
the analysis of nitrate and nitrite.  For the nitrate analysis, the 
seawater sample was passed through a cadmium reduction column where 
nitrate was quantitatively reduced to nitrite.  Sulfanilamide was 
introduced to the sample stream followed by N-(1-naphthyl)ethylenediamine 
dihydrochloride which coupled to form a red azo dye.  The stream was then 
passed through a 15mm ﬂowcell and the absorbence measured at 540nm.  The 
same technique was employed for nitrite analysis, except the cadmium column 
was bypassed, and a 50mm ﬂowcell was used for measurement.  

Phosphate was analyzed using a modiﬁcation of the Bernhardt and 
Wilhelms [Bern67] technique.  An acidic solution of ammonium molybdate 
was added to the sample to produce phosphomolybdic acid, then reduced 
to phosphomolybdous acid (a blue compound) following the addition of 
dihydrazine sulfate.  The reaction product was heated to ~55°C to 
enhance color development, then passed through a 50mm ﬂowcell and the 
absorbence measured at 820nm.  

Explicit corrections for carryover in nutrient analyses are not made.  
In a typical AutoAnalyzer system, sample to sample carryover is ~ 1-2% 
of the concentration difference between samples.  This effect is 
minimized by running samples in order of increasing depth such that 
concentration differences between samples are minimized.  The initial 
surface samples were run twice since these samples followed standard 
peaks.  


Sampling and Data Processing 

3306 nutrient samples were analyzed of these 429 were analyzed for 
Trace Metal casts.  

Nutrient samples were drawn into 45 ml polypropylene, screw-capped 
"oak-ridge type" centrifuge tubes.  The tubes were cleaned with 10% 
HCl and rinsed with sample 2-3 times before ﬁlling.  Standardizations 
were performed at the beginning and end of each group of analyses 
(typically one cast, up to 36 samples) with an intermediate 
concentration mixed nutrient standard prepared prior to each run 
from a secondary standard in a low-nutrient seawater matrix.  
The secondary standards were prepared aboard ship by dilution from 
primary standard solutions.  Dry standards were pre-weighed at the 
laboratory at ODF, and transported to the vessel for dilution to the 
primary standard.  Sets of 7 different standard concentrations were 
analyzed periodically to determine any deviation from linearity as a 
function of absorbence for each nutrient analysis.  A correction for 
non-linearity was applied to the ﬁnal nutrient concentrations when 
necessary.  A correction for the difference in refractive indices of 
pure distilled water and seawater was periodically determined and 
applied.  In addition, a "deep seawater" high nutrient concentration 
check sample was run with each station as an additional check on data 
quality.  The pump tubing was changed 3 times.  

After each group of samples was analyzed, the raw data ﬁle was 
processed to produce another ﬁle of response factors, baseline values, 
and absorbences.  Final nutrient concentrations were then determined 
from this ﬁle.  The data were then added to the cruise database.  

Nutrients, reported in micromoles per kilogram, were converted from 
micromoles per liter by dividing by sample density calculated at 1 atm 
pressure (0 db), in situ salinity, and a per-analysis measured 
analytical temperature.  


Standards 

Primary standards for silicate (Na2SiF6) and nitrite (NaNO2) were 
obtained from Johnson Matthey Chemical Co.; the supplier reported 
purities of >98% and 97%, respectively.  Primary standards for nitrate 
(KNO3) and phosphate (KH2PO4) were obtained from Fisher Chemical Co.; 
the supplier reported purities of 99.999% and 99.999%, respectively.  
The efﬁciency of the cadmium column used for nitrate was monitored 
throughout the cruise and ranged from 99-100%.  

No major problems were encountered with the measurements.  The 
temperature of the laboratory used for the analyses ranged from 23.0°C 
to 24.5°C.  


References 

Arms67. 
    Armstrong, F.A.J., Stearns, C.R., 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). 

Bern67. 
    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). 

Brow78. 
    Brown, N.L. and Morrison, G.K., "WHOI/Brown conductivity, 
    temperature and depth microprofiler," Technical Report No. 78-23, 
    Woods Hole Oceanographic Institution (1978). 

Carp65. 
    Carpenter, J.H., "The Chesapeake Bay Institute technique for the 
    Winkler dissolved oxygen method," Limnology and Oceanography, 10, 
    pp.141-143 (1965). 

Culb91. 
    Culberson, C.H., Knapp, G., Stalcup, M., Williams, R.T., and 
    Zemlyak, F., "A comparison of methods for the determination of 
    dissolved oxygen in seawater," Report WHPO 91-2, WOCE Hydrographic 
    Programme Office (Aug 1991). 

Gord92. 
    Gordon, L.I., Jennings, J.C., Jr., Ross, A.A., and 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). 

Joyc94. 
    Joyce, T., ed. and Corry, C., ed., "Requirements for WOCE 
    Hydrographic Programme Data Reporting," Report WHPO 90-1, WOCE 
    Report No. 67/91, pp. 52-55, WOCE Hydrographic Programme Office, 
    Woods Hole, MA, USA (May 1994, Rev. 2). UNPUBLISHED MANUSCRIPT. 

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). 

UNES81. 
    UNESCO, "Background papers and supporting data on the Practical 
    Salinity Scale, 1978,"UNESCO Technical Papers in Marine Science, 
    No. 37, p.144 (1981). 


BOTTLE DEPTH SCHEME

The bottle depths used during I8S followed the 3-scheme plan originally 
developed by Paul Robbins, adapted slightly for high latitudes.  Stations 
rotated through the three schemes, so samples collected principally on 
alternate stations received the same pattern, but every six stations.  The 
table shows the three schemes used during I8S.

        Scheme #1               Scheme #2              Scheme #3
       ----------               ---------              ---------
    1    surface                 surface                surface     
    2       25                      35                     15     
    3       50                      70                     40     
    4       75                      90                     85     
    5      100                     120                    135     
    6      150                     140                    160     
    7      200                     170                    185     
    8      250                     220                    235     
    9      300                     270                    285     
   10      350                     320                    335     
   11      400                     370                    385     
   12      450                     420                    435     
   13      500                     470                    485     
   14      600                     520                    570     
   15      700                     640                    670     
   16      800                     740                    770     
   17      900                     840                    870     
   18     1000                     940                    970     
   19     1100                    1040                   1070     
   20     1200                    1140                   1170     
   21     1300                    1240                   1270     
   22     1400                    1340                   1370     
   23     1500                    1440                   1470     
   24     1600                    1540                   1570     
   25    (1700)                  (1640)                 (1670)     
   26     1800                    1740                   1770     
   27    (1900)                  (1840)                 (1870)     
   28     2000                    1940                   1970     
   29     2250                    2100                   2170     
   30     2500                    2350                   2420     
   31     2750                    2600                   2670     
   32     3000      Z < 4400      2850                   2920     Z < 4400
                    --------                                      --------
   33     3300       (3250)       3100      Z < 4300     3250      (3170)
                                            -------- 
   34     3600       (3500)       3400       (3350)      3550      (3420)
   35     3900       (3750)       3700       (3600)      3850      (3670)
   36     4200       (4000)       4050       (3850)      4150      (3920)
          4550       (4250)       4400       (4100)      4500      (4170)
          4900      (bottom)      4750      (bottom)     4850     (bottom)
       bottom-200     5050     bottom-200                  
         bottom    bottom-200    bottom                  
                     bottom                         
 

