CRUISE REPORT: P14S / S04 / S04I / I09S (MR12-05)
(Updated JUL 2015)







Highlights


                           Cruise Summary Information


               Section Designation  Leg 1  n/a
                                    Leg 2  P14S/S04/S04I/I09S
                                    Leg 3  S04I
Expedition designation (ExpoCodes)  Leg 1  49NZ20121105
                                    Leg 2  49NZ20121128  
                                    Leg 3  49NZ20130106
                  Chief Scientists  Leg 1  Katsuro Katsumata/JAMSTEC
                                    Leg 2  Katsuro Katsumata/JAMSTEC
                                    Leg 3  Hiroshi Uchida/JAMSTEC
                             Dates  Leg 1  2012 NOV 5 - 2012 NOV 26
                                    Leg 2  2012 NOV 28 - 2013 JAN 4
                                    Leg 3  2013 JAN 6 - 2013 FEB 15
                              Ship  R/V Mirai
                     Ports of call  Leg 1  Sekinehama, JPN;
                                           Hachinohe, JPN – Auckland, NZ
                                    Leg 2  Auckland, NZ - Hobart, AUS
                                    Leg 3  Hobart, AUS - Fremantle, AUS

                                                 40° 29.82' N
             Geographic Boundaries  33° 29.21' E             174° 2.83' E
                                                 68° 3.65' S

                          Stations  Leg 1  3
                                    Leg 2  54 (Includes 6 XCTD-only)
                                    Leg 3  77
      Floats and drifters deployed  Leg 1
                                    Leg 2  3 Argo floats
                                    Leg 3  4 Deep NINJA floats
    Moorings deployed or recovered  2 including 1 emergency recovery of 
                                    Southern Ocean Flux Buoy (Bureau of 
                                    Meteorology, Australia

                              Contact Information:

         Japan Agency for Marine-Earth Science and Technology (JAMSTEC)
              2-15 Natsushima, Yokosuka, Kanagawa, Japan 237-0061
                  Katsuro Katsumata: k.katsumata@jamstec.go.jp
                      Hiroshi Uchida: huchida@jamstec.go.jp












                                       WHP P14S, S04I REVISIT IN 2012 DATA BOOK


                                                                      Edited by
                                                      Hiroshi Uchida (JAMSTEC),
                                                   Katsuro Katsumata (JAMSTEC),
                                                        Toshimasa Doi (JAMSTEC)


The photograph on the front and back cover of floating ice with an iceberg was 
taken at the southernmost station in the cruise MR12-05 by Ms. Aiko Miura. The 
photograph on the inside cover of a whale was also taken by Ms. Aiko Miura.


WHP P14S, S04I REVISIT IN 2012 DATA BOOK


March 27, 2015 Published

Edited by Hiroshi Uchida (JAMSTEC), Katsuro Katsumata (JAMSTEC) and Toshimasa 
Doi (JAMSTEC)


Published by © JAMSTEC, Yokosuka, Kanagawa, 2015
Japan Agency for Marine-Earth Science and Technology
2-15 Natsushima, Yokosuka, Kanagawa 237-0061, Japan
Phone +81-46-867-9474, Fax +81-46-867-9835
Printed by Aiwa Enterprise, Ltd.
3-22-4 Takanawa, Minato-ku, Tokyo 108-0074, Japan



















Contents

Contents                                                    …………………………………………  3
Preface                                                     …………………………………………  4
    M. Fukasawa (JAMSTEC)

