CRUISE REPORT: I07N
(Created: July 5, 2018. Updated: April 30, 2019)










                         Cruise Summary Information

              Section Designation  I07N
Expedition Designation (ExpoCode)  33RO20180423
                  Chief Scientist  Denis L. Volkov / AOML / CIMAS-UM
                            Dates  23 April 2018 – 6 June 2018
                             Ship  NOAA Ship Ronald H. Brown
                    Ports of Call  Durban, South Africa – Victoria, 
                                   Seychelles – Mormugao, India 

                                                18° N
            Geographic Boundaries  31° E                     73.8° E
                                                30° S

                         Stations  128 (including 2 test stations)
     Floats and Drifters Deployed  15 Argo floats and 10 SVP drifters
  Moorings Deployed and Recovered  0

                             Contact Information

       NOAA-AOML • Atlantic Oceanographic and Meteorological Laboratory
                 4301 Rickenbacker Causeway • Miami, FL 33149
             Tel.: 305-361-4344 • E-mail: Denis.Volkov@noaa.gov








                  Report assembled by Jerry Kappa, UCSD/SIO


















                    Cruise Report for the 2018 US GO-SHIP
                         Reoccupation of I07N Section
                          (Last edited 12 July 2018)


                                    Leg 1
                          NOAA Ship Ronald H Brown
                         23 April 2018 – 15 May 2018
                 Durban, South Africa – Victoria, Seychelles

                               Chief Scientist:
                             Dr. Denis L. Volkov
            National Oceanic and Atmospheric Administration, AOML
          Cooperative Institute for Marine and Atmospheric Studies,
                             University of Miami

                             Co-Chief Scientist:
                             Dr. Viviane Menezes
                     Woods Hole Oceanographic Institution

                                    Leg 2
                          NOAA Ship Ronald H Brown
                          19 May 2018 – 6 June 2018
                      Victoria, Seychelles – Goa, India

                               Chief Scientist:
                             Dr. Denis L. Volkov
            National Oceanic and Atmospheric Administration, AOML
          Cooperative Institute for Marine and Atmospheric Studies,
                             University of Miami

                             Co-Chief Scientist:
                             Dr. Viviane Menezes
                    Woods Hole Oceanographic Institution


                            CTD Data Submitted by:
                            Kristene E. McTaggart
                Pacific Marine Environmental Laboratory (PMEL)
           National Oceanic and Atmospheric Administration (NOAA)
                                 Seattle, WA

                     Preliminary Bottle Data Submitted by:
                               Denis L. Volkov
            National Oceanic and Atmospheric Administration, AOML
          Cooperative Institute for Marine and Atmospheric Studies,
                             University of Miami





Table of Contents

    Cruise Summary Information                                             1
1.  INTRODUCTION                                                           5
2.  PARTICIPANTS                                                           5
    2.1.  PARTICIPATING INSTITUTIONS                                       5
    2.2.  PROGRAMS AND PRINCIPAL INVESTIGATORS                             5
    2.3.  SCIENTIFIC PERSONNEL (LEGS 1 AND 2)                              6
3.  PROGRAM AND PROJECT OVERVIEW                                           7
4.  THE I07N SECTION                                                       8
5.  CRUISE NARRATIVE                                                       9
    5.1.  START OF THE CRUISE                                              9
    5.2.  FOREIGN CLEARANCES                                               9
    5.3.  ISSUES WITH THE AFT WINCH                                       11
    5.4.  ATTEMPT TO FIND A PMEL MOORING                                  11
    5.5.  CTD WIRE SITUATION                                              12
    5.6.  SCIENTIFIC STAFFING                                             12
6.  UNDERWAY DATA ACQUISITION                                             13
    6.1.  ACOUSTIC DOPPLER CURRENT PROFILER MEASUREMENTS                  13
    6.2.  UNDERWAY PCO2 ANALYSES                                          14
7.  CONDUCTIVITY, TEMPERATURE, DEPTH (CTD) STATIONS                       15
    7.1.  CTD DATA ACQUISITION                                            15
    7.2.  CTD DATA PROCESSING                                             17
    7.3.  PRESSURE CALIBRATION                                            18
    7.4.  TEMPERATURE CALIBRATION                                         18
    7.5.  CONDUCTIVITY CALIBRATION                                        19
    7.6.  OXYGEN CALIBRATION                                              19
    7.7.  DISCRETE NISKIN SAMPLING                                        20
    7.8.  BOTTLE DATA PROCESSING                                          21
    7.9.  COLLECTED SAMPLES                                               22
8.  SHIP-BOARD ANALYSIS SECTION                                           22
    8.1.  TEMPERATURE                                                     22
    8.2.  SALINITY                                                        22
    8.3.  DISSOLVED OXYGEN                                                22
    8.4.  TOTAL CO2                                                       22
    8.5.  TOTAL ALKALINITY / PH                                           22
    8.6.  NUTRIENTS                                                       23
    8.7.  CHLOROFLUOROCARBONS (CFCS) / SF6                                23
9.  INDIVIDUAL SUB-PROJECT REPORTS                                        23
    9.1.  DEPLOYMENTS                                                     23
          9.1.1.  Argo floats                                             23
          9.1.2.  Surface Velocity Program (SVP) drifters                 24
          9.1.3.  Wave buoys                                              24
    9.2.  LOWERED ACOUSTIC DOPPLER CURRENT PROFILER (ADCP)                25
    9.3.  DISCRETE SALINITY SAMPLING                                      27
    9.4.  DISSOLVED OXYGEN (DISCRETE)                                     28
    9.5.  DISSOLVED INORGANIC CARBON (DIC)                                31
    9.6.  DISCRETE PH ANALYSES                                            34
    9.7.  TOTAL ALKALINITY                                                37
    9.8.  NUTRIENTS                                                       39
    9.9.  CHLOROFLUOROCARBONS (CFCS) AND SULFUR HEXAFLUORIDE (SF6)        41
    9.10.  DOC AND TDN SAMPLING                                           44
    9.11.  GENETICS AND PARTICULATE ORGANIC MATTER                        45
    9.12.  DISSOLVED INORGANIC CARBON ISOTOPES IN SEAWATER (DI14C)        46
    9.13.  DISSOLVED ORGANIC MATTER 14C, BLACK CARBON 14C                 47
    9.14.  DOM BIOMARKERS AND MOLECULAR COMPOSITION                       48
    9.15.  DISSOLVED CALCIUM                                              51
    9.16.  DENSITY (JAMSTEC)                                              52
    9.17.  DENSITY (UM/RSMAS)                                             53
    9.18.  TRANSMISSOMETER MEASUREMENTS                                   53
    9.19.  BIOLOGICAL UNDERWAY MEASUREMENTS                               54
    9.20.  BIOLOGICAL SAMPLES FROM NISKIN BOTTLES                         56
    9.21.  BIOLOGICAL FILTRATION MEASUREMENTS                             57
    9.22.  NET TOWS                                                       58
    9.23.  ISOTOPIC COMPOSITION OF NITRATE                                59
    9.24.  Density; Post-Cruise Processing (JAMSTEC)                      60
    9.25.  Dissolved Calcium; Post-Cruise Processing (JAMSTEC)            63

10.  APPENDIX                                                             65
     10.1.  STATION PLAN                                                  65
     10.2.  PROPERTIES MEASURED DURING I07N                               67
     10.3.  SAMPLING NOTES                                                68
     10.4.  WEEKLY REPORTS                                                76
            10.4.1.  Week 0                                               76
            10.4.2.  Week 1 (Apr. 23-29)                                  76
            10.4.3.  Week 2 (Apr 30 - May 6)                              77
            10.4.4.  Week 3 (May 7 - May 13)                              78
            10.4.5.  Week 4 (May 14 - May 20)                             80
            10.4.6.  Week 5 (May 21 - May 27)                             81
            10.4.7.  Week 6+ (May 28 – June 5)                            83
CCHDO DATA PROCESSING NOTES                                               84




































1.  INTRODUCTION

Hydrographic measurements were carried out along the I07N section in the 
western Indian Ocean (Figure 1.1) in April-June 2018 under the auspices of 
the Global Ocean Ship-Based Hydrographic Investigation Program (GO-SHIP). 
The unique aspect of the 2018 I07N research cruise is that it was the first 
reoccupation of the I07N section since 1995. The section was not revisited 
for about 23 years because of the rise of piracy in the region. This cruise 
report details the cruise objectives, all science operations carried out 
during the cruise, as well as problems that were encountered.
 

Fig. 1: I07N cruise track in Apr-Jun 2018


2.  PARTICIPANTS


2.1.  Participating Institutions

Primary:
United States Department of Commerce
National Oceanic and Atmospheric Administration (NOAA)
Atlantic Oceanographic and Meteorological Laboratory (AOML)
4301 Rickenbacker Causeway, Miami, FL 33149, USA
Tel.: 305-361-4420
Fax: 305-361-4449

Additional (alphabetical)
 CCU      Coastal Carolina University
 CIMAS    Cooperative Institute for Marine and Atmospheric Studies, 
          University of Miami
 JAMSTEC  Japan Agency for Marine-Earth Science and Technology
 JISAO    Joint Institute for the Study of Atmosphere and Ocean, Univ. of  
          Washington
 LDEO     Lamont-Doherty Earth Observatory
 PMEL     NOAA Pacific Marine Environmental Laboratory
 PU       Princeton University
 RSMAS    Rosenstiel School of Marine and Atmospheric Sciences, University 
          of Miami
 SCCWRP   Southern California Coastal Water Research Project
 SIO      Scripps Institution of Oceanography
 TAMU     Texas A&M University
 UCI      University of California Irvine
 UH       University of Hawaii
 UMar     University of Maryland
 UW       University of Washington
 WHOI     Woods Hole Oceanographic Institution
 WWU      Western Washington University


2.2.  Programs and Principal Investigators

Program                PIs                   Institution  E-mail
—————————————————————  ————————————————————  ———————————  ——————————————————————————
CTD                    Molly Baringer        NOAA-AOML    molly.baringer@noaa.gov
                       Gregory Johnson       NOAA-PMEL    gregory.c.johnson@noaa.gov
Salinity               Molly Baringer        NOAA-AOML    molly.baringer@noaa.gov
LADCP                  Andreas Thurnherr     LDEO         ant@ldeo.columbia.edu
Dissolved Oxygen       Christopher Langdon   UM/RSMAS     clangdon@miami.edu
Nutrients              Jia-Zhong Zhang       NOAA-AOML    jia-zhong.zhang@noaa.gov
                       Calvin Mordy          NOAA-PMEL    calvin.w.mordy@noaa.gov
CFCs/SF6               John Bullister        NOAA-PMEL  
Total CO2 (DIC)        Rik Wanninkhof        NOAA-AOML    rik.wanninkhof@noaa.gov
                       Richard Feely         NOAA-PMEL    richard.a.feely@noaa.gov
Total Alkalinity/pH    Rik Wanninkhof        NOAA-AOML    rik.wanninkhof@noaa.gov
                       Frank Millero         UM/RSMAS     fmillero@rsmas.miami.edu
DI14C                  Ann McNichol          WHOI         amcnichol@whoi.edu
                       Robert Key            PU           key@princeton.edu
DOM / DOC              Dennis Hansell        UM/RSMAS     dhansell@miami.edu
DO14C / Black Carbon   Ellen Druffel         UCI          edruffel@uci.edu
Biomarkers and         Brett Walker          UCI          brett.walker@uci.edu
Molecular Composition 
Genetics and POM       Adam Martiny          UCI          amartiny@uci.edu
Net tows               Nina Bernardsek       SCCWRP       NinaB@sccwrp.org
Underway pCO2          Rik Wanninkhof        NOAA-AOML    rik.wanninkhof@noaa.gov
                       Denis Pierrot         AOML/CIMAS   denis.pierrot@noaa.gov
Dissolved Calcium      Akihiko Murata        JAMSTEC      murataa@jamstec.go.jp
Density                Akihiko Morata        JAMSTEC      murataa@jamstec.go.jp
                       Frank Millero         UM/RSMAS     fmillero@rsmas.miami.edu
Biological Samples /   Victoria Coles        UMar         vcoles@umces.edu
Filtration             Raleigh Hood          UMar         rhood@umces.edu
                       Joaquim Goes          LDEO         jig@ldeo.columbia.edu
Transmissiometry       Wilf Gardner          TAMU         wgardner@ocean.tamu.edu
Argo floats            Gregory Johnson       NOAA-PMEL    gregory.c.johnson@noaa.gov
                       Elizabeth Steffen     NOAA-PMEL    elizabeth.steffen@noaa.gov
SVP drifters           Rick Lumpkin          NOAA-AOML    rick.lumpkin@noaa.gov
                       Shaun Dolk            AOML/CIMAS   shaun.dolk@noaa.gov
Wave buoys             Kerstin Paulsson      SIO          kpaulsson@ucsd.edu
Fluorometry      
Bathymetry             Ship personnel        NOAA         ops.ronald.brown@noaa.gov
Underway TSG           Ship personnel        NOAA         ops.ronald.brown@noaa.gov
ADCP                   Ship personnel        NOAA         ops.ronald.brown@noaa.gov
Nitrate isotopes       Chawalit Charoenpong  WHOI         
                       Scott D. Wankel    


2.3.  Scientific Personnel (Legs 1 and 2)

    Duties                 Name                  Affiliation  Email
—————————————————————————  ————————————————————  ———————————  —————————————————————————————
 1  Chief Scientist        Denis Volkov          AOML/CIMAS   denis.volkov@noaa.gov
 2  Co-Chief Scientist     Viviane Menezes       WHOI         vmenezes@whoi.edu
 3  CTD Processing         Kristene McTaggart    PMEL         kristene.e.mctaggart@noaa.gov
 4  CTD/Salinity/LADCP/ET  Andrew Stefanick      AOML         andrew.stefanick@noaa.gov
 5  CTD/Salinity/LADCP     James Hooper          AOML/CIMAS   james.hooper@noaa.gov
 6  CTD Watch              Andrew Whitley        TAMU         awhitley@tamu.edu
 7  CTD Watch              Yashwant Meghare      WWU          yashmeghare@yahoo.com
 8  LADCP                  Amanda Fay            LDEO         afay@ldeo.columbia.edu
 9  Dissolved O2           Samantha Ladewig      CCU          smladewig@g.coastal.edu
10  Dissolved O2           Leah Chomiak          RSMAS        l.chomiak1@umiami.edu
11  Nutrients              Eric Wisegarver       PMEL         eric.wisegarver@noaa.gov
12  Nutrients              Ian Smith             AOML/CIMAS   ian.smith@noaa.gov
13  Total CO2 (DIC)        Dana Greeley          PMEL         dana.greeley@noaa.gov
14  Total CO2 (DIC)        Charles Featherstone  AOML         charles.featherstone@noaa.gov
15  Total Alkalinity / pH  Carmen Rodriguez      RSMAS        crodriguez@rsmas.miami.edu
16  Total Alkalinity / pH  Annelise Hill         RSMAS        anhill95@gmail.com
17  Total Alkalinity / pH  Holly Westbrook       RSMAS        holly.westbrook@uconn.edu
18  CFCs / SF6             Bonnie Chang          UW           bxc@uw.edu
19  CFCs / SF6             Charles Kleinwort     WWU          kt.96@hotmail.com
20  CFCs / SF6             Kathryn Williams      WWU          charles.kleinwort@gmail.com
21  DOM / DOC / DI14C      Shinichiro Umeda      JAMSTEC      umedas@jamstec.go.jp 
22  DOC14                  Christian Lewis       UCI          lewiscb@uci.edu
23  Biogeochemistry        Victoria Coles        U. Maryland  vcoles@umces.edu
24  Biogeochemistry        Hannah Morrissette    U. Maryland  hmorrissette@umces.edu
25  POM                    Catherine Garicia     UCI          catgar@uci.edu
26  POM                    Jenna Alyson Lee      UCI          jennaal@uci.edu

3.  PROGRAM AND PROJECT OVERVIEW

The I07N cruise is part of the decadal re-occupation of select NOAA 
hydrographic transects to determine natural and man-made changes in chemical 
and physical properties in the ocean as part of the USA component of the 
international GO-SHIP program. This cruise is one of approximately 60 
decadal repeated globally as part of this program with the goal of 
quantifying changes and variability in ocean heat content, chloro-
fluorocarbons (CFCs) dissolved inorganic and organic carbon, oxygen, 
alkalinity, pH, nutrients, and other natural and man-made tracers of ocean 
circulation. The cruises also measure and infer variability in ocean 
currents and water mass distributions. Earlier programs under the Joint 
Global Ocean Flux Study (JGOFS), World Ocean Circulation Experiment (WOCE), 
and Climate Variability and predictability (CLIVAR) programs provided an 
approximately decadal set of observations on hydrographic lines, including 
the I07N line that GO-SHIP builds upon. Examples of critical findings made 
possible by decadal measurements include ongoing ocean uptake and subsurface 
storage of anthropogenic CO2 with consequent ocean acidification, ongoing 
warming and freshening of the deepest bottom waters, and accelerated 
overturning of intermediate depth water masses in the Southern Ocean. The 
repeat hydrography cruises are the only means to obtain climate quality data 
to study changes and impacts in the ocean, and they provide a robust 
observational framework to monitor these long-term changes.

The GO-SHIP program serves to address the following overlapping scientific 
objectives:

• Collect data for carbon system studies
• Study ocean circulation, heat and freshwater storage and fluxes
• Study deep and shallow water mass changes and their ventilation time 
  scales
• Collect data for model calibration and validation, as well as for 
  calibration of autonomous sensors

The I07N cruise started in Durban, South Africa on April 23rd 2018 and ended 
in Goa, India, on June 6th 2018.  The cruise consisted of two legs with a 
mid-point port stop in Victoria (The Republic of Seychelles) from May 15th 
2018 to May 19th 2018. Twenty-six scientists from 15 different institutions 
were engaged in surface and full-depth water column measurements, surface 
water measurements form the scientific seawater supply line, and deployment 
of profiling (Argo) floats and drifters en route.  During the cruise 126 CTD 
casts (including 2 test casts) were carried out, and 15 Argo floats, 10 SVP 
drifters, and 3 wave buoys were deployed.  The CTD/Rosette operations were 
carried out using 24, 12-L bottles.

The 2018 I07N research cruise was jointly funded by the USA agencies: 
National Oceanic and Atmospheric Administration (NOAA) and National Science 
Foundation (NSF). The cruise was led by NOAA Atlantic Oceanographic and 
Meteorological Laboratory and NOAA Pacific Marine Environmental Laboratory. 
Numerous US academic institutions as well as Japan Agency for Marine-Earth 
Science and Technology (JAMSTEC) took part in the cruise.






4.  THE I07N SECTION 

The operating area was in the western Indian Ocean, with a schematic of the 
I07N-2018 cruise track shown in Figure 1. The I07N section runs across the 
Madagascar and Mascarene Basins in the south, crosses the Amirante Trench, 
and after the Seychelles Bank it crosses the Somalia Basin, Carslberg Ridge, 
and the Arabian Sea in the north. This section, if completed all the way to 
the coast and combined with the new I07S section, that will be occupied by 
Japanese oceanographers, would provide a constraint for estimates of the 
cross-basin fluxes. The final segment of the I07N line in the Arabian Sea is 
of particular interest because it crosses the Arabian Sea oxygen minimum 
zone (OMZ) and the local salinity maximum. The Arabian Sea OMZ is the 
thickest of the three oceanic OMZ and it is of global biogeochemical 
significance. The local salinity maximum just beneath the mixed layer is an 
indicator of the subduction processes of high-salinity surface water during 
the monsoon period.

The spacing between the stations along the I07N line varied from ~15 nm over 
the complicated topography and in the eddy-rich Madagascar Basin to ~30-34 
nm in other regions. Measurements were made at each station for a variety of 
physical, chemical, and biological parameters. Underway sampling was 
conducted throughout the entire cruise, ceasing briefly at the boundary 
between the Mauritius and the Seychelles Exclusive Economic Zones (EEZs) due 
to a lapse in getting the EEZ clearance from the Seychelles. The underway 
systems were also turned off over the Seychelles Bank as the ship was 
sailing in the territorial waters and in the Indian EEZ.

The NOAA Ship “Ronald H. Brown” departed Durban, South Africa, on April 23, 
2018 and headed strictly eastward along 30aS towards 54.5°E, where the I07N-
2018 section started. While in transit to the first I07N station, two test 
stations (A and B in Fig. 1) were carried out. A segment of the I07N section 
between the first station (54.5°E and 30°S) and station 31 (~55°E and ~18°S) 
repeats stations along the eastern segment of I04 cruise conducted in 1995. 
Between stations 23 and 25, due to the French military exercises just 
southwest of La Reunion, we had to deviate from our route and do station 24 
about 10 nm west off the line, but still keeping it at the same latitude 
(54.3°E and 21.5°S). Starting from station 31, the I07N-2018 cruise followed 
strictly the footsteps of the I07-1995 cruise except for the final segment 
in the Arabian Sea.


Figure 2: A map with stations near the Amirante Trench. Stations 48, 50, 52, 
          54, and 58 were canceled.


Near the Amirante Trench in the Mascarene Basin, due to a 1-day delay caused 
by waiting for the Seychelles Marine Scientific Research (MSR) clearance, we 
had to skip 4 stations south and 1 station just north of the Amirante 
Trench. A map of stations near the Amirante Trench, including those 
canceled, is displayed in Figure 2.  Cancelling the stations increased the 
spacing between the stations along the corresponding segments from 17 to 34 
nm. This was not critical along the more or less flat bottom topography. But 
we retained the short spacing between the stations over the Amirante Trench.

In the Arabian Sea, the original I07N-1995 section went all the way towards 
to the coast of Oman. Unfortunately, due to existing safety concerns in the 
region, we were not able to reoccupy the original line in the Arabian Sea. 
As a compromise plan A for this cruise was to reach 18°N and head straight 
towards the Indian continental slope (Figure 3). This plan depended on 
obtaining the MSR clearance to sample in the Indian EEZ. We also had an 
alternative plan B in case the Indian MSR clearance was not granted. 
According to this plan B, starting from the turning point at station 111 
(~14.9°N) we would dogleg towards ~69.5°E and 17.6°N, which would bring us 
as close as possible to the continental slope, but still keep us outside the 
Indian EEZ (Figure 3). Unfortunately, we did not receive the Indian MSR, 
neither before reaching station 111 nor later, and decided to follow plan B. 
Station 121 was the last station on the segment between the turning point at 
station 111 and the Indian EEZ. Upon reaching station 121, we still had 
about 2 days available for doing more stations. As one of the wishes for our 
cruise was to get as deep into the Oxygen Minimum Zone (OMZ) as possible, we 
decided to head northwestward and do 3 more stations up to 18°N – this is 
the northernmost latitude the ship agreed to sail to due to safety concerns.


Figure 3: Plans A (black dots) and B (red dots).




5. CRUISE NARRATIVE

Detailed weekly descriptions of operations during the cruise are provided in 
Appendix 10.3. Here, we describe and categorize challenges that we had to 
deal with prior and during the cruise.


5.1.  Start of the cruise

The I07N cruise was initially planned to start in February and end in March, 
2018. However, prior to sailing from Charleston (USA) to Durban (South 
Africa) the ship discovered engine problems that had to be fixed in port. 
Due to lengthy repairs, the entire yearly schedule of “Ronald H. Brown” was 
shifted, and our new tentative departure was set on April 23, 2018. This 
eventually became our actual departure date, as after the repairs the ship 
made it to Durban without any additional delays. Most of our scientific 
gear, including 3 containers (PMEL CFC van, and AOML DIC and gear storage 
vans), was loaded on the Brown while the ship was in Charleston and during a 
port call in Fort Lauderdale. Only the LADCP gear and some additional sample 
bottles were shipped to Durban. This made the mobilization and loading in 
Durban relatively easy and fast. After clearing immigration and customs, the 
ship departed from Durban on April 23, 2018 at 2 pm local time.


5.2.  Foreign clearances

The I07N-2018 cruise was crossing the EEZs of 5 coastal states: South 
Africa, France (La Reunion), Mauritius, Seychelles, and India. In addition, 
the cruise crossed the EEZ of Tromelin Island, which is a disputed territory 
between France and Mauritius. As the initial departure was scheduled for 
February 2018, all foreign clearance requests were submitted via NOAA to the 
Department of State in August 2017. Considering that the cruise was 
eventually delayed by about 2.5 months, there was more than enough time to 
process these requests in timely manner. By the beginning of the cruise we 
had received clearances from South Africa (for underway survey only) and 
from France for sampling in La Reunion and Tromelin EEZs. The French 
clearance, however, was for initial dates of the cruise (in February), so an 
appropriate amendment with updated dates of the cruise was also submitted.

When we left Durban, we had no other EEZ clearances besides from South 
Africa and France. As we were approaching the Mauritius EEZ, the situation 
was becoming nervous as we had no clearance to sample there. We were in 
contact we a person in charge at the US Embassy in Mauritius, but the 
situation did not resolve until we brought it to the attention of NOAA’s 
Climate Program Office (CPO). Fortunately for the cruise, the CPO’s 
International Coordinator Dr. Thurston knew a person in the Mauritius 
government, who also happened to be the one who issues MSR clearances for 
the Mauritius EEZ. To our surprise, this person did not hear anything about 
our cruise. However, he was very accommodating and graciously expedited the 
issuance of the MSR clearance for “Ronald Brown”, which we received several 
hours before entering the Mauritius EEZ. 

It was a temporary relief for us because our transit in the Mauritius EEZ 
lasted only 2 days and we still did not have clearance for the Seychelles 
EEZ. It was also the US Embassy in Mauritius that was in charge for handling 
our MSR clearance request for the Seychelles, but this time we did not have 
any acquaintances in the Seychelles government to approach them directly. On 
May 9 in the afternoon, we came to the boundary between the Mauritius and 
Seychelles EEZs without clearance for the latter. Since we could not 
proceed, we decided to do an extra CTD cast at the boundary and just wait. 
The situation was complicated by the fact that the Mauritius clearance was 
expiring at midnight, which meant that we had to seize all operations and 
turn off the underway systems. As there was no certainty about the 
Seychelles clearance, we started to think about an alternative route around 
the Seychelles EEZ and sent a request to extend our clearance for the 
Mauritius EEZ for several more days. Fortunately, clearance for the 
Seychelles EEZ was eventually granted, but it costed us one full sea day, 
during which we stayed at the boundary without a possibility to do any 
research, and 5 canceled stations thereafter.

As opposed to the situation with Mauritius and the Seychelles, the person in 
charge of our clearance request for the Indian EEZ at the US Embassy was 
very proactive. And in the end, a conditional clearance was granted, but it 
contained the provisions that the ship’s leadership found unacceptable. One 
of these provisions was a potential Naval inspection of the ship, which 
would undermine the sovereign status of “Ronald Brown”. A request to waive 
unacceptable condition was submitted, but the Indian authorities were not 
willing to change anything in the formal document. Unfortunately for the 
entire science project, this resulted in a denial of our MSR request to 
sample in the Indian EEZ.

Lessons learned.

• Stay in a regular contact with the NOAA’s Office of Marine and Aviation 
  Operations and make sure they do their part by coordinating clearance 
  requests with the Department of State in timely manner, including regular 
  checks of the status of already submitted requests.

• If a research cruise involves transiting multiple EEZs that border each 
  other, consider asking for more transit time than actually needed. If one 
  of the clearances is not granted, there will be an option to go around 
  that particular EEZ and continue sampling while on the way.

• Some reconsideration of NOAA policy with respect to the applicability of 
  sovereign status of NOAA vessels is desired. The rules need to become more 
  specific, and both the ship’s leadership and the chief scientist need to 
  be aware of how flexible the ship can be with regard to the requirements 
  imposed by other states in their EEZs. There must be a general understand-
  ing that if a research vessel wants to measure in foreign waters, that 
  foreign state has a right to impose certain requirements. In our 
  particular situation with India, it appears that if we were a UNOLS 
  vessel, there would not be a problem at all, and we would get the Indian 
  clearance. It is also very unlikely that any Naval inspection, indicated 
  in the formal document, would ever happen. If the scientists knew that a 
  conditional clearance from India would not be accepted by the NOAA ship, 
  it would be more reasonable to do this cruise on a UNOLS vessel, given 
  such a rare opportunity to measure in the western Indian Ocean and in the 
  Indian waters in particular. Unfortunately, in our case, science suffered 
  from bureaucracy on both sides.  