ARGO FLOATS
(Annie Wong)

During the CLIVAR/CO2 2007 repeat of I8S, 14 autonomous CTD profiling floats 
were deployed along the cruise track in waters deeper than 2000 dbar. These 
floats are part of the Argo project (www.argo.ucsd.edu), and are provided by 
Dr. Steve Riser from the University of Washington. Each of these floats has 
been ballasted differently for different latitudes. Of these 14 floats, 9 
contain oxygen sensors, and 2 are "ice floats" that are part of the Antarctic 
field trial. These 2 "ice floats" are programmed to remain subsurface and 
store data when under sea ice. All floats were deployed at CTD stations, at 
the end of all station casts. All floats were deployed from the starboard 
stern of the ship, with the ship moving forward at about 1 knot. No CTD oil 
slick was found at any of the deployment stations. Deployment was done by 
using a rope to lower the floats from the deck to the water. All 14 floats 
successfully self-activated via pressure activation. Data from all Argo 
floats are publicly available in real-time via the two global servers at 
www.usgodae.org and www.coriolis.eu.org. The following are the approximate 
positions where the 14 floats were deployed.


                    Float ID   Latitude   Longitude
                    --------   --------   ---------
                      5058     65 09' S   84 18' E
                      5062     63 57' S   83 08' E
                      5074     57 37' S   82 23' E
                      5079     56 54' S   83 18' E
                      5093     56 03' S   84 15' E
                      5071     53 06' S   87 29' E
                      5094     50 07' S   90 25' E
                      5072     47 09' S   93 09' E
                      5095     44 00' S   95 01' E
                      5073     41 00' S   94 59' E
                      5075     37 59' S   94 59' E
                      5100     35 00' S   95 00' E
                      5119     33 30' S   95 00' E
                      5092     32 00' S   95 00' E


TOTAL DISSOLVED INORGANIC CARBON (DIC)

The DIC analytical equipment was set up in a seagoing container modified for 
use as a shipboard laboratory. The analysis was done by coulometry with two 
analytical systems (PMEL-1 and PMEL-2) used simultaneously on the cruise.  
Each system consisted of a 5011 coulometer (UIC, Inc.) coupled with a SOMMA 
(Single Operator Multiparameter Metabolic Analyzer) inlet system developed by 
Ken Johnson (Johnson et al., 1985,1987,1993; Johnson, 1992) of Brookhaven 
National Laboratory (BNL).  In the coulometric analysis of DIC, all carbonate 
species are converted to CO2 (gas) by addition of excess hydrogen to the 
seawater sample, and the evolved CO2 gas is carried into the titration cell of 
the coulometer, where it reacts quantitatively with a proprietary reagent 
based on ethanolamine to generate hydrogen ions.  These are subsequently 
titrated with coulometrically generated OH-. CO2 is thus measured by 
integrating the total change required to achieve this.

The coulometers were each calibrated by injecting aliquots of pure CO2 
(99.99%) by means of an 8-port valve outfitted with two sample loops (Wilke 
et al., 1993).  The instruments were calibrated at the beginning and end of 
each full station with a set of the gas loop injections.

Secondary standards were run throughout the cruise on each analytical system; 
these standards are Certified Reference Materials (CRMs) consisting of 
poisoned, filtered, and UV irradiated seawater supplied by Dr. A. Dickson of 
Scripps Institution of Oceanography (SIO), and their accuracy is determined 
shoreside manometrically.  On this cruise, the overall accuracy and precision 
for the CRMs on both instruments combined was 0.75 µmol/kg respectively 
(n=131).  Preliminary DIC data reported to the database have not yet been 
corrected to the Batch 78 CRM value, but a more careful quality assurance to 
be completed shoreside will have final data corrected to the secondary 
standard on a per instrument basis. 

Samples were drawn from the Niskin-type bottles into cleaned, precombusted 
300-mL Pyrex bottles using Tygon tubing with silicone ends. Bottles were 
rinsed once and filled from the bottom, overflowing half a volume taking care 
not to entrain any bubbles. The tube was pinched off and withdrawn, creating 
a 6-mL headspace, and 0.12 mL of 50% saturated HgCl2 solution was added as a 
preservative. The sample bottles were sealed with glass stoppers lightly 
covered with Apiezon-L grease, and were stored at room temperature for a 
maximum of 24 hours prior to analysis.

Over 2500 samples were analyzed for discrete DIC; full profiles were 
completed on odd numbered stations, with replicate samples taken from the 
surface, oxygen minimum, Salinity Maximum, and bottom Niskin-type bottles.  
On the even numbered stations, samples were drawn throughout the water column 
with focus on the upper 1000m.  The replicate samples were interspersed 
throughout the station analysis for quality assurance of the integrity of the 
coulometer cell solutions. No systematic differences between the replicates 
were observed.  

In addition to the samples drawn from the Niskin-type bottles, we collected 
underway surface (~5 meter) sea-water samples from the sea chest. We did on 4 
hour intervals this during the transit from New Zealand to station 1 and 
during the transit to Australia after the end of station 88.


References

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

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

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.

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.

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.

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

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.

 
UNDERWAY pCO2

Equipment and Analytical Techniques: Underway pCO2 System (Version 2.5) AOML:

The shipboard automated underway pCO2 system is situated in the hydrolab.  It runs on an hourly cycle during which three gas standards, eight headspace 
samples from the equilibrator, and three ambient air samples are analyzed.  
The system consists of an equilibrator box where surface seawater from the 
bow intake is equilibrated with headspace, a valve box that contains the 
infrared analyzer, and a computer and interface boards that control valves 
and log sensors.

The equilibrator is a cylindrical Plexiglas(tm) chamber approximately 22.5 cm 
high and 8.8 cm wide.  Surface seawater flows through a spiral spray head in 
the top at a rate of 2 ±0.5 l/min. The water spray through the ~0.5-l 
headspace and the turbulence of the water streams impinging on the surface of 
0.5 l of water cause the gases in water and headspace to equilibrate.  Excess 
water flows through an outlet at the bottom of the equilibrator into an over-
the-side drain.  Two vents in the top of the equilibrator insure that the 
headspace remains at the measured laboratory pressure.  Headspace gas 
circulates in a closed loop driven by a KNF pump at 150 ± 50 ml/min.  From 
the equilibrator the gas passes through a condenser, a column of magnesium 
perchlorate, a mass flow meter (MFM), a 1.0 µm Acro(r) disk filter, the 12 ml 
sample cell of a Licor(tm) Model 6251 non-dispersive infrared analyzer (IR), 
and back into the equilibrator headspace.

A second KNF pump draws marine air from an intake on the bow mast through 100 
m of 0.95 cm (= 3/8") OD Dekoron(tm) tubing at a rate of 6-8 l/min.  A filter 
of glass wool at the intake prevents particles from entering the gas stream.  At designated times, the program diverts 175 ± 25 ml/min of air from this line 
into the Licor sample cell for analysis.  Excess marine air empties into a 
rotometer on the front panel of the valve box.

Both sample streams (equilibrator headspace and marine air) are analyzed bone 
dry.  They pass first through a cold trap (condenser) at 3°C and then through 
a column of magnesium perchlorate.  Standard gases also run through the 
magnesium perchlorate.