Documents and station summary files
   1  Cruise Narrative                                      …………………………………………  1
         K. Katsumata and H. Uchida (JAMSTEC)
   2  Underway Measurements
   2.1  Navigation                                          ………………………………………… 14
          S. Sueyoshi (GODI) et al.
   2.2  Swath Bathymetry                                    ………………………………………… 15
          T. Matsumoto (Univ. Ryukyus), 
          M. Nakanishi (Chiba Univ.) et al.
   2.3  Surface Meteorological Observation                  ………………………………………… 17
          S. Sueyoshi (GODI) et al.
   2.4  Thermo-Salinograph and Related Measurements         ………………………………………… 21
          H. Uchida (JAMSTEC) et al.
   2.5  Underway pCO2                                       ………………………………………… 24
          A. Murata (JAMSTEC) et al.
   2.6  Shipboard ADCP                                      ………………………………………… 26
          S. Kouketsu (JAMSTEC) et al.
   2.7  XCTD                                                ………………………………………… 29
          H. Uchida (JAMSTEC) et al.
   2.8  Photosynthetically Available Radiation (PAR)        ………………………………………… 31
          H. Uchida (JAMSTEC)
   3  Hydrographic Measurement Techniques and Calibrations
   3.1  CTDO2 Measurements                                  ………………………………………… 32
          H. Uchida (JAMSTEC) et al.
   3.2  Bottle Salinity                                     ………………………………………… 48
          H. Uchida (JAMSTEC) et al.
   3.3  Density                                             ………………………………………… 51
          H. Uchida (JAMSTEC)
   3.4  Oxygen                                              ………………………………………… 54
          Y. Kumamoto (JAMSTEC) et al.
   3.5  Nutrients                                           ………………………………………… 60
          M. Aoyama (MRI/JMA) et al.
   3.6  Chlorofluorocarbons and Sulfur Hexafluoride         ………………………………………… 73
          K. Sasaki (JAMSTEC) et al.
   3.7  Carbon Items (CT, AT and pH)                        ………………………………………… 77
          A. Murata (JAMSTEC) et al.
   3.8  Chlorophyll a                                       ………………………………………… 83
          H. Uchida (JAMSTEC) et al.
   3.9  LADCP                                               ………………………………………… 84
          S. Kouketsu (JAMSTEC) et al.
   3.10  Expendable Microstructure Profiler                 ………………………………………… 86
          K. Katsumata (JAMSTEC)


Station Summary (see online data files)


Figures (see PDF version)



Preface

Please forgive me for starting the preface of this data book with the sentence 
“At last, we have arrived at offshore of the Adelie Coast”.

Also, one might be aware that JAMSTEC tends to select zonal lines of GO-SHIP 
(and WHP-revisit) plan as our target.

Concerning the revisit of WHP lines, we firstly undertook the revisit of P01 in 
1999. Analysis of data from P01:1999 showed that there was a basin-wide warming 
of bottom layer compared to the former P01 cruise in 1985 carried out by US 
scientists. This finding of the bottom layer warming in the North Pacific 
received worldwide attention of scientists and generated quite a few studies 
for investigating/clarifying physical mechanisms of the warming.

As the results, several WHP-revisit cruises reported the same warming of bottom 
layer as found along P01 obviously along the pathway of the Lower Circumpolar 
Deep Water (LCDW) and/or the North Pacific Deep Water (NPDW).

On the other hand, a numerical model of bottom layer of the world ocean has 
suggested that such warming of bottom layer in the Pacific is likely to occur 
under an abrupt decrease in the formation rate of Antarctic Bottom Water (AABW) 
off the Adelie Coast. The model showed that the bottom layer, even in the 
northern most part of the Pacific, will be warmed by 0.005°C within only 50 
years after the abrupt decrease in the bottom water formation. We anticipated 
that our finding on P01 could be traced up to Adelie Coast and that an enormous 
change was occurring in the meridional overturn system in the Pacific. The most 
recent comprehensive analysis using ocean data assimilation including the data 
from WHP-revisits and/or GO-SHIP cruises concluded that the bottom layer 
warming in the Pacific might be traced up to the surface of Adelie Coast and to 
possible changes in the physical parameters of subducted water there.

Of course, JAMSTEC’s contribution to WHP-revisits and/or GO-SHIP cruises has 
brought various scientific advancements not only in the fields of climate 
research but also of biogeochemical study as have been shown in IPCC reports 
and other scientific magazines. All of those results have been strong driving 
forces of our effort toward each cruise and data sharing. However, it is also 
true that we have conducted our observational efforts of WHP-revisits and/or 
GO-SHIP cruises in line with our genuine scientific interest. And….this is the 
reasons why JAMSTEC, a scientific research organization, could have contributed 
so positively to any international frameworks of data acquisition and sharing 
such as GO-SHIP.

Lastly, I would like to thank all scientists for your referring our data book 
as often. As mentioned before, such reference from scientists also proves the 
scientific importance of GO-SHIP and consequently helps JAMSTEC to continue GO-
SHIP activities.