5.3.  Issues with the aft winch

Problems with the aft winch on the Brown started well before our cruise. In 
fact, the ship left Charleston on a round-the-world trip knowing that the 
aft winch might not be operable. The aft winch was used during the first 
test CTD cast. The cast resulted in multiple modulo errors on the CTD, in 
particular during the upward cast. Tests indicated that the problem was not 
related to the termination of cable, but it was rather in the winch itself. 
There was nothing we could do with the aft winch during the cruise, and we 
decided to proceed with the forward winch. The forward winch was used during 
the second test CTD cast that went all the way to just above the bottom at 
5240 m. The forward winch worked perfectly, and it was used for the 
remainder of the cruise.

Lessons learned.

• Because mechanical problems are inevitable during oceanographic cruises, 
  it is very risky to start a long cruise with having only one operable 
  winch, and such situations need to be avoided by all means possible. 
  During our cruise, we were just lucky that nothing serious happened, 
  although it could easily happen as described in the next section.


5.4.  Attempt to find a PMEL mooring

One of the requests we had for the cruise was to attempt to find a mooring, 
the communication with which was lost 5 years ago. If the buoy were present, 
at the very least, we were asked to photograph it, and recover the mooring 
if the schedule allowed. We arrived at the mooring location in the dark, 
however, the weather was favorable, and the visibility was good enough. 
Being well equipped with the ship’s radar, night vision device, and a 
searchlight we started the search. Our plan was to locate the buoy, proceed 
to the next station (#42), and then return to the mooring and recover it 
next day in the morning. However, the buoy was not present. After hovering 
around for about an hour, the transducer was lowered at the last reported 
position of the mooring and disable command was sent. Unfortunately, the 
mooring is lost.

5.5.  CTD wire situation

After leaving Victoria (the Republic of Seychelles), we entered a very 
strong eastward current, possibly associated with the seasonal Wyrtki Jet, 
with surface velocities exceeding 1 m/s. A little further north, in addition 
to the strong eastward current near the surface there a was strong westward 
current between about 100 and 200 m depth. Probably because of this strong 
velocity shear we started to experience twists on the forward winch cable 
that were causing modulo errors on the CTD and caging of the wire. This 
situation was causing a lot of concern and worries, especially given the 
fact that we did not have a backup winch. The cable was re-terminated while 
the ship was in port in Victoria, but the visible degradation of the cable, 
while we were experiencing the strong current, made it necessary to re-
terminate it 2 more times. A continued use of the forward winch with 
degrading cable was increasing the chances of losing the entire package, but 
the only solution we had was to closely monitor the state of the cable after 
each station and hope that the situation would improve once we exit the 
strong current. Fortunately, the situation did improve once we left the 
current. A few modulo errors on the CTD that we were getting after re-
terminations were not critical, and overall, we were getting high quality 
data. We continued to keep a close eye on the state of the cable until the 
end of cruise, but no more re-terminations were required.

Lessons learned.

• CTD casts are routinely carried out in stronger currents than the one we 
  experienced. Although we were sailing across the region of strong vertical 
  velocity shear, we did not expect that the cable would start degrading so 
  fast. It is likely that the cable was defective from the start and, 
  therefore, the quality of the cable is one of the things that require 
  close attention prior to starting a cruise.

• The state of the cable needs to be routinely monitored, in particular in 
  the regions of strong currents.

 
5.6.  Scientific staffing

The I07N science party consisted of 26 scientists. Because the cruise was 
crossing the High-Risk Area, the ship decided to increase the number of crew 
members to add additional security watches on the bridge. This was not clear 
how critical that was, but as a result, the science personnel had to be cut 
by 2 persons and 2 groups were understaffed. Namely, the Alkalinity/pH group 
was one person less than the usual four, and we had only 2 CTD watch-
standers. We also did not have a dedicated data manager. The data management 
role was fulfilled by the chief and the co-chief scientists using the PMEL 
Bottle Data Management System software (PMEL-BDMS). Fortunately, 
participants from ancillary programs provided sufficient help for the 
understaffed groups. While the CTD was operated by the same persons and no 
help was necessary, much help was provided during sampling. 

One berth was reserved for an Indian scientist who was supposed to join the 
cruise in the Seychelles. The first Indian scientist, who was cleared by 
NOAA to sail on the Brown, canceled his participation before the start of 
the cruise, and was substituted by another one. It took us some efforts to 
expedite the clearance process for the second scientist, however, he also 
canceled his participation several days prior to our arrival in Victoria. As 
a result, there was no Indian representation during the I07N cruise.

Lessons learned.

• Data management can be easily fulfilled by the chief and co-chief 
  scientists, perhaps sometimes with some involvement of student helpers. 
  The PMEL-BDMS is easy to learn and use.

• If understaffing is inevitable, it is important to make everybody aware 
  what groups/people require help. Participants from some ancillary programs 
  usually have some spare time to help others. During our cruise we had no 
  problems with that at all. Help was always there when it was needed.





6.  UNDERWAY DATA ACQUISITION

Underway data collection included meteorological parameters, upper ocean 
current measurements from the shipboard ADCP, surface oceanographic 
(temperature, salinity, pCO2) from the ship's underway clean seawater 
intake, bathymetric data, and measurements of atmospheric CO2, CFCs, SF6 and 
ozone.

Navigation data were acquired at 1-second intervals from the ship’s Furuno 
Marine Touch Screen navigational radar from the start of the cruise. In 
addition, centerbeam depth data, with a correction for hull depth included 
in each data line, were acquired directly from the ship’s 
Multibeam/Kongsberg EM122 system. These data were used to determine the 
position and ocean depth information for each station and deployment. The 
centerbeam depths were also continuously displayed, and data were manually 
recorded at cast start/bottom/end on CTD Cast Logs.


6.1.  Acoustic Doppler Current Profiler Measurements
      PI’s: Eric Firing (UH) and Jules Hummon (UH)


The NOAA Ship “Ronald H. Brown” has a permanently mounted 75 kHz acoustic 
Doppler current profiler (“ADCP” Teledyne RDI) for measuring ocean velocity 
in the upper water column. The ADCP is a Phased Array instrument, capable of 
pinging in broadband mode (for higher resolution), narrowband mode (lower 
resolution, deeper penetration), or interleaved mode (alternating). On this 
cruise, data were collected with 8 m broadband pings and 16 m narrowband 
pings. The data were collected for the entire duration of I07N except when 
the ship was over the Seychelles Bank in the territorial waters of the 
Republic of Seychelles and in the Indian EEZ. The ADCP was also turned off 
along with all underway systems while the ship was waiting for the 
Seychelles MSR clearances at the boundary between the Mauritius and 
Seychelles EEZs.

The shipboard ADCP data are acquired and processed by specialized software 
developed at the University of Hawaii and installed on the Brown. The 
acquisition system ("UHDAS", University of Hawaii Data Acquisition System) 
acquires data from the ADCPs, gyro heading (for reliability), position and 
orientation systems for marine vessels (POSMV) headings (for increased 
accuracy), and GPS positions from various sensors. Single-ping ADCP data are 
automatically edited and combined with ancillary feeds, averaged, and 
disseminated via the ship's web, as regularly-updated figures on a web page 
and as Matlab and netCDF files. The automated at-sea product should be good 
enough for preliminary use, and the final dataset should be among the best 
to come from this ship.


6.2.  Underway pCO2 Analyses
      PI’s: Rik Wanninkhof (NOAA/AOML) and Denis Pierrot (UM/CIMAS)	
      Technicians: Charles Featherstone (NOAA/AOML) and Dana Greeley 
                   (NOAA/PMEL)

An automated underway pCO2 system from AOML was installed in the Hydro Lab 
of the RV Ronald H.  Brown.  The design of the instrumental system is based 
on Wanninkhof and Thoning (1993) and Feely et al. (1998), while the details 
of the instrument and of the data processing are described in Pierrot, 
et.al. (2009).

The repeating cycle of the system included 4 gas standards, 5 ambient air 
samples, and 100 headspace samples from its equilibrator every 4.5 hours.  
The concentrations of the standards range from 280 to 550 ppm CO2 in 
compressed air. These field standards were calibrated with primary standards 
that are directly traceable to the WMO scale.  A gas cylinder of ultra-high 
purity air was used every 20 hours to set the zero of the analyzer.

The system included an equilibrator where approximately 0.6 liters of 
constantly refreshed surface seawater from the bow or mid-ship intake was 
equilibrated with 0.8 liters of gaseous headspace.  The water flow rate 
through the equilibrator was 1.5 to 2.2 liters/min.

The equilibrator headspace was circulated through a non-dispersive infrared 
(IR) analyzer, a LI-COR™ 6262, at 50 to 120 ml/min and then returned to the 
equilibrator.  When ambient air or standard gases were analyzed, the gas 
leaving the analyzer was vented to the lab.  A KNF pump constantly pulled 6-
8 liter/min of marine air through 100 m of 0.95 cm (= 3/8") OD Dekoron™ 
tubing from an intake on the bow mast.  The intake had a rain guard and a 
filter of glass wool to prevent water and larger particles from 
contaminating the intake line and reaching the pump.  The headspace gas and 
marine air were dried before flushing the IR analyzer.

A custom program developed using LabView™ controlled the system and 
graphically displayed the air and water results.  The program recorded the 
output of the IR analyzer, the GPS position, water and gas flows, water and 
air temperatures, internal and external pressures, and a variety of other 
sensors.  The program recorded all of these data for each analysis.

The automated pCO2 analytical system had several issues during the cruise:  

1. April 23, 2018 – Start of IO7N cruise system turned on at 12:25
2. April 26, 2018 – System shut down at 13:00 restarted computer and the 
   system resumed normal operations
3. April 26, 2018 – Unplugged TSG and plugged back in at approx. 21:52
4. April 27, 2018 – Tried to dislodge air bubbles from SBE 45 at approx. 
   21:01
5. May    6, 2018 – System went into emergency shutdown mode at approx. 
   17:06
6. May 7, 2018 – System restarted normal functions at approx. 21:22
7. May 9, 2018 – TSG water flow turned off at approx. 11:05 because of 
   entering the Mauritius EEZ while awaiting approval to sample in the 
   Seychelles’ EEZ.  The water flow was off for approx. 24 hrs.
   The system worked well for the remainder of the cruise.


Standard Gas Cylinders

                           Cylinder#  ppm CO2
                           —————————  ———————
                           CA04957    280.55
                           CC05863    380.22
                           CB09696    453.04
                           CB09032    539.38


References

Pierrot, D.; Neill, C.; Sullivan, K.; Castle, R.; Wanninkhof, R.; Luger, H.; 
    Johannessen, T.; Olsen, A.; Feely, R.A.; and Cosca, C.E. (2009). 
    Recommendations for autonomous underway pCO2 measuring systems and data-
    reduction routines.  Deep-Sea Res., II, v. 56, pp. 512-522.

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

Wanninkhof, R., and Thoning, K. (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.





7.  CONDUCTIVITY, TEMPERATURE, DEPTH (CTD) STATIONS

The CTD/rosette system was deployed off the starboard side. The ship's 
personnel were responsible for the deployment and recovery of the 
CTD/rosette with assistance of experienced scientific personnel.  During 
recovery, the CTD/rosette package was lowered onto a cart and rail system, 
maintained by the ship, allowing the CTD/rosette package to be safely 
brought into the staging bay. One of two 24-position AOML rosette systems 
with 12 litter bottles was used for CTD/rosette casts. The second backup 
package was secured in a readily accessible area, but it was never 
required.  An altimeter was mounted on the rosette system and used during 
casts to monitor distance from the bottom.


7.1.  CTD data acquisition

The CTD data acquisition system consisted of the ship’s SBE-11plus (V2) deck 
unit s/n 11P111660 and a networked Dell Optiplex 7040 Windows 10 workstation 
running SBE Seasave V7 version 7.26.7.107 software.  NMEA GPS data were 
received through the deck unit.  The workstation was used for data 
acquisition and to close bottles on the rosette.  Raw data files were 
archived immediately after each cast on a USB drive as well as on Survey and 
PMEL networked PCs.  No real-time data were lost during this cruise.

CTD deployments were initiated by Survey after the Bridge advised that the 
ship was on station. The transmissometer windows were uncapped, washed, and 
deployed wet.  The computer console operator maintained a CTD Cast log 
recording position and depth information at the surface, depth, and end of 
each cast; a record of every attempt to close a bottle, and any pertinent 
comments.

After the underwater package entered the water, the winch operator lowered 
it to 20-30 meters and held position. After a 60-second startup delay, the 
pumps turned on.  The console operator watched the CTD data for reasonable 
values, waited three minutes at the soak depth for sensors to stabilize, 
instructed the winch operator to bring the package to the surface, paused 
for 30 seconds, and began the descent to a target depth approximately 10 
meters above the sea floor. The descent rate was nominally 30 m/min to 50 m, 
45 m/min to 200 m, and 60 m/min deeper than 200 m.  These rates could vary 
depending on sea cable tension and the sea state.

The console operator monitored the progress of the deployment and quality of 
the CTD data through interactive graphics and operational displays.  The 
chief or co-chief scientist created a sample log for the cast that would be 
used to record the water samples taken from each Bullister bottle.  The 
altimeter channel, CTD depth, wire-out, and EM122 bathymetric depth were all 
monitored to determine the distance of the package from the bottom, allowing 
a safe approach to within 10 meters.  

Bottles were closed on the up-cast through the software and were tripped 30 
seconds after stopping at each bottle depth to allow the rosette wake to 
dissipate and the bottles to flush.  The winch operator was instructed to 
proceed to the next bottle stop 15 seconds after closing bottles to ensure 
that stable CTD and reference temperature data were associated with the 
trip.  

Near the surface, Survey directed the winch to stop the rosette just beneath 
the surface.  After the surface bottle was closed, the package was 
recovered.  Once on deck, the console operator terminated data acquisition, 
turned off the deck unit, and assisted with rosette sampling.

At the end of each cast, primary and secondary CTD/O2 sensors were flushed 
with a solution of dilute Triton-X in de-ionized water using syringes fitted 
with tubing. The syringes were left attached to the temperature ducts 
between casts, with the temperature and conductivity sensors immersed in the 
rinsing solution to guard against airborne contaminants.  The rosette 
carousel was rinsed with warm freshwater.  The transmissometer windows were 
rinsed with DI water, dried, and capped after each cast.  








Table 7.1: Package component and calibration data

Manufacturer / Model                    Serial    Calibration  Stations 
                                        Number       Date        Used
————————————————————————————————————  ——————————  ———————————  ————————
Sea-Bird 9plus CTD                       1292     14-Sep-16     1-128
      
Sea-Bird 3Plus primary  temperature      4569     22-Sep-17     1-128
Sea-Bird 4C primary conductivity         3068     22-Sep-17     1-128
Sea-Bird 43 primary oxygen               3419     10-Oct-17     1-128
Sea-Bird 5T primary pump                 7265        n/a        1-89
Sea-Bird 5T primary pump                 8774        n/a       90-128
      
Sea-Bird 3Plus secondary temperature     4193     21-Oct-17     1-128
Sea-Bird 4C secondary conductivity       2882     22-Sep-17     1-128
Sea-Bird 43 secondary oxygen             3420     10-Oct-17     1-128
Sea-Bird 5T secondary pump               7741        n/a        1-128
      
Sea-Bird 35 reference temperature         76      28-Oct-13     1-128
Sea-Bird 32 24-position carousel          500        n/a        1-128
      
Valeport VA500 altimeter                56634     16-Sep-16     1-128
WET Labs C-Star transmissomter          1636DR    04-Dec-17     1-128
WET Labs ECO chlorophyll fluorometer  FLRTD-2125  21-Dec-10     1-128


7.2.  CTD data processing

The reduction of profile data began with a standard suite of processing 
modules using Sea-Bird Data Processing Version 7.23.2 software in the 
following order:

DATCNV converts raw data into engineering units and creates a ROS bottle 
file.  Both down and up casts were processed for scan, elapsed time(s), 
pressure, t0, t1, c0, c1, oxvo1, oxvo2, ox1 and ox2.  Optical sensor data 
were converted to voltages and also carried through the processing stream.  
MARKSCAN was used to skip over scans acquired on deck and while priming the 
system under water.

ALIGNCTD aligns temperature, conductivity, and oxygen measurements in time 
relative to pressure to ensure that derived parameters are made using 
measurements from the same parcel of water.  Primary and secondary 
conductivity were automatically advanced in the V2 deck unit by 0.073 
seconds.  No further alignment was warranted.  It was not necessary to align 
temperature or oxygen.

BOTTLESUM averages burst data over an 8-second interval (within ± 4 seconds 
of the confirm bit) and derives both primary and secondary salinity, 
potential temperature (θ), and potential density anomaly (σθ).  Primary 
and secondary oxygen (in µmol/kg) were derived in DATCNV and averaged in 
BOTTLESUM, as recommended recently by Sea-Bird.

WILDEDIT makes two passes through the data in 100 scan bins.  The first pass 
flags points greater than 2 standard deviations; the second pass removes 
points greater than 20 standard deviations from the mean with the flagged 
points excluded.  Data were kept within 0.005 of the mean.

FILTER applies a low pass filter to pressure with a time constant of 0.15 
seconds.  In order to produce zero phase (no time shift) the filter is first 
run forward through the file and then run backwards through the file.

CELLTM uses a recursive filter to remove conductivity cell thermal mass 
effects from measured conductivity.  In areas with steep temperature 
gradients the thermal mass correction is on the order of 0.005 PSS-78.  In 
other areas the correction is negligible.  Nominal values of 0.03 and 7.0 s 
were used for the thermal anomaly amplitude (α) and the thermal anomaly time 
constant (ß^(-1)), respectively, as suggested by Sea-Bird.

LOOPEDIT removes scans associated with pressure slowdowns and reversals.  If 
the CTD velocity is less than 0.25 m s-1 or the pressure is not greater than 
the previous maximum scan, the scan is omitted.

DERIVE uses 1-dbar averaged pressure, temperature, and conductivity to 
compute primary and secondary salinity, as well as more accurate oxygen 
values.

BINAVG averages the data into 1-dbar bins.  Each bin is centered on an 
integer pressure value, e.g. the 1-dbar bin averages scans where pressure is 
between 0.5 dbar and 1.5 dbar.  There is no surface bin.  The number of 
points averaged in each bin is included in the data file.

STRIP removes oxygen that was derived in DATCNV.

TRANS converts the binary data file to ASCII format.

Package slowdowns and reversals owing to ship roll can move mixed water in 
tow to in front of the CTD sensors and create artificial density inversions 
and other artifacts.  In addition to Seasoft module LOOPEDIT, MATLAB program 
deloop.m computes values of density locally referenced between every 1 dbar 
of pressure to compute the square of the buoyancy frequency, N(^2), and 
linearly interpolates temperature, conductivity, and oxygen voltage over 
those records where N2 is less than or equal to -1 × 10(^-5) s(^-2).  Some 
profiles failed the criteria near the surface.  These data were retained and 
flagged as questionable in the final CCHDO formatted .CSV files.

Program calctd.m reads the delooped data files and applies calibrations to 
pressure, temperature, conductivity, and oxygen; and computes calibrated 
salinity.    


7.3.  Pressure calibration

An on-deck pressure offset of -0.5 dbar was entered into the instrument 
configuration file and applied during acquisition.  On-deck pressure 
readings prior to each cast were examined at sea and their offsets remained 
within 0.5 dbar throughout the cruise.  Differences between first and last 
submerged pressures for each cast were also examined and the residual 
pressure offsets were less than 0.6 dbar.


7.4.  Temperature calibration

A viscous heating correction of -0.0006°C was applied (as recommended by 
Sea-Bird) prior to preliminary temperature, conductivity, and oxygen 
calibrations; and to the preliminary data set at the end of the cruise.  

SBE 35 reference temperature sensor data were used to correct SBE 3 
temperature sensor data.  SBE 35 s/n 76 was used for all stations.  Primary 
SBE 3 temperature sensor s/n 4569 and secondary SBE 3 temperature sensor s/n 
4193 was used for all stations.  At sea, residuals between the reference 
data and those from the primary SBE 3 were minimized (giving the deeper 
values more weighting than the shallower ones in the fit) to determine a 
linearly station-dependent offset, and a linear pressure-dependent 
correction applied only to temperatures collected at pressures exceeding a 
value estimated by the minimization.  The best fit for primary SBE 3 
temperature sensor s/n 4569 applied a slope of 4.487824e-006, an offset of 
0.000204°C, and a pressure correction term of 2.50659e-007.  

Temperature corrections were applied to profile data using program calctd.m 
and to burst data using calclo.m.


7.5.  Conductivity calibration

Seasoft module BOTTLESUM creates a sample file for each cast.  These files 
were appended using program sbecal.f.  Program addsal.f matched sample 
salinities to CTD salinities by station/sample number.  

Primary conductivity sensor s/n 3068 was used for all stations and 
calibrated as a single group.  At sea, program calco2p1.m calculated a 
station-dependent slope, a single conductivity bias and quadratic term, and 
a single pressure correction term (pressure times measured conductivity) 
that best fit this sensor:

Stations: 1-124

number of points used:    2251
total number of points:   2744
% of points used in fit:  82.03
fit standard deviation:   0.002571
fit bias:                 0.0072818444
fit co pressure fudge:   -5.0916431e-007 
min fit slope:            0.9996982
max fit slope:            0.99970231

Conductivity calibrations were applied to profile data using program 
calctd.m and to burst data using calclo.m.


7.6.  Oxygen calibration

A hybrid of the Owens-Millard (1985) and Murphy-Larson (revised 2010) oxygen 
sensor modeling equations was used to calibrate the SBE-43 oxygen sensor 
data from this cruise.  The equation has the form

Ox=Soc*(V+Voff+Tau*exp(DI*P+D2*T).*dV/dt).*Os.*exp(Tcor*T).*exp(Pcor*P./
(273.15+T));

Where Ox is the CTD oxygen (in µmol/kg), V is the measured oxygen voltage 
(in volts), dV/dt is the temporal gradient of the oxygen voltage (in volts/s 
estimated by running linear fits made over 5 seconds), P is the CTD pressure 
(in dbar), T is the CTD temperature (in °C), and Os is the oxygen saturation 
computed from the CTD data following Garcia & Gordon (1992).  Oxygen sensor 
hysteresis was improved by matching upcast bottle oxygen data to downcast 
CTD data by potential density anomalies referenced to the closest 1000-dbar 
interval using program match_sgn.m.  We used the values provided by SBE for 
each sensor for the constants D1 (1.9263e-4) and D2 (-4.6480e-2) to model 
the pressure and temperature dependence of the response time for the sensor. 
For each group of stations fit we determined values of Soc (sometimes 
station dependent), Voff, Tau, Tcor, and Pcor by minimizing the residuals 
between the bottle oxygen and CTD oxygen.  W represents fitting switches.  
If the switches are set to 0,0 the fit is a regular L2 (least squares) norm 
for the entire group.  If the switches are set to 1,0 the fit is a regular 
L2 norm for the entire group but with a slope that is a linear function of 
station number.  If the switches are set to 2,0 the program first fits the 
entire group, then goes back and fits a slope and bias to individual 
stations, keeping the other parameters at the group values.  If the switches 
are set to 0,1 the fit is a regular L2 norm for the entire group, but it is 
weighted by the nominal oxygen bottle spacing, thus fitting the deep portion 
of the water column better.

At sea, program addsal.f matched bottle sample oxygen values to CTD oxygen 
values by station/sample number. Program run_oxygen_cal_ml.m was used to 
determine calibration coefficients by visual inspection for primary oxygen 
sensor s/n 3419 used for all stations.


 Stns      Soc            Voff     Tau     Tcor    Pcor   Npts  %Used  StdDev   W
———————  —————————————  ———————  ——————  ———————  ——————  ————  —————  ——————  ———
  1-29   0.5101-0.5127  -0.4664  6.5938   0.0004  0.0399  677   88.6   0.6213  1,0
 30-38   0.5144         -0.4761  6.3184   0.0004  0.0409  215   87.0   0.9457  0,0
 39-49   0.5249         -0.4910  7.2989  -0.0002  0.0412  263   86.7   0.7751  0,0
 50-58   0.5395         -0.4970  6.1816  -0.0032  0.0402  216   80.1   0.7658  0,1
 59-81   0.5386         -0.4967  4.8043  -0.0030  0.0401  524   84.2   0.8331  0,1
 82-112  0.5363         -0.4947  6.7710  -0.0011  0.0401  738   90.5   0.7504  0,1
113-124  0.5321         -0.4918  5.7279  -0.0010  0.0401  762   90.7   0.7590  0,1 


Oxygen calibration coefficients were applied to profile data using program 
calctd.m, and to burst data using calclo.m.  


7.7.  Discrete Niskin sampling

Most rosette casts were lowered to just about 10 meters above the bottom, 
using an altimeter to determine distance above the bottom. Up to about 
11.5US a simple sampling scheme AB was utilized to stagger sample depths. 
Staggering sample depths was to avoid spatial aliasing with in this sample 
data set. Because with spacing between the stations of 17-30 nm the CFC 
group was able to sample every other station, so they were getting the same 
depths. In order to make their samples also staggered, we decided to follow 
an ABC scheme for all stations almost throughout the entire cruise. At 
station 112 in the Arabian Sea, to better resolve sharp vertical gradients, 
we modified the sampling scheme by firing more bottles in the near-surface 
layer of the ocean. However, we quickly realized that this modified scheme 
with fewer bottles at mid-depths was not optimal for all groups, and we went 
back to the original ABC scheme. The sampling depths used during the I07N-
2018 cruise are shown in Figure 4.


Figure 4: I07N-2018 bottle sample distribution


The 24-place SBE32 carousel had few bottle lanyard or mis-tripped bottle 
problems. Rosette maintenance was performed on a regular basis. O-rings were 
replaced, and lanyards repaired as necessary. Rosette bottle maintenance was 
performed each day to insure proper closure and sealing. Valves were 
inspected for leaks and repaired or replaced as needed. Periodic leaks were 
noted on sample logs. Log notes were cross-referenced with sample data 
values and quality coded. Log notes, mis-trips, bottle lanyard issues and 
associated quality codes can be found in the Appendix 10.3.

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

• Chlorofluorocarbons (CFCs) and SF6
• Dissolved oxygen (O2)
• Dissolved Inorganic Carbon (DIC)
• pH
• Total Alkalinity
• DI14C
• Dissolved Organic Carbon (DOC)
• Nutrients
• Salinity
• Biomarkers
• Black Carbon/ DO14C / Walker Dissolved Organics 
• Calcium
• Density
• Nitrate (NO3-)
• Genetic samples
• Particulate Organic Matter (POM)
• Biological samples

Properties measured during the cruise are also listed in Appendix 10.2.


7.8. Bottle data processing
 
Water properties that were analyzed from samples onboard during the cruise 
were managed centrally through a Fortran-based bottle data management system 
(BDMS) developed by Dr. John Bullister at PMEL. The system was set up on a 
Ubuntu Linux workstation with network access to the ship and shell scripts 
for pulling data and pushing summary HY1 files.

Once the rosette was sampled, sample quality flags (1 = sampled or 9 = not 
sampled) plus comments were

recorded for every parameter from the sample logsheets. Approximately daily, 
the BDMS was

updated, combining all available CTD bottle data and analytical data (with 
their associated quality flags).

Quality flags follow the coding scheme developed for the World Ocean 
Circulation Experiment (WOCE)

Hydrographic Programme (WHP, Table 6.4.3).

Various consistency checks and detailed examination of the data continued 
throughout the cruise. A summary of Cast Log and Sample Log comments, mis-
trips, bottle lanyard issues and associated quality codes can be found in 
Appendix 10.3.