A custom developed program run under LabView(tm) controls the system and 
graphically displays air and water XCO2 readings.  The program logs the 
voltage and temperature of the infrared analyzer, water flow, gas flows, 
equilibrator temperature, and barometric pressure.  The program writes all of this data to disk at the end of each measurement phase.

The details of instrumental design can be found in Wanninkhof and Thoning 
(1993), Ho et al. (1995), and Feely et al. (1998).



Sampling Cycle:

The system runs on an hourly cycle during which three standard gases, three 
marine air samples, and eight surface water samples (from the equilibrator 
headspace) are analyzed on the schedule listed below.  A Valco multi-port 
valve selects the gas to be analyzed.  Each measurement phase starts by 
flowing either standard (@~50ml/min), equilibrator headspace (@~150 ml/min), 
or marine air (@~175 ml/min) through the Licor.  Fifteen seconds before the 
end of each phase, a solenoid valve stops the gas flow.  Ten seconds later, 
the program logs all sensors and writes the data to disk.


Table 2.14.  Hourly sampling cycle for the underway pCO2 system (version 2.5).

          Minutes after the Hour   Sample
          ----------------------   ----------------------------------
                    4              Low standard
                    8              Mid standard
                   12              High standard
                   16.5            Water (= headspace of equilibrator)
                   21              Water
                   25.5            Water
                   30              Water
                   34              Air (marine air from the bow line)
                   38              Air
                   42              Air
                   46.5            Water
                   51              Water
                   55.5            Water
                   60              Water

Standards:

The unit is standardized every hour with three compressed air standards 
containing known amounts of CO2 gas in (natural) air. The standard gases are 
purchased from NOAA/CMDL in Boulder and are directly traceable to the WMO 
scale.

The standards used on the cruise are:

                                   Mole Fraction
                       Tank #    CO2 (ppm) (= XCO2)
                      --------   ------------------
                       CA06827         284.71
                       CA05334         380.98
                       CA06380         448.29

Units:

All XCO2 values are reported in parts per million (ppm), and fCO2 values are 
reported in micro atmospheres (µatm).


Data Availability: 

The system ran well during the entire cruise from February 4 to March 17 
except for one period from 1230 to 1630 GMT on February 8 when the seawater 
system shut down temporarily.  The data will be posted on the web 
approximately 1 month after the end of the cruise at:
<http://www.aoml.noaa.gov/ocd/gcc/index.php>.


References

Feely, R.A., R. Wanninkhof, H.B. Milburn, C.E. Cosca, M. Stapp, and P.P. 
    Murphy, 1998: A new automated underway system for making high precision 
    pCO2 measurements onboard research ships.  Analytica Chim. Acta, v. 377, 
    pp. 185-191.

Ho, D.T., R. Wanninkhof, J. Masters, R.A. Feely, and C.E. Cosca, 1997:  
    Measurement of underway fCO2 in the eastern equatorial Pacific on NOAA 
    ships Baldrige and Discoverer.  NOAA Data Report, ERL AOML-30, 52 pp.

Wanninkhof, R., and K. Thoning, 1993: Measurement of fugacity of CO2 in 
    surface water using continuous and discrete sampling methods. Mar. Chem., 
    v. 44, no. 2-4, pp. 189-205.


ALKALINITY
(Susan Alford and George Anderson, Last Revised: March 15, 2007)

Description of Equipment and Technique

Analysis of samples was carried out using an open cell system per A.G. 
Dickson (complete reference info to be provided later) using a two-step 
titration. While the sample was being stirred slowly, an approximately 2.5 ml 
aliquot of acid was added to bring the pH of the sample to ~3.5.  After 4.5 
minutes of vigorous stirring and bubbling with CO2 free air, additional 
aliquots of 0.05 mls of the acid were added.

Sampling and data processing techniques

On every other station, complete profiles were drawn with up to 3 duplicates.  
On the alternate stations, sampling was done in conjunction with the D.I.C 
and C-14 sampling programs and typically consisted of less than full 
profiles.  

The samples were drawn from Niskin bottles into rinsed 280ml Pyrex serum 
bottles.  To avoid organic contamination during sampling, a silicon drawing 
tube (provided by the CDOM sampling group) was used.  Following collection, 
the samples were poisoned with 0.056 microliters of a saturated mercuric 
chloride solution.

The volume of sample to be run for analysis was measured using a 100 ml 
calibrated pipet.  The filling and emptying of the pipet were controlled 
using an automated system consisting of a peristaltic pump, an aquarium pump 
(making the pipet a blow-out unit), solenoid pinch valves and a ChronTrol 
programmable timer/controller. This system allowed for the measurement of 
each sample to be run, the dispensing of this volume into the cell to be used 
during analysis, and the rinsings of the pipet between samples.

During analysis, after each addition of acid during the titration, the volume 
added, a cell temperature, and a millivolt reading were electronically 
recorded.  The data was then processed by applying a modified linear fit to 
the data falling between pH 3.5 and 3.0 in order to calculate a preliminary 
alkalinity value for each sample that was run.  

As titrations were completed, all preliminary alkalinity values were plotted 
versus pressure to check for samples that should be rerun.  Having this plot 
available proved very helpful in this regard.

Calibration 

All equipment used in our analyses was calibration ashore prior to the cruise 
during the timeframe of December 2006 through January 2007.  This includes: 
YSI and Guildline thermometers, Keithley multimeter, Dosimat model 665 buret 
with a 5ml exchange unit, 100ml Pyrex pipet, Cole-Parmer  0-200 ml/min 
flowmeter and spares.  

Error Estimates

The stability of the alkalinity system was monitored using Batch 78 of the 
Dickson Laboratory DIC/ALK reference materials (certified value: 2158.57 +/- 
0.45 µmoles/kg) The CRM data were plotted versus time to monitor system 
performance.  The preliminary data indicate an offset of ~1 µmoles/kg needs 
to be applied to the data, with the measured values being higher than the 
certified value.
   
Replicate Analyses

When duplicate samples were collected from the Niskin bottles, the surface or 
near surface bottle, an intermediate depth bottle, and the bottom or near 
bottom bottle were sampled.  These replicates were interspersed amongst the 
other samples during analysis with the deep replicate being run first, the 
surface replicate about half-way through the station samples and the mid-
depth replicate just before the sample from Niskin 1, the deepest sample in 
the cast.

For calculations completed on analyses thus far, the standard deviation of 
the difference between preliminary alkalinity values of duplicates and the 
"matching" bottle drawn from the same Niskin average to be about 1.5 
µmoles/kg-sol, scattering equally around zero.

Standards

The stability of the alkalinity system was monitored using Batch 78 of the 
Dickson Laboratory DIC/ALK reference materials (certified value: 2158.57 +/- 
0.45 µmoles/kg)

Reagents

A saturated mercuric chloride solution prepared onshore in January 2007 was 
used to poison all samples before the samples were analyzed.  In addition, a 
well-characterized ~0.1 molar hydrochloric acid in 0.6 molar sodium chloride 
solution was used for all titrations.
  

DOC/DON 

A total of 1522 seawater samples were collected and frozen during the I8 leg 
for DOC/DON analysis. The frozen seawater samples will be retuned to the 
University of Miami, Rosenstiel School of Marine and Atmospheric Science for 
analysis using High Temperature Catalytic Oxidation (HTCO).  For further 
information about the analysis or data availability please contact Dr. Dennis 
Hansell (dhansell@rsmas.miami.edu).