On the memorial day after three years of the Tragic Earthquake and Tsunami


On National Foundation Day
Masao Fukasawa
Operating Executive Director, JAMSTEC


*Acronyum

JAMSTEC  Japan Agency for Marine-Earth Science and Technology
WHP      World Ocean Circulation Experiment Hydrographic Program
GO-SHIP  Global Ocean Ship-Based Hydrographic Investigation Program
IPCC     Inter-governmental Panel for Climate Change


1  Cruise Narrative
     September 30, 2014

     Katsuro Katsumata (JAMSTEC)
     Hiroshi Uchida (JAMSTEC)

1.1  Highlights

Cruise code:              MR12-05

Expocode:                 Leg 1: 49NZ20121105
                          Leg 2: 49NZ20121128
                          Leg 3: 49NZ20130106

WOCE section designation: P14S, S04I

Ship:                     R/V Mirai

Ports of call:            Leg 1: Sekinehama, Japan; Hachinohe, Japan – 
                                 Auckland, New Zealand
                          Leg 2: Auckland, New Zealand – Hobart, Australia
                          Leg 3: Hobart, Australia – Fremantle, Australia

Cruise date:              Leg 1: 5 November 2012 – 26 November 2012
                          Leg 2: 28 November 2012 – 4 January 2013
                          Leg 3: 6 January 2013 – 15 February 2013

Chief scientists:         Legs 1 and 2: Katsuro Katsumata 
                                        (k.katsumata@jamstec.go.jp)
                          Leg 3: Hiroshi Uchida (huchida@jamstec.go.jp)
                          Ocean Climate Change Research Program
                          Research Institute for Global Change (RIGC)
                          Japan Agency for Marine-Earth Science and Technology 
                          (JAMSTEC)
                          2-15 Natsushima, Yokosuka, Kanagawa, Japan 237-0061
                          Fax: +81-46-867-9835

Number of Stations:       Leg 1: 3 stations
                          Leg 2: 54 stations including 6 XCTD-only stations
                          Leg 3: 77 stations

Floats and drifters deployed:
                          3 Argo floats (Leg 1) and 4 Deep NINJA floats (Leg 2)

Mooring recovery:         2 including 1 emergency recovery of Southern Ocean 
                          Flux Buoy
                          (Bureau of Meteorology, Australia)


Figure 1.1.1: MR12-05 cruise track. White circles show the deployment position 
              of Argo floats. White diamonds show neuston net sampling (the 
              northernmost station overlaps the northern most Argo deployment). 
              White large triangles show the XMP deployment stations. Star is 
              the flux-buoy recovery position. Black dots show CTD/bottle 
              sampling stations. Black circles show the Deep NINJA deployment 
              positions (one position overlaps the flux-buoy position). Small 
              white triangle shows Australian SOFS buoy recover position.

Figure 1.1.2: Water sampling positions. Meridional segments on S04I are not 
              included.



1.2  Cruise Summary


(1) Geographic boundaries

MR12-05 cruise (Fig. 1.1.1) re-occupied two WOCE hydrographic sections; P14S 
and S04I. The P14S is a meridional section nominally along 174ºE, between 53ºS 
and 65ºS. The S04I is a zonal section nominally along 62ºS between 33ºE and 
170ºE.


(2) Stations occupied

A total of 152 stations were occupied using a CTD/O2/LADCP package equipped 
with 36 Niskin bottles. The package consists of a SBE911 plus, SBE35, SBE43, 
RINKO, Chlorophyll fluorometer, altimeter, transmissometer,, PAR and an RDI 
ADCP. At 5 stations, two or three casts were made to collect sufficient sample 
for radio-isotope analysis. A total of 7 stations were occupied using XCTD. All 
stations are shown on Fig.1.1.1.


(3) Sampling and measurement

Water samples were analyzed for salinity, oxygen, nutrients, CFC11, CFC12, 
CFC113, SF6, total alkalinity, DIC, pH, density and chlorophyll-a. Staggered 
sampling scheme was employed (see Fig.1.1.2). Samples for radio-isotopes were 
also collected. Underway measurements were conducted along the cruise track for 
pCO2, temperature, salinity, oxygen, surface current, bathymetry and 
meteorological parameters.


(4) Floats and drifters deployed

Three ARGO floats were deployed on the Leg 1. Four Deep NINJA floats were 
launched on the Leg 2.


(5) Mooring deployed and recovered

One mooring at approximate location of 60ºS, 140ºE was recovered successfully. 
An emergency recovery was conducted of SOFS buoy (Bureau of Meteorology, 
Australia) at approximate location of 45.7ºS, 144.6ºE.


1.3  Principle investigators and personnel in charge onboard

The principal investigators (PI) and the persons responsible for major 
parameters are listed in Table 1.3.1.


Table 1.3.1: List of principal investigator and person in charge on the ship.