7.9.  Collected samples

Samples analyzed onboard during 
the cruise                       Samples collected (not analyzed at sea)
———————————————————————————————  ———————————————————————————————————————
Chlorofluorocarbons(CFCs)/SF6    DI14C
Dissolved O2                     DOC
Total CO2 (DIC)                  Black Carbon / Biomarkers / DO14C
pH                               Walker Dissolved Organics
Total Alkalinity                 Density
Nutrients                        Calcium
Salinity                         NO3-
Biological samples               Genetics / Particulate Organic Matter




8.  SHIP-BOARD ANALYSIS SECTION


8.1.  Temperature

Figure 5: Potential temperature


8.2.  Salinity

Figure 6: Salinity


8.3.  Dissolved Oxygen

Figure 7: Dissolved oxygen


8.4.  Total CO2

Figure 8: Total Carbon


8.5.  Total Alkalinity / pH

Figure 9: Total Alkalinity

Figure 10: pH


8.6.  Nutrients

Figure 11: Nitrate

Figure 12: Phosphate

Figure 13: Silicate



8.7.  Chlorofluorocarbons (CFCs) / SF6

Figure 14: CFC-11

Figure 15: CFC-12

Figure 16: SF6




9.  INDIVIDUAL SUB-PROJECT REPORTS


9.1.  Deployments

During the I07N-2018 cruise we deployed 15 Argo floats (Table 9.1), 10 SVP 
drifters (Table 9.2), and 3 wave buoys (Table 9.3). The following sections 
contain tables that show the serial numbers of these autonomous devices, and 
the locations and times of their deployment. All assets were deployed from 
the starboard side of the stern and at the speed of around 1.5-2 knots. The 
Argo floats were carefully lowered in the water by three people using a 
rope. The drifters were thrown overboard by one person, and the wave buoys 
were carefully lowered in the water by one person holding the parachute of 
the buoy.


9.1.1.  Argo floats

PIs: Elizabeth Steffen (PMEL), Gregory Johnson (PMEL)
Shipboard personnel: Kristene McTaggart (PMEL), Denis Volkov (AOML/CIMAS), 
James Hooper (AOML/CIMAS), Andrew Stefanick (AOML)


Table 9.1:  The list of Argo floats deployed during the I07N-2018 cruise

Device Type       Deployment Location      Deployment Time 
and Number      Latitude       Longitude        (UTC)
———————————  —————————————   ————————————  ————————————————
Navis F0839   29° 59.976’S   42° 42.005’E   4/25/2018 18:28
 Apex 7023    23° 59.278’    54° 30.534’E  05/02/2018 12:05
 Apex 5599    21° 59.680’S   54° 31.122’E  05/03/2018 16:17
Navis F0837   18° 0.965’S    55° 0.087’E   05/05/2018 20:24
Navis F0836   15° 05.350’S   55° 00.256’E  05/07/2018 05:55
 Apex 7024     3° 28.613’S   55° 48.374’E  05/20/2018 01:10
Navis F0835    2° 44.518’S   56° 25.870’E  05/20/2018 16:17
 Apex 5600     1° 45.773’S   57° 13.435’E  05/20/2018 05:33
Navis F0825    0° 51.545’S   57° 15.395’E  05/21/2018 19:56
 Apex 5601     0° 00.213’N   57° 16.443’E  05/22/2018 12:10
Navis F0840    1° 27.892’N   57° 18.558’E  05/23/2018 18:33
Navis F0841    5° 11.985’N   60° 15.657’E  05/26/2018 03:29
 Apex 5023     7° 11.570’N   62° 05.422’E  05/27/2018 11:30
Navis F05602  13° 47.283’N   64° 39.935’E  05/31/2018 08:18
 Apex F05024  16° 47.032’N   67° 59.598’E  06/02/2018 02:17


9.1.2.  Surface Velocity Program (SVP) drifters

PIs: Rick Lumpkin (AOML), Shaun Dolk (AOML/CIMAS)
Shipboard personnel: Denis Volkov (AOML/CIMAS), James Hooper (AOML/CIMAS), 
                     Andrew Stefanick (AOML)


Table 9.2. The list of SVP drifters deployed during the I07N-2018 cruise

                     Deployment Location      Deployment Time 
Drifter Number     Latitude       Longitude        (UTC)
———————————————  ————————————   ————————————  ————————————————
300234065701170  29° 50.950’S   32° 12.730’E  04/23/2018 18:11
300234065701160  29° 58.826’S   39° 00.040’E  04/25/2018 00:37
300234065701130  25° 59.939’S   54° 30.110’E  04/30/2018 01:40
300234065701120   7° 01.284’S   53° 58.247’E  05/13/2018 23:35
300234065701110   3° 13.912’S   56° 00.135’E  05/20/2018 05:52
300234065701020   2° 15.527’S   56° 49.452’E  05/20/2018 22:52
300234065700990   0° 00.400’N   57° 16.440’E  05/22/2018 12:15
300234065700950   3° 11.588’N   58° 25.983’E  05/24/2018 20:00
300234065700970   6° 47.436’N   61° 43.390’E  05/27/2018 05:10
300234065700980   7° 40.467’N   62° 32.011’E  05/27/2018 18:40


Most of SVP drifters were deployed according to the plan developed by the 
PIs Rick Lumpkin (AOML) and Shaun Dolk (AOML/CIMAS). A map in Figure 17 
highlights the areas with drifter data gaps (colors from yellow to blew) 
that were selected for deployment. We deviated from this plan a little by 
deploying one drifter in a strong eastward current (Wyrtki Jet) at about 2kS 
just north of the Seychelles Bank. Due to a miscommunication between the day 
and night shifts, we mistakenly deployed two last drifters close to each 
other, at 6°47’N and at 7°40’N (see Table 9.2).


Figure 17: Drifter Deployment Value model, highlighting areas to fill data 
           sparse regions, as well as to maximize drifter lifetimes. Red 
           means low priority and blue means high priority for deployment.


9.1.3: Wave buoys

PI: Kerstin Paulsson (SIO)
Shipboard personnel: Denis Volkov (AOML/CIMAS), James Hooper (AOML/CIMAS), 
Andrew Stefanick (AOML)

During the I07N-2018 cruise we deployed 3 GPS-based wave sensing buoys 
(Table 9.3), part of a 72-buoy array deployed throughout a 3-year program, 
provided by the Scripps Institution of Oceanography. The buoys measure the 
u,v,w of the ocean surface, process for the first 5 moments of the 
directional wave height coefficients, and relays the information in near-
real time back to SIO. A near-surface drogue allows the buoys to follow the 
upper O(1)m currents. The focus of the deployments is twofold: basin-scale 
observations of the surface wave field, and intensive sampling of the Somali 
Current and the resulting wave-current interactions. The buoy trajectories 
as well as the measured significant wave heights as of July 10 are shown in 
Figure 18.


Table 9.3: The list of wave buoys deployed during the I07N-2018 cruise

                     Deployment Location      Deployment Time 
Drifter Number     Latitude       Longitude        (UTC)
———————————————  ————————————   ————————————  ————————————————
     545         29° 59.957’S   45° 00.419’E  04/25/2018 03:45
     548         13° 56.631’S   55° 00.343’E  05/07/2018 19:48
     547          6° 03.299’S   54° 38.344’E  05/14/2018 12:13

	
	
Figure 18: A map showing the wave buoy trajectories as of July 10, 2018 
           (above), and significant wave heights measured by these buoys 
           (right panel).
	

9.2.  Lowered Acoustic Doppler Current Profiler (ADCP)

PI: Andreas Thurnherr (LDEO)	
Operator: Amanda Fay (LDEO)


Introduction

LADCP data were collected during the full-depth CTD cast at all stations. 
Preliminary processing and QC was performed onboard by Amanda Fay. Casts 
were sent to A. Thurnherr for shore-based processing as internet access 
allowed. A full QC will be carried out after the cruise by A. Thurnherr.

LADCP System Configuration

An AOML custom 48V lead acid rechargeable battery pack was used for all 
deployments. Instruments and battery pack were interfaced using a standard 
RDI star cable. Custom AOML deck leads were used for communications and 
charging between casts. The battery pack was periodically vented manually to 
prevent pressure build up. Battery power was periodically checked to ensure 
proper charge level of 52V was being maintained before deployments. Both the 
battery pack and the ADCP's were affixed to the CTD package using custom 
tabbed brackets aligned on horizontal cross-members of the package. The 
upward ADCP was positioned between niskin bottles 1 and 24 towards the outer 
ring, while the downward ADCP was affixed in the middle of the package about 
4 inches from the bottom ring. The configuration is shown in Figure 19.

The power supply and data transfer were handled independently from any CTD 
connections. While on deck, a communications and power cable was connected 
to a cable in the staging bay that ran into the wet lab. This cable 
connected to a battery charger located in the wet lab for power supply and 
also to an acquisitions computer via USB connection for data download. The 
LADCP acquisitions computer clock was synced to the master clock in the 
computer lab via network.

Table 01: Instruments used on cruise. DL = downlooker UL = uplooker.

Model                Serial Number     Stations used    
———————————————————  —————————————  ———————————————————
Teledyne RDI WHM300       150        1- 6, 11-44 (UL)
Teledyne RDI WHM300      24497      7- 10, 45- 124 (UL)
Teledyne RDI WHM150      24544          1-124 (DL)

Three different ADCP instruments were used during this cruise (table 01). 
Initial configuration consisted of the WHM15O #24544 as downlooker and the 
WHM300 #150 as uplooker. After perfect performance on the test casts, the 
downlooker reported a weak beam 1 on casts 1-3 and by cast 4 it appeared to 
have failed completely. We did not have a spare WHM150 onboard, so we did 
not replace the instrument. Around station 26 the beam came back as “weak” 
rather than “failed” and continued in this manner for the rest of the 
stations. The original UL, #150, was used for stations 1-6 before being 
swapped out for the alternate due to poor vertical velocities at depth due 
to the scattering environment. Unfortunately, the replacement UL (# 24497) 
did not improve the situation so at station 11 we went back to UL # 150. 
After recovering at station 11 however, the instrument came back reported 
that beam 3 was broken on the uplooker. We chose to maintain this setup 
regardless of the broken beam but kept a close eye on the data after each 
cast in case of another failure. At station 44 we noticed that beam 4 was 
cutting in-and-out at a depth around 1000 m. Before station 45 we installed 
the replacement UL (#24497) and continued with this setup throughout the 
rest of the stations without incident.

All ADCPs were set up to record velocity data with 8m pulses/bins and zero 
blanking. At station 69 we increased the number of bins for the DL because 
of improved acoustic scattering conditions. Staggered pinging was used to 
avoid previous ping interference, which is particularly important for 150kHz 
instruments. 

Problems/Setup Changes
——————————————————————
    Test Station B, cast 1: Switched to aft winch. Maintained aft winch 
                            throughout cruise. 
    Station 4-25:           Beam 1 of DL SN # 24544 reported failed
    Station 7:              Replaced UL from SN #150 to SN #24497
    Station 11:             Replaced UL from SN #24497 to SN #150
    Station 25-124:         Beam 1 of DL SN # 24544 reported as weak
    Station 45:             Replaced UL from SN #150 to SN #24497
    Station 69, cast 1:     MASTER.cmd changed from LN25 to LN30
    Station 73, cast 1:     Wire was trimmed and reterminated before this 
                            station.
    Station 85, cast 1:     Acquisition computer shut down between 
                            station 84 and 85. No issues once rebooted. 

LADCP Operation

ADCP programming and data acquisition were carried out using the LDEO 
Acquire software running on a MacBook Pro laptop. Communications between the 
acquisitions computer and the ADCPs took place across two parallel RS232 
connections via a Keyspan USA-49WG 4-port USB-to-RS232 adapter. No 
significant communications issues were encountered throughout the cruise. 
After sending the corresponding command files to the instruments prior to 
each cast, communication between the computer and the instrument was 
terminated, the deck cables were disconnected, and all connections were 
sealed with dummy plugs and secured. After the CTD was brought back on deck 
following a cast, the data and the power supply cable were reconnected to 
the computer and battery charger via the deck cables. Data acquisition was 
terminated and the data were downloaded using the Acquire software. The 
battery charger remained on from the time of data download until the time 
the instrument was prepared for the next cast. Log files were kept for each 
cast to ensure that all the steps were completed.

Data Processing and Quality Control

The LADCP data were processed by A. Fay at least once per day using the 
Matlab-based LDEO IX_10 processing software (1). Thurnherr also conducted 
additional processing in his lab on the data in batches of 2-4 stations. 
Processing warnings and diagnostic figures created during processing were 
reviewed for signs of anomalies, which included checking the realism of 
final profile values, checking for any biased shear, examining the agreement 
between aligned CTD/LADCP time series, and monitoring beam strength and 
range. Thurnherr was sent data and consulted when questionable profiles were 
observed.

The cruise-processed profiles of LADCP-derived horizontal velocity are shown 
in Figure 20. Comparison of the LADCP velocities in the upper ocean with the 
corresponding on-station SADCP velocities (Figure 21) indicates that the 
quality of these data is improved as we moved North due to improved 
scattering environment. Data quality will be assessed more quantitatively 
during additional post-cruise QC and re-processing by Thurnherr at LDEO. 

(1) available for download at http ://www.ldeo.columbia.edu/LADCP


Figure 19: Instruments and battery pack on rosette. UVP is not mounted in 
           this photo.

Figure 20: LADCP-derived velocities observed during I07N from preliminary 
           processing. Upper panel: Zonal velocity component (u). Lower 
           panel: Meridional velocity component (v).

Figure 21: RMS difference between the SADCP and LADCP velocities, showing 
           improved agreement as cruise progressed.


9.3. Discrete Salinity Sampling

PI: Molly Baringer (AOML)
Shipboard analysts: James Hooper (AOML/CIMAS), Andrew Stefanick (AOML)


A single Guildline Autosal, model 8400B salinometers (S/N 61664, nicknamed 
Miller Freeman), located in the salinity analysis room, was used for all 
salinity measurements. The autosals was calibrated on 9/2016. The 
salinometer readings were logged on a computer using Ocean Scientific 
International’s logging hardware and software. The Autosal’s water bath 
temperature was set to 24°C, which the Autosal is designed to automatically 
maintain. The laboratory’s temperature was also set and maintained to just 
below 24°C, to help further stabilize reading values and improve accuracy. 
Salinity analyses were performed after samples had equilibrated to 
laboratory temperature at least 12 hours after collection and at least 18 
hours in colder waters. The salinometer was standardized for each group of 
samples analyzed (usually 2 casts and up to 52 samples) using two bottles of 
standard seawater: one at the beginning and end of each set of measurements. 
The salinometer output was logged to a computer file. The software prompted 
the analyst to flush the instrument’s cell and change samples when 
appropriate.  Prior to each run a sub-standard flush, approximately 200 ml, 
of the conductivity cell was conducted to flush out the DI water used in 
between runs.  For each calibration standard, the salinometer cell was 
initially flushed 6 times before a set of conductivity ratio reading was 
taken. For each sample, the salinometer cell was initially flushed at least 
3 times before a set of conductivity ratio readings were taken.  After each 
run the autosal conductivity cell was flushed with approximately 200 ml of a 
triton-DI water solution and then rinsed and stored with DI water until the 
net run. 

IAPSO Standard Seawater Batch P-160 was used to standardize all casts.

The salinity samples were collected in 200 ml Kimax high-alumina 
borosilicate bottles that had been rinsed at least three times with sample 
water prior to filling. The bottles were sealed with custom-made plastic 
insert thimbles and Nalgene screw caps. This assembly provides very low 
container dissolution and sample evaporation. Prior to sample collection, 
inserts were inspected for proper fit and loose inserts replaced to insure 
an airtight seal.  PSS-78 salinity [UNES81] was calculated for each sample 
from the measured conductivity ratios. The offset between the initial 
standard seawater value and its reference value was applied to each sample. 
Then the difference (if any) between the initial and final vials of standard 
seawater was applied to each sample as a linear function of elapsed run 
time. The corrected salinity data was then incorporated into the cruise 
database. When duplicate measurements were deemed to have been collected and 
run properly, they were averaged and submitted with a quality flag of 6. On 
I07N, 2832 salinity measurements were taken, including 205 duplicates, and 
approximately 140 vials of standard seawater (SSW) were used. Up to two 
duplicate samples, one for shallow casts, were drawn from each cast to 
determine total analytical precision.  

The standard calibration values and duplicates are below in Figure 22 and 
Figure 23.  The duplicates taken during the cruise showed a median precision 
of -0.0002 +/- 0.004 psu.


Figure 22: Standard vial calibrations throughout the cruise.  The left 
           vertical axis is 100 X the conductivity ration and the right axis 
           is the corresponding salinity.

Figure 23: Duplicates throughout the cruise.


9.4. Dissolved Oxygen (discrete)

Analysts Leg1: Samantha Ladewig and Leah Chomiak
Analysts Leg2: Samantha Ladewig and Leah Chomiak
PIs: Chris Langdon, RSMAS, Molly Baringer, AOML

Equipment and Techniques

Dissolved oxygen analyses were performed with an automated titrator using 
amperometric end-point detection [Langdon, 2012]. Sample titration, data 
logging, and graphical display were performed with a PC running a LabView 
program written by Ulises Rivero of AOML. The temperature-corrected molarity 
of the thiosulfate titrant was determined as given by Dickson [1994].  
Thiosulfate was dispensed by a 2 mL Gilmont syringe driven with a stepper 
motor controlled by the titrator.  The whole-bottle titration technique of 
Carpenter [1965], with modifications by Culberson et al. [1991], was used.  
Three to four replicate 10 mL iodate standards were run every 3-4 days (SD<1 
uL). The reagent blank was determined as the difference between V1 and V2, 
the volumes of thiosulfate required to titrate 1-mL aliquots of the iodate 
standard, was determined at the beginning and end of the cruise.  

Sampling and Data Processing

Dissolved oxygen samples were drawn from Niskin bottles into calibrated 125-
150 mL iodine titration flasks using silicon tubing to avoid contamination 
of DOC and radiocarbon samples. Samples were drawn by counting while the 
flask was allowed to fill at full flow from the Niskin.  This count was then 
doubled and repeated thereby allowing the flask to be overflowed by two 
flask volumes. At this point the silicone tubing was pinched to reduce the 
flow to a trickle.  This was continued until a stable draw temperature was 
obtained on the Oakton meter.  These temperatures were used to calculate 
umol/kg concentrations and provide a diagnostic check of Niskin bottle 
integrity.  1 mL of MnCl2 and 1 mL of NaOH/NaI were added immediately after 
drawing the sample using a re-pipettor bottle-top dispenser. The flasks were 
then stoppered and shaken well. DI water was added to the neck of each flask 
to create a water seal. 24 samples plus two duplicates were drawn at each 
station. The total number of samples collected from the rosette was 3206.

The samples were stored in the lab in plastic totes at room temperature for 
1-2 hours before analysis. The data were incorporated into the cruise 
database shortly after analysis.

Thiosulfate normality was calculated for each standardization and corrected 
to the laboratory temperature.  This temperature ranged between 17.5 and 
19.9 C.

A total of 11 standardizations were performed during legs 1 and 2 
(mean=706.487, SD=1.26 uL).  Reagent blanks were run at the beginning 
(1.8±1.4 uL) and end of the cruise (1.8±0.5 uL).  

Volumetric Calibration

The dispenser used for the standard solution (SOCOREX Calibrex 520) and the 
burette used to dispense the thiosulfate titrant were calibrated 
gravimetrically just before the cruise.  Oxygen flask volumes were 
determined gravimetrically with degassed deionized water at AOML. The 
correction for buoyancy was applied. Flask volumes were corrected to the 
draw temperature.

Duplicate Samples

Duplicate samples were drawn at two depths on every cast.  The Niskins 
selected for the duplicates and hence the oxygen flasks were changed for 
each cast.  A total of 247 sets of duplicates were run. The average standard 
deviation of all sets was 0.248 umol kg-1.  

Quality Coding

Based on preliminary quality control performed during the cruise the 
following quality flags were assigned.


Quality  Number  Note
flag    
———————  ——————  ——————————————————————————————————————————————————————————
2        2824    Good
3        66      Questionable - stopper loose, Niskin leak, bubble in flask
4        45      Bad - overshot endpoint, maxed out data points during 
                 titration
6        247     Duplicate
9        23      Not Sampled


Problems

Flask 181 had an incorrect volume value (typo) in the bottle volumes .txt 
file, resulting in an incorrect oxygen calculation. This was discovered 
after Station 36. The correct value of the flask was fixed in the .txt file 
and each calculation derived from flask 181 was recalculated with the proper 
volume for Stations 1-36; all calculations were updated in the logbook, 
final data file, and respective ABR files. 

The re-pipettor bottle-top dispenser for the NaI reagent bottle was replaced 
at Station 5 after a crack in the neck occurred. 

At Station 12, the electrode probe (SN8137155P) was replaced with a new 
probe (SN3129026P) due to erratic behavior. 

At Station 23, the electrode was replaced again (SN6235027P) due to abnormal 
readings. 

At Station 41, the electrode was replaced again (SN3350011P) due to erratic 
behavior. 

At Station 105, upon entering the OMZ with recorded O2 values <5umol/kg, the 
titrator began having difficulties completing the titration script and 
calculating the final endpoint. The U=2 endpoint was recorded, and later the 
final endpoint was derived using the TRT script files to manually create a 
regression of the intercept between the current detector readings and uL 
titrant added. This regression endpoint was then used to manually calculate 
O2 in umol/L and umol/kg. The issue persisted from Station 105 through the 
last station, 124.

Cross-over comparisons

None this cruise.


References

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

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).

Dickson, A. G., "Determination of dissolved oxygen in seawater by Winkler 
    titration," WHP Operations and Methods (1994a).

Langdon, C. (2010). Determination of dissolved oxygen in seawater by Winkler 
    titration using the amperometric technique. The GO-SHIP Repeat 
    Hydrography Manual: A Collection of Expert Reports and Guidelines. E. M. 
    Hood, C. L. Sabine and B. M. Sloyan, IOCCP Report Number 14, ICPO 
    Publication Series Number 134.



9.5.  Dissolved Inorganic Carbon (DIC)
 
PI’s: Rik Wanninkhof (NOAA/AOML) and Richard A. Feely (NOAA/PMEL)	
Technicians: Charles Featherstone (NOAA/AOML) and Dana Greeley (NOAA/PMEL)


Sample collection:

Samples for DIC measurements were drawn (according to procedures outlined in 
the PICES Publication, Guide to Best Practices for Ocean CO2 Measurements) 
from Niskin bottles into 294 ml borosilicate glass bottles using silicone 
tubing. The flasks were rinsed once and filled from the bottom with care not 
to entrain any bubbles, overflowing by at least one-half volume. The sample 
tube was pinched off and withdrawn, creating a 6 ml headspace, followed by 
0.12 ml of saturated HgCl2 solution which was added as a preservative. The 
sample bottles were then sealed with glass stoppers lightly covered with 
Apiezon-L grease and were stored at room temperature for a maximum of 12 
hours. 

Equipment:

The analysis was done by coulometry with two analytical systems (AOML 3 and 
AOML 4) used simultaneously on the cruise. Each system consisted of a 
coulometer (CM5015 UIC Inc) coupled with a Dissolved Inorganic Carbon 
Extractor (DICE).  The DICE system was developed by Esa Peltola and Denis 
Pierrot of NOAA/AOML and Dana Greeley of NOAA/PMEL to modernize a carbon 
extractor called SOMMA (Johnson et al. 1985, 1987, 1993, and 1999; Johnson 
1992).

The two DICE systems (AOML 3 and AOML 4) were set up in a seagoing container 
modified for use as a shipboard laboratory on the aft main working deck of 
the R/V Ronald H. Brown.

DIC Analysis:

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

DIC Calculation:

Calculation of the amount of CO2 injected was according to the CO2 handbook 
(DOE 1994).  The concentration of CO2 ([CO2]) in the samples was determined 
according to:

    [CO2] = Cal. Factor * (Counts – Blank * Run Time)* K µmol/count
                          —————————————————————————————————————————
                             pipette volume * density of sample

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

The instrument has a salinity sensor, but all DIC values were recalculated 
to a molar weight (µmol/kg) using density obtained from the CTD’s salinity.  
The DIC values were corrected for dilution due to the addition of 0.120 ml 
of saturated HgCl2 used for sample preservation.  The total water volume of 
the sample bottles was 294 ml (calibrated by Esa Peltola, AOML).  The 
correction factor used for dilution was 1.00037.  A correction was also 
applied for the offset from the CRM.  This additive correction was applied 
for each cell using the CRM value obtained at the beginning of the cell.  
The average correction was 0.93 µmol/kg for AOML 3 and 1.8 µmol/kg for AOML 
4.

The coulometer cell solution was replaced after 25 – 28 mg of carbon was 
titrated, typically after 9 – 12 hours of continuous use.  Normally the 
blank is less than 30, but we were forced to run them with blanks in the 12 
– 51 range.

Calibration, Accuracy, and Precision:

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

1) Gas loops were run at the beginning of each cell
2) CRM’s supplied by Dr. A. Dickson of SIO, were analyzed at the beginning 
   of the cell before sample analysis.
3) Duplicate samples from the same niskin, were measured near the beginning; 
   middle and end of each cell.

Each coulometer was calibrated by injecting aliquots of pure CO2 (99.999%) 
by means of an 8-port valve (Wilke et al., 1993) outfitted with two 
calibrated sample loops of different sizes (~1ml and ~2ml). The instruments 
were each separately calibrated at the beginning of each cell with a minimum 
of two sets of these gas loop injections.

The accuracy of the DICE measurement is determined with the use of standards 
(Certified Reference Materials (CRMs), consisting of filtered and UV 
irradiated seawater) supplied by Dr. A. Dickson of Scripps Institution of 
Oceanography (SIO). The CRM accuracy is determined manometrically on land in 
San Diego and the DIC data reported to the data base have been corrected to 
this batch 169 CRM value.  The CRM certified value for this batch is 2063.31 
µmol/kg1. 

The precision of the two DICE systems can be demonstrated via the replicate 
samples.  Approximately 7% of the niskins sampled were duplicates taken as a 
check of our precision.  These replicate samples were interspersed 
throughout the station analysis for quality assurance and integrity of the 
coulometer cell solutions. The average absolute difference of these 
replicates is 1.68 (AOML 3) and 1.64 (AOML) µmol/kg - No major systematic 
differences between the replicates were observed2.

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


                   Calibration data during this cruise:

 UNIT    Ave Gas     Pipette      Ave CRM       Std   Ave Difference 
        Cal Factor                              Dev       Dupes
——————  ——————————  —————————  ———————————————  ————  ——————————————
AOML 3    1.00172   27.928 ml  2062.38, N = 63  1.91      1.68
AOML 4    1.00204   29.366 ml  2061.51, N = 61  2.44      1.64


Underway DIC Samples

Underway samples were collected from the flow thru system in the forward 
Main Lab during transit.  Discrete DIC samples were collected approximately 
every 4 hours with duplicates every fifth sample.  A total of 24 discrete 
DIC samples including duplicates were collected while underway.  The average 
difference for replicates of underway DIC samples was 0.56 µmol/kg and the 
average STDEV was 0.33.

Summary

The overall performance of the analytical equipment was good during the 
cruise.  No problems occurred with either of the systems during leg 1 and 
leg 2.

Including the duplicates, over 3047 samples were analyzed from 124 CTD casts 
for dissolved inorganic carbon (DIC) which means that there is a DIC value 
for approximately 96% of the niskins tripped.  The DIC data reported to the 
database directly from the ship are to be considered preliminary until a 
more thorough quality assurance can be completed shore side.


References

DOE (U.S. Department of Energy). (1994). Handbook of Methods for the 
    Analysis of the Various Parameters of the Carbon Dioxide System in 
    Seawater. Version 2.0.

ORNL/CDIAC-74. Ed. A. G. Dickson and C. Goyet. Carbon Dioxide Information 
    Analysis Center, Oak Ridge National Laboratory, Oak Ridge, Tenn.

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

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.

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

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

Wilke, R.J., D.W.R. Wallace, and K.M. Johnson (1993): "Water-based 
    gravimetric method for the determination of gas loop volume."



9.6.  Discrete pH Analyses
 
PI’s: Rik Wanninkhof (NOAA/AOML) and Frank Millero (UM/RSMAS)	
Analysts: Carmen Rodriguez (UM/RSMAS), Annelise Hill (UM/RSMAS), Holly 
Westbrook (UM/RSMAS)


Sampling

Samples were collected in 125ml glass serum bottles, sealed with rubber 
stoppers and crimped aluminum caps. They were rinsed a minimum of 2 times 
and allowed to overflow 1.5 times the volume. Immediately after collection, 
2.5ml of sample were withdrawn from the bottles and they were subsequently 
preserved with 25ul of concentrated mercury (II) chloride to prevent 
biological alterations of pH. Samples were thermostated to 25°C before 
analysis. Three duplicates were collected from each station. One sample per 
station was collected and analyzed with excess indicator in order to correct 
for pH perturbations due to the indicator addition. This correction has not 
been applied to the preliminary data. All data should be considered 
preliminary.