CARBON-14 

A total of 470 seawater samples were collected and preserved for 14C 
analysis.  The samples will be returned to Woods Hole Oceanographic 
Institution for analysis.  For more information about the data or analysis 
please contact Ann McNichol (amcnichol@whoi.edu).


CHLOROFLUOROCARBON (CFC) MEASUREMENTS  

PI:                    John L. Bullister 

Samplers and Analysts: David Wisegarver
                       Eric Wisegarver
                       David Cooper

Samples for the analyses of dissolved CFC-11 and CFC-12 were drawn from 
2000 water samples collected during the expedition. Water samples were 
collected in specially designed Niskin bottles, that use a modified end-
cap design to minimize the contact of the water sample with the end-cap 
O- rings after closing. Stainless steel springs covered with a nylon 
powder coat were substituted for the internal elastic tubing provided 
with standard Niskin bottles. When taken, water samples for CFC  were the 
first samples drawn from the 10-liter bottles. Care was take to 
coordinate the sampling of CFCs with other samples to minimize the time 
between the initial opening of each bottle and the completion of sample 
drawing. In most cases, dissolved oxygen, 3He, samples were collected 
within several minutes of the initial opening of each bottle. To minimize 
contact with air, the CFC samples were drawn directly through the 
stopcocks of the 10-liter bottles into 250 ml precision glass syringes 
equipped with three-way plastic stopcocks. The syringes were immersed in 
a holding tank of clean surface seawater held at approximately 0 degrees 
Centigrade until 30 minutes before being analyzed.  At that time, the 
syringe was place in a bath of surface seawater heated to 25 degrees C.   

For atmospheric sampling, a ~100 m length of 3/8" OD Dekaron tubing was 
run from the CFC, van located on the fantail, to the bow of the ship. A 
flow of air was drawn through this line into the main laboratory using a 
Kadet 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 valves of the CFC  analytical systems, while the bulk flow of the 
air (>7 l min-1) was vented through the backpressure regulator. Air 
samples were only analyzed when the relative wind direction was within 60 
degrees of the bow of the ship to reduce the possibility of shipboard 
contamination.  Analysis of bow air was performed at 16 locations along 
the cruise track. At each location, at least five measurements were made 
to increase the precision. The measured concentrations are reported in 
Tables 1 and 2.  Concentrations of CFC-11 and CFC-12 in air samples, 
seawater, and gas standards were measured by shipboard electron capture 
gas chromatography (EC-GC) using techniques modified from those described 
by Bullister and Weiss (1988). 

For seawater analyses, water was transferred from a glass syringe to a 
glass-sparging chamber (~190 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 175 ml min-1. Water 
vapor was removed from the purge gas during passage through an 18 cm 
long, 3/8" diameter glass tube packed with the desiccant magnesium 
perchlorate. 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) and a 22 cm section packed with Carboxen 
1004.  A neslab cryocool was used to cool the trap, to -70°C.  After 6 
minutes of purging, the trap was isolated, and it was heated electrically 
to ~175°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 precolum (5 cm of 1/8" O.D. Stainless steel 
tubing packed with  MS5A, 80°C) 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 100°C).  After CFC-11 had passed 
through the first precolumn, the remaining gases were backflushed from 
the precolumn and vented.  Column #1 and the precolumns were in a Shimadzu 
GC8 gas chromatograph with electron capture detector (340°C).  Column #2 
was in a Shimadzu Mini2 gas chromatograph, also with electon capture 
detector (250°C).

Both of the analytical systems were calibrated frequently using a 
standard gas of known CFC composition. Gas sample loops of known volume 
were thoroughly flushed with standard gas and injected into the system. 
The temperature and pressure was recorded so that the amount of gas 
injected could be calculated. The procedures used to transfer the 
standard gas to the trap, 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 ~11 minutes.  Concentrations of the CFCs  in air, 
seawater samples, and gas standards are reported relative to the SIO98 
calibration scale (Cunnold et al., 2000). 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 45186) 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-range calibration 
curves were run at intervals of 4-5 days 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. 

On this expedition, based on the analysis of 150 duplicate samples, we 
estimate precisions (1 standard deviation) of less than 1% or 0.005 
(whichever is greater) for both dissolved CFC-11 and  CFC-12 
measurements.  A very small number of water samples had anomalously high 
CFC concentrations relative to adjacent samples. These samples occurred 
sporadically during the cruise and were not clearly associated with other 
features in the water column (e.g., anomalous dissolved oxygen, salinity, 
or temperature features). This suggests that these samples were probably 
contaminated with CFCs during the sampling or analysis processes. 
Measured concentrations for these anomalous samples are included in the 
preliminary data, but are given a quality flag value of either 3 
(questionable measurement) or 4 (bad measurement). A quality flag of 5 
was assigned to samples which were drawn from the rosette but never 
analyzed due to a variety of reasons (e.g., leaking stopcock, plunger 
jammed in syringe barrel).


References 

Bullister, J.L., and R.F. Weiss, 1988: Determination of  CC13F and CC12F2 
    seawater and air. Deep-Sea Res., v. 25,  pp. 839-853.
 
Prinn, R.G., R.F. Weiss, P.J. Fraser, P.G. Simmonds, D.M.  Cunnold, F.N. 
    Alyea, S. O'Doherty, P. Salameh, B.R.  Miller, J. Huang, R.H.J. Wang, 
    D.E. Hartley, C. Harth,  L.P. Steele, G. Sturrock, P.M. Midgley, and 
    A. McCulloch,  2000: A history of chemically and radiatively 
    important gases in air deduced from ALE/GAGE/AGAGE. J. Geophys.  
    Res., v. 105, pp. 17,751-17,792. 


TRACE METALS 
(Joe Resing, NOAA/PMEL)

Hydrographic sampling for the trace elements Al and Fe was conducted during 
leg 1 of I8S aboard the R/V Revelle.  Samples were collected using a 
specially designed rosette system which consists of 12 x 12L Go-Flo bottles 
mounted on a powder-coated  rosette frame.  The package is equipped with a 
SeaBird SBE 911 ctd that also has an SBE 43 oxygen sensor and a Wet Labs FL1 
fluorometer.  The package is lowered using a Kevlar conducting cable and 
bottles were tripped at pre-determined depths from the ship using a deck box.  
Water samples were collected in the upper 1000 m at a total of 37 stations, 
spaced at ~1 degree intervals.  

Dissolved Al, Fe and Mn were determined on these water samples using 
shipboard FIA (C.I. Measures, University of Hawaii).  In addition samples 
were collected for shore-based ICP MS determinations of dissolved and 
dissolvable Fe, Ni, Cu, Zn, Cd, and Pb by isotope dilution (W.M. Landing, 
FSU).  Additional samples were collected by Amir Hamidian for shore-based Cd 
determinations at Otago University, New Zealand.  Particulate samples were 
also collected for shore-based determination of trace elements by EDXRF.