Item                 Principal Investigator                 Person in charge onboard
------------------   -------------------------------------  -------------------------------------
Underway

Navigation           Data Management Group (CEIST/JAMSTEC)  Souichiro Sueyoshi (GODI) (legs 1, 3)
                     dmo@jamstec.go.jp                      Kazuho Yoshida (GODI) (leg 2)
                     
Bathymetry           Takeshi Matsumoto (Univ. of Ryukyus)   Souichiro Sueyoshi (GODI) (legs 1, 3)
                     tak@sci.u-ryukyu.ac.jp                 Kazuho Yoshida (GODI) (leg 2)
                      
Meteorology          Data Management Group (CEIST/JAMSTEC)  Souichiro Sueyoshi (GODI) (legs 1, 3)
                     dmo@jamstec.go.jp                      Kazuho Yoshida (GODI) (leg 2)
                     
Thermo-salinograph   Hiroshi Uchida (JAMSTEC)               Kanako Yoshida (MWJ) (legs 1, 3)
                     huchida@jamtec.go.jp                   Misato Kuwahara (MWJ) (leg 2)

pCO2                 Akihiko Murata (JAMSTEC)               Yoshiko Ishikawa (MWJ)
                     murataa@jamstec.go.jp

pCO2/pCH4 by Cavity  Ring-Down Spectroscopy    
                     Sohiko Kameyama (Hokkaido Univ.)       Sohiko Kameyama (Hokkaido Univ.)
                     skameyama@ees.hokkaido.ac.jp

ADCP                 Shinya Kouketsu (JAMSTEC)              Souichiro Sueyoshi (GODI) (legs 1, 3)
                     skouketsu@jamstec.go.jp                Kazuho Yoshida (GODI) (leg 2)

Ceilometer           Data Management Group (CEIST/JAMSTEC)  Souichiro Sueyoshi (GODI) (legs 1, 3)
                     dmo@jamstec.go.jp                      Kazuho Yoshida (GODI) (leg 2)
                    
Water Isotopes       Yasushi Fujiyoshi (Hokkaido Univ.)     Souichiro Sueyoshi (GODI)
                     
                     fujiyo@lowtem.hokudai.ac.jp

Sky Radiometer       Kazuma Aoki (Univ. of Toyama)          None
                     kazuma@sci.u-toyama.ac.jp

Lidar                Nobuo Sugimoto (NIES)                  None
                     nsugimot@nies.go.jp

Gravity              Takeshi Matsumoto (Univ. of Ryukyus)   Souichiro Sueyoshi (GODI) (legs 1, 3)
                     tak@sci.u-ryukyu.ac.jp                 Kazuho Yoshida (GODI) (leg 2)
                      
Magnetic Field       Takeshi Matsumoto (Univ. of Ryukyus)   Souichiro Sueyoshi (GODI) (legs 1, 3)
                     tak@sci.u-ryukyu.ac.jp                 Kazuho Yoshida (GODI) (leg 2)
                      
Cesium magnetometer  Masao Nakanishi (Chiba Univ.)          Souichiro Sueyoshi (GODI)
                     nakanisi@earth.s.chiba-u.ac.jp

Photosynthetically Available Radiation
                     Hiroshi Uchida (JAMSTEC)               Hiroshi Uchida (JAMSTEC)
                     huchida@jamstec.go.jp

XCTD                 Hiroshi Uchida (JAMSTEC)               Souichiro Sueyoshi (GODI) (Legs 1, 3)
                     huchida@jamstec.go.jp                  Kazuho Yoshida (GODI) (Leg 2)


Hydrography

CTD/O2               Hiroshi Uchida (JAMSTEC)               Shinsuke Toyoda (MWJ)
                     huchida@jamstec.go.jp

Salinity             Hiroshi Uchida (JAMSTEC)               Tatsuya Tanaka (MWJ)
                     huchida@jamstec.go.jp

Density              Hiroshi Uchida (JAMSTEC)               Hiroshi Uchida (JAMSTEC)
                     huchida@jamstec.go.jp

Oxygen               Yuichiro Kumamoto (JAMSTEC)            Misato Kuwahara (MWJ) (leg 2)
                     kumamoto@jamstec.go.jp                 Kanako Yoshida (MWJ) (leg 3)
                      

Nutrients            Michio Aoyama (Fukushima Univ.)        Minoru Kamata (MWJ)
                     r706@ipc.fukushima-u.ac.jp

CFCs/SF6             Ken’ichi Sasaki (JAMSTEC)              Ken’ichi Sasaki (JAMSTEC)
                     ksasaki@jamstec.go.jp

DIC Akihiko          Murata (JAMSTEC)                       Yoshiko Ishikawa (MWJ)
                     murataa@jamstec.go.jp