Analysis

pH (µmol/kg seawater) on the seawater scale was measured using an Agilent 
8453 spectrophotometer according to the methods outlined by Clayton and 
Byrne (1993). An RTE10 water bath maintained spectrophotometric cell 
temperature at 25°C. A 10 cm micro-flow through cell (Sterna, Inc) was 
filled automatically using a Kloehn 6v syringe pump. The purified 
sulfonephthalein indicator m-cresol purple (mCP) was also injected 
automatically by the Kloehn 6v syringe pump into the spectrophotometric 
cells, and the absorbance of light was measured at four different 
wavelengths (434 nm, 578 nm, 730 nm, and 488 nm). The ratios of absorbances 
at the different wavelengths were used to calculate pH on the total and 
seawater scales using the equations of Liu et al (2011). The equations of 
Dickson and Millero (1987), Dickson and Riley (1979), and Dickson (1990) 
were used to convert pH from the total to seawater scale. The isobestic 
point (488nm) will be used for the indicator correction. Salinity data were 
obtained from the conductivity sensor on the CTD. These data were later 
corroborated by shipboard measurements. Temperature of the samples was 
measured immediately after spectrophotometric measurements using a Fluke 
Hart 1523 digital platinum resistance thermometer. Due to ship berthing 
limitations, only one technician was available to analyze pH samples. All 
samples were analyzed, however, within 12 hours of collection.


Reagents

The mCP indicator dye was a concentrated solution of ~2.0 mM. Purified 
indicator provided by Dr. Robert Byrne, University of South Florida.


Standardization

The precision of the data can be accessed from measurements of duplicate 
samples, certified reference material (CRM) Batch 169 (Dr. Andrew Dickson, 
UCSD) and TRIS buffers (Ramette et al. 1977). The measurement of CRM and 
TRIS was alternated at each station. 


Data Processing

Addition of the indicator affects the pH of the sample, and the degree to 
which pH is affected is a function of the pH difference between the seawater 
and indicator. Therefore, a correction is applied for each batch of dye. One 
sample from each station was measured twice, once normally and a second time 
with double the amount of indicator. The change in the ratio is then plotted 
verses the change in the isobestic point to develop an empirical 
relationship for the effect of the indicator on the pH. This correction has 
not yet been applied to the preliminary data. A summary of the preliminary 
quality control of the data is given in Table 1. Underway samples were 
collected approximately every 4 hours prior to the start of the first 
station, but are not included in Table 1.


Table 9.1: Preliminary Quality Control

Number of Samples        2846
Good (flag=2)            2470
Dup (flag=6)             357
questionable (flag = 3)  13
bad (flag=4)             5
lost (flag = 5)          1


Problems

No major problems occurred during the cruise. 



References

Clayton, T. D. and Byrne, R. H., “Spectrophotometric seawater pH 
    measurements: Total hydrogen ion concentration scale calibration of m-
    cresol purple and at-sea results,” Deep-Sea Res., 40, pp. 2315-2329 
    (1993).

Dickson, A. G. and Millero, F. J., “A comparison of the equilibrium 
    constants for the dissociation of carbonic acid in seawater media,” 
    Deep-Sea Res., Part A, 34, 10, pp. 1733-1743 (1987).

Dickson, A. G. and Riley, J. P., “The estimation of acid dissociation 
    constants in seawater media from potentiometric titration with strong 
    base, 1: The ionic product of water-KSUS-w,” Mar. Chem., 7, 2, pp. 89-99 
    (1979).

Dickson, A. G., “Thermodynamics of the dissociation of boric acid in 
    synthetic seawater from 273.15 to 318.15 K,” Deep-Sea Res., Part A, 37, 
    5, pp. 755-766 (1990).

Liu, X, Patsavas, M. C., and Byrne, R. H., “Purification and 
    characterization of meta-cresol purple for spectrophotometric seawater 
    pH measurements,” Environ. Sci. and Tech. 45, pp 4862-4868 (2011).

Millero, F.J., The Marine Inorganic Carbon Cycle, Chemical Reviews, 107(2) 
    308-341 (2007).

Ramette, R. W., Culberson, C. H., and Bates, R. G., “Acid-base properties of 
    Tris(hydroxymethyl)aminomethane (Tris) buffers in seawater from 5 to 
    40°C,” Anal. Chem., 49, pp. 867-870 (1977).



9.7.  Total Alkalinity
 
PI’s: Rik Wanninkhof (NOAA/AOML) and Frank Millero (UM/RSMAS)	
Analysts: Carmen Rodriguez (UM/RSMAS), Annelise Hill (UM/RSMAS), Holly 
Westbrook (UM/RSMAS)


Sampling

At each station total alkalinity (TA) samples were drawn from Niskin bottles 
into 500 ml borosilicate bottles using silicone tubing that fit over the 
petcock. Bottles were rinsed with a small volume, then filled from the 
bottom and allowed to overflow 1.5 times the bottle volume.  The sampler was 
careful not to entrain any bubbles during the filling procedure. 
Approximately 15 ml of water is withdrawn from the bottle by halting the 
sample flow and removing the sampling tube, thus creating a reproducible 
headspace for thermal expansion during thermal equilibration. The sample 
bottles were sealed at a ground glass joint with a glass stopper. The 
samples were then thermostated at 25°C before analysis.  Three duplicates 
were collected at each station. 


Analyzer Description

The sample TA was evaluated from the proton balance at the alkalinity 
equivalence point, pH T 4.5 at 25°C and zero ionic strength using a closed 
cell HCl titration.  This method utilizes a multi-point hydrochloric acid 
titration of seawater (Dickson 1981). The instrument program uses a 
Levenberg-Marquardt nonlinear least-squares algorithm to calculate the TA 
and DIC from the potentiometric titration data. The program is patterned 
after those developed by Dickson (1981), Johansson and Wedborg (1982), and 
U.S. Department of Energy (DOE) (1994).  The least-squares algorithm of the 
potentiometric titrations not only give values of TA but also those of DIC, 
initial pH as calculated from the initial EMF, the standard potential of the 
electrode system (E0), and the first dissociation constant of CO2 at the 
given temperature and ionic strength (pK1). Two titration systems, A and B 
were used for TA analysis. Each of them consists of a Metrohm 765 Dosimat 
titrator, an Orion 720A, or 720A+, pH meter and a custom designed plexiglass 
water-jacketed titration cell (Millero et al, 1993).  The titration cell 
allows for the titration to be conducted in a closed system by incorporating 
a 5mL ground glass syringe to allow for increased volume with acid addition.  
The seawater samples were temperature equilibrated to a constant temperature 
of 25 d 0.1°C with a water bath (Thermo, HAAKE A10).  The electrodes used to 
measure the EMF of the sample during a titration were a ROSS glass pH 
electrode (Orion, model 810100) and a double junction Ag, AgCl reference 
electrode (Orion, model 900200).  The water-jacketed cell is similar to the 
cells used by Bradshaw and Brewer (1988) except a larger volume (~200 ml) is 
employed to increase the precision. Each cell has a solenoid fill and drain 
valve which increases the reproducibility of the volume of sample contained 
in the cell.  A typical titration records the stable solution EMF (deviation 
less than 0.09 mV) and adds enough acid to change the voltage a pre-assigned 
increment (~13 mV). A full titration (~25 points) takes about 20 minutes.  A 
6 port valve (VICI, Valco EMTCA-CE) allows 6 samples to be loaded into the 
instrument and successively measured.


Reagents

A single 50-L batch of ~0.25 m HCl acid was prepared in 0.45 m NaCl by 
dilution of concentrated HCl (AR Select, Mallinckrodt), to yield a total 
ionic strength similar to seawater of salinity 35.0 (I = 0.7 M). The acid is 
standardized with alkalinity titrations on seawater of known alkalinity 
(certified reference material, CRM, provided by Dr. Andrew Dickson, Marine 
Physical Laboratory, La Jolla, California). The calibrated normality of the 
acid used was 0.24494 ± 0.0001 N HCl. The acid is stored in 500-ml glass 
bottles sealed with Apiezon® M grease for use at sea.


Standardization

The reproducibility and precision of measurements are checked using low 
nutrient surface seawater collected from the ship’s underway seawater 
system, used as a substandard, and Certified Reference Material (Dr. Andrew 
Dickson, Marine Physical Laboratory, La Jolla, California).  The CRM was 
utilized to account for instrument drift over the duration of the cruise and 
to maintain measurement precision.  At each station, the drift and precision 
of each system was monitored by alternate measurements of either a CRM or a 
low nutrient surface water sample.  Duplicate analyses (2 samples taken from 
the same Niskin bottle) provided additional quality assurance. Three 
duplicates samples were collected at each station; one set is analyzed on 
system A, one on system B, and one split between systems A and B. This 
provided a measure of the precision on both the same system and between 
systems.  Laboratory calibrations of the Dosimat burette system with water 
indicate the systems deliver 3.000 ml of acid (the approximate value for a 
titration of 200 ml of seawater) to a precision of ± 0.0004 ml, resulting in 
an error of ±0.3 µmol/kg in TA. All samples were analyzed less than 12 hours 
after collection.


Data Processing

Measurements were made on CRM batch 169. The difference between the measured 
and certified values will be used to correct the TA values produced on each 
system, however, no correction has been made on preliminary data at this 
time. Eighteen different batches of low nutrient surface water were used. 
They all had standard deviations of <3 µmol/kg, and were generally less than 
2 µmol/kg. The preliminary quality control results are shown in table 1. 
Underway samples were collected every 4 hours prior to the first station, 
but the data and are not included in table 1.


Table 9.2: Preliminary quality control

Total Samples          2815
Good (flag=2)          2414
Duplicate (flag=6)     363
questionable (flag=3)  20
Bad (flag=4)           9
lost (flag=5)          9


Problems

No major problems occurred during the cruise. 


References

Bradshaw, A. L. and Brewer, P. G., High precision measurements of alkalinity 
    and total carbon dioxide in seawater by potentiometric titration, Mar. 
    Chem., 23, pp. 69-86 (1988).

DOE, (U.S. Department of Energy), Handbook of Methods for the Analysis of 
    the Various Parameters of the Carbon Dioxide System in Seawater. Version 
    2.0. ORNL/CDIAC-74, Carbon Dioxide Information Analysis Center, Oak 
    Ridge National Laboratory, Oak Ridge, Tenn. (1994).

Dickson, A. G., An exact definition of total alkalinity and a procedure for 
    the estimation of alkalinity and total CO2 from titration data, Deep-Sea 
    Res., Part A, 28, pp. 609-623 (1981).

Johansson, 0. and Wedborg, M., "On the evaluation of potentiometric 
    titrations of seawater with hydrochloric acid," Oceanologica Acta, 5, 
    pp. 209-218 (1982).

Millero, F. J., Zhang, J-Z., Lee, K., and Campbell, D. M., Titration 
    alkalinity of seawater, Mar. Chem., 44,pp. 153-165 (1993b).



9.8.  Nutrients
 
PI’s: Jia-Zhong Zhang (NOAA/AOML) and Calvin Mordy (NOAA-PMEL)	
Technicians: Eric Wisegarver (NOAA/PMEL) and Ian Smith (UM/CIMAS)


Equipment and Techniques

Dissolved nutrients (phosphate, silicate, nitrate and nitrite) were measured 
by using a Seal Analytical AA3 HR automated continuous flow analytical 
system with segmented flow and colormetric detection. Detailed methodologies 
are described by Gordon et al. (1992).

Silicic acid was analyzed using a modification of Armstrong et al. (1967).  
An acidic solution of ammonium molybdate was added to a seawater sample to 
produce silicomolybic acid.  Oxalic acid was then added to inhibit a 
secondary reaction with phosphate.  Finally, a reaction with ascorbic acid 
formed the blue compound silicomolybdous acid.  The color formation was 
detected at 660 nm.  The use of oxalic acid and ascorbic acid (instead of 
tartaric acid and stannous chloride by Gordon et al.) were employed to 
reduce the toxicity of our waste steam.

Nitrate and Nitrite analysis were also a modification of Armstrong et al. 
(1967).  Nitrate was reduced to nitrite via a copperized cadmium column to 
form a red azo dye by complexing nitrite with sulfanilamide and N-1-
naphthylethylenediamine (NED).  Color formation was detected at 540 nm.  The 
same technique was used to measure nitrite, (excluding the reduction step).

Phosphate analysis was based on a technique by Bernhart and Wilhelms (1967).  
An acidic solution of ammonium molybdate was added to the sample to produce 
phosphomolybdate acid.   This was reduced to the blue compound 
phosphomolybdous acid following the addition of hydrazine sulfate.  The 
color formation was detected at 820 nm.


Sampling and Standards

Nutrient samples were drawn in 50ml HDPE Nalgene sample bottles that had 
been stored in 10% HCl.  The bottles are rinsed 3-4 times with sample prior 
to filling.  A replicate was normally drawn from the deep Niskin bottle at 
each station for analysis to reduce carry over.   Samples were then brought 
to room temperature prior to analysis.  Fresh mixed working standards were 
prepared before each analysis.  In addition to the samples, each analysis 
consisted of 3 replicate standards, 3 DIW blanks and 3 Matrix blanks placed 
at the beginning and then repeated at the end of each run.   Also, one mixed 
working standard from the previous analytical run was used at the beginning 
of the new run to determine differences between the two standards.  Samples 
are analyzed from deep water to the surface.  Low Nutrient Seawater (LNSW) 
was used as a wash, base line carrier and medium for the working standards.

The working standard was made by the addition of 0.1ml of primary nitrite 
standard and 10.0 ml of a secondary mixed standard (containing silicic acid, 
nitrate, and phosphate) into a 250ml calibrated volumetric flask of LNSW.  
Working standards were prepared for each station. 

Dry standards of a high purity were pre-weighed at PMEL. Nitrite standards 
were dissolved at sea. The secondary mixed standard was prepared by the 
addition of 30ml of a nitrate - phosphate primary standard to the silicic 
acid standard.  Lab temperatures were recorded for each analytical run. 
Nutrient concentrations were reported in micromoles per kilogram. All the 
pump tubing was replaced at least two times during the I07N cruise.

Approximately 2900 samples were analyzed.


References

Armstrong, F.A.J., Stearns, C.R. and Strickland, J.D.H. (1967), The 
    measurement of upwelling and subsequent biological processes by means of 
    the Technicon AutoAnalyzer and associated equipment.  Deep-Sea Res. 
    14:381-389.

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

Gordon, L.I., Jennings Jr., J.C., Ross, A.A. and Krest, J.M. (1993)  A 
    suggested protocol for the continuous automated analysis of seawater 
    nutrients (phosphate, nitrate, nitrite and silicic acid) in the WOCE 
    Hydrographic program and the Joint Global Ocean Fluxes Study, WOCE 
    Operations Manual, vol. 3: The Observational Programme, Section 3.2: 
    WOCE Hydrograghic Programme, Part 3.1.3: WHP Operations and Methods.  
    WHP Office Report WHPO 91-1; WOCE Report No. 68/91.  November 1994, 
    Revision 1, Woods Hole, MA., USA, 52 loose-leaf pages.



9.9.  Chlorofluorocarbons (CFCs) and Sulfur Hexafluoride (SF6)
 
PI: John Bullister (NOAA/PMEL)
Lead Analyst: Bonnie Chang, NOAA/PMEL and UW (Leg 1 and Leg 2)
CFC analysts:  Charles Kleinwort and Kathryn Williams (Leg 1 and Leg 2)


The PMEL analytical system (Bullister and Wisegarver, 2008) was used for 
CFC-11, CFC-12, sulfur hexafluoride (SF6) and nitrous oxide (N2O) analyses 
on the GOSHIP I07N expedition. Greater than 2300 samples of dissolved CFC-
11, CFC-12 and SF6 ('CFC/SF6') were analyzed.

In general, the analytical system performed well for CFCs, SF6 and N2O 
during the cruise.  Typical dissolved SF6 concentrations in modern surface 
water are ~1-2 fmol kg-1 seawater (1 fmol= femtomole = 10-15 moles), 
approximately 1000 times lower than dissolved CFC-11 and CFC-12 
concentrations. The limits of detection for SF6 were approximately 0.04 fmol 
kg-1 on this cruise.

Water samples were collected in bottles designed with a modified end-cap 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 collected for dissolved CFC-11, CFC-12 
and SF6 analysis were the first samples drawn from the bottles. Care was 
taken to coordinate the sampling of CFC/SF6 with other samples to minimize 
the time between the initial opening of each bottle and the completion of 
sample drawing. Samples easily impacted by gas exchange (dissolved oxygen, 
3He, DIC and pH) were collected within several minutes of the initial 
opening of each bottle. To minimize contact with air, the CFC/SF6 samples 
were drawn directly through the stopcocks of the 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 
~10°C until 20 minutes before being analyzed. At that time, the syringe was 
place in a bath of surface seawater heated to 32°C.

For atmospheric sampling, a 75 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 an Air Cadet 
pump. The air was compressed in the pump, with the downstream pressure held 
at ~1.5 atm, using a backpressure regulator. A tee allowed a flow of ~100 ml 
min-1 of the compressed air to be directed to the gas sample valves of the 
CFC/SF6 analytical systems, while the bulk flow of the air (>7 L min-1) was 
vented through the back-pressure regulator. Air samples were analyzed only 
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 ~12 locations along the cruise track. At each location, 
at least four air measurements were made to improve the precision of the 
measurements.

Concentrations of CFC-11, CFC-12 and SF6 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) and Bullister and Wisegarver (2008), as outlined below. For 
seawater analyses, water was transferred from a glass syringe to a glass-
sparging chamber (volume 200 ml). The dissolved gases in the seawater sample 
were extracted by passing a supply of CFC/SF6-free N2 through the sparging 
chamber for a period of 6 minutes at 150 ml min-1. Water vapor was removed 
from the purge gas during passage through a Nafion drier. Carbon dioxide was 
removed with an 18 cm long, 3/8" diameter glass tube packed with Ascarite 
and a small amount of magnesium perchlorate desiccant. The sample gases were 
concentrated on a cold-trap consisting of a 1/16" OD stainless steel tube 
with a 2.5 cm section packed tightly with Porapak Q, a 15 cm section packed 
with Carboxen 1000 and a 2.5 cm section packed with MS5A. A Neslab Cryocool 
CC-100 was used to cool the trap to -65°C. After 6 minutes of purging, the 
trap was isolated, and it was heated electrically to 170°C. The sample gases 
held in the trap were then injected onto a precolumn (~61 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, CFC-11, SF6 from later eluting peaks.

After the SF6 and CFC-12 had passed from the pre-column and into the second 
pre-column (26 cm of 1/8" O.D. stainless steel tubing packed with MS5A, 
160°C) and into the analytical column #1(174 cm of 1/8" OD stainless steel 
tubing packed with MS5A + 60 cm Porasil C held at 80°C), the outflow from 
the first pre-column was diverted to the second analytical column (180 cm 
1/8" OD stainless steel tubing packed with Porasil B, 80-100 mesh, held at 
80°C). The gases remaining after CFC- 11 had passed through the first pre-
column, were backflushed from the precolumn and vented. After CFC-12 had 
passed through the second pre-column, a flow of Argon:Methane (95:5) was 
used to divert the N2O to a third analytical column (30 cm of MS5A, 150°C). 
Column #3 and the second pre-column were held in a Shimadzu GC8AIE gas 
chromatograph with an electron capture detector (ECD) held at 330°C. Columns 
#1, and the first pre-column were in another Shimadzu GC8AIE gas 
chromatograph with ECD. The column #2 was also in a Shimadzu GC8AIE gas 
chromatograph with the ECD held at 330°C.

The analytical system was calibrated frequently using a standard gas of 
known CFC/SF6 composition (PMEL-WRS-72611). 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, pre-columns, main chromatographic column, and ECD 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/SF6 free gas) were 
injected and analyzed in a similar manner. The typical analysis time for 
seawater, air, standard or blank samples was ~12 minutes. Concentrations of 
the CFC-11 and CFC-12 in air, seawater samples, and gas standards are 
reported relative to the SIO98 calibration scale (Bullister and Tanhua, 
2010). Concentrations of SF6 in air, seawater samples, and gas standards are 
reported relative to the SIO-2005 calibration scale (Bullister and Tanhua, 
2010). 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) and SF6 concentrations in fmol kg-1. CFC/SF6 
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 WRS72611) into the analytical instrument. The response of the 
detector to the range of moles of CFC/SF6 passing through the detector 
remained relatively constant during the cruise. Full-range calibration 
curves were run at several times during the cruise and partial curves were 
run as frequently as possible, usually while sampling. Single injections of 
a fixed volume of standard gas at one atmosphere were run much more 
frequently (at intervals of 90 minutes) to monitor short-term changes in 
detector sensitivity.

The purging efficiency was estimated by re-purging a high-concentration 
water sample and measuring the residual signal. At a flow rate of 150 ml 
min-1 for 6 minutes, the purging efficiency for SF6 and both CFC gases was > 
99%. The efficiency for N2O was typically about 96%.

On this expedition, based on the analysis of more than 180 pairs of 
duplicate samples, we estimate precisions (1 standard deviation) of about 
0.5% or 0.003 pmol kg-1 (whichever is greater) for dissolved CFC-12 and 1% 
or 0.005 pmol kg-1 for CFC-11 measurements. The estimated precision for SF6 
was 3% or 0.04 fmol kg-1, (whichever is greater). The estimated precision 
for N2O was 3% or 0.2 nmol kg-1, (whichever is greater). Overall accuracy of 
the measurements (a function of the absolute accuracy of the calibration 
gases, volumetric calibrations of the sample gas loops and purge chamber, 
errors in fits to the calibration curves and other factors) is estimated to 
be about 2% or 0.004 pmol kg' for CFC-11 and CFC-12 and 4% or 0.04 fmol kg-1 
for SF6.

A small number of water samples had anomalously high CFC-12 and/or SF6 
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/SF6 during the sampling or analysis processes.

Measured concentrations for these anomalous samples are included in the data 
file, but are given a quality flag value of either 3 (questionable 
measurement) or 4 (bad measurement). Less than 1% of samples were flagged as 
bad or questionable during this voyage. 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, etc.).

Radio frequency interference (RFI) occasionally occurred and was manifested 
as negative excursions in the signal acquired from the CFC-11 channel. RFI 
was avoided by keeping hand-held radio transmissions on their low power 
setting (<0.5W) at a distance >15ft from the CFC lab van. 

Some N2O samples had elevated re-strip and stripper blank values which is 
due to biological growth on the glass frit or walls of the stripper. These 
were not used in the determination of the stripper efficiency corrections. 
During the purging process with nitrogen gas, the seawater samples and 
interior of the stripping chamber become anoxic, which may lead to in-situ 
production of N2O in the stripping chamber.  The stripping chamber remains 
anoxic during subsequent 12-minute stripper blank and re-strip analyses, and 
any in-situ N2O production during this period would increase the N2O values 
of the re-strip or stripper blank measurements.  Washing the stripper frit 
and walls with 10% HCl immediately reduced the stripper blank and re-strip 
values.   However, these values often significantly increased within a day 
or so after the acid rinses.   During the cruise the stripper frit was 
washed with 10% HCl at 24-48hr intervals to maintain a stripper efficiency 
of approximately 96%.


References 

Bullister, J.L., and T. Tanhua (2010): Sampling and measurement of 
    chlorofluorocarbons and sulfur hexafluoride in seawater. In The GO-SHIP 
    Repeat Hydrography Manual: A Collection of Expert Reports and 
    Guidelines. E.M. Hood, C.L. Sabine, and B.M. Sloyan (eds.), IOCCP Report 
    Number 14, ICPO Publication Series Number 134. Available online at 
    http://www.go- ship. org/HydroMan.html

Bullister, J.L., and R.F. Weiss, 1988: Determination of CC13F and CC12F2 in 
    seawater and air. Deep-Sea Res., y. 25, pp. 839-853.

Bullister, J.L., and D.P. Wisegarver (2008): The shipboard analysis of trace 
    levels of sulfur hexafluoride, chlorofluorocarbon-11 and 
    chlorofluorocarbon-12 in seawater. Deep-Sea Res. I, 55,1063-1074.

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. Stunock, 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., y. 105, pp. 
    17,751- 17,792.



9.10.  DOC and TDN Sampling

 
Objectives: Determine the distributions of dissolved organic carbon (DOC) 
and total dissolved nitrogen (TDN) along a meridional section of the western 
Atlantic Ocean.  The ultimate goal is to understand the role of DOC in the 
ocean carbon cycle, while TDN provides an estimate of the concentrations of 
dissolved organic nitrogen (DON) in the ocean (DON = TDN – DIN, where DIN is 
the concentration of inorganic N).  DON, in turn, serves as a nutrient 
source to photoautotrophs in meso- and oligotrophic surface ocean waters. 

Sampling was done at alternating stations along the cruise track, such that 
sampling was done at about 1o latitude intervals.  Full water column 
sampling was done, which returns 24 samples per station.  Since the goal is 
to measure dissolved organic matter, samples from the upper 250 m of the w 
ater column are gravity filtered through in-line polycarbonate filter 
holders; the filters employed were 45 mm Whatman GF/F, precombusted at 400oC 
before use.  Water taken from >250 m are sampled unfiltered since the 
particulate organic matter concentrations are typically inconsequential at 
those depths.

Analyses are by high temperature combustion of 100 microliters of sample 
water injected into 680oC tube furnace.  An oxygen carrier gas allows 
combustion to CO2 and NO, gaseous products that are assessed with IR and 
chemiluminescent detectors, respectively.  DOC analysis is performed using a 
Shimadzu Model TOC-L.  The system configuration and operating parameters are 
as follows:  Ultra high purity O2 is used as a carrier gas, flowing through 
the system at 150 ml min-1.  100 µl of sample is injected with automation 
through a Teflon/sliding injection port into a quartz combustion tube packed 
with Pt gauze and 5% Pt on alumina catalyst heated to 680°C.  Samples are 
acidified with 37% HCl (15 µl per 10 ml of sample; 0.15%) and, immediately 
prior to injection, sparged with ultra-high purity, CO2 free oxygen for 1.5 
minutes to remove inorganic carbon.  Samples are combusted in the furnace 
and the resulting gas passed through water traps and a final copper halide 
trap before entering the detector. 

To minimize the system blank, conditioning of the combustion tube is 
required prior to analysis of samples.  Conditioning is performed through 
repeated injections of Milli-Q water and/or seawater.  After conditioning, 
the system blank is assessed with ampoulated low carbon reference water 
(LCW). Typical relative standard deviations of replicate DOC analyses are 
2%. The instrument response factor is determined with potassium hydrogen 
phthalate in Milli-Q (LCW) water (0, 40, 80, 160 mM C) and potassium nitrate 
in LCW (0, 5, 10, 20, 40 mM N).  The instrument blank is measured every 4-6 
samples using LCW water.


9.11.  Genetics and Particulate Organic Matter

PI: Adam Martiny (UCI)
Samplers: Catherine Garcia and Jenna Lee (UCI)


Genetics

Genetics samples were collected approximately every half degree of latitude 
from the surface Niskin bottle ~5m deep. In total, 54 samples were collected 
from the surface niskin bottle. Water was also collected from the 
uncontaminated underway seawater system every four hours (04:00, 08:00, 
12:00, 16:00, 20:00, and 24:00 local time) for each sampling day. Up to 4L 
of seawater was collected into a plastic cubitainer and filtered immediately 
after collection. Water was filtered through a Sterivex 0.22μm filter using 
a peristaltic pump at a low speed. Once all water is pumped through the 
Sterivex cartridge, one end is sealed with Crito-seal putty. 1620μL of 
sterile lysis buffer is pipetted into the filter cartridge and the other end 
is sealed with a luer-lok cap. The filter is placed in a Ziplok bag and 
preserved frozen at -20°C until shipment to the Adam Martiny lab at UC 
Irvine for further analysis. Final filtration volume was recorded for all 
samples. Gloves were worn during all steps. 