TRACE METALS ROSETTE SAMPLING:
(Dr. William M. Landing and Clifton S. Buck/FSU)

We deployed the trace metals rosette at 37 stations, collecting roughly 450 
samples. Bad weather (high winds and rough seas) prevented us deploying at 
several stations. We had some electrical issues that caused two casts to be 
aborted at Stations 042 and 043 respectively.  The problems were resolved by 
a combination of reseating of signal cables and retermination of the Kevlar 
cable.  We also did not collect samples at Station 001 because the bottles 
did not trip correctly as the pylon was frozen while on deck from a fresh 
water rinse normally given to the rosette before deployment.

Subsamples were taken from each GoFlo bottle for at-sea analysis of salinity, 
nutrients, and dissolved total Fe and Al (Bill Hiscock of the Measures 
Group). Archived subsamples are described below.


AEROSOL SAMPLING 
(Clifton Buck, FSU Oceanography PhD student)

Aeolian transport and deposition of soluble aerosol Fe is believed to 
influence phytoplankton primary productivity in the majority of the open 
ocean (far from Fe inputs from rivers and coastal sediments). The purpose of 
the FSU aerosol sampling program is primarily to measure the concentration of 
total aerosol Fe, and to quantify the aerosol Fe fractions that are soluble 
in natural surface seawater and in ultra-pure deionized water. Additional 
analyses are conducted on the samples in an effort to understand the 
atmospheric processes that yield differences in the aerosol Fe solubility. 

The aerosol sampling equipment consists of four replicate filter holders 
deployed on a 20' fold-down aerosol tower mounted on the forward, starboard 
corner of the 03 deck of the ship. One of the replicate filters (0.4 µm 

Nuclepore polycarbonate track-etched) is used for total aerosol measurements 
(see below); one replicate filter (0.45 µm polypropylene) is used to quantify 
the seawater-soluble fraction; one replicate filter (0.45 µm polypropylene) is 
used to quantify the ultra-pure deionized water soluble fraction; and one 
replicate filter (0.45 µm polypropylene) is used for precision (QA) tests or 
stored as a backup sample. Size-fractionated aerosols are also collected for 
72 hour intervals starting every fourth day using a MOUDI cascade impactor 
(>3.2 µm, 1.0 µm, 0.56 µm, 0.056 µm).

Air is pulled through the filters using two high-capacity vacuum pumps. The 
sampling is controlled by a Campbell Scientific CR10 datalogger that 
immediately shuts off the flow when the wind might blow stack exhaust forward 
towards the sampling tower, or when the wind drops below 0.5 m/s. Air flow is 
measured using Sierra mass-flow meters. 

We have collected 24-hour integrated aerosol samples each day for the entire 
leg (23 days of sampling) for the following analyses:

  • Total aerosol Si, Al, Fe (to be analyzed using Energy Dispersive X-Ray 
    Fluorescence by Dr. Joe Resing at NOAA/PMEL). 
  • Seawater-soluble aerosol Al and Fe (to be run back at FSU).
  • Ultra-pure water soluble Si, Al, Ti, Fe, chloride, sulfate, nitrate, sodium 
    (to be run back at FSU). The MOUDI size-fractionated aerosol filters are also 
    leached with ultra-pure water for these same analytes.


OTHER SAMPLING

We collected archived samples from each trace metal cast (37 stations, 
approx. 650 samples) for FSU shore-based analysis of dissolved Fe, Ni, Cu, 
Zn, Cd, and Pb using isotope dilution ICPMS.

We collected 237 samples for Amir Hamidian of University of Otago who will 
analyze them for dissolved Cd.

The TSM from each trace metal cast was collected on 47 mm 0.4 um Nuclepore 
filters for EDXRF analysis of total particulate Si, Mn, Fe, and Al (Joe 
Resing, NOAA/PMEL). 

200 mL of rain was collected during a squall at 40°S and 95°E.  The samples 
were filtered and frozen for analyses at FSU for soluble Si, Al, Ti, Fe, 
chloride, sulfate, nitrate, and sodium.


LOWERED ACOUSTIC DOPPLER CURRENT PROFILERS

Two lowered acoustic Doppler current profiler systems were brought on this 
cruise.  All instruments were manufactured by Teledyne R.D. Instruments.  One 
system was from University of Hawaii, and consisted of 150kHz broadband ADCP 
(BB150), manufactured in the mid-1990s.  The other was a pair of 300kHz "work 
horse" ADCPs, one of which was a higher-powered prototype (WH300 and HP-
WH300, respectively).  Both systems are self-contained, attached to the 
rosette but not attached to the CTD cable.  Either system, when deployed, is 
powered by a 48V lead-acid gel cell (or absorbed glass mat) battery system, 
contained in an oil-filled plastic box sealed by a urethane sheet.  These 
batteries are a vast improvement over the older gas-filled pressure cases 
(usually aluminum).  The newer batteries are known as the Safe Orange Battery 
due to the color of the case.  In 300-400 CLIVAR casts there has been no sign 
of any of the internal oil getting out, and we maintain a vigilant watch for 
any leaks.

Mainly due to the lower frequency, the older BB150 instruments are capable of 
greater profiling range than the newer instruments.  Each ping has more 
range, so a given vertical slab is sampled more during a cast by a BB150 than 
a WH300, which has half the range (or less)in a given profile. RDI does not 
manufacture the BB150 any longer.  The only current viable replacement is the 
WH system.  An individual WH300 can profile to the bottom of the ocean when 
particles exist throughout the water column (e.g. high latitudes).  In 
regions of low scattering (center of a gyre) they often cannot profile below 
1000-1500m.  WH instruments are usually used in pairs with one looking up and 
one looking down, to increase the number of samples in a vertical slab during 
a cast.  The HP-WH300 is a prototype RDI hopes will improve profiling range, 
especially in regions of low scattering.

The plan for this cruise was to use the WH pair until scattering was 
sufficiently low that they were not profiling to the bottom.  At that time we 
would switch to the BB150, which would extend the range of each ping, and 
hence the depth to which the instrument can profile.

During the long steam to the first station communication with the HP-WH300 
was problematic, and after opening the pressure case and reseating the PCMCIA 
memory card, it was determined that the bulkhead connector was also bad.  
Because the WH300 was potentially to weak an instrument to work alone, the 
BB150 was put on for the first  station.  Unfortunately, the BB150 was in a 
confused state, or its up/down mercury switch was stuck in the wrong 
position.  The first 7 casts were full of reasonable-looking data which were 
acquired with some incorrect transformation, so the final velocities are 
junk. On cast 8 we switched to the remaining functional instrument, the 
WH300.  That instrument did in fact profile to the bottom until cast 48.  
However, with increasing frequency, it only returned a very short cast 
(truncated after minutes).  Between casts 8 and 48, 4 casts were lost from 
this problem, three of which occurred close together.  

On cast 49 we switched to the BB150.  It has a single eroded pin in the 
bulkhead connector but is still functional.  A new cable and attention to 
seating the cable appear to have kept its connector  in good condition 
because the instrument had no problems from station 49 to 88 the BB150 had no 
problems.  One cast was lost because the  serial port on the acquisition 
computer failed at the time of deployment.  Because of all the earlier 
communications trouble, a quick decision was made to send the cast down with 
the LADCP  not pinging.  During the cast the PC was rebooted and the serial 
port functioned again.  As it turns out, the PC involved suffered a  
catastrophic hard drive (or other hardware) failure at the end of the cruise 
(after all casts and backups).  It is not clear whether the  serial port 
failure was a harbinger of bad news.  Two casts were lost due to operator 
error.