Alkalinity           Akihiko Murata (JAMSTEC)               Tomonori Watai (MWJ)
                     murataa@jamstec.go.jp

pH                   Akihiko Murata (JAMSTEC)               Tomonori Watai (MWJ)
                     murataa@jamstec.go.jp

DMS and Isoprene     Sohiko Kameyama (Hokkaido Univ.)       Sohiko Kameyama (Hokkaido Univ.)
                     skameyama@ees.hokkaido.ac.jp

Chlorophyll-a        Hiroshi Uchida (JAMSTEC)               Hiroshi Uchida (JAMSTEC)
                     huchida@jamstec.go.jp

Chlorophyll isotopes
                     Osamu Yoshida                          Osamu Yoshida (Rakuno Gakuen Univ.)
                     (Rakuno Gakuen Univ.)                  yoshida@rakuno.ac.jp

Pigment/Bacterial abundance
                     Sohiko Kameyama (Hokkaido Univ.)       Sohiko Kameyama (Hokkaido Univ.)
                     skameyama@ees.hokudai.ac.jp

Δ14C/δ13C            Yuichiro Kumamoto (JAMSTEC)            Yuichiro Kumamoto (JAMSTEC)
                     kumamoto@jamstec.go.jp

134Cs/137Cs          Yuichiro Kumamoto (JAMSTEC)            Yuichiro Kumamoto (JAMSTEC) 
                     kumamoto@jamstec.go.jp

δ18O                 Shigeru Aoki (Hokkaido Univ.)          Katsuro Katsumata (JAMSTEC) (leg 2)
                     shigeru@lowtem.hokudai.ac.jp           Kazuhiko Hayashi (JAMSTEC) (leg 3)

PFAS                 Nobuyoshi Yamashita (AIST)             Nobuyoshi Yamashita (AIST) (leg 2)
                     nob.yamashita@aist.go.jp               Hiroshi Uchida (JAMSTEC) (leg 3)

N2O/CH4              Osamu Yoshida (Rakuno Gakuen Univ.)    Osamu Yoshida (Rakuno Gakuen Univ.)
                     yoshida@rakuno.ac.jp

LADCP                Shinya Kouketsu (JAMSTEC)              Shinya Kouketsu (JAMSTEC) (leg 2)
                     skouketsu@jamstec.go.jp                Hiroshi Uchida (JAMSTEC) (leg 3)

XMP                  Katsuro Katsumata (JAMSTEC)            Katsuro Katsumata (JAMSTEC)
                     k.katsumata@jamstec.go.jp


Biology

Oceanic Halobates    Tetsuo Harada (Kochi Univ.)            Tetsuo Harada (Kochi Univ.)
                     haratets@kochi-u.ac.jp

Floats

ARGO/Deep NINJA floats
                     Toshio Suga (JAMSTEC)                  Tetsuya Tanaka (MWJ) (leg 1)
                     sugat@jamstec.go.jp                    Tomoyuki Takamori (MWJ) (leg 2)

Mooring

Southern Ocean Flux Mooring
                     Shoichiro Baba (JAMSTEC)               Shoichiro Baba (JAMSTC)
                     sbaba@jamstec.go.jp

—————————————————————————————————————————————————————————————————————————————————————————————————
    CEIST    Center for Earth Information Science and Technology
    GODI     Global Ocean Development Inc.
    JAMSTEC  Japan Agency for Marine-Earth Science and Technology
    MWJ      Marine Works Japan, Ltd.
    NIES     National Institute for Environmental Studies
    AIST     National Institute of Advanced Industrial Science and Technology



1.4  Scientific programme and methods


(1) Objectives

It is well established that oceans play important roles in the global climate 
system, but quantitative description of the oceans’ roles and their 
variabilities are still yet to be made. Given natural variabilities of the 
oceans, it is necessary to observe them as frequently as practicable and as 
accurate as possible. In this research cruise, we observed, with state-of-art 
precision, the Southwestern Pacific and Southern oceans, which are known to be 
one of the most sensitive regions in the world oceans to the global climate 
change, particularly as a likely source of the recently-established Pacific 
near-bottom warming. These oceans are also known to ventilate the intermediate-
depth and deep oceans and exchange anthropogenic carbon. We also recovered a 
JAMSTEC southern ocean mooring, which continuously measured the air-sea flux in 
this region for almost a year for the first time. This expedition was conducted 
under the Global Ocean Ship-based Hydrographic Investigation Programme (GO-SHIP 
http://www.go-ship.org).