Prior to the cruise, all silicone tubing, Omnifit caps and cubitainers were 
cleaned in soapy water, 10% HCL, and Milli-Q water. Weekly, the tubing and 
Omnifit caps were soaked in a 10% bleach solution overnight and rinsed with 
Milli-Q water. Between sample collections, the tubing and sample container 
were rinsed 2x with 0.7μm filtered seawater. 

Problems: If the Sterivex filter was abnormally dark, the sample was noted 
as potential biofilm contamination from the sea water system. This was 
noticed to be a problem only when the underway valve was turned on at a high 
blast. Comparison samples of underway and station Niskin water were 
collected for potential contamination problems.  


Particulate Organic Matter

Particulate organic matter (POM) samples were collected for particulate 
organic carbon (POC), nitrogen (PON), phosphorous (POP) and biological 
oxygen demand (BOD). The underway seawater system was chosen to increase 
water volumes and replication. In total, 749 underway stations were sampled. 
Each sample was pre-filtered through a 30μm nylon mesh and passed through a 
GF/F filter (nominal pore size 0.7μm). An aspirator pump was used to pull 
water through the filters at a vacuum setting of -0.06 to -0.08 MPa. South 
of 54°S an additional set of samples was collected without a pre-filter. 
Twelve carboys were filled with 6-8L of water (volume biomass-dependent) and 
designated as follows: 3x POP, 3x POC/PON, 3x BOD method 1, 3x BOD method 2. 
Single replicates were taken for POC/PON and POP every hour, with triplicate 
samples every day at noon. BOD samples were collected in triplicate on a two 
day on, one day off rotation. An additional BOD triplicate set was taken on 
silver filters to reduce particulate oxygen contamination every three days. 
Two triplicate sets of BOD were collected for method development and 
comparison.  POP filters were rinsed with 5mL of 0.017M Na2SO4 to remove 
traces of dissolved organic phosphorous at the end of filtration. BOD 
filters were rinsed with MilliQ water to remove salt ions. Filters were 
folded and stored frozen at -20°C in pre-combusted foil squares. 

All carboys were rinsed 1x with sample water before collection. GF/F filters 
and foil squares were pre-combusted at 500°C for 4.5 hours. Prior to the 
cruise, all silicone tubing, filter holders, and carboys were cleaned in 
soapy water, 10% HCL, and Milli-Q water. The 30μm nylon mesh was rinsed with 
filtered seawater between sample collections.  All filters will be shipped 
frozen and analyzed by the Martiny lab at UC Irvine. Gloves were used for 
all steps mentioned above. 

Problems: As stated above, contamination by a biofilm in the underway system 
was noted if the filters were abnormally dark. This was only an occurrence 
if the valve was opened too far. The silver BOD samples filtered far slower 
than the GF/F filters. To keep filtration times under two hours, the 
collection volume was halved (3-4L).


9.12.  Dissolved Inorganic Carbon Isotopes in Seawater (DI14C)

PIs: Robert Key (PU) and Ann McNichol (WHOI)
Sampler: Shinichiro Umeda (JAMSTEC)


Project Goals

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

Sampling

Approximately 400 samples were collected from 19 stations along the I07N 
transect (Figure 24). Each of the major basins encountered was sampled with 
two or more profiles. Full water column profiles were mixed with profiles 
that focused on the upper water column down to approximately 1500m.  A 
random duplicate was taken at some stations to provide a check of accuracy.

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

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

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

Radiocarbon values will be reported as D14C using established procedures 
modified for AMS applications. The 13C/12C of the CO2 extracted from 
seawater is measured relative to the 13C/12C of a CO2 gas standard 
calibrated to the PDB standard using an isotope ratio mass spectrometer at 
NOSAMS.


Figure 24. Station plot showing 14C sampling along the I07N cruise. Red 
           squares represent full profile casts, and green triangles 
           represent stations where only the upper water column (1500-2000m) 
           was sampled.


9.13.  Dissolved organic matter 14C, black carbon 14C

PI: Ellen R.M. Druffel, Earth System Science, 
    University of California, Irvine 
Sample Collection: Christian Lewis, Earth System Science, 
                   University of California, Irvine


DOC is the largest pool of organic carbon in the ocean, comparable to the 
total carbon content in the atmosphere. Knowing the carbon isotopic 
signatures of DOC is important for understanding the biogeochemistry and 
dynamics of DOC cycling and is essential for the C cycle modeling community. 
This study addresses fundamental gaps in our knowledge of the global carbon 
cycle and the dynamic nature of DOC in the ocean. These results will provide 
much needed, quantitative information on the timescale of DOC cycling in the 
ocean. These results will also help to determine the amount of 
terrestrially-derived organic carbon (e.g., black carbon, BC) in the open 
ocean. DOC may serve as a sink for excess carbon dioxide produced from 
fossil fuel and biomass burning. Most of this excess carbon will end up in 
the ocean, and it is critical to improve our understanding of the processes 
that are important for its long-term storage. Results of this research will 
be made available for use in models that assess present and future 
concentrations of atmospheric CO2.

The average radiocarbon (14C) age of dissolved organic carbon (DOC) in the 
deep ocean ranges from 4000 – 6500 14C years. However, the data set used to 
estimate this range is based on only a few sites in the world ocean. The main 
objective of this research is to determine the 14C signatures of DOC in 
seawater from the North Indian Ocean and Arabian Sea for which there is no 
data. High-precision ∆14C measurements will be performed on samples using AMS 
(accelerator mass spectrometry) of DOC in water samples. Another objective is 
to isolate black carbon from DOC and determine the ∆14C and δ13C signatures 
of this recalcitrant DOC fraction. We are testing the following hypotheses: 

(1) 14C of bulk DOC in the Indian Ocean are similar to those in Pacific and 
    Atlantic Oceans. 
(2) Black carbon constitutes a significant amount of DOC in open ocean 
    water, and its 14C age is greater than 20,000 14C years in the deep 
    ocean. 
 
A summary of stations and number of depths sampled for DO14C and Black 
Carbon on I07 are provided in the table below.

Dissolved Organic Carbon-14 Sampling and Analysis 

Dissolved organic carbon-14 (as ∆14C) samples were sampled in pre-combusted 
(540°C/2 hours) 1L borosilicate bottles (amber boston rounds). We collected 
7x DOC samples below 1000m and 7x samples above 1000m at each station plus 
one duplicate. Samples above 900m depth were filtered using pre-combusted 
70mm GF/F filters, acid cleaned silicone tubing and a stainless-steel filter 
manifold. Samples were immediately frozen after collection and stored at -
20°C for analysis at UCI. Once in the lab, samples will be acidified and 
sparged of dissolved inorganic carbon, and CO2 will be produced from DOC via 
UV oxidation and vacuum line extraction. This CO2 will then be graphitized, 
and its radiocarbon content measured via AMS at the Keck Carbon Cycle AMS 
laboratory at UCI. DOC δ13C will also be measured in a split of the CO2 from 
each sample using light isotope mass spectrometry.

Black Carbon-14 Sampling

Due to extremely low concentrations of Black carbon in seawater (~<5% of the 
DOC pool), 1x 4 gallon filtered surface (0-200m) samples and 1x8 gallon deep 
(~2000m) samples were collected. Surface samples were filtered using pre-
combusted 150mm GF/F filters, acid-cleaned silicone tubing and a PVC filter 
manifold. The concentration and carbon isotopes (14C and 13C) of black 
carbon in these samples will be measured using the benzene polycarboxylic 
acid (BPCA) method. These data will be used to estimate the abundance and 
source of black carbon in oceanic DOC. Individual BPCAs will be isolated 
using a preparative capillary gas chromatograph (PCGC). These fractions will 
be combusted to CO2 gas, graphitized and radiocarbon content measured by 
AMS.


9.14.  DOM Biomarkers and Molecular Composition

PI: Dr. Brett Walker, Earth System Science, University of California, Irvine 
Co-PI: Dr. Karl Kaiser, Department of Marine Sciences and Oceanography, 
Texas A&M University Galveston Campus 
Co-PI: Dr. Hussain Abdulla, Department of Physical & Environmental Sciences, 
Texas A&M University, Corpus Christi 
Sample Collection: Christian Lewis, Earth System Science, University of 
California, Irvine

Dissolved organic matter (DOM) represents the largest reservoir of organic 
carbon in the ocean, comparable to the total carbon content in the 
atmosphere. Marine DOM fuels microbial food webs and has also been 
implicated to modulate transient warming events in Earth’s history. 
Fundamental to the role of DOM in ocean biogeochemical cycles is its ability 
to control, store and release energy. Hence, fluxes of biologically labile 
DOM constituents between carbon reservoirs are arguably more important than 
net fluxes of total DOM. Thus, DOM cycling is largely determined by 
selective source and removal mechanisms. This study addresses fundamental 
gaps in our knowledge of DOM sources, molecular structures and removal of 
DOM in several unique ocean environments. Coupled with radiocarbon dating of 
dissolved inorganic and dissolved organic carbon (DIC, DOC), knowledge of 
DOM sources and composition provide much needed, quantitative information on 
the timescale and magnitude of DOM cycling in the north Indian Ocean and 
Arabian Sea, where currently no data exists. 

The main objectives of this research are 1) to investigate the formation of 
recalcitrant DOM by microbial processes, and 2) to identify mechanisms that 
remove recalcitrant DOM from the water column. Our approach relies on a 
comprehensive analysis of the chemical composition of DOM including organic 
biomarkers (carbohydrates, DL-amino acids, lignin phenols), Proton Nuclear 
Magnetic Resonance (1H-NMR) and Fourier Transform Ion Cyclotron Resonance 
Mass Spectrometry (FT-ICR-MS). These measurements will be integrated with 
existing GO-SHIP measurements (DOC and DIC 14C/13C, Black Carbon, O2, 
Nutrients, CFCs, etc.) and will provide an unprecedented analysis of DOM 
chemical composition in a major ocean basin. In addition, our analysis of 
DOM composition will evaluate the biogeochemistry of OMZs, which are 
predicted to expand in a warming ocean.

We will test the following hypotheses: 

(1) The combination of biomarker analysis with high-resolution spectroscopic 
    techniques (NMR, FT-ICR-MS) will reveal origins, structures and removal 
    mechanisms of recalcitrant DOM (RDOM) molecules in the deep ocean. RDOM 
    dynamics will be compared with the radiocarbon age of DOM (determined by 
    Druffel Group) and thus help constrain processes responsible for DOM 
    cycling on millennial timescales. We hypothesize that both carboxyl-rich 
    alicyclic molecules (CRAM) and a specific dissolved organic nitrogen 
    (DON) component will accumulate in the deep ocean, and that D-amino 
    acids will indicate this to be the result of microbial degradation 
    processes. 
(2) Distinct DOM molecular compositions will be observed in the ODZ in the 
    ETP/ETSP reflecting intense microbial cycling of DOM. We expect to find 
    high bacterial contributions to DOM due to the importance of bacterial 
    chemoautotrophy, and likely differences that can be attributed to 
    specific chemoautotrophic metabolism (i.e. denitrification vs. anaerobic 
    ammonium oxidation). 
 
A summary of stations and number of depths sampled for dissolved biomarkers 
and molecular-level composition on IO7 are provided in the Table 9.3 below.

Dissolved Organic Matter Biomarker Sampling and Analysis: 

Dissolved organic matter (DOM) biomarker samples were collected into 60 mL 
acid-soaked (10% HCl) and rinsed (18.2 MΩ Milli-Q water) high density 
polyethylene (HDPE) bottles. Sample depths shallower than 400m were filtered 
through a pre-combusted (540°C/2hr) GF/F filter and clean stainless-steel 
manifold. On biomarker stations (Table 9.3), all Niskins were sampled. All 
samples were frozen immediately at -20°C and will be stored frozen until 
they can be shipped overnight and analyzed at Texas A&M Galveston (Co-PI 
Kaiser). Biomarker samples will be analyzed for many individual biomolecules 
including a suite of: total dissolved amino acids (including D-enantiomeric 
forms), amino sugars and neutral sugars. These will be measured via high 
performance liquid chromatography and ion chromatography by PI Kaiser at 
Texas A&M Galveston. 

Dissolved Organic Matter Molecular Composition Sampling and Analysis: 

Samples were taken for characterization of DOM composition at molecular 
level. As per all sample types, depths shallower than 400m were filtered 
through pre-combusted (540°C/2hrs) GF/F filter manifolds. We collected 6x 
DOC samples below 1000m and 8x samples above 1000m at each station and often 
one duplicate. First, samples were collected into pre-combusted (540°C/2hrs) 
10 mL glass ampoules in triplicate, and subsequently poisoned with 1 drop 
saturated mercuric chloride (HgCl2) or 1 drop 12N hydrochloric acid. These 
ampoules were flame sealed and will be stored at room temperature in the 
dark until analysis via Proton Nuclear Magnetic Resonance Spectroscopy (1H-
NMR) at the University of California, Irvine (PI Walker). This analysis will 
allow for the “bulk” molecular characterization of DOM at the functional 
group level. In addition, 1000 mL samples were collected into acid-soaked 
(10% HCl) and rinsed (18.2 MΩ Milli-Q water) polycarbonate bottles. These 
samples were immediately frozen at -20°C and stored until further sample 
processing at Texas A&M Corpus Christi (Co-PI Abdulla). At Texas A&M, 1L 
samples be split for biomarker analysis (Texas A&M, Galveston) and the 
remaining 600ml of DOM isolated by solid phase extraction (SPE) and analyzed 
via either an Orbit Trap MS (Texas A&M Corpus Christi), or via Fourier 
Transform Ion Cyclotron Resonance Mass Spectrometry (FT-ICR-MS). These 
latter two analyses will allow for the characterization of several thousand 
individual DOM molecules and fragments.


Table 9.3: Summary of stations sampled for PI Walker and Druffel parameters 
           on GO-SHIP I07N. (n) indicates the number of Niskin bottles 
           sampled from each station depth profile for each measurement 
           parameter.

            I07N                         Biomarker
           Station  Latitude  Longitude      +      WDO  DO14C  DBC
              #                          Molecular 
           ———————  ————————  —————————  —————————  ———  —————  ———
               2     -29.499   54.496                            11
               3     -28.974   54.4988               11    14    
               7     -27.660   54.4955      24                 
              14     -25.330   54.5048      24                 
              19     -23.656   54.5153      24                 
              22     -22.495   54.5003                           10
              23     -21.995   54.507                11    14    
              24     -21.499   54.5                       
              28     -19.489   54.6705      24                 
              35     -15.652   55.0007      24                 
              43     -11.499   54.1085      24                 
              45     -10.752   53.211                            11
              46     -10.383   52.7675               11    14    
              71      -1.770   57.2205                           11
              72      -1.229   57.2372               11    14    
              73      -0.865   57.2473                       
              76      -0.001   57.2693      24                 
              80       1.194   57.2995               11        
              83       2.399   57.6923      24                 
              86       3.591   58.7945      24                 
              89       4.796   59.8912               11        
              93       6.394   61.3570      24                 
              96       7.594   62.4597                            11
              97       7.994   62.8283               11    14    
              98       8.396   63.1947                       
             101       9.598   64.2978      24                 
             104      11.075   64.6652      24                 
             107      12.703   64.6672               11        
             111      14.866   64.6673      24                 
             114      16.211   65.4435      24                 
             118      16.785   67.9927                           11
             119      17.059   68.470                11    14    
             123      17.865   68.48        24              6      


9.15.  Dissolved Calcium

PI: Akihiko Murata (JAMSTEC)-not onboard
Sampler: Shinichiro Umeda (JAMSTEC)


Objectives

According to the recent IPCC report, concentrations of CO2 in the atmosphere 
have increased by 40% since pre-industrial times, primarily by fossil fuel 
burning and secondarily by net land use change. The ocean is said to absorb 
about 30% of the emitted anthropogenic CO2, accordingly moderating 
progression of global warming. However, the ocean suffers from ocean 
acidification by the uptake of anthropogenic CO2. Ocean acidification is 
characterized by an increase of H+ (i.e., a decrease of pH) and a concurrent 
decrease of carbonate ion concentration (CO3(^2–)). The decrease of CO3(^2–) 
is unfavorable to marine calcifying organisms, which utilize CO3(^2–), 
together with Ca(^2+), to produce their calcium carbonate (CaCO3) shells and 
skeletons. To evaluate dissolution and precipitation of calcium carbonate, 
we measure concentration of calcium in water columns in the western part of 
the Indian Ocean.


Sampling

The samples were collected into 60 mL of HDPE bottles from Niskin bottles 
attached to the CTD system. The sampling was made at 11 stations, with a few 
replicates at individual stations (see Figure 25). In total, 265 samples 
were collected during the cruise. The samples will be stored at room 
temperature for 3-4 months until shipped back to onshore laboratory for 
analysis. 


Analytical method

The measurement will be made in a laboratory on land. The method is based on 
a photometry proposed by Culkin and Cox (1966). We use a modified Dissolved 
Oxygen Titrator DOT-01 (Kimoto Electronic Co. Ltd.), which bandpass filter 
is replaced to f0=620nm. The titrant is calibrated by 1000 mg/l Ca standard 
solution (produced by Wako Pure Chemical Industries, Ltd.).


Results

Results will be publicly available within 2 years of measurements.


References

Culkin, F. and Cox, R.A. (1966). Sodium, potassium, magnesium, calcium and 
    strontium in seawater. Deep Sea Research 13: 789-804.


Figure 25: Map of cruise track (red) and collected stations (green) are 
           shown on the left panel. Sampling layers are shown on the right 
           panel.


9.16.  Density (JAMSTEC)

PI: Akihiko Murata (JAMSTEC)-not onboard
Sampler: Shinichiro Umeda (JAMSTEC)


Objectives

The aim of this study is to evaluate and update the algorithm for estimating 
Absolute Salinity adopted in TEOS-10 (the International Thermodynamic 
Equation of Seawater 2010. IOC et al., 2010) by accumulating accurate 
seawater density data, especially for the Arabian Sea in which density of 
seawater have not yet measured directly.


Materials and methods

The water samples for seawater densities were collected in 100-mL aluminum 
bottles (Mini Bottle Can, Daiwa Can Company, Japan) at a number of stations 
shown in Figure 26. The bottles are stored at room temperature (~23 °C) 
upside down for 3-4 months until shipped back to onshore laboratory. Total 
240 bottles from 10 stations were collected (shown in figure). Seawater 
densities will be measured at 20 °C by using an oscillation-type density 
meter (DMA 5000M, Anton-Paar GmbH, Graz, Austria) with a sample changer 
(Xsample 122, Anton-Paar GmbH) to load samples automatically from up to 
ninetysix 12-mL glass vials, in accordance with a method described in Uchida 
et al. (2011). Density salinity can be back calculated from measured density 
and temperature (20 °C) with TEOS-10, and will be submitted as a dataset. 


Results

Results will be publicly available within 2 years of measurements.


References

IOC, SCOR and IAPSO (2010): The international thermodynamic equation of 
    seawater – 2010: Calculation and use of thermodynamic properties. 
    Intergovernmental Oceanographic Commission, Manuals and Guides No. 56, 
    United Nations Educational, Scientific and Cultural Organization 
    (English), 196 pp.

Uchida, H., T. Kawano, M. Aoyama and A. Murata (2011): Absolute salinity 
    measurements of standard seawaters for conductivity and nutrients. La 
    mer, 49, 237-244.


Figure 26: Map of cruise track (red) and collected stations (green) are 
           shown on the left panel. Sampling layers are shown on the right 
           panel.


9.17.  Density (UM/RSMAS)

PI Frank Millero (UM/RSMAS)	
Analyst: Carmen Rodriguez (UM/RSMAS)


Density samples were collected at eleven stations during the cruise. The 
full cast was sampled on 10 stations (Stations 29, 76, 88, 95, 99, 109, 113, 
115, 117 & 121). A partial cast was sampled on Station 123 (from four niskin 
bottles). 

The samples were drawn into 125 mL HDPE bottles rinsing three times before 
filling. These samples will be analyzed for density using an Anton-Parr 
vibrating densitometer and re-analyzed for salinity (to account for any 
evaporation) back in Miami.


9.18. Transmissometer Measurements

PIs: Wilford Gardner1, Mary Jo Richardson1, Alexey Mishonov2
1Texas A&M University, 2University of Maryland - CICS


Our WetLabs C-STAR 1636DR (650 nm LED) was factory calibrated in particle-
free water. A WetLabs algorithm corrected for instrument internal 
temperature hysteresis during the cast. The voltage was corrected for 
temporal drift in the instrument during the cruise by using factory and 
field air and blocked beam readings:

Tr = ((VSig -VBlock) / (VFac - VBlock))*( VFacAir /VFieldAir),

where - VSig –is the measured output voltage,
VBlock is the output voltage with the beam blocked during calibration,
VFac – is the factory clean-water value,
VFacAir – is the factory measured voltage output in air, 
VFieldAir – is the field measured voltage output in air. 

Transmissometer windows were cleaned prior to each cast and air calibrations 
through the CTD were made every 20 casts. Without in situ particle samples 
we employed the common method of using the cruise minimum voltage or a 
cruise-average minimum on each cast because particle concentrations are very 
low in mid-ocean depths. 

The transmissometer measures in volts (0-5 volts (V)) the transmission (T) 
of light across a path of known length (r = 0.25 m). Voltage is then 
converted to beam attenuation of light (c) by the equation:

V/5 = T = e^(-cr),

which can be rewritten as

c = -(1/r) *ln (T)

Internal firmware subtracts attenuation due to water (cw) from the output 
data stream leaving cp, the attenuation due to particles. Processing of the 
data includes data averaging (1 or 2 db binning), and examination and 
removal of transient spikes.

cp is linearly correlated with particle concentration (PM or POC). Thus, 
either regressing particle concentrations from filtered water samples from 
the cast with cp, or using cp/PM correlations from other studies, we are 
able to quantify the particle concentration throughout the water column. 
Particle concentration can be correlated with other parameters measured from 
the CTD (e.g. particle backscatter, particle size distribution, acoustic 
backscatter from the ADCP, chlorophyll fluorescence, temperature, oxygen) to 
study sources and sinks of particulate matter. We will also compare particle 
distributions in 2018 with those obtained in 1995. For an example, see 
Gardner, W.D., A.V. Mishonov, M.J. Richardson, 2018. Decadal Comparisons of 
Particulate Matter in Repeat Transects in the Atlantic, Pacific, and Indian 
Ocean Basins,  Geophysical Research Letters 
                    https://doi.org/10.1002/2017GL076571.


9.19.  Biological Underway Measurements

PIs: Victoria Coles1, Raleigh Hood(1), Joaquim Goes(2)
Cruise Participants: Victoria Coles(1), Hannah Morrissette(1)
 (1) University of Maryland Center for Environmental Science, Horn Point 
     Laboratory
 (2) Columbia University, Lamont Doherty Earth Observatory


Scientific Goals: The goal of the underway measurements collected as part of 
the IO7 line were to collect observations of the plankton size structure and 
community composition as well as physiological status of the phytoplankton 
community in order to improve and validate remote sensing observations of 
surface chlorophyll and primary productivity, and to better understand how 
local variability in physics and biogeochemistry contributes to the 
variability in plankton community structure. 

To meet these goals, two underway instruments were deployed in the flow 
through uncontaminated seawater system in the Biological Lab.

The benchtop FlowCAM system version 3.4 (Fluid Imaging Technologies, Inc. 
www.fluidimaging.com) was operated primarily in flow through mode, with 10ml 
samples drawn at 30 minute intervals. Particles were imaged at an 
0.9ml/minute flow rate, resulting in a sample processing period of 11 
minutes. Sample was debubbled, then drawn into the imaging chamber by a 
pump. With a laser in triggering mode, images were captured at 18 frames per 
second with a 4x optical magnifier. Pixels that are identified as particles 
are segmented out of the image, and stored for further analysis. A pre-
filter removed images of particles less than 5 microns as recommended for 
the 4x objective for most of the cruise, though other sizer were tested due 
to particles sticking on the glass of the flow cell. The system produces 
images of the plankton community as well as measures of particle size and 
other quantities (Area, Area (filled), Aspet ration, Average blue, Average 
green, Average red, Capture x, Capture y, Circle fit, Circularity, 
Circularity hu, Compactness, Convex perimeter, Convexity, D (ABD), D (ESD), 
Diameter (ESD), Diameter (ABD), Diameter (FD), Edge gradient, Elapsed time, 
Elongation, Fiber curl, Fiber straightness, Geodesic aspect ratio, Geodesic 
length, Geodesic thickness, Image Height, Image width, Intensity, Length, 
Particles per chain, Perimeter, Ratio Blue/Green, Ratio Red/Blue, Ratio 
Red/Green, Roughness, Sigma Intensity, Sum intensity, Symmetry, 
Transparency, Volume (ABD), Volume (ESD), Width). No classification has been 
performed on the images, though daily plankton samples were collected for 
deriving a classification library.

The instrument arrived functioning well, however the flow cell was highly 
clogged with particles stuck to the cell glass and attempts to clean the 
flow cell were initially unsuccessful resulting in very high numbers of 
spurious particles identified. High levels of pruning were required to 
remove these spurious particles, and as a result real particles with similar 
characteristics were certainly lost. An automated filter that removed 
particles less than 9 microns was employed to reduce manual pruning 
required. 

As of 5/4/2018, when a new detergent (dawn dishwashing liquid) was employed, 
the flow cell conditions improved, and the initial filter was relaxed back 
to 5 microns. 

After the port stop in the Seychelles, 5/19/2018, discrete sampling at the 
upper 4 Niskin bottles in the productivity cast was initiated each morning. 
Not all samples have been analyzed yet.

The mini-FIRe system (Miniaturized fluorescence induction and relaxation) 
was also deployed in flow through mode. Samples were collected at 36 second 
intervals for 20 minutes. Then a 5-minute light profile with increasing 
actinic light was performed on a sample, and this pattern was repeated.  The 
machine was developed to measure photosynthetic and physiological 
characteristics of photosynthetic organisms (Gorbunov and Falkowski 2005), 
including photochemistry in photosystem II, and photosynthetic electron 
transport down to fixation of carbon. Blanks were collected twice and run 
for removal of the dissolved water fluorescence signal.

After the port stop in the Seychelles when a cuvette was procured, discrete 
samples were also collected for both the underway and the actinic light 
source protocols at primary production stations in the upper four Niskin 
bottle samples when water was available. 

Preliminary assessment indicates that the instrument was functioning well, 
however all the data have not yet been assessed, and the light profiles have 
not been analyzed.


Figure 27: 25th, 50th, and 75th percentile equivalent spherical diameter and 
           volume for samples along the cruise track by Julian day.

Figure 28: Surface CTD fluorescence voltage (uncalibrated) in light green, 
           and at the depth of the fluorescence maximum in dark green. 
           Photosynthetic yield during high ambient light periods in light 
           purple and averaged over a daylong period in dark purple.


9.20.  Biological Samples from Niskin Bottles

PIs: Joaquim Goes(2), Victoria Coles(1), Raleigh Hood(1)
Cruise Participants: Victoria Coles(1), Hannah Morrissette(1)
 (1) University of Maryland Center for Environmental Science, Horn Point 
     Laboratory
 (2) Columbia University, Lamont Doherty Earth Observatory

Scientific Goals: The goal of the oxygen based primary productivity 
incubation measurements was to relate net community production to local 
environmental conditions and community composition, and to validate remote 
sensing estimates of primary productivity. 

Oxygen based primary productivity measurements were performed daily with 24 
hour on-deck incubations at the surface from bucket samples and at the depth 
of the deep chlorophyll maximum as determined by the CTD fluorometer. 
Samples were collected into oxygen flasks at the local time of the CTD cast 
closest to dawn. Samples were analyzed using Winkler oxygen reagents 
[Carpenter, 1965] for oxygen determination on an automated titrator using 
amperometric end point detection [Langdon, 2012]. (See CTD oxygen 
measurements. Standards were drawn four times during the cruise using the 
standard KIO3 of the oxygen titration group.) The temperature of the water 
samples was not measured, and corrections were not made for this difference. 
However, the temperatures of the surface and DCM waters rarely diverged by 
more than 5 degrees C. Note that due to limitations in water budgets, the 
productivity water samples were not collected following typical oxygen 
measurement procedures. Instead, simultaneity for collection of all samples 
was emphasized to ensure that the difference in oxygen concentration between 
the initial and incubated samples would remain constant. 