In all, 34 WH300 casts were obtained and 38 BB150 casts were obtained. No 
data were acquired with the HP-WH300.  Spare bulkhead connectors and o-rings 
are en route to Fremantle awaiting a future date with these instruments.

Final LADCP processing is the responsibility of the LDEO group, but the 
components are in place.  The shipboard data from the NB150 are of sufficient 
quality that they can be used on the second leg "live", and on this leg a 
final processed dataset will be available for the LADCP operator.  GPS 
position files are available for the entire cruise, and ODF (the CTD group) 
has provided a 1/2 second time series of pressure, temperature, salinity, and 
other variables, for use with LADCP processing.  Preliminary processing for 
leg 1 shows good agreement between the shipboard and lowered ADCP data in the 
upper 200m.


SHIPBOARD DOPPLER CURRENT PROFILERS

The Revelle has three Doppler sonars for measuring ocean velocity. One of 
these, a commercial 150kHz narrowband instrument, is considered to be the 
primary shipboard current profiler for CLIVAR cruises.  The other two "High-
resolution Doppler Sonar System" (HDSS, 50kHz and 140kHz) were designed at 
Scripps Institute of Oceanography specifically for installation on the 
Revelle.  Their design characteristics were optimized for high-quality ocean 
shear measurements, and the ability to provide high-quality ocean velocity is 
under evaluation.  Comparison of the ocean velocity data from the HDSS and 
RDI instruments will enable a decision as to whether the HDSS velocities 
should be included in the shipboard final ocean velocity dataset. 


The CLIVAR Shipboard Ocean Velocity component

The primary instrument (NB150) was made by R.D. Instruments (now owned by 
Teledyne) in the late 1980s.  The original commercial acquisition and 
averaging software ran under DOS and required a fairly slow computer.  A new 
acquisition system written at the University of Hawaii was temporarily 
installed on a laptop for the P16S CLIVAR leg in Jan 2005.  The laptop was 
subsequently replaced with an SIO-owned rack-mount unit. 

The acquisition system (UHDAS, University of Hawaii Data Acquisition System) 
is written in C and Python; processing software is in C, Python, and Matlab.  
UHDAS acquires data from the NB150 instrument, gyro heading (for reliability), 
Ashtech heading (for accuracy), and GPS positions from various sensors.  
Single-ping data are converted from beam to earth coordinates using known 
transducer angles and gyro heading, and are corrected by the average Ashtech-
gyro difference over the duration of the 5-minute profile.  This scheme 
insulates the heading correction against short gaps or loss of fixes.  For 
Ashtech gaps (up to 2 hours), the previous available correction is used.

Groups of single-ping ocean velocity estimates must be averaged to  decrease 
measurement noise.  These groups commonly comprise 5 minutes. Bad pings must 
be edited out prior to averaging.  This is done by UHDAS using a collection 
of criteria tailored to the instrument type and frequency, and to the 
specific installation.

UHDAS uses a CODAS (Common Oceanographic Data Access System) database for 
storage and retrieval of averaged data.  Various post-processing steps can be 
administered to the database after a cruise is over, but the at-sea data 
should be acceptable for preliminary work.

UHDAS provides access to regularly-updated figures and data via the ship's 
network.  The software used is all open-source and is available via samba 
share and nfs export, as well as through the web interface. The web site has 
regularly-updated figures showing the last 5-minute ocean velocity profile 
with signal return strength, and hourly contour and vector plots of the last 
3 days of ocean velocity. 


Shipboard Doppler sonar work on this cruise

NB150:

UHDAS is undergoing a transformation to remove dependence on Matlab. This 
transition will take some time and of necessity takes place in increments.  
On this cruise, work towards that transition included development of 
preliminary versions of all figures used in batch processing and on the web 
site.  The UHDAS system provided a valuable test platform for the figures but 
they will not be incorporated into the system as they have been tested for 
robustness.  Updates to acquisition and processing code were implemented that 
addressed various bugs and improved reliability.  A revised transducer angle 
(orientation relative to the ship) is possible after this cruise  and will be 
updated on the acquisition computer.

A new Ashtech receiver was shipped out to Dunedin for this cruise because the 
previous one (an older ADU2 unit) had failed.  The new (replacement) deck 
unit is using the original antennas and survey configuration.  For the most 
part it has been reliable, but there were several times when it locked up and 
had to be restarted  (trace the correct power cable on the bridge, unplug it, 
wait 15 seconds, and plug it in -- a reset using the button was insufficient).
Post-processing of the NB150 data will include an improved heading correction 
to account for the few long gaps.


HDSS:

On the P16S 2005 CLIVAR cruise, CODAS processing steps were adapted for use 
with the HDSS data.  Those instruments had, at the time, three beams and two 
beams out of four, for the 140kHz and 50kHz instruments, respectively.  In January 2006 the 140kHz was repaired and the broken 50khz beams were replaced.  The HDSS data acquisition system is also undergoing a transformation, but for the moment, the data format and associated peculiarities are consistent with the present CODAS processing code.  One change to CODAS processing was made to accommodate a newer and more precise binary data storage standard required in newer Matlab versions (newer Matlab failed to read the binary HDSS data without this change).  This will be passed along to the proprietors of the HDSS system for their use.

HDSS data will be compared to NB150 data after the best final processing of 
each has been finished.  If the data look good, they will be included in the 
ADCP archive along with the NB150 data.


CHROMOPHORIC DOM

Project Title:    Chromophoric DOM -- A Photoactive Tracer of Geochemical Process

PIs:              D. Siegel, N. Nelson, C. Carlson
                  University of California, Santa Barbara

Support:          NASA Ocean Biology and Biogeochemistry; NSF Chemical Oceanography

Field Team (I8S): N. Nelson (PI), D. Menzies (Sr. Engineer)
Field Team (I9N): C. Swan (GS), E. Wallner (GS)


Project Goals:

Our goals are to determine chromophoric dissolved matter (CDOM) distributions 
over a range of oceanic regimes on selected sections of the CO2/CLIVAR Repeat 
Hydrography survey, and to quantify and parameterize CDOM production and 
destruction processes with the goal of mathematically constraining the 
cycling of CDOM. CDOM is a poorly characterized organic matter pool that 
interacts with sunlight, leading to the production of climate-relevant trace 
gases, attenuation of solar ultraviolet radiation in the water column, and an 
impact upon ocean color that can be quantified using satellite imagery. We 
believe that the global distribution of CDOM in the open ocean is controlled 
by microbial production and solar bleaching in the upper water column, and 
relative rates of advection and remineralization in intermediate and deep 
waters. Furthermore, changes in the optical properties of CDOM and its 
relationship with DOC over time suggest the use of CDOM as an indicator of 
the prevalence of refractory DOC in the deep ocean. We are testing these 
hypotheses by a combination of field observation and controlled experiments. 
We are also interested in the deep-sea reservoir of CDOM and its origin and 
connection to surface waters and are making the first large-scale survey of 
the abundance of CDOM in the deep ocean. 