(2) Cruise narrative

The first leg was a shift from R/V Mirai’s home – Sekinehama – to the Southern 
Hemisphere, although some observational activities were conducted including 
Argo float deployments and concurrent CTD casts for salinity calibration as 
well as hull pump water sampling for radio-isotope analysis after the 3.11 
disaster in 2011 of the Japanese nuclear powerplant.

Most of the scientists and technicians joined the cruise at Auckland. It was 
anticipated some days might be lost in Roaring Fourties and Furious Fifties, 
but Mirai managed to steam through a narrow gap in the low pressure systems 
with 27 successful CTD and sampling casts. More serious problem was posed by 
sea ice. This leg of the expedition was initially planned to a much later 
season, but with logistic reasons we had to move up the schedule. With recent 
trend of ice area increase in and near the Ross Sea, the southern stations were 
unapproachable. We decided to skip stations in this region and to extend the 
S04I leg further to the west rather than spending ship-time wading through the 
icebergs. See the next section for detail. One of the big events in Leg 2 was a 
recovery of the JAMSTEC buoy which had been measuring the air-sea interaction 
for nearly 11 months. The window of best weather was sought on weather charts 
and a two-day window was found between 18th and 20th of December. The recovery 
was successful. After a CTD cast and a float deployment, reoccupation of S04I 
was resumed. The ice condition did not show much improvement and we had to cut 
short this leg to head to Hobart. The extra time was used to reoccupy southern 
3 stations of the WOCE I09S section since its 2012 occupation did not have CFC 
sampling. On the way back to Hobart, a buoy was recovered that had broken 
loose.

Two days of resupply and six-day steaming (one way) gives almost 2 weeks 
between legs 2 and 3. During this period, sea ice condition was much improved 
and icebergs were not as much threat as were in leg 2. Weather was very kind in 
leg 3, although there were some casts under rough conditions (e.g., stations 
112 to 115). We covered all stations as planned in this leg with successful 
sampling. The leg was completed after 13 days of steaming back to Australia, 
which gave us a plenty of time for packing and celebrating.

 

1.5 Major problems and goal not achieved


(1) Stations not occupied, position changed, not close to previous occupations

For the P14S reoccupation, data were not disclosed north of 55ºS due to JAMSTEC 
in-house problem with cruise documentation. It was our intention to cover the 
P14S section to the southern most station at 66ºS, but due to ice cover, 
southernmost 2 stations (south of 65ºS) were not occupied. Our plan was to 
connect to the stations of WOCE S04P cruise (90KDIOFFE6_1) and work westward on 
the WOCE S04/S03 stations (09AR9404_1). To keep a safe distance to the ice 
edge, we had to place new stations (our station number 402, 404, 406, 408, 410) 
along 64ºS and hastened with station distance of about 75 miles interpolated by 
XCTD casts in-between to re-connect to the WOCE S04 station (our station 50). 
After meeting the WOCE stations, however, fickle movements of the ice edge and 
icebergs kept us away from some of the WOCE location. Most of the stations, we 
managed to measure within 1 mile, but some stations (e.g. our station 70 to 
WOCE S04 station 28) were more than 3 miles away. Ice condition was much 
improved for leg 3 and all stations were located close to the WOCE stations.


(2) Misfiring and mistrip of water sampling

None.


(3) Time lost

At station 56, about half an hour during the cast and about 4 hours after the 
cast were lost due to mechanical trouble with the CTD winch. At station 139, 
CTD data from the first cast was noisy and the cast was repeated – 
approximately 45 minutes were lost. Similarly casts were re-started at station 
143 and 165 and a total of approximately 40 minutes were lost. Weather 
condition had been kind to us. We only lost about 12 hours before the first 
cast of Leg 2 and about 1 hour between stations 11 and 12 due to bad weather.


1.6  Cruise Participants

List of Participants for leg 1
——————————————————————————————————————————————————————————————————————————
Katsuro Katsumata     Chief scientist                     RIGC/JAMSTEC
Yuichiro Kumamoto     C14                                 RIGC/JAMSTEC
Hiroshi Uchida        Thermosalinograph/chlorophyll-a     RIGC/JAMSTEC
Tetsuo Harada         Halobates                           Kochi University
Ryuta Ide             Halobates                           Kochi University
Takero Sekimoto       Halobates                           Kochi University
Kentaro Emi           Halobates                           Kochi University
Tomonori Watai        Chief technician/carbon items       MWJ
                      preparation
Tatsuya Tanaka        CTD/Float                           MWJ
Makoto Takada         Carbon items preparation            MWJ
Shinsuke Toyoda       CTD                                 MWJ
Katsunori Sagishima   CFCs preparation                    MWJ
Hironori Sato         CFCs preparation                    MWJ
Kanako Yoshida        Thermosalinograph                   MWJ
Emi Deguchi           Carbon items preparation            MWJ
Souichiro Sueyoshi    Chief technician/meteorology/       GODI
                      geophysics/ADCP
Koichi Inagaki        Meteorology/geophysics/ADCP         GODI