Surface triplicate oxygen samples (9 total) were simultaneously submerged in 
a bucket water sample, removed, bubbles clinging to the flask walls were 
tapped out manually, then all samples were closed as quickly as possible and 
the initial samples were pickled. Dark bottles (3) were covered to remove 
light, and incubated on deck in a clear incubator with ship’s flow through 
seawater running continuously. Light bottles (3) were also incubated. The 
incubator was screened to reduce the surface light intensity slightly to 
mimic in water conditions. Samples from the deep chlorophyll maximum were 
collected into a 4l polycarbonate bottle, then poured into oxygen flasks. 
They were then treated identically to the surface bucket derived samples. 
After 24 hours, samples were recovered from the incubator and pickled with 
oxygen reagents. The samples were equilibrated to the laboratory temperature 
(with DIW in the bottle necks) for no less than 5 hours. Samples were then 
analyzed. 

The difference between the initial oxygen concentration and the final 
concentrations incubated for 24 hours either in the dark (Respiration) or 
the light (Net Community Production; both phytoplankton production and 
bacterial respiration) provide a measure of the community metabolism. The 
difference between net community production and respiration is assumed to be 
the gross primary production under the assumption that light and dark 
respiration are equivalent. 

Over the course of the cruise, precision in the initial time zero samples 
(triplicate) improved markedly, illustrating that sampling procedures are 
key to accurate measurements. Sampling improvements included: tapping out 
bubbles clinging to the oxygen flask sides, using manual pipettes that were 
wiped with a kimwipe prior to each sample pickling, wetting the oxygen flask 
necks with DIW prior to measurement, careful thiosulfate reagent purging 
prior to sample analysis and careful attention to cleaning the electrode 
between samples.


Figure 29: Gross primary productivity values (umol/kg) are shown as colored 
           circles (scale to right).


Standard deviation between triplicate initial samples varied, but decreased 
from initial average values of 2.4 standard deviation to later values of 
0.65. 


References

Carpenter JH (1965) The accuracy of the Winkler method for dissolved oxygen 
    analysis. Limnol Oceanogr 10:135−140 

Langdon, C. (2010). Determination of dissolved oxygen in seawater by Winkler 
    titration using the amperometric technique. The GO-SHIP Repeat 
    Hydrography Manual: A Collection of Expert Reports and Guidelines. E. M. 
    Hood, C. L. Sabine and B. M. Sloyan, IOCCP Report Number 14, ICPO 
    Publication Series Number 134.



9.21.  Biological Filtration Measurements
 
PIs: Victoria Coles(1), Raleigh Hood(1), Greg Silsbe(1)
Cruise Participants: Victoria Coles(1), Hannah Morrissette(1)
 (1) University of Maryland Center for Environmental Science, Horn Point 
     Laboratory

Scientific Goals: Then goal of the HPLC, absorption, chlorophyll-a, and CDOM 
measurements was to characterize the different factors that combined 
determine ocean color for satellites. 

Filtered samples for determination of HPLC, chlorophyll-a, absorption, and 
CDOM were collected at each primary production station and also at net tow 
stations. Samples were collected from the surface bucket sample and the 
upper 4 Niskin bottles and filtered using a vacuum pump through Whatman GF/F 
25mm filters. Filters were stored folded in half in histoprep capsules (or 
flat for absorption) in liquid nitrogen for further analysis at NASA GSFC 
(HPLC) and HPL (Chlorophyll, CDOM, Absorption). CDOM samples were filtered 
through a 0.2 micron filter into pre-combusted amber glass vials with pre-
combusted tin foil shielding the sample from the lids and stored in the 
refrigerator. One liter was filtered for chlorophyll and absorption samples, 
2-4 liters were filtered for HPLC. Small volume samples were collected and 
stored with lugols iodine for phytoplankton taxonomic enumeration. 

          Sample Type                                    Total
          —————————————————————————————————————————————  —————
          High Performance Liquid Chromatography (HPLC)    51
          Absorption                                       50
          Chlorophyll C                                   230
          Colored Dissolved Organic Matter (CDOM)          45
          Preserved phytoplankton sample for microscopy    45
          Sun Photometer                                  460



9.29.  Net Tows

PIs: Nina Bednarsek(1), Victoria Coles(2), James Pierson(2)
Cruise Participants: Victoria Coles(2), Hannah Morrissette(2), Catherine 
Garcia(3)
 (1) Southern California Coastal Water Research Project
 (2) University of Maryland Center for Environmental Science, Horn Point   
     Laboratory
 (3) University of California, Irvine

Scientific Goals: Net tows were conducted through the upper 80m of the 
watercolumn at night. The goal was to examine the skeletons of organisms 
with aragonite shells such as pteropods for evidence of stress or 
dissolution associated with changing pH levels in the ocean due to 
increasing carbon dioxide levels in the atmosphere. Tows were also stored 
for taxonomic analysis and potential genetic analysis. 

Net tows were conducted at 14 stations throughout the cruise. A .32m radius, 
200 micron mesh ring net with a self-draining cod end was used. The net was 
towed off the aft CTD winch except for stations with heavy current when the 
net tow was at risk of exacerbating concerns about twisting the CTD wire. 
These exceptions are detailed below. Net tows took place between 10pm and 
3am local time in the dark. The net was lowered with a 60-80 pound weight 
and a modest underway speed to maintain a 45 degree wire angle measured with 
a clinometer. 125m of wire were released at 20m/minute, then the net was 
gradually raised to the surface while maintaining the 45 degree wire angle 
at 6-7m/minute speed. The distance towed was computed from the start and end 
time using the ship underway GPS measurements. On deck, the net was rinsed 
with seawater, and the sample returned to the Bio laboratory. Wet volume of 
the sample was measured in a graduated cylinder before and after filtering 
with 200micron mesh. The sample was photographed, and stored in 190 proof 
ethanol. After 24-48 hours, the ethanol was replaced fresh.


          Date     Sta-   Zooplankton      Total net      Volume 
          (GMT)    tion  wet volume (ml)  distance (m)  cleared m3
        —————————  ————  ———————————————  ————————————  ——————————
        4/29/2018    7         21         1388.726339    1.39E+03
        5/3/2018    23         17         979.2020705    9.77E+02
        5/4/2018    27         26         1326.747508    1.32E+03
        5/7/2018    38         31         932.8277148    9.30E+02
        5/9/2018    44         46         1853.209033    1.85E+03
        5/19/2018   65         48         1653.164587    1.65E+03
        5/22/2018   77         35         598.3642288    5.97E+02
        5/24/2018   86         29         915.6759636    9.13E+02
        5/26/2018   93         24         997.6232758    9.95E+02
        5/28/2018  100         33         1648.371472    1.64E+03
        5/29/2018  104         29         1190.714023    1.19E+03
        5/30/2018  107         31         1172.336773    1.17E+03
        5/31/2018  111         46         1042.752852    1.04E+03
        6/4/2018   122         63         1341.914122    1.34E+03
        ——————————————————————————————————————————————————————————
        total tows: 14        
        

The samples will be analyzed to evaluate stress on pteropod shell formation 
resulting from ocean acidification. Remaining samples will be shipped to 
Horn Point Laboratory for microscope counting. 

5/22/2018, 5/24/2018: the net was towed off the starboard side on the crane 
with Kevlar line. Wire out was estimated from 10m increment markings on the 
Kevlar line. Wire angle was measured with the clinometer, and depth was 
inferred.


9.23.  Isotopic Composition of Nitrate
 
PIs: Chawalit “Net” Charoenpong and Scott D. Wankel (WHOI)
Samplers: Viviane Menezes, Amanda Fay and Cathy Garcia


Nitrate (NO3-) is the dominant dissolved inorganic nitrogen ions. Like other 
nutrients, it is depleted in the surface due to biological consumption and 
abundant in the ocean interior due to remineralization. Natural abundance 
isotopic composition is a powerful tool to elucidate the sources and the 
processes that affect the nitrate concentrations. For example, 
denitrification which consumes NO3- during its reaction should be prevalent 
in the low-oxygen region of the Arabian Sea and impart isotopic signature on 
the remaining NO3-. 

Samples from Niskin bottles were taken for analyses of isotopic composition 
of nitrate (NO3-), δ15N-NO3- and δ18O-NO3-. Samples for NO3- isotopic 
analysis (storeed in 30ml LDPE bottles) were preserved by mild acidification 
with hydrochloric and sulfuric acid to pH 2 to 3. These steps are in place 
to ensure the retention of the δ15N and δ18O signatures and remove any 
nitrite in the sample (Granger and Sigman, 2009). Samples bottles were 
stored at room temperature until analysis. No onboard analysis was carried 
out and all samples will be analyzed back in the Wankel lab for stable 
isotope biogeochemistry at WHOI with the denitrifier method (Casciotti et 
al., 2002; Sigman et al., 2001) which quantitatively convert NO3- to N2O 
before being extracted and purified (as in McIlvin and Casciotti, 2010) 
before being analyzed by the IRMS.


References

Casciotti, K. L., D. M. Sigman, M. G. Hastings, J. K. Böhlke, and A. Hilkert 
    (2002), Measurement of the oxygen isotopic composition of nitrate in 
    seawater and freshwater using the denitrifier method, Anal. Chem., 
    74(19), 4905–4912, doi:10.1021/ac020113w. 

Granger, J., & Sigman, D. M. (2009). Removal of nitrite with sulfamic acid 
    for nitrate N and O isotope analysis with the denitrifier method. Rapid 
    Communications in Mass Spectrometry, 23(23), 3753-3762.

McIlvin M. R., Casciotti K. L. (2010). Fully automated system for stable 
    isotopic analyses of dissolved nitrous oxide at natural abundance 
    levels. Limnology and Oceanography: Methods 8, 54-66, doi: 
    10.4319/lom.2010.8.54

Sigman, D. M., K. L. Casciotti, M. Andreani, C. Barford, M. Galanter, and J. 
    K. Böhlke (2001). A bacterial method for the nitrogen isotopic analysis 
    of nitrate in seawater and freshwater, Anal. Chem., 73(17), 4145–4153, 
    doi:10.1021/ ac010088e.




9.24.  Density; Post-Cruise Processing (JAMSTEC)
       28 November 2018

PI: Hiroshi Uchida (JAMSTEC)-not onboard
Sampler: Shinichiro Umeda (JAMSTEC)


Objectives

The aim of this study is to evaluate and update the algorithm for estimating 
Absolute Salinity adopted in TEOS-10 (the International Thermodynamic 
Equation of Seawater 2010. IOC et al., 2010) by accumulating accurate 
seawater density data, especially for the Arabian Sea in which density of 
seawater have not yet measured directly.

Materials and methods

The water samples for seawater densities were collected in 100-mL aluminum 
bottles (Mini Bottle Can, Daiwa Can Company, Japan) at 10 stations shown in 
Fig. 31. The bottles are stored upside down in a marine container on-deck of 
the ship for about 6 months until shipped back from Miami, USA to JAMSTEC, 
Japan. A total of 240 bottles were collected (shown in Fig. 31). Seawater 
densities were measured at 20 ºC by using two oscillation-type density 
meters (DMA 5000M, S/N 80570578 [No. 1] and S/N 81661961 [No. 2], Anton-Paar 
GmbH, Graz, Austria) with sample changers (Xsample 122, Anton-Paar GmbH) to 
load samples automatically from up to forty-eight (for No. 2) or ninety-six 
(for No. 1) 12-mL glass vials, in accordance with a method described in 
Uchida et al. (2011) with slight modification. Density salinity can be back 
calculated from measured density and temperature (20 °C) with TEOS-10. 
Offset and time drift of the density meters were corrected with measurements 
of the Reference Material for Oceanic O2 and CO2 Measurements (lot Pre18, 
S/N 147, 168, and 269, Kanso Technos Co., Ltd., Osaka, Japan). Properties of 
the reference material at the production are listed in Table 9.4. Density of 
the Pre18 were periodically measured at about every 20 measurements (10 
bottles of samples) (Fig. 32). Density of the Pre18 S/N 269 was increased 
about 0.003 kg/m3 due to leakage of seawater. Density samples for stations 
76, 95, 109, 115, and 121 were measured by the No. 1 density meter and that 
for station 88, 99, 113, 117, and 123 were measured by the No. 2 density 
meter. To check the offset correction, IAPSO Standard Seawater (lot P160, 
Ocean Scientific International Ltd., Havant, Hampshire, United Kingdom) was 
measured. Density of P160 at 20 °C is expected to be 1024.7609 kg/m3, and 
the measured densities was 1024.7590 kg/m3 and 1024.7600 kg/m3 for No. 1 and 
No. 2 density meter, respectively. 

Practical Salinities for the rest of the density samples were also measured 
at 24 °C by using a salinometer (AUTOSAL 8400B, S/N 60132, Guildline 
Instruments Ltd., Ontario, Canada) within 24 hours after the density 
measurements. Practical Salinity data measured on-board are usually used to 
estimated Absolute Salinity anomalies for the density samples. However, 
Practical Salinities for the rest of the density samples were measured to 
estimated Absolute Salinity anomalies from the density measurements, since 
the Practical Salinity data measured on-board were noisy. 

Results

Practical Salinities measured for the rest of the density samples are 
compared with the CTD salinity and bottle sampled salinity measured on-board 
(Fig. 33). The Practical Salinity measured for the density samples well 
agreed with the CTD salinity and bottle sampled salinity for depths below 
2000 dbar. However, the Practical Salinity measured for the density samples 
is slightly (about 0.002 in salinity) smaller than the CTD salinity for 
depths above 2000 dbar. The CTD salinity data for depths above 2000 dbar 
might be affected by largely (positively) deviated bottle sampled salinity 
data there in the in situ calibration using the bottle sampled salinity 
data. 

Absolute Salinity anomalies estimated from the density and practical 
salinity measurements are compared with the calculated Absolute Salinity 
anomalies (Fig. 34). The measured Absolute Salinities well agreed with 
calculated Absolute Salinities for latitude south of 8°N. However, for 
latitude north of 8ºN, both of the Absolute Salinities measured by the two 
density meters tend to be larger than the calculated Absolute Salinities 
(Fig. 35).


References

IOC, SCOR and IAPSO (2010): The international thermodynamic equation of 
    seawater – 2010: Calculation and use of thermodynamic properties. 
    Intergovernmental Oceanographic Commission, Manuals and Guides No. 56, 
    United Nations Educational, Scientific and Cultural Organization 
    (English), 196 pp.

Pawlowicz, R., D.G. Wright and F.J. Millero (2011): The effects of 
    biogeochemical processes on ocean conductivity/salinity/density 
    relationships and the characterization of real seawater. Ocean Science, 
    7, 363-387.

Uchida, H., T. Kawano, M. Aoyama and A. Murata (2011): Absolute salinity 
    measurements of standard seawaters for conductivity and nutrients. La 
    mer, 49, 237-244.



Table 9.4. Properties of Pre18 at the production (18 December 2013).

        Parameter            Initial       Unit/       Contribution to the
                              value        Scale      Density anomaly (kg/m3)
——————————————————————————  —————————  —————————————  ——————————————————————
Practical Salinity            34.2797     PSS-78
Dissolved Inorganic Carbon  2213.14       umol/kg           0.0005
Total Alkalinity            2310.85       umol/kg           0.0004
Silicate                      67.26       umol/kg           0.0026
Nitrate                       30.30       umol/kg           0.0009
Dissolved Organic Carbon      75.0        umol/kg           0.0010
Estimated density           1024.2223  kg/m3 @ 20 °C



Figure 31. Map of cruise track (red) and collected stations (green) are 
           shown on the left panel. Sampling layers are shown on the right 
           panel.

Figure 32. Time series of the density for the reference material Pre18 
           measured during the density measurements.

Figure 33. Vertical profiles of difference in Practical Salinity between CTD 
           salinity and salinity measured for the density samples (blue 
           dots). Difference between CTD salinity and bottle sampled 
           salinity measured on-board are also shown (red dots and red 
           crosses).

Figure 34. Vertical profiles of Absolute Salinity anomalies. Blue dots show 
           results from the density measurements. Red dots show estimates 
           from nutrients and carbonate system parameter data by an equation 
           of Pawlowicz et al. (2011).

Figure 35. Vertical profiles of Absolute Salinity anomalies. Blue and green 
           dots show results from the density measurements by No. 1 and No. 
           2 density meter, respectively. Red dots show estimates from 
           nutrients and carbonate system parameter data by an equation of 
           Pawlowicz et al. (2011). 



9.25.  Dissolved Calcium; Post-Cruise Processing (JAMSTEC)
       (2019/03/12)

PI: Akihiko Murata (JAMSTEC)-not onboard
Sampler: Shinichiro Umeda (JAMSTEC)

Objectives

According to the recent IPCC report, concentrations of CO2 in the atmosphere 
have increased by 40% since pre-industrial times, primarily by fossil fuel 
burning and secondarily by net land use change. The ocean is said to absorb 
about 30% of the emitted anthropogenic CO2, accordingly moderating 
progression of global warming. However, the ocean suffers from ocean 
acidification by the uptake of anthropogenic CO2. Ocean acidification is 
characterized by an increase of H+ (i.e., a decrease of pH) and a concurrent 
decrease of carbonate ion concentration (CO3^(2–)). The decrease of CO3^(2–) 
is unfavorable to marine calcifying organisms, which utilize CO3^(2–), 
together with Ca^(2+), to produce their calcium carbonate (CaCO3) shells and 
skeletons. To evaluate dissolution and precipitation of calcium carbonate, 
we measure the concentration of calcium in water columns in the western part 
of the Indian Ocean.

Sampling

The samples were collected into 60 mL of HDPE bottles from Niskin bottles 
attached to the CTD system. The sampling was made at 11 stations, with a few 
replicates at individual stations (see Figure 36a). In total, 265 samples 
were collected during the cruise. The samples were stored for 5 months until 
shipped back to the onshore laboratory for analysis. 

Analytical method

The measurement was made in a laboratory on land. The method was based on 
photometry proposed by Culkin and Cox (1966). We used a modified Dissolved 
Oxygen Titrator DOT-01 (Kimoto Electronic Co. Ltd.), which bandpass filter 
is replaced to f0=620nm. Approximately 20 mM of EGTA (Ethylene Glycol 
Tetraacetic Acid) solution was used as a titrant. The titrant was calibrated 
several times by in-house Ca-standard solution whose Ca-source was pure CaCO3 
produced by NMIJ (CRM 3013-a).

Results

Results of calibrations are shown in Table 9.5 and Figure 36b with the 
concentrations of the titrant. The total number of the replicate sample 
pairs in good measurement (flagged 2) was 9, and its standard deviation was 
0.0177 mmol/kg calculated by a procedure (SOP23) in DOE (1994). For 6 
samples, Practical Salinities for the rest of the calcium samples were also 
measured at 24 °C by using a salinometer (AUTOSAL 8400B, S/N 60132, 
Guildline Instruments Ltd., Ontario, Canada) after the calcium measurements. 
Averaged anomalies from Practical Salinity data measured onboard was +0.03% 
(+0.0097 +/- 0.0041 psu (standard deviation)), regarded as an effect of 
evaporation during the shipment to the laboratory. A previous work (Culkin 
and Cox, 1966) points out that magnesium (Mg) and strontium (Sr) cause 
positive bias to the titrated volume of Ca because of their interference 
with the reaction between EGTA and Ca; the bias caused by Mg was 0.729% and 
by Sr was 0.388%. No correction for the evaporation and interference was 
given to the data.

References

Culkin, F. and Cox, R.A. (1966). Sodium, potassium, magnesium, calcium and 
    strontium in seawater. Deep Sea Research 13: 789-804.

DOE (1994) Handbook of methods for the analysis of the various parameters of 
    the carbon dioxide system in sea water; version 2. A.G. Dickson and C. 
    Goyet (eds), ORNL/CDIAC-74.


Figure 36a. Section plot of dissolved calcium and sampling layers (top 
            panel). Map of collected stations (bottom panel). 


Table 9.5. Results of the calibrations during the analysis. %CV means 
           coefficient of variation for the calibrations (S.D. / Average).

EGTA      Dates      Average   S.D.   N   %CV       Stations
 No.                   (mM)    (mM) 
————  —————————————  ———————  ——————  ——  ————  —————————————————
 2    2018/11/06-08  19.9220  0.0067  11  0.03  117, 121
 3    2018/11/08-12  19.3451  0.0164   8  0.08  105, 111
 4    2018/11/13     19.6633  0.0351   5  0.18  76, 93
 5    2018/11/14-22  19.7043  0.0252  20  0.13  2, 15, 27, 35, 48


Figure 36b. Results of the calibrations during the analysis. Each result is 
            shown with the average concentration (solid line) with error bar 
            of +/- 2sigma (dotted line), +/- 3sigma (broken line).












10.  APPENDIX


10.1.  Station Plan

Table A1: I07N-2018 Station Plan

  Station       Lat         Lon       dist   depth     Arrival       Depart
  Number       (dec)       (dec)      (nm)    (m)     Time (LT)     Time (LT)
———————————  ——————————  ——————————  ——————  —————  ————————————  ————————————
  Durban       -29.86 S     31.02 E    0.00         23-Apr 14:00  23-Apr 14:00
Test cast A       -30 S        40 E  466.9   3000   25-Apr 5:24   25-Apr 8:08
First Argo     -30.00 S     42.70 E  140.3          25-Apr 20:20  25-Apr 20:35
Test cast B       -30 S        50 E  379.3   5000   27-Apr 9:15   27-Apr 13:06
      1           -30 S      54.5 E  233.8   4315   28-Apr 3:23   28-Apr 6:52
      2       -29.494 S   54.4975 E   30.4   4910   28-Apr 9:45   28-Apr 13:34
      3      -28.9747 S   54.4988 E   31.2   4799   28-Apr 16:32  28-Apr 20:17
      4      -28.6643 S   54.4992 E   18.6   5062   28-Apr 22:03  29-Apr 2:57
      5      -28.3243 S   54.4967 E   20.4   5144   29-Apr 4:53   29-Apr 9:50
      6      -27.9927 S   54.4958 E   19.9   5131   29-Apr 11:43  29-Apr 15:39
      7      -27.6605 S   54.4955 E   19.9   5149   29-Apr 17:33  29-Apr 21:29
      8      -27.3302 S   54.4848 E   19.8   5199   29-Apr 23:58  30-Apr 4:56
      9      -27.0028 S   54.4863 E   19.6   5269   30-Apr 6:48   30-Apr 10:49
     10      -26.6698 S   54.4883 E   20.0   5265   30-Apr 12:43  30-Apr 16:43
     11      -26.3257 S    54.503 E   20.7   5258   30-Apr 18:41  30-Apr 22:41
     12      -25.9997 S   54.5015 E   19.6   5250    1-May 0:33    1-May 5:33
     13      -25.6608 S   54.5037 E   20.3   4996    1-May 7:29    1-May 11:38
     14      -25.3308 S   54.5048 E   19.8   5048    1-May 13:32   1-May 17:25
     15      -24.9965 S   54.4997 E   20.1   4856    1-May 19:19   1-May 23:06
     16      -24.6613 S    54.502 E   20.1   4663    2-May 1:01    2-May 4:41
     17      -24.3355 S   54.5198 E   19.6   4805    2-May 6:23    2-May 10:08
     18      -23.9925 S   54.5107 E   20.6   4423    2-May 11:56   2-May 15:43
     19      -23.6563 S   54.5153 E   20.2   4062    2-May 17:28   2-May 20:48
     20      -23.3332 S   54.5027 E   19.4   4199    2-May 22:29   3-May 1:54
     21      -22.9938 S   54.5037 E   20.4   3911    3-May 3:40    3-May 6:56
     22       -22.495 S   54.5003 E   29.9   4294    3-May 9:32    3-May 13:00
     23      -21.9957 S    54.507 E   30.0   4237    3-May 15:36   3-May 19:17
     24       -21.499 S      54.5 E   29.8   4160    3-May 22:27   4-May 1:50
     25      -21.0012 S   54.5083 E   29.9   4051    4-May 4:52    4-May 8:11
     26      -20.4973 S   54.5095 E   30.2   4334    4-May 11:04   4-May 14:33
     27      -19.9972 S   54.4963 E   30.0   4599    4-May 17:25   4-May 21:03
     28      -19.4893 S   54.6705 E   32.0   4769    5-May 0:06    5-May 3:50
     29      -19.0028 S   54.8292 E   30.5   4749    5-May 7:39    5-May 11:22
     30      -18.5032 S   54.9898 E   31.3   4225    5-May 14:21   5-May 17:47
     31      -18.0208 S   55.0017 E   29.0   4571    5-May 20:32   6-May 0:24
     32      -17.3653 S   54.9973 E   39.3   4594    6-May 4:09    6-May 7:47
     33      -16.7958 S   54.9997 E   34.2   4319    6-May 10:47   6-May 14:15
     34      -16.2275 S    54.997 E   34.1   4605    6-May 17:06   6-May 20:56
     35       -15.652 S   55.0007 E   34.5   4579    6-May 23:49   7-May 3:26
     36      -15.0912 S    55.001 E   33.6   4195    7-May 6:39    7-May 9:45
     37      -14.5183 S   55.0042 E   34.4   4144    7-May 12:53   7-May 16:16
     38      -13.9545 S   54.9988 E   33.8   4486    7-May 20:29   8-May 0:04
     39      -13.3905 S   54.9938 E   33.8   4437    8-May 3:00    8-May 6:33
     40      -12.8193 S   54.9997 E   34.3   4284    8-May 9:32    8-May 12:59
     41       -12.244 S    54.994 E   34.5   4664    8-May 15:59   8-May 19:40
    PMEL          -12 S        55 E   14.6           8-May 20:53   8-May 21:05
  mooring
     42      -11.8757 S   54.5507 E   27.4   4606    8-May 23:22   9-May 3:00
     43      -11.4995 S   54.1085 E   34.4   4453    9-May 5:52    9-May 9:26
     44      -11.3085 S   53.8792 E   17.7   4810    9-May 12:46  10-May 14:07
     45       -11.128 S   53.6645 E   16.6   4837   10-May 15:30  10-May 19:23
     46      -10.7523 S   53.2110 E   35.0   4640   10-May 22:18  11-May 1:57
     47      -10.3837 S   52.7675 E   34.3   4315   11-May 4:49   11-May 8:17
     48      -10.1902 S   52.5425 E   17.6   4422   11-May 9:58   11-May 13:30
     48      -10.0013 S   52.3187 E   35.1   4257   11-May 11:13  11-May 14:39
     50       -9.8157 S   52.0942 E   17.3   4205   11-May 16:49  11-May 20:14
     49        -9.632 S   51.8723 E   34.5   4071   11-May 17:32  11-May 20:52
     52       -9.4473 S   51.6482 E   17.3   2862   11-May 22:31  12-May 1:11
     50       -9.2572 S   51.4292 E   34.5   3714   11-May 23:45  12-May 2:53
     54       -9.0887 S   51.6630 E   17.1   3722   12-May 4:31   12-May 7:40
     51       -8.9137 S   51.8988 E   34.6   3308   12-May 5:47   12-May 8:42
     52       -8.7343 S   52.1455 E   18.2   4148   12-May 10:25  12-May 13:48
     53       -8.5548 S   52.3827 E   17.7   4264   12-May 15:30  12-May 18:57
     54       -8.3755 S   52.6263 E   18.0   5130   12-May 20:40  13-May 0:35
     55        -8.198 S   52.8623 E   17.6   3579   13-May 2:16   13-May 5:20
     56       -8.1088 S   53.0750 E   13.7   2773   13-May 6:38   13-May 9:27
     57       -8.0047 S   53.2950 E   14.5   4039   13-May 10:50  13-May 14:17
     58       -7.7588 S   53.4590 E   17.7   4047   13-May 15:58  13-May 19:17
     58        -7.518 S   53.6290 E   35.3   3961   13-May 17:38  13-May 20:55
     59       -7.0385 S   53.9592 E   34.8   3890   14-May 0:05   14-May 3:20
     60       -6.5525 S   54.2903 E   35.2   3756   14-May 6:32   14-May 9:42
     61       -6.0688 S   54.6257 E   35.2   3516   14-May 12:54  14-May 15:56
     62       -5.5885 S   54.9570 E   35.0   3489   14-May 19:07  14-May 22:08
     63       -5.3452 S   55.1177 E   17.5   3031   14-May 23:43  15-May 2:29
     64        -5.105 S   55.2842 E   17.5    898   15-May 4:04   15-May 5:29
  Victoria    -4.6254 S   55.4627 E   30.7          15-May 8:16   19-May 16:30
     65       -3.7119 S   55.4607 E   54.8    540   19-May 21:28  19-May 22:41
     66       -3.4822 S   55.7865 E   23.9   3261   20-May 0:45   20-May 3:39
     67       -3.2358 S   55.9963 E   19.4   3854   20-May 5:20   20-May 8:33
     68        -2.996 S   56.1943 E   18.6   4229   20-May 10:11  20-May 13:36
     69       -2.7423 S   56.4045 E   19.8   4373   20-May 15:24  20-May 19:10
     70       -2.2587 S   56.8150 E   38.0   4423   20-May 22:37  21-May 2:10
     71       -1.7707 S   57.2205 E   38.1   4445   21-May 5:37   21-May 9:25
     72       -1.2292 S   57.2372 E   32.5   4470   21-May 12:22  21-May 15:56
     73       -0.8653 S   57.2473 E   21.8   4671   21-May 20:18  22-May 0:14
     74        -0.502 S   57.2568 E   21.8   4644   22-May 2:25   22-May 6:04
     75       -0.2507 S   57.2645 E   15.1   4769   22-May 7:57   22-May 11:41
     76       -0.0012 S   57.2693 E   15.0   4686   22-May 13:11  22-May 17:07
     77        0.2482 N   57.2787 E   15.0   4715   22-May 18:37  22-May 22:19
     78        0.4995 N   57.2788 E   15.1   4764   22-May 23:49  23-May 3:33
     79        0.9295 N   57.2958 E   25.8   4333   23-May 6:08   23-May 9:37
     80        1.1943 N   57.2995 E   15.9   4438   23-May 11:13  23-May 14:45
     81         1.461 N   57.3095 E   16.0   4645   23-May 16:21  23-May 20:16
     82         2.004 N   57.3285 E   32.6   4583   23-May 23:32  24-May 3:09
     83        2.3995 N   57.6923 E   32.2   4587   24-May 6:23   24-May 10:00
     84        2.7998 N   58.0615 E   32.7   4730   24-May 13:38  24-May 17:20
     85        3.1943 N   58.4270 E   32.2   4619   24-May 20:16  24-May 23:55
     86        3.5913 N   58.7945 E   32.4   4440   25-May 3:10   25-May 6:42
     87        3.9982 N   59.1555 E   32.6   4633   25-May 9:58   25-May 13:37
     88          4.39 N   59.5233 E   32.2   4082   25-May 16:33  25-May 19:54
     89        4.7962 N   59.8912 E   32.8   3914   25-May 23:11  26-May 2:26
     90        5.1963 N   60.2593 E   32.6   3380   26-May 5:41   26-May 8:54
     91         5.594 N   60.6242 E   32.3   3156   26-May 12:08  26-May 14:58
     92        5.9937 N   60.9907 E   32.5   3419   26-May 18:13  26-May 21:11
     93        6.3948 N   61.3570 E   32.5   3019   27-May 0:26   27-May 3:12
     94        6.7917 N   61.7237 E   32.3   3551   27-May 6:26   27-May 9:29
     95        7.1922 N   62.0882 E   32.4   4065   27-May 12:34  27-May 16:09
     96        7.5947 N   62.4597 E   32.7   4070   27-May 19:26  27-May 22:46
     97        7.9943 N   62.8283 E   32.5   4344   28-May 2:01   28-May 5:31
     98        8.3963 N   63.1947 E   32.5   4673   28-May 8:46   28-May 12:26
     99        8.7948 N   63.5632 E   32.4   4564   28-May 15:40  28-May 19:17
    100        9.1963 N   63.9295 E   32.4   4506   28-May 22:32  29-May 2:07
    101        9.5985 N   64.2978 E   32.5   4464   29-May 5:22   29-May 8:56
    102         9.992 N   64.6687 E   32.2   4423   29-May 11:51  29-May 15:24
    103       10.5407 N   64.6662 E   32.9   4384   29-May 18:08  29-May 21:39
    104       11.0757 N   64.6652 E   32.1   4314   30-May 0:20   30-May 3:48
    105       11.6222 N   64.6673 E   32.8   4249   30-May 6:32   30-May 9:59
    106       12.1607 N   64.6680 E   32.3   4209   30-May 12:40  30-May 16:05
    107       12.7032 N   64.6672 E   32.6   4158   30-May 18:48  30-May 22:11
    108       13.2435 N   64.6673 E   32.4   4091   31-May 2:15   31-May 5:36
    109       13.7855 N   64.6662 E   32.5   4055   31-May 8:51   31-May 12:26
    110       14.3258 N   64.6673 E   32.4   3946   31-May 15:40  31-May 18:57
    111       14.8667 N   64.6673 E   32.5   3927   31-May 22:11   1-Jun 1:27
    112       15.1408 N   65.1405 E   32.0   3854    1-Jun 4:39    1-Jun 8:52
    113       15.4149 N   65.6143 E   32.0   3795    1-Jun 12:04   1-Jun 16:15
    114        15.689 N   66.0888 E   32.0   3800    1-Jun 18:55   1-Jun 23:07
    115       15.9631 N   66.5639 E   32.0   3830    2-Jun 1:47    2-Jun 4:59
    116       16.2372 N   67.0397 E   32.0   3649    2-Jun 7:39    2-Jun 11:33
    117       16.5112 N   67.5161 E   32.0   3127    2-Jun 14:13   2-Jun 17:02
    118       16.7853 N   67.9932 E   32.0   3528    2-Jun 19:57   2-Jun 23:59
    119       17.0593 N   68.4710 E   32.0   3594    3-Jun 2:54    3-Jun 7:28
    120       17.3334 N   68.9496 E   32.0   3479    3-Jun 10:23   3-Jun 14:23
    121        17.575 N   69.4833 E   33.8   3385    3-Jun 17:28   3-Jun 21:25
    122       17.7202 N   68.9816 E   30.0   3494    4-Jun 0:09    4-Jun 3:10
    123       17.8654 N   68.4795 E   30.0   3458    4-Jun 5:54    4-Jun 8:54
    124            18 N   68.0000 E   28.5   3426    4-Jun 11:29   4-Jun 14:28
    Goa         15.43 N   73.7900 E  366.7      0    6-Jun 7:00    6-Jun 7:00