Activities on I8S and I9N:

Profiling Instruments

Once each day we are casting a hand-deployed free-fall Satlantic MicroPro II 
multichannel UV/Visible spectroradiometer. This instrument has 14 upwelling 
radiance sensors and 14 downwelling irradiance sensors in wavelength bands 
ranging from 305 to 683 nm. The package also mounts a WetLabs ECO chlorophyll 
fluorometer, plus ancillary sensors including X-Y tilt, internal and external 
temperatures. The instrument is allowed to trail away behind the port-side 
stern, then free-falls to 150m and is hand-recovered. We are using the 
radiometric data to study the effects of CDOM on the underwater light 
environment, to validate satellite ocean radiance sensor data, and to develop 
new algorithms employing satellite and in situ optical sensor data to 
retrieve ocean properties such as CDOM light absorbance, chlorophyll 
concentration, and particulate backscattering. 

On the core CTD we are deploying a WetLabs UV fluorometer (Ex 370 nm, Em 460 
nm), which stimulates and measures fluorescence of CDOM. We are evaluating 
the use of this instrument to supplement or enhance bottle CDOM measurements, 
as bottle samples often do not have the depth resolution needed to resolve 
the observed strong near-surface gradients in CDOM concentration, and on 
cruises such as this we are not able to sample CDOM on every station. 
Differences between the fluorescence and absorption profiles, may reveal 
gradients in chemical composition of CDOM. On I8S the fluorometer has 
performed very well: problems with temperature compensation encountered on 
P16N have been corrected. Signal to noise ratios remain low for the open 
ocean areas we are studying. 

This fluorometer is ganged to a WetLabs C-star 660 nm 0.25m pathlength beam 
transmissometer belonging to Dr. Wilford Gardner, TAMU. The transmissometer 
is used to gauge particle load in the water column, which can be calibrated 
to produce estimates of particulate carbon. Decline of the particle load with 
depth can then be related to POC flux, another element of the carbon system. 


Bottle Samples

CDOM is at present quantified by its light absorption properties. We are 
collecting samples of seawater for absorption spectroscopy on one deep ocean 
cast each day. CDOM is typically quantified as the absorption coefficient at 
a particular wavelength or wavelength range (we are using 325 nm). We 
determine CDOM at sea by measuring absorption spectra (280-730 nm) of 0.2um 
filtrates using a liquid waveguide spectrophotometer with a 200cm cell. On 
I8S duplicate samples were collected at a rate of ca. 2 samples per cast. RMS 
differences in absorption coefficient at 325 nm between the duplicate samples 
were just over 0.003 m-1, which is ca. 4% of the average absorption 
coefficient at that wavelength.

We also concurrently collecting samples for bacterial abundance and DOM 
characterization (including carbohydrate and neutral sugar analysis) to 
compare the distribution of these quantities to that of CDOM. In surface 
waters (< 300m) we are also estimating bacterial productivity of field 
samples by measuring the uptake of bromo-deoxyuridine (BrdU), a non-
radioactive alternative to the standard bacterial productivity technique 
using tritiated thymidine.  

Because of the connections to light availability and remote sensing, we are 
collecting surface samples (from the ship's uncontaminated seawater system) 
for chlorophyll, carotenoid, and mycosporine-like amino acid pigment analysis 
(HPLC), chlorophyll a (fluorometric), and particulate absorption 
(spectrophotometric). We are sporadically collecting large volume (ca. 2L) 
samples for CDOM photolysis experiments back at UCSB, and occasionally 
collecting large volume samples for POC analysis to compare with 
transmissometer data. We have the cooperation of the Trace Metals group for 
the large-volume subsurface samples from their Go-Flo bottles. We are only 
analyzing the CDOM and chlorophyll a at sea and the rest of the samples we 
are preparing and storing for later analysis.


Outreach Team

The I8S Public Outreach Team is a collaboration between Pien Huang, Cassandra 
Lopez, and Daniel Park, formed through an independently submitted proposal to 
Chief Scientist Jim Swift. By using oceanography as an example, they intend 
to inform the public of the basic scientific process. They will reach both 
classrooms and the general adult public by means of written and multimedia 
features in print and on the web.
 
We have been documenting our experiences on an informal blog which has 
gathered a solid readership beyond our family and friends by becoming a 
surprise hit with Ms. Brice's 8th grade class. Throughout the cruise, we have 
been lucky to have had outreach opportunities presented to us. Mid-cruise, we 
were invited to submit materials to a new NSF program which feeds articles to 
the widely read and distributed website LiveScience.com. Our primary efforts, 
however, have been focused on gathering material for longer articles and a 
feature-length documentary.
 
We brought to this cruise very few preconceptions of oceanography, but 
through first-hand experience we have improved our understanding of ocean 
measurement. We've realized that data collection is a difficult and often 
tedious process, but having participated in field work we now appreciate this 
necessary effort in the context of developing and clarifying ocean and 
climate models. Better data inform better models which in turn will forecast 
climate to the benefit of society. We hope our projects will enable the 
public to see and value the contributions of every member of this cruise.
 
And of course we've really enjoyed our time on the Revelle and the chance 
we've had to work closely with so many fun and talented people!


GRADUATE STUDENTS

Each of the four graduate students was asked to write some form of report or 
comments of their choice about their participation.



JJ Becker (UCSD/SIO)

"Jim,

"Thanks for allowing me to participate on the I8S cruise. It was a pleasant 
trip and I hope I added something to effort. I especially enjoyed making the 
occasional plot and spreadsheet; always nice to be useful.

"I have down loaded the CTD and multi-beam data and plan on using it very 
soon in a upcoming paper relating the first derivative of each to the other.

"I greatly enjoyed my time with Rob. He has a pleasant manner and is a 
natural teacher. It was a pleasure to work with Jean again, as his knowledge 
of the ship and the science made my life easier and my time more productive.

"Finally it was pleasant and instructive to stand watch with you. I learned a 
great deal about the way NSF and the funding process really works and also 
enjoyed spending time with you. I hope I can participate again in another one 
of your cruises."



David Ullman (University of Wisconsin)

"My participation as a graduate student on board the I8S cruise has 
contributed immensely to my graduate education.  I have been able to get a 
glimpse of the true nature of oceanography work.  Back in the land-locked 
state of Wisconsin, I had been struggling with my research in carbon cycle 
modeling because of a disconnect between my first-hand work experience and my 
physical surroundings, never experiencing the deep blue sea in the flesh.  I 
used to always joke that I study the North Atlantic in Wisconsin using a 
supercomputer in Colorado.  Before embarking on this voyage, I was excited to 
resolve this disconnect. 

Being my first time at sea, I did not know what to expect.  Would I get sea 
sick?  Could I do the work required of me?  Would I enjoy the people on 
board?  Would I like the food?  Fortunately, the answer to all these 
questions was "yes" (unfortunately so was the first one, but I found my sea 
legs eventually).

"For the most part, the work was quite enjoyable, a different change of pace 
from my life of working with FORTRAN, FERRET, and MATLAB.  Literally getting 
my hands dirty (and wet), I enjoyed the challenges that came with life on a 
ship, working on the rosette and its instruments and the related computing 
tools to "drive" this VW-beetle-on-a-wire to the ocean floor.  Preparing the 
rosette allowed for a basic understanding of the mechanics of ocean data 
collection.  Deployment and recovery were particularly challenging and 
exciting (I know I'm not supposed to use this word), a physical challenge to 
guide a 15 foot pole in 40 knot winds to attach a tag line in rough seas.  
Sampling and the art of the "sample-cop" was a fun time, usually a jovial yet 
professional atmosphere as everyone joked and sampled their way around the 
rosette.  And while the actual "driving" of the rosette had its boring 
moments, I did enjoy sitting at the computer hearing Jim's sea/life stories 
and picking his brain for a better understanding for big-picture and small-
scale physical oceanography.  It was fun to watch the data write itself in 
front of our eyes, truly real-time oceanography.