List of Participants for leg 2
——————————————————————————————————————————————————————————————————————————
Katsuro Katsumata     Chief scientist/XMP/water sampling  RIGC/JAMSTEC
Yuichiro Kumamoto     DO/thermosalinograph /Δ14C          RIGC/JAMSTEC
Hiroshi Uchida        LADCP/density/chlorophyll-a         RIGC/JAMSTEC
Shinya Kouketsu       LADCP/ADCP/water sampling           RIGC/JAMSTEC
Kazuhiko Hayashi      Water sampling                      RIGC/JAMSTEC
Ken’ichi Sasaki       CFCs                                MIO/JAMSTEC
Shoichiro Baba        Mooring/water sampling              MARITEC/JAMSTEC
Takero Sekimoto       Halobates/water sampling            Kochi University
Nobuyoshi Yamashita   PFASs/water sampling                AIST
Eriko Yamazaki        PFASs/water sampling                AIST
Sohiko Kameyama       DMS/isoprene/water sampling         Hokkaido University
Tomohide Noguchi      Chief technician/mooring/water      MWJ
                      sampling
Tomonori Watai        pH/total alkalinity                 MWJ
Tatsuya Tanaka        Salinity/mooring                    MWJ
Shinsuke Toyoda       CTD/mooring/water sampling          MWJ
Atsushi Ono           DIC                                 MWJ
Emi Deguchi           pH/total alkalinity                 MWJ
Shungo Oshitani       CTD/mooring/water sampling          MWJ
Tomoyuki Takamori     CTD/mooring/water sampling          MWJ
Rei Ito               CTD/mooring/water sampling          MWJ
Minoru Kamata         Nutrients                           MWJ
Yoshiko Ishikawa      DIC                                 MWJ
Yasuhiro Arii         Nutrients                           MWJ
Hideki Yamamoto       CFCs                                MWJ
Shoko Tatamisashi     CFCs                                MWJ
Misato Kuwahara       DO/thermosalinograph                MWJ
Masahiro Orui         CFCs                                MWJ
Keitaro Matsumoto     DO/mooring/water sampling           MWJ
Keisuke Tsubata       Salinity                            MWJ
Takuhiro Osumi        DO                                  MWJ
Kohei Miura           Nutrients                           MWJ
Yuki Komuro           Water sampling                      MWJ
Takehiro Shibuya      Water sampling                      MWJ
Saeko Kumagai         Water sampling                      MWJ
Mizuho Yasui          Water sampling                      MWJ
Hitomi Takahashi      Water sampling                      MWJ
Ai Ozaki              Water sampling                      MWJ
Kazuho Yoshida        Chief technician/meterology/        GODI
                      geophysics/ADCP/XCTD
Shinya Okumura        Meteorlology/geophysics/ADCP/XCTD   GODI
Masanori Murakami     Meteorology/geophysics/ADCP/XCTD    GODI