 
10.2. Properties Measured During I07N

Property        Description      Units      Principal Investigator       Responsible Party      
  Name                                                                        Onborad        
——————————  ———————————————————  ——————  ————————————————————————————  ——————————————————————
ctdprs      CTD Pressure         dbars        Molly Baringer /         Kristene McTaggart
                                              Gregory Johnson
ctdtmp      CTD Temperature      ITS-90           ditto                      ditto
ctdsal      CTD Salinity         PSS78            ditto                      ditto
ctdoxy      CTD Oxygen           umol/kg          ditto                      ditto
LADCP       N/S velocity         m/s          A. Thurnherr             Amanda Fay
LADCP       E/W velocity         m/s              ditto                      ditto
LADCP       Vertical velocity    m/s              ditto                      ditto
btlsal      Bottle salinity      PSS78        Molly Baringer           Andrew Stefanick
oxygen      Bottle dissolved     umol/kg      Chris Langdon            Emma Pontes / Samantha 
             oxygen                                                    Ladewig
silcat      silicate             umol/kg      Jia-Zhong Zhang /        Ian Smith /Eric 
                                              Calvin Mordy             Wisegarver
phspht      phosphate            umol/kg          ditto  
nitrat      nitrate              umol/kg          ditto  
nitrit      nitrite              umol/kg          ditto  
            amonnia              umol/kg          ditto  
tcarbn      dissolved inorganic  umol/kg      Rik Wanninkhof (AOML)    Chuck Featherstone & 
            carbon                                                     Dana Greeley
underway    surface water        uatm             ditto                      ditto
 pco2        pCO2
cfc11       CFC-11               pmol/kg      John Bullister           Bonnie Chang
cfc12       CFC-12               pmol/kg          ditto                      ditto
sf6         sulfur               fmol/kg          ditto                      ditto
             hexafluoride
ph          pH                   1  Rik       Wanninkhof (AOML) /      Ryan Woosley
                                              Frank Millero (RSMAS)
alkali      total alkalinity     umol/kg          ditto                Ryan Woosley
doc         dissolved organic    umol/kg      Dennis Hansell           Shinichiro Umeda
            carbon
tdn         total dissolved      umol/kg          ditto                      ditto
            nitrogen
di14c       dissolved inorganic  ∆14C         14C: A. McNichol/        Shinichiro Umeda
            14C                               R. Key/A. Gagnon
POC         Particulate Organic  umol/L       A. Martiny               Catherine Garcia
            Carbon
PON         Particulate Organic  umol/L           ditto                      ditto
            Nitrogen
POP         Particulate Organic  umol/L           ditto                      ditto
            Phosphorus
TBD         DNA metagenomic      none             ditto                      ditto
            analysis
DNSSAL      Density salinity     g/kg         Hiroshi Uchida           Shinichiro Umeda
CALCIUM     Calcium              mmol/kg      Akihiko Murata /         Shinichiro Umeda
                                              Shinichiro Umeda
DOC14       DOC 14C              ∆14C         Druffel/Walker           Christian Lewis
Black       Black Carbon 14C     ∆14C         Druffel/Walker/Lewis     Christian Lewis
 Carbon
WDO         Walker dissolved                  Walker/Abdulla           Christian Lewis
             organics
Biomarkers  Dissolved amino      nanomole/kg  Walker/Kaiser            Christian Lewis
             acids
CTDBEAMCP   Beam c               /meter       Wilford Gardner/         Kristene McTaggart
                                              Mary Jo Richardson
Density     Density              g/kg         Frank Millero (RSMAS)/   Fen Huang
                                              Ryan Woosley (MIT)
Pteropods   Bongo net                         Nina Bednarsek (SCCWRP)  Catherine Garcia, 
            sampling                                                   Victoria Coles






10.3. Sampling Notes

Note: #x = Niskin x (where x = position 1-24, not serial number)

Station 1, Cast 1:
#1 sampled without gloves.
#2 sampled without gloves.
#10 did not fire.

Station 2, Cast 1:
#13 leaking from the bottom cap.

Station 3, Cast 1:
Gloves required.
#13 small leak from the bottom cap.

Station 4, Cast 1:
#24 replaced valve on 278 CFC syringe 

Station 5, Cast 1:
Gloves required
#10-12 No sampling on these bottles because of there was a problem to fire 
them
#13 small leak 

Station 6, Cast 1:
#7 small leak at the bottom.

Station 7, Cast 1:
Gloves required

Station 8, Cast 1:
#24 was not fired (operators mistake).
#18 valve is hard to close

Station 9, Cast 1:
Gloves required

Station 10, Cast 1: [no comments]

Station 11, Cast 1:
Gloves required
02 flask #173 was dropped with the cap closed. no visible damage.

Station 12, Cast 1:
#11 endcap closed over the lanyard when tripped. Oxygen draw temperature 
seems to be an outlier.

Station 13, Cast 1:
Add sample flags for Chl on Niskins 21-24

Station 14, Cast 1:
Gloves required

Station 15, Cast 1:
Gloves required

Station 16, Cast 1:
#06 broken peacock. No samples, except for nuts and salt
#12 valve was open

Station 17, Cast 1
#06 broken peacock. No samples, except for nuts and salt

Station 18, Cast 1: [no comments]

Station 19, Cast 1: [no comments]
Gloves required

Station 20, Cast 2: [no comments]

Station 21, Cast 1: 
Gloves required
#10 broken peacock, but it has been fixed before CFC sampling

Station 22, Cast 1: [no comments]

Station 23, Cast 1: 
Gloves required
#6 needs new o-ring
#22 probably misfired.

Station 24, Cast 1: [no comments]

Station 25, Cast 1:
Gloves required
#7 small leak at the bottom.

Station 26, Cast 1: [no comments]

Station 27, Cast 1:
Gloves required

Station 28, Cast 1:
Gloves required

Station 29, Cast 1:
Gloves required
#21 is leaking from the bottom cap

Station 30, Cast 1: [no comments]

Station 31, Cast 1: 
Gloves required

Station 32, Cast 1: 
Acquired as station 31 cast 2, renamed afterward

Station 33, Cast 1: 
Gloves required
#2 bottle was fired at a wrong depth (4060 instead of 4163)

Station 34, Cast 1: [no comments]

Station 35, Cast 1:
Gloves required

Station 36, Cast 1:
Gloves required

Station 37, Cast 1:
#15 heavy leaking. no sampling.

Station 38, Cast 1:
Gloves required

Station 39, Cast 1:
#11 small leak from bottom

Station 40, Cast 1:
Gloves required
#22 closed at 130 instead of 90 dbar
#23 closed at 90 instead of 49 dbar
#24 closed at 49 instead of surface (no surface sample)

Station 41, Cast 1: [no comments]

Station 42, Cast 1:
Gloves required
#18 peacock broken. Only CFC has been sampled.

Station 43, Cast 1:
#11 small leak from bottom cap
#18 peacock broken but all samples were collected.

Station 44, Cast 1:
This is an added station (not initially planned), because the ship had to 
wait for the MSR clearance for the Seychelles
Gloves required
#2 and #3 same depth
#18 o-ring fell off
#23 cracks on o-ring 

Station 45, Cast 1: [no comments]

Station 46, Cast 1:
Gloves required
#12 vent was open

Station 47, Cast 1: 
Gloves required
#11 and #16 run out water. No salts, DOC14 and WDO samples.
#24 runs out water. no genetic and chl-a sample

Station 48, Cast 1: 
Gloves required

Station 49, Cast 1: [no comments]

Station 50, Cast 1: 
Gloves required

Station 51, Cast 1:
#5 peacok broken but all parameters were sampled
#24 ctd cames out during the firing due to a rogue wave

Station 52, Cast 1:
Gloves required

Station 53, Cast 1:
Gloves required because of biomarkers
O-ring broke on #5, repared by Dana
O2 temperature was not recorded on #5

Station 54, Cast 1: 
Gloves required

Station 55, Cast 1: [no comments]

Station 56, Cast 1: 
Gloves required
#17 o-ring broken before cfc sampling. it was replaced by a new ones. all 
samples have been taken
#24 small bottom leaking

Station 57, Cast 1: 

Station 58, Cast 1: 

Station 59, Cast 1:
#2 tripped on surface
#7 heavy leak from bottom
#11 leak from bottom
#24 leak from bottom

Station 60, Cast 1: 
Gloves required
#7 heavy leak from bottom
#11 small leak from bottom

Station 61, Cast 1:
#16 dripping from the nipple reported, but then stopped
#20 small drip from the bottom cap

Station 62, Cast 1: 
Gloves required

Station 63, Cast 1:
#20 small leak

Station 64, Cast 1:
Gloves required

Station 65, Cast 1: 
Gloves required
#14 extra bottle fired at Chl-maximum

Station 66, Cast 1:
#18 broken during CFC. fixed.

Station 67, Cast 1: 
Gloves required
#23 leaked out

Station 68, Cast 1: 
#16 o-ring was replaced
#18 o-ring went off but not damaged

Station 69, Cast 1:
Gloves required
#17 ph was sampled after #20

Station 70, Cast 1:
#1 leaking from bottom but it was fixed during the CFC sampling

Station 71, Cast 1:
Gloves required
#23 and #24 software error, but bottles have been fired 

Station 72, Cast 1:
Gloves required
#6 vent was open
#22 leaked from the bottom cap
#23 didnt close well. no sampling.

Station 73, Cast 1: [no comments]

Station 74, Cast 1: 
Gloves required
Oxygen #6 was sampled after #7

Station 75, Cast 1:
#6 was leaking from bottom when came out

Station 76, Cast 1:
Gloves required
#1 was leaking from bottom

Station 77, Cast 1:
#1 did not fire

Station 78, Cast 1:
Gloves required
#15 leaked out. No sampling.

Station 79, Cast 1:
air may have entered bottle #18 during CFC sampling

Station 80, Cast 1:
bottle #1 leaking out the back o-ring
bottle #15 broke, no sampling from it

Station 81, Cast 1: 
Gloves required

Station 82, Cast 1:
#1 had a small leak
#15 and #18 broken before CFC, but they have been fixed
#22 giving air bubbles CFC sampling

Station 83, Cast 1:
it took time to sample bottle #3 for O2
o-ring on bottle #11 broke
o-ring on bottle #18 went off, but was put back with no damages

Station 84, Cast 1: 
#23 strong leak from the bottom, no sampling

Station 85, Cast 1:
Gloves required

Station 86, Cast 1:
Gloves required
#2 is probably contaminated by surface waters. Oxygen was off.

Station 87, Cast 1:
#1 o-ring has little cracks
#9 pull ring was in, but vent was closed, no leak seen

Station 88, Cast 1:
Gloves required
#15 and #16 fired at the same depth (600 m)

Station 89, Cast 1: [no comments]

Station 90, Cast 1:
Gloves required
#22 vent was open
bottles specifically fired at #12 (02 minimum), #13 (subsurface salinity 
max), #14 oxycline and #22 (DCM)

Station 91, Cast 1: [no comments]

Station 92, Cast 1:
Gloves required
#15 leaked from the bottom cap. No sampling.
#20 02 flask 256- chemical may not been pushed all the way to the bottom.

Station 93, Cast 1:
Gloves required
line #3 got caugth by bottom 2
#1 small leak
#3 leaked bad. No CFC, O2, DIC, ph, alkalinity, calcium, salt samples. Nuts 
and biomarkes samples were taken.

Station 94, Cast 1: [no comments]

Station 95, Cast 1:
Gloves required

Station 96, Cast 1:
Gloves required
#16 was supposed to be fired at 700m, but this depth was missed, fired at 
550m instead

Station 97, Cast 1:
Gloves required
#20 intermittent little leak

Station 98, Cast 1:
#20 had a small leak from the bottom endcap
#23 no duplicates

Station 99, Cast 1:
Gloves required
#6 lanyard caught in bottom endcap, badly leaking, not sampled
#20 Niskin will be replaced prior to station 100

Station 100, Cast 1:[no comments]

Station 101, Cast 1: 
Gloves required
#13 and #20 small leaking

Station 102, Cast 1:

Station 103, Cast 1: [no comments]

Station 104, Cast 1:
Gloves required

Station 105, Cast 1:
Gloves required
#20 leaking peacock after close

Station 106, Cast 1:
Gloves required
#22 depth changed to capture fluorescence maximum

Station 107, Cast 1: [no comments]

Station 108, Cast 1:
#15 o-ring came out twice, but fixed
#23 water was coming out of the niki bottle even with closed vent. Only 
nuts, salt and chrolophyll samples have been taken

Station 109, Cast 1:
Gloves required 

Station 110, Cast 1: [no comments]

Station 111, Cast 1: 
Gloves required
#20 o-ring broken, but fixed

Station 112, Cast 1:
#13 small leaking bottle cap

Station 113, Cast 1:

Station 114, Cast 1:

Station 115, Cast 1:
Gloves required

Station 116, Cast 1:
#7 o-ring broken

Station 117, Cast 1:
Temperature for O2 on #14 looks suspicious. The two temperature probes used 
were showing different temperatures on #24.
When taken indores for inspection, they were back to normal. Suspec 
sensitivity to hot weather and humidity.

Station 118, Cast 1:
Gloves required
#13 small leaking from bottom

Station 119, Cast 1:
Gloves required
#22, #23, and #24 run out water. Bio group only sample #23 for DCM

Station 120, Cast 1: [no comments]

Station 121, Cast 1:
Gloves required
vent on bottle #23 was not closed

Station 122, Cast 1: [no comments]

Station 123, Cast 1:
Gloves required
#2 oxygen was sampled after #4

Station 124, Cast 1: [no comments]



 

10.4. Weekly Reports

10.4.1. Week 0

Departed Durban (South Africa) on April 23, 2018, headed for I07N

The I07N cruise was initially planned to start in February, however, due to 
the ship’s engine problems all cruises onboard the R/V Ronald Brown 
scheduled this year were postponed. Our departure date was shifted to April 
23. Most of our scientific gear was loaded on the Brown while the ship was 
in Charleston and during a port call in Fort Lauderdale. Only the LADCP gear 
and some additional sample bottles were shipped to Durban. This made the 
mobilization in Durban relatively easy. All I07N scientist safely made it to 
Durban without delays. Half of the group came to the ship on April 20 and 
started setting up their lab spaces and equipment, and all scientists moved 
onboard on April 22, our official staging day. On this day, we also had our 
first All-Hands meeting, when all participants introduced themselves to the 
rest of the group, the chief scientist talked about the station plan and 
schedule for the first 2 weeks, and both the operations and the security 
officers did a ‘welcome onboard’ briefing. After clearing customs and 
immigration, we departed at 2 pm local time on April 23. So far everything 
is going smoothly and according to the schedule. Our next report will cover 
our transit towards the first station of I07N at 30oS and 54.5SE, during 
which we will do two test casts, deploy an Argo float, a wave buoy, and 
drifters.


10.4.2. Week 1 (Apr. 23-29)

Departed Durban (South Africa) on April 23, 2018, headed for I07N


The rosette is being lowered at the I07N first test station.

We departed from Durban on April 23 at 2 pm local time. During the first day 
and night the ocean was a little rough, but everybody onboard could cope 
with it reasonably well. On the first day of the cruise we deployed the 
first SVP drifter in the Agulhas Current. On the second day, we did the 
“fire” and “abandon the ship” drills. Later we also had an “Egress” drill 
when everybody had to find the way out being blindfolded (that was a lot of 
fun!). The crew is paying significant attention to safety, and everybody 
understands that safety is our top priority.

The second SVP drifter was deployed on April 25. On the same day we reached 
the first test station and did a CTD cast down to 3000 m firing all Niskin 
bottles. Two bottles were fired at the same depth (80 m) as was requested by 
our oxygen group. Because the ship had issues with the aft winch during 
previous cruises, we decided to test this winch once again using it for the 
first test cast. The first cast showed that the issue remains, and it is 
reflected in modulo error, in particular during the upward cast. Tests 
indicate that the problem is unlikely to be related to the cable or 
termination, but it’s rather in the winch itself. Unfortunately, there is 
nothing that can be done onboard to fix the problem. We will proceed using 
the forward winch instead, which worked flawlessly during the previous 
cruises. The first test cast was mostly dedicated to teaching students, so 
not all groups were involved, and not all depths were sampled. On April 25, 
we also deployed the first (NAVIS type) Argo float from NOAA-PMEL. The ship 
slowed down to 1.5 knots, and the float was released from the port side of 
the stern. On April 26 we deployed the first (out of four) wave buoy from 
Scripps Institution of Oceanography. We decided to move the location of the 
second test station a little further east than we initially planned, because 
we wanted to do a cast deeper than 5000 m and past a sea mountain on our 
way, so eventually we did the second test cast down to just above the bottom 
at 5240 m.  This time we used the forward winch and it worked very well. 
After about 14 hours of steaming from the second test station, we reached 
the first station of the I07N line in time according to our schedule, and 
the I07N survey officially began. By the end of the week, we have completed 
7 stations. On station 7 we did the first net tow, and our biologists seem 
to be satisfied with the catch. 

We have not had major issues overall. The forward winch has worked very 
well. Among the minor issues, we have occasional leakages from the bottom 
caps of Niskin bottles that are easily fixed between the stations. 

One of the minor concerns so far is timing. The distance between the 
stations south of 22.5 S (stations 4 to 21) is only 20 miles, which takes 
less than 2 hours of steaming. When all groups are sampling, sometimes we 
are not able to complete sampling before we arrive at the next station. Upon 
the arrival at the next station, the ship is just waiting for sampling to be 
completed and then the rosette goes in the water right away. Because of 
this, we are currently running about 4 hours behind the schedule. The most 
time consuming was sampling for black carbon on stations 2-4. We will not do 
black carbon until station 22, so we are hoping that our sampling time will 
improve, and we will be able to make some time to return on schedule. When 
the distance between the stations increases to 30 nm, the ship will be able 
to steam at a higher speed, which will also bring us closer to the schedule.

The ship’s leadership and the entire crew has been very professional and 
attentive to our needs. The galley is keeping us well fed, including those 
with dietary restrictions. We have been enjoying calm seas and everybody 
onboard is doing well.


10.4.3. Week 2 (Apr 30 - May 6)

On the second week of the cruise the science team is very well adjusted to 
the daily routine: shifts, CTD casts, sampling, data and sample analysis, 
meals, sleep, etc.. The beginning of the week was rather dense, because the 
distance between the stations was ~20 nm, but at the end of the week the 
distance increased to ~30 nm, which took off some stress and let us return 
on schedule by steaming faster during transits. The weather has been 
relatively good. Occasionally we have some wind and swell, but nothing major 
yet that would impact operations. Hopefully, we will have the same weather 
all the way to Goa. As we go north, when the sky is clear, which is almost 
every day, we enjoy watching the sunset on the port side of the ship 
followed by a spectacular moonrise on the starboard (as shown by photographs 
above).

By the afternoon of May 6, we have completed 33 stations (25 stations last 
week), so exactly a quarter of all planned stations on the I07N line. We 
deployed a drifter and 3 Argo floats. Everything worked well, and we 
experienced no major issues. On station #24, close to the Reunion Island, we 
had to deviate a little from our route, because the French were conducting 
military exercises offshore the island, and our station was in the “no sail” 
area. Because of this, we decided to move station #24 10 nm westward, but 
still keeping it on the same latitude. As we were approaching the Exclusive 
Economic Zone (EEZ) of Tromelin Island, which is a disputed territory 
between France and Mauritius, we were getting more and more anxious about 
not having the Marine Scientific Research clearance from Mauritius. We 
finally received it when we were only a day away from entering the Tromelin 
EEZ. That was a big relief! Now we are still waiting for clearances from the 
Seychelles and India…

As a quarter of the I07N stations is already behind the stern, we are 
starting to look at the data we have collected. Displayed in the left figure 
below is the potential temperature for the first 26 stations if I07N 
obtained by CTD (this is raw data without corrections). Stations 1-26 run 
along the 54.5 E meridian. The top panel shows the upper layer and bottom 
panel the whole water column. Black curves in the top panels are sigma-0 
density; in the bottom panels they are sigma-0 (above 200 m) and sigma-4 
(below 3000 m) densities. The volume between 27 and 27.6 is occupied by the 
AAIW (Antarctic Intermediate Water). Below 3000 m, the cold waters (< 3oC) 
represent the AABW (Antarctic Bottom Water). The AAIW, trapped in the 27-
27.6 density layer, is clearly seen in the middle plot that shows the 
salinity profile. Near the surface at ~28S, there is a signature of the 
subduction of the saltier subtropical water. The vertical profile of oxygen 
(the right plot) shows an increased oxygen concentration near the bottom, 
indicating recent ventilation, which is a clear AABW signature. 

Our biologists have been busy too. By the end of the second week of the 
cruise, they have completed 3 net tows. One of the reasons for towing the 
net is to collect samples for studying whether the skeletons of pteropods 
are gradually dissolving because of the increase in acidity of the oceans 
due to increasing CO2. Victoria Coles and Hannah Morrissette caught a bunch 
of them on their filters the other night (see photo on the left). Pteropod’s 
shells are aragonite and are sensitive to the pH of the ocean. Just like a 
soda, adding CO2 to the ocean makes it more acid.

We are making 12 knots towards our next station #34, which should be 
completed by the end of May 6. Next week we will be crossing the Mascarene 
Basin, and we will attempt to find and (if found) to recover a PMEL mooring, 
the communication with which was lost 5 years ago. Stay tuned! 


10.4.4. Week 3 (May 7 - May 13)

This week was relatively rich for events. It started as usual with routine 
operations at stations. An Argo float and a mini wave buoy were deployed on 
the first day of the week. The weather was good as in previous weeks, and 
all operations were going smoothly. On the second day we entered the 
Mauritius EEZ, and by the end of the day we reached the location of a PMEL 
mooring, communication with which was lost 5 years ago. We were asked to 
attempt to find the mooring and, if the buoy is present, to recover the 
mooring or at least to make pictures of the buoy if we are off the schedule. 
We arrived at the mooring location in the dark, however, the weather was 
favorable, and the visibility was good enough. Being well equipped with the 
ship’s radar, night vision device, and a searchlight we started the search. 
Our plan was to locate the buoy, proceed to the next station (#42), and then 
return to the mooring and recover it next day in the morning. However, the 
buoy was not present. After hovering around for about an hour, the 
transducer was lowered at the last reported position of the mooring and 
disable command was sent. Unfortunately, the mooring is lost. 