"Perhaps the best part of this cruise were the people on board.  From the 
stories I've heard, things are not always as nice as on this cruise.  
Everyone was pleasant, helpful, and knowledgeable.  Life on this ship could 
have been much worse if the scientists and crew were not so agreeable.  I 
feel fortunate to have experienced my first cruise with such a group.  I 
really enjoyed hearing about everyone's previous experiences, quite amazing 
to have so many experts in oceanography in such a small amount of space.  I 
felt comfortable to ask any kind of question, and most questions could be 
answered by someone on board.  I really tried to draw upon all the expertise 
on board.  My goal on this trip was to be a sponge for information.  
Fortunately there was a lot of water to absorb on a boat in the middle of the 
sea.  I was particularly glad to have J.J. as my partner-in-crime, a man with 
a great amount of experience and knowledge (and a superior sense of humor).  
The pairing of experienced and inexperienced graduate students was a great 
idea.

"Finally, I would like express my great thanks to Jim Swift for allowing me 
to come along on this cruise.  I know that it was quite a gamble to bring 
along some unknown kid from the Midwest all the way to the Southern Ocean, 
but I'm glad that he took the chance.  I hope that my presence on this cruise 
was as helpful to the research goals of the project as it has been to my own 
education.            



Dian Putrasahan (UCSD/SIO)

The I8S cruise is the first research cruise that I have participated and it 
has been a wonderful experience. At the beginning of the cruise, the main 
concern was the extent and duration of my seasickness. It was rather worrying 
if the motion sickness did not wear off, since it would affect my ability to 
work onboard. However, the one-and-a-half week steam to the first station 
gave ample time to adapt to the motion and switch my time schedule to get 
into the work shift (midnight to noon). 

"Being a modeler, I had no idea how data is collected, how much effort it 
took and the obstacles that can occur such as equipment and instruments that 
would generate outrageous results or discontinuities, mechanical problems 
with the cable, human mistakes, data outliers, etc. This cruise has exposed 
me to some of the many problems that come along with data collection at sea, 
not only sampling uncertainties, but also working in rocky conditions. 
However, it was during this period of time that I got to learn many things. 

"As a graduate student, the main task was to help deploy and retrieve the 
rosette, as well as sample for nutrients and salts. Occasionally, I would be 
on the console watching and relaying the wire out, observing the tension in 
the cable, and calculating how far deep the rosette can go, making sure it 
does not hit the bottom. In the course of casting at stations, one realizes 
the importance of teamwork for the deployment and retrieval of the rosette. 
There were 5 people on the deck working together to cast at the stations (2 
at the outboard, one on the inboard, the resident technician (person in-
charge) and the boom operator). It was very important to secure the taglines 
and ensuring they do not knot. For this, I learnt how to tie the bowline 
knot. Most of the time, I was the boon operator, in which I had to listen 
carefully for instructions to pull in or push out the frame and landing the 
rosette onto the cart. After the rosette has been retrieved, I would flush 
the sensors with freshwater and proceed to sample cop. A sample cop is there 
to make certain that samples were taken in the right sequence, with the 
extraction for gas samples given as a priority. Half-way through being a 
sample-cop, I would usually pass it on to someone else so as to help draw 
nutrient and salt samples. This in itself has now become second nature. Once 
all the samples have been taken, the Niskin bottles are then drained, and 
then I would that sample logs to make copies, scan them, and place them 
online for all to use. It is then followed by preparing the rosette for the 
next cast, which includes closing the vents and spigots and cocking the 
Niskin bottles.

"Aside from sampling, I had learnt to run salts on the auto-sampler. First it 
was learning how to do it, trying to have it become second nature. And then 
slowly noticing how the salinity profile looked like and comparing them to 
the CTD salinity profile. It was important to note the air and bath 
temperature (no more than +- 3°C between air and bath temperature) to avoid 
drifting of the salinity readings. The sensitivity of salinity to temperature 
was clearly visible when drifting occurred. It was also essential to observe 
how the cells fill up, whether bubbles formed, and the pump speed to use to 
obtain more stable and reliable readings. It was vital for the salt runs to 
keep up with the sampling as there is a limited number of sampling bottles. 
Many a times, longer intervals are given between stations so as to allow more 
time for the analysis of chemicals. 

"This cruise has certainly given me great insights of doing fieldwork as an 
oceanographer. I have gained much knowledge and experience from it and would 
hope to contribute back from what I have received. I would be delighted to 
participate again in the future."



Lora Van Uffelen (UCSD/SIO)

"During the midnight to noon hours of the past six weeks I could barely be 
missed traversing the main hallway on the R/V Roger Revelle wearing a 
selection of brightly colored attire.  This attire was indicative of the 
tasks I was performing during my stint as a CLIVAR I8-S student research 
assistant in the southern ocean.

"First of all, there was the mustang or "pumpkin" suit.  This was a head-to-
toe cocoon of vivid orange that kept me nice and warm out on the deck while 
we were deploying the rosette amongst the icebergs.  It doubled as a safety 
work vest while we were handling tag lines, leaning over the side of the ship 
to hook the rosette, and bringing it safely back aboard.  

"After the rosette was secured in the sampling bay, the pumpkin suit was 
traded for a pair of yellow rain pants for the water-sampling phase of the 
rosette process.  These coveralls were protection against the sometimes sub-
zero waters that came spilling out of the 36 Niskin bottles as we worked our 
way around the rosette filling flasks for nutrient and salt analysis. 

"Lastly, there was the LADCP "uniform," which consisted of a pair of brightly 
colored Croc shoes and the teal LADCP fanny pack.  The Crocs were only part 
of the uniform because coincidentally Dr. Jules Hummon, who graciously 
imparted her knowledge of Lowered Acoustic Doppler Current Profilers, 
happened to wear orange Croc shoes while I sport yellow ones.  I had the 
opportunity on this cruise to learn a lot about the instrumentation and data 
collection process of the LADCP, and was able to look at some of the data 
immediately after it was acquired.  This was particular interest to me since 
my research area is ocean acoustics.  The fanny pack held such treasures as 
black electrical tape, which was used to seal the dummy plug onto the 
instrument's connector before it was deployed, and paper towels and kimwipes 
to dry the connector after recovery.  After the package was brought on deck, 
the data was downloaded and quality checked and the battery was recharged for 
the next cast.

"Other things that kept us busy were monitoring the progress of the CTD as it 
descended, tripping bottles at specified depths on its ascent to the surface, 
preparing the rosette for a cast by cocking the bottles open, and playing 
sample cop while the various sampling groups took their turns around the 
rosette.  Despite the darkness of the night shift hours, this cruise was full 
of not only bright colors, but also great experiences.  Besides my 
introduction to the LADCP, I have learned more about the geography and 
oceanography of the southern ocean, have seen my first iceberg and my first 
aurora australis, and I finally know how to tie a bowline."