Although we did not have to spend much time for the recovery and proceeded 
to the next station right away, our anxiety was growing because we still did 
not have the Marine Scientific Research (MSR) clearance from the Seychelles. 
And by the time we reached the boundary between the Mauritius and Seychelles 
Exclusive Economic Zones (EEZs), the clearance was not issued. Whatever the 
bureaucratic reasons were involved, we were just stranded. Apparently, up to 
this moment the cruise was going too smooth, so something had to happen. And 
it happened. The situation was complicated by the fact that our Mauritius 
clearance was expiring at midnight on the day we arrived at the boundary. 
Therefore, there was not much we could do inside the Mauritius EEZ. We did a 
full-depth CTD cast just 3 nm off the Seychelles EEZ boundary, which became 
our new station 44. Then we did a net tow at around 10 pm. But at midnight 
all science operations were ceased, and all underway systems were turned 
off. We decided to wait for the clearance at station 44 and not to proceed 
to the next station. This would allow us to have continuous in space 
underway data once the clearance is issued. On the next day by noon, we 
still did not have clearance, so we started to prepare for the worst. We 
sent a request to the person who issued clearance for Mauritius asking him 
for an extension, which would let us return to a turning point at station 40 
and head northeastward around the Seychelles EEZ. We had identified possible 
locations for 10 new stations inside the Mauritius EEZ. Fortunately, the 
Seychelles clearance came at around 2 pm, and we immediately rushed to the 
next I07N station. 

The delay with clearance costed us one full day at sea, but at least we did 
not have to change the route. As a result, we had to cancel 5 stations to 
return on schedule. We decided to cancel stations 48, 50, 58, located over 
relatively flat bottom topography, and stations 52 and 54, located over the 
slopes of sea mountains. Cancelling the stations increased the spacing 
between the stations along the corresponding segments from 17 to 34 nm. But 
we still retained the short spacing between the stations over the Amirante 
Trench.  A map of stations near the Amirante Trench, including those 
canceled, is displayed in fig. 1. We are still a little behind the schedule 
as the sea state does not permit seaming faster than 10 knots. Postponing 
the last station on leg 1 to leg 2 is not a desirable option, however, 
because it would take about half a day from the leg 2 schedule just for 
steaming given the large area of the Seychelles bank we will have to cross. 
But we will do that if necessary as there’ll be no more cancellations on the 
leg 1.
    

Figure 1: A map with stations near the Amirante Trench. Stations 48, 50, 52, 
          54, and 58 were canceled.


As we are completing the first leg of the cruise, some interesting 
scientific findings are starting to emerge. Below are the profiles of 
temperature, salinity, and oxygen from station 1 at 30rS to station 57 at 
about 8SS (fig. 1). We have passed a warm pool bounded by the eastward South 
Indian Countercurrent in the south and the westward South Equatorial Current 
in the north. We have observed the saltier subtropical water that subducts 
under the warm and less saline near-surface water. This subtropical water 
was still seen at our last CTD cast. The Antarctic Intermediate Water (AAIW) 
is not observed beyond station 38 (~14iS). The increased oxygen 
concentrations near the bottom associated with the Antarctic Bottom Water 
(AABW) are observed everywhere along the first leg of the cruise. What we 
find particularly interesting with regard to AABW is the observed 
concentrations of CFC in comparison to those observed in 1995 (see fig. 2). 
As you can see, in 2018 we have observed substantially higher concentrations 
of CFC in the AABW layer, which means that new AABW was formed over the last 
23 years and advected all the way to the tropical latitudes of the Indian 
Ocean.

We are just one day away from our port stop in Victoria. Besides the issues 
with clearances and the necessity to cancel 5 stations on the first leg, 
everything else has been going well. The instruments are working great, no 
problems with the forward winch. The next report will cover only 3 days at 
sea during the fourth week as the other 4 days we will spend on shore. 

Figure 2: The profiles of (a) potential temperature, (b) salinity, and (c) 
oxygen concentration between stations 1 and 57 along the I07N line (leg 1). 
The white contours in the upper panels show sigma-0 density, while in the 
lower panels they show sigma-0 density above 2000 m and sigma-4 below 3000 m
	
Figure 2. CFC concentrations along the I07N line (left panel) in 1995 and 
(right panel) in 2018.


10.4.5. Week 4 (May 14 - May 20)

Leg 2: Departed Victoria on May 19, headed to Goa (India)

And here, we would probably end the past week’s report … ☺

… if the port call in the Seychelles lasted the whole week. But science 
operations ended on Tuesday morning and re-started after our departure from 
Victoria on Saturday afternoon. On Monday and Tuesday, we did stations 59-64 
(6 CDT casts with depths ranging from about 900 to 3800 m) with no 
cancelations like during the previous week. We deployed a drifter at 7sS and 
a wave buoy at 6SS. Upon completing the last station of leg 1, we steamed to 
Victoria and anchored off shore. After clearing customs and being briefed by 
an NCIS agent, we disembarked and enjoyed the solid ground and the beauty of 
the island… Overall, the port stop worked very well, in particular for the 
moral onboard, because in the end people returned back safe, well-rested, 
and enthusiastic about the second leg of the cruise. So, we are all grateful 
for that. A photograph below shows some scientists onboard the Brown after 
their return. Yes, only some, 18 out of 26…

But do not worry. Nobody decided to stay or was left behind in the 
Seychelles! ☺ One person was taking the picture and the rest were either 
helping or watching Andy Stefanick and Jay Hooper to wire the rosette. We 
will definitely make another group picture after we complete all stations of 
the cruise. In Victoria, we were expecting an Indian scientist to board the 
ship and join the cruise. Unfortunately, the Indian participant did not 
arrive as his participation was eventually not approved by his institution. 
This, however, has no impact on our science operations, and we will continue 
as we did during the leg 1. The entire science team is working together very 
well, everybody is very professional and responsible, knows the needs of 
each other, so help is always there when required.

Since our departure from Victoria, we have completed 7 stations, which makes 
the total of 71 stations from the beginning of the I07N cruise. The first 
station after Victoria (#65) was done about 5 nm westward from the location 
occupied in 1995. The reason for that is that the original station 65 is 
located within the territorial waters of Seychelles (within 12 nm zone of 
Denis Island), and we did not have MSR clearance to sample in the 
territorial waters. Since the beginning of the leg 2 we have already 
deployed 3 Argo floats, 2 drifters, and did 1 net tow. At station 69 we 
experienced a very strong surface current, because of which the ship drifted 
about 1 nm eastward while doing a CTD cast. The ship’s 75KHz "Ocean 
Surveyor" ADCP showed the eastward component of the current with a strength 
of up to 1 m/s (see figure below on the left). We think this current is 
related to the strong eastward Wyrtki Jets (WJ), forced directly by the 
equatorial westerlies.

The WJ occur during the monsoon transition periods of spring and fall, so 
our cruise happened to be at the right time to observe it. The WJ are 
associated with increased salinity, which is clearly seen in CTD casts at 
stations 69-70 (see the right figure on the left). Within the area of the 
WJ, in addition to CTD casts and underway measurements, we deployed 2 Argo 
floats at stations 69 and 71 and one drifter at station 70. The drifter 
deployment at this location was not pre-planned, so it is a “bonus” 
deployment that we decided to do while transiting this interesting oceanic 
feature.

Since we started talking about currents, and because the past work week was 
short, we thought it would also be interesting to bring everybody’s 
attention to a very strong vertical flow we observed during the first leg of 
the cruise at station 33 (16.8aS). The vertical velocity (w) is derived from 
LADCP data using a technique developed by Andreas Thurnherr from Lamont-
Doherty Earth Observatory, University of Columbia (Amanda Fay is our onboard 
LADCP operator, but Andreas is the PI of LADCP measurements on GO-SHIP 
cruises). As displayed in the figure on the right, there was an 
instantaneous w of up to 4 cm/s between about 300-1000 m depth. Our initial 
guess was that we saw a signature of an internal wave, which was later 
confirmed by Andreas. Because the buoyancy period, which is the shortest 
possible period for w in the internal-wave field, is not long compared to 
the sampling time of a CTD/LADCP profile, the down- and up-cast data are 
processed separately. The figure shows that the amplitude of w is similar 
during the downcast (orange) and upcast (green). 

Our research cruise continues and by the end of week 5 we expect to cross 
the Carlsberg Ridge and enter the Arabian Sea. Stay tuned!


10.4.6. Week 5 (May 21 - May 27)

Leg 2: Departed Victoria on May 19, headed to Goa (India)

In the week 4 report, we told you about the observation of a strong eastward 
current north of the Seychelles Bank, which we associated with the seasonal 
Wyrtki Jet. The strong surface eastward flow with velocities ranging from 
0.4 to above 1 m/s was observed over about 7/ latitudinal band (fig. 1). 
Because of this current, starting from station 69 (~2.75 S) we started to 
have twists on the forward winch cable that were causing modulo errors on 
the CTD. The biggest unloading of twists and caging occurred during recovery 
of cast 71 (~1.75hS), when the ship’s ADCP recorded a strong vertical shear 
of the flow in the upper 200 m: there was a strong eastward flow in the 
upper 100 m  and a strong westward flow between 100-200 m (fig. 1). 


Figure 1: Zonal velocity measured by the ship’s ADCP along the I07N transect 
          north of the Seychelles Bank. 


We had no evidence of caging after cast 72 (~1.2WS), but there was a severe 
twist near the mechanical termination and several static bends that 
warranted a re-termination of the cable. The re-termination helped, because 
we did not have modulo errors at station 73. But when the package was lifted 
onboard there was a wire twist again. This situation was causing a lot of 
concern, because we do not have a backup winch to use. As we mentioned in 
the week 1 report, the aft winch is not usable, because it makes 
unacceptable amount of modulo errors on the CTD, and all attempts to fix the 
winch had failed. A continued use of the forward winch with degrading cable 
would increase the chances of losing the entire package. However, the only 
solution we had is to keep an eye out for the cable and hope that the 
situation will improve once we exit the strong current. The cable was re-
terminated again after station 77 and between 250-300 m of wire were cut. 
Fortunately, as the current was getting weaker on our way northward, the 
cable situation improved considerably. There are no more twists, and most of 
the time there are no modulo errors on the CTD. We continue to pay attention 
at the cable and hope that everything goes smoothly for the remainder of the 
cruise.

By the end of May 27th, we have completed 96 stations. During the past week, 
we completed 26 stations, deployed 6 Argo floats, 4 drifters, and 1 wave 
buoy, and did 4 net tows. We still have 32 stations ahead assuming we obtain 
the MSR clearance from India. If clearance is not obtained until the end of 
cast 111, we will change the route and follow our plan B, which will bring 
us as close as possible to the Indian continental slope, but still keeping 
us outside the Indian Exclusive Economic Zone.


Figure 2: Profiles of potential temperature, salinity, oxygen and CFC 
          concentrations along the I07N transect in Apr-May 2018.


As can be seen in Figure 2, after passing the Seychelles Bank (4-5AS) and 
entering the Somali Basin, we started to observe considerable increase of 
salinity and decrease of oxygen concentration in the upper ocean – the first 
signs of approaching the oxygen minimum and salinity maximum zones in the 
Arabian Sea. During the first leg of the cruise we reported on increased 
concentrations of CFCs in the Antarctic Bottom Water that were not observed 
during the previous occupation of the I07N section in 1995. In the Somali 
Basin, we observe only slightly elevated CFC concentrations near the bottom.

Although the monsoon season has started in the Arabian Sea, the weather has 
been very favorable to us so far. In fig. 3, you can see the weather 
forecast for May 27-28 with our track shown by the broken line with circles. 
It is amazing to see that our track lies right in the middle of the white 
swath of calm seas. We are tending to think that since we are a NOAA cruise, 
the NOAA’s National Weather Service is taking a special care of us ☺. 


Figure 3: Weather maps for May 27-28.


10.4.7. Week 6+ (May 28 – June 5)

Leg 2: Departed Victoria (Seychelles) on May 19, arriving in Goa (India) on 
June 6.

Figure 1: I07N 2018

This is our last weekly report for the GO-SHIP I07N cruise. And here, we are 
reporting on the last 9 days of the cruise. We just completed station 124, 
and we expect to arrive in Goa at 8 am on Wednesday, June 6. Overall, the 
cruise was a success, because we almost completely reoccupied the I07N 
transect for the first time since 1995. We had some issues with the winch 
cable (see our previous week 5 cruise report), but after taking some extra 
care of the cable, the problem was mitigated. During the last 9 days we were 
keeping a close eye on the state of the cable after each cast. We had to do 
one more re-termination after getting several modulo errors on the CTD. 
However, thanks to the extra measures we undertook, the cable situation had 
no impact on the quality of the data.

At the end of the previous report we left you somewhere over the Carlsberg 
Ridge. Upon crossing the ridge, we entered the Arabian Sea. Station 111 
(~14.9N) was our decision point, from which we would either follow our 
initial plan A (black dots) or an alternative plan B (red dots) depending on 
the situation with the Indian Marine Scientific Research (MSR) clearance. 
Unfortunately, we did not receive the Indian MSR, neither before reaching 
station 111 nor later. As a result, we decided to follow plan B, which took 
us as close as possible to the continental slope, but still staying outside 
the Indian Exclusive Economic Zone (EEZ). Station 121 was the last station 
on the segment between the turning point at station 111 and the EEZ. Upon 
reaching station 121, we still had about 2 days available for doing more 
stations. As one of the wishes for our cruise was to get as deep into the 
Oxygen Minimum Zone (OMZ) as possible, we decided to head northwestward and 
reach the 18N latitude – this is the northernmost latitude the ship agreed 
to sail to due to safety concerns.


Figure 2: Plans A (black dots) and B (red dots)


Entering the OMZ was a unique experience for the CTD watchstanders and other 
members of the science party, observing in real-time the oxygen sharply 
dropping to zero (Figure 3). 


Figure 3: Oxygen Profile at station 121 (17.53o N; 64.48o E). Observe the 
          thick layer of very low oxygen between 160 and 900 m. Red dots 
          indicate the depths that the bottles have been fired.


To better resolve the Arabian Sea sharp features, we changed our sampling 
scheme at station 112, firing more bottles at the surface layer. We quickly 
learned that the new scheme was not optimal for all groups since several 
samples into the deep ocean are also needed. Thus, after only one station, 
we decided to go back to the previous scheme that was the best possible 
solution for all of us. We found that even under the old scheme, the OMZ is 
well defined, occupying a thick layer between 150 and 1000 m as can be seen 
in Figure 4. Unfortunately, because the final segment of the I07N cruise in 
2018 does not follow the same track as the I07N cruise in 1995, we cannot 
compare the newest data with the previous ones. In 1995, the I07N path 
headed to Oman in the western Arabian Sea, but due to safety concerns, we 
couldn’t follow their footsteps.


Figure 4: Oxygen concentration between stations 111 and 124 (Plan B in 
          Figure 2)


Another feature of oxygen that caught our attention and let us intrigued was 
the lower oxygen near the bottom (Figure 5). This feature started around 
station 104, reached minimum oxygen concentration at station 111 (our 
inflection point to plan B in Figure 2) and persisted until station 114.  A 
quick look at the 1995 data indicated that this feature was not prominent in 
that year.  Several hypotheses have been discussed onboard from biological 
to physical mechanisms, but we couldn’t decide the best ones without 
performing a more extensive investigation.  


Figure 5: Oxygen below 200m between stations 102 and 122


After spending almost 40 days at sea (excluding 4 days of the port stop in 
Victoria), covering about 5200 nautical miles, completing 126 CTD casts 
(including 2 test casts at the beginning of the cruise), collecting and 
analyzing over 36000 liters of water from depths ranging from 5 to about 
5500 m (excluding underway water intake) everybody is looking forward to 
return home. We have worked hard, had great and productive time onboard, met 
new people and made good friends. Now it is the time to analyze the data we 
have collected, and we know that we have observed many interesting features 
that still need to be investigated in detail and explained.

Although our cruise is ending, the GO-SHIP program continues. Therefore, see 
you next time!




CCHDO Data Processing Notes

•  File Online Carolina Berys
cruise_report_calcium_post.docx (download) #aefd9 
Date: 2019-04-16 
Current Status: unprocessed

•  File Online Carolina Berys
cruise_report_densitysalinity_post.doc (download) #dccb3 
Date: 2019-04-16 
Current Status: unprocessed

•  File Online Carolina Berys
33RO20180423.exc.csv.JAM_add.20190312.csv (download) #e077b 
Date: 2019-04-16 
Current Status: unprocessed

•  File Submission Shinichiro Umeda
33RO20180423.exc.csv.JAM_add.20190312.csv (download) #e077b 
Date: 2019-03-12 
Current Status: unprocessed 
Notes
This file contains final values and flags for the following parameters 
measured at the onshore laboratory in JAMSTEC.
-DNSSAL / DNSSAL2 (Density)
-SALNTY_HU / SALNTY_HU2 (Practical Salinities for the density samples)
-CALCIUM(Dissolved Calcium)
Supplemental documents for these data are also attached.

•  File Submission Shinichiro Umeda
cruise_report_densitysalinity_post.doc (download) #dccb3 
Date: 2019-03-12 
Current Status: unprocessed 
Notes
This file contains final values and flags for the following parameters 
measured at the onshore laboratory in JAMSTEC.
-DNSSAL / DNSSAL2 (Density)
-SALNTY_HU / SALNTY_HU2 (Practical Salinities for the density samples)
-CALCIUM(Dissolved Calcium)
Supplemental documents for these data are also attached.

•  File Submission Shinichiro Umeda
cruise_report_calcium_post.docx (download) #aefd9 
Date: 2019-03-12 
Current Status: unprocessed 
Notes
This file contains final values and flags for the following parameters 
measured at the onshore laboratory in JAMSTEC.
-DNSSAL / DNSSAL2 (Density)
-SALNTY_HU / SALNTY_HU2 (Practical Salinities for the density samples)
-CALCIUM(Dissolved Calcium)
Supplemental documents for these data are also attached.

•  File Online Carolina Berys
Final winkler quality flags 05Mar19.csv (download) #20918 
Date: 2019-03-11 
Current Status: unprocessed

•  File Submission Chris Langdon
Final winkler quality flags 05Mar19.csv (download) #20918 
Date: 2019-03-05 
Current Status: unprocessed 
Notes
Final Winkler quality flags for 33RO20180423 IO7N cruise.

•  File Online Carolina Berys
33RO20180423.exc.csv (download) #ad0bb 
Date: 2019-01-28 
Current Status: unprocessed

•  File Submission Robert Key
33RO20180423.exc.csv (download) #ad0bb 
Date: 2019-01-24 
Current Status: unprocessed 
Notes
This file now contains final values for TCARBN, PHSWS and ALKALI.
Values have been QC'ed.
Do NOT take vanilla values from this file.
NOTE there are a few bottle numbers equal to -9 in this file and probably in 
other versions. Needs to be fixed but I don't know correction.
bob

•  File Online Carolina Berys
33RO20180423.exc.csv (download) #d4957 
Date: 2019-01-11 
Current Status: unprocessed

•  File Merge Carolina Berys
I7n_2018_hy1.csv (download) #96b54 
Date: 2019-01-08 
Current Status: merged

•  File Merge Carolina Berys
33RO20180423_IO7N_DIC_Data_Final.csv (download) #e21de 
Date: 2019-01-08 
Current Status: merged

•  File Merge Carolina Berys
33RO20180423.exc.csv (download) #d4957 
Date: 2019-01-08 
Current Status: unprocessed

•  Bottle file online, includes TCARBN update Carolina Berys 
Date: 2019-01-08 
Data Type: Bottle 
Action: Website Update 
Note: 
I07N 2018 33RO20180423 processing - BTL/merge - processing, TCARBN

2019-01-08

C Berys

Submission

filename                              submitted by          date       id   
----------------------------------------------------------------------------
I7n_2018_hy1.csv                      Denis Volkov          2016-01-13 14083
33RO20180423_IO7N_DIC_Data_Final.csv  Charles Featherstone  2016-01-13 14242
33RO20180423.exc.csv                  Bob Key               2016-01-13 14253

Changes

* fMOL to FMOL for SF6
* PH_TEMP to PH_TMP
* N2O_FLAG to N2O_FLAG_W
* fill value for OXYGEN from -999.9900 to -999.0000

Merge

Merged 33RO20180423_IO7N_DIC_Data_Final.csv into I7n_2018_hy1.csv using 
hydro 0.8.2-48-g594e1cb. Renamed 33RO20180423_hy1.csv.

merged parameters: TCARBN, TCARBN_FLAG_W

All comment lines from original file copied back in following merge. 
33RO20180423_hy1.csv opened in JOA with no apparent problems.

Conversion
----------

file                    converted from       software               
--------------------------------------------------------------------
33RO20180423_nc_hyd.zip 33RO20180423_hy1.zip hydro 0.8.2-48-g594e1cb
33RO20180423hy.txt      33RO20180423_hy1.csv hydro 0.8.2-48-g594e1cb

Updated Files Manifest
----------------------

file                    stamp            
-----------------------------------------
33RO20180423_hy1.csv    20190108CCHSIOCBG
33RO20180423_nc_hyd.zip 20190108CCHSIOCBG
33RO20180423hy.txt 
					
•  File Online Carolina Berys
33RO20180423.exc.csv (download) #d4957 
Date: 2018-12-14 
Current Status: unprocessed

•  File Submission Robert Key
33RO20180423.exc.csv (download) #d4957 
Date: 2018-12-12 
Current Status: unprocessed 
Notes
Merged DIC from file "33RO20180423_IO7N_DIC_Data_Final.csv" then QC. 
Additional QC on nuts and O2, but this will likely be overwritten once final 
values are uploaded. (and ok)

•  File Online Carolina Berys
33RO20180423_IO7N_DIC_Data_Final.csv (download) #e21de 
Date: 2018-12-04 
Current Status: merged

•  File Submission Charles Featherstone
33RO20180423_IO7N_DIC_Data_Final.csv (download) #e21de 
Date: 2018-11-29 
Current Status: merged 
Notes
DIC Data for the IO7N cruise, expocode-33RO20180423

•  File Merge CCHSIO
i07n_prelim_ct1.zip (download) #50b3f 
Date: 2018-10-25 
Current Status: merged

•  File Merge CCHSIO
i07n_final_kem.zip (download) #b4065 
Date: 2018-10-25 
Current Status: merged

•  File Merge CCHSIO
i07n_fixed_lon_ct1.zip (download) #23e1b 
Date: 2018-10-25 
Current Status: merged

•  update data from As Received to Data Set CCHSIO 
Date: 2018-10-25 
Data Type: CTD 
Action: Website Update 
Note: 
    2018 33RO20180423 processing - CTD/merge - 
CTDPRS,CTDTMP,CTDSAL,CTDOXY,CTDNOBS,CTDXMISS,CTDFLUOR

2018-10-25

CCHSIO

Submission

filename               submitted by     date       id  
---------------------- ---------------- ---------- -----
i07n_prelim_ct1.zip    Kristy McTaggart 2018-07-17 14090
i07n_final_kem.zip     Kristy McTaggart 2018-09-10 14162
i07n_fixed_lon_ct1.zip Kristy McTaggart 2018-09-12 14169

Changes
-------
i07n_prelim_ct1.zip
	- moved to  Data History, not used
i07n_final_kem.zip 
	- moved to  Data History, not used

i07n_fixed_lon_ct1.zip
        - Renamed files to match EXCHANGE standard. Put original file name 
in file as a comment.
        - No flags submitted for parameters CTDNOBS, CTDXMISS (0-5VDC), 
CTDFLUOR(0-5VDC)
        - STNNBR: removed leading 0s from number
        - added cruise and header information as comments

Conversion
----------
file                    converted from       software               
----------------------- -------------------- -----------------------
33RO20180423_nc_ctd.zip 33RO20180423_ct1.zip hydro 0.8.2-48-g594e1cb


Updated Files Manifest
----------------------

file                    stamp            
----------------------- --------------
33RO20180423_ct1.zip    20181025CCHSIO
33RO20180423_nc_ctd.zip 20181025CCHSIO

:Updated parameters: CTDPRS,CTDTMP,CTDSAL,CTDOXY,CTDNOBS,CTDXMISS,CTDFLUOR

opened in JOA 5.2.1 with no apparent problems:
     33RO20180423_ct1.zip
     33RO20180423_nc_ctd.zip

opened in ODV with no apparent problems:
     33RO20180423_ct1.zip
					
•  File Online Carolina Berys
i07n_fixed_lon_ct1.zip (download) #23e1b 
Date: 2018-09-27 
Current Status: merged

•  File Submission Kristy McTaggart
i07n_fixed_lon_ct1.zip (download) #23e1b 
Date: 2018-09-12 
Current Status: merged 
Notes
These are final CTDO data (profiles only) resubmitted with corrected 
longitudes in all file headers from GO-SHIP cruise I07N (33RO20180423).

•  File Online Carolina Berys
i07n_final_kem.zip (download) #b4065 
Date: 2018-09-10 
Current Status: merged

•  File Submission Kristy McTaggart
i07n_final_kem.zip (download) #b4065 
Date: 2018-09-10 
Current Status: merged 
Notes
These are final CTDO data (profiles and discrete) and documentation from GO-
SHIP cruise I07N (33RO20180423).

•  File Merge Jerry Kappa
33RO20180423_do.txt (download) #ca4dc 
Date: 2018-08-14 
Current Status: dataset

•  File Submission Jerry Kappa
33RO20180423_do.txt (download) #ca4dc 
Date: 2018-08-09 
Current Status: dataset 
Notes
The text version of i07n_2018's cruise report is ready to be added to the 
CCHDO Dataset.  It includes all of the PI-provided data reports and CCHDO 
summary and Data Processing Notes.

•  File Merge Carolina Berys
I07N_CruiseReport.docx (download) #a2ecb 
Date: 2018-08-06 
Current Status: merged

•  File Merge Carolina Berys
I07N_CruiseReport.pdf (download) #e7e31 
Date: 2018-08-06 
Current Status: merged

•  File Merge Jerry Kappa
33RO20180423_do.pdf (download) #957e9 
Date: 2018-08-06 
Current Status: dataset

•  File Submission Jerry Kappa
33RO20180423_do.pdf (download) #957e9 
Date: 2018-07-31 
Current Status: dataset 
Notes
The pdf version of i07n_2018's cruise report is ready to be added to the 
dataset.  It contains all of the PI-provided data reports as well as CCHDO 
summary pages and Data Processing Notes.

•  File Online Carolina Berys
i07n_prelim_ct1.zip (download) #50b3f 
Date: 2018-07-26 
Current Status: merged

•  File Submission Kristy McTaggart
i07n_prelim_ct1.zip (download) #50b3f 
Date: 2018-07-17 
Current Status: merged 
Notes
These are preliminary CTDO data from GO-SHIP cruise I07N (33RO20180423). 
Preliminary calibrations were applied at sea and all data flags default as 
'2'.  Any near-surface instabilities flagged as '9' will be added back and 
flagged as '3' later.

•  File Online Carolina Berys
I07N_CruiseReport.docx (download) #a2ecb 
Date: 2018-07-14 
Current Status: merged

•  File Submission Denis Volkov
I07N_CruiseReport.docx (download) #a2ecb 
Date: 2018-07-13 
Current Status: merged 
Notes
I07N cruise, Apr 23 - Jun 6, 2018

•  File Online Carolina Berys
I07N_CruiseReport.pdf (download) #e7e31 
Date: 2018-07-13 
Current Status: merged

•  File Online Carolina Berys
I7n_2018_hy1.csv (download) #96b54 
Date: 2018-07-13 
Current Status: merged

•  File Submission Denis Volkov
I07N_CruiseReport.pdf (download) #e7e31 
Date: 2018-07-12 
Current Status: merged 
Notes
NOAA Ship "Ronald H. Brown", I07N cruise, April 23 - June 6, 2018

•  File Submission Denis Volkov
I7n_2018_hy1.csv (download) #96b54 
Date: 2018-07-12 
Current Status: merged 
Notes
NOAA Ship "Ronald H. Brown", I07N cruise, April 23 - June 6, 2018