List of Participants for leg 3
——————————————————————————————————————————————————————————————————————————————————
Hiroshi Uchida        Chief scientist/LADCP/density/      RIGC/JAMSTEC
                      chlorophyll-a
Akihiko Murata        Carbon items/water sampling         RIGC/JAMSTEC
Toshimasa Doi         LADCP/water sampling                RIGC/JAMSTEC
Kazuhiko Hayashi      Water sampling                      RIGC/JAMSTEC
Ken’ichi Sasaki       CFCs                                MIO / JAMSTEC
Osamu Yoshida         CH4 and N2O/water sampling          Rakuno Gakuen University
Haruka Tamada         CH4 and N2O/water sampling          Rakuno Gakuen University
Yuko Kanayama         CH4 and N2O/water sampling          Rakuno Gakuen University
Okura Shinozaki       CH4 and N2O/water sampling          Rakuno Gakuen University
Sohiko Kameyama       DMS/isoprene/water sampling         Hokkaido University
Hideki Yamamoto       Chief technician/water sampling     MWJ
Tomonori Watai        pH/total alkalinity                 MWJ
Minoru Kamata         Nutrients                           MWJ
Yoshiko Ishikawa      DIC                                 MWJ
Misato Kuwahara       DO/thermosalinograph/watersampling  MWJ
Masahiro Orui         CFCs                                MWJ
Satoshi Ozawa         CTD/water sampling                  MWJ
Tamami Ueno           Salinity                            MWJ
Hiroshi Matsunaga     CTD/water sampling                  MWJ
Naoko Miyamoto        CTD/water sampling                  MWJ
Hiroki Ushiromura     Salinity                            MWJ
Takami Mori           CTD/water sampling                  MWJ
Masanori Enoki        Nutrients                           MWJ
Atsushi Ono           pH/total alkalinity                 MWJ
Elena Hayashi         Nutrients                           MWJ
Kanako Yoshida        DO                                  MWJ
Katsunori Sagishima   CFCs                                MWJ
Hironori Sato         CFCs                                MWJ
Keisuke Tsubata       DIC                                 MWJ
Takuhiro Osumi        DO/water sampling                   MWJ
Aiko Miura            Water sampling                      MWJ
Manami Kamei          Water sampling                      MWJ
Sachi Miyake          Water sampling                      MWJ
Yuta Furukawa         Water sampling                      MWJ
Iori Fujiwara         Water sampling                      MWJ
Yuki Kawabuchi        Water sampling                      MWJ
Souichiro Sueyoshi    Chief technician/meteorology/       GODI
                      geophysics/ADCP/XCTD
Katsuhisa Maeno       Meteorology/geophysics/ADCP/XCTD    GODI
Koichi Inagaki        Meteorology/geophysics/ADCP/XCTD    GODI


AIST     National Institute of Advanced Industrial Science and Technology
GODI     Global Ocean Development Inc.
JAMSTEC  Japan Agency for Marine-Earth Science and Technology
MARITEC  Marine Technology and Engineering Center
MIO      Mutsu Institute of Oceanography
MWJ      Marine Works Japan Ltd.
RIGC     Research Institute for Global Change
















2  Underway Measurements

2.1  Navigation

(1) Personnel

            Souichiro Sueyoshi  (GODI)         -leg1, leg3-
            Koichi Inagaki      (GODI)         -leg1, leg3-
            Kazuho Yoshida      (GODI)         -leg2-
            Shinya Okumura      (GODI)         -leg2-
            Masanori Murakami   (GODI)         -leg2-
            Katsuhisa Maeno     (GODI)         -leg3-
            Ryo Kimura          (MIRAI Crew)   -leg1, leg2-
            Ryo Ohyama          (MIRAI Crew)   -leg3-


(2) System description

Ship’s position and velocity were provided by Radio Navigation System on R/V 
Mirai. This system integrates GPS position, log speed, gyro compass heading and 
other basic data for navigation, and calculated speed/course over ground on 
workstation. Radio navigation System also distributed ship’s standard time 
synchronized to GPS time server via Network Time Protocol. These data were 
logged on the network server as “SOJ” data every 5 seconds.

Sensors for navigation data are listed below;

    i) GPS system:      MultiFix6 (software version 1.01), Differential GPS system.
                        Receiver: Trimble SPS751, with two GPS antennas located on 
                                  navigation deck, starboard side and port side, 
                                  manually switched as to GPS receiving state and 
                                  offset to radar-mast position, datum point.
                        Decoder:  Fugro STARFIX 4100LR
   ii) Doppler log:     Furuno DS-30, which use three acoustic beam for current 
                                  measurement under the hull.
  iii) Gyrocompass:     Tokimec TG-6000, sperry type mechanical gyrocompass.
   iv) GPS time server: SEIKO TS-2540 Time Server, synchronizing to GPS 
                        satellite every 1 second.


(3) Data period (Times in UTC)

         Leg1: 07:00, 05 Nov. 2012 - 20:30, 25 Nov. 2012
         Leg2: 21:10, 27 Nov. 2012 - 23:20, 03 Jan. 2013
         Leg3: 22:50, 05 Jan. 2013 - 06:23, 15 Feb. 2013


(4) Remarks (Times in UTC)

    i) The following periods, navigation data was invalid due to the system error.
       23:25:05, 22 Nov. 2012
       23:30:40, 22 Nov. 2012 - 23:36:30, 22 Nov. 2012
       23:38:15, 22 Nov. 2012 - 23:38:30, 22 Nov. 2012
       23:38:40, 22 Nov. 2012 - 23:38:55, 22 Nov. 2012
       23:39:05, 22 Nov. 2012
       18:07:50, 04 Dec. 2012
       15:26:05, 05 Dec. 2012
       21:32:10, 07 Dec. 2012
       18:01:50, 09 Dec. 2012
       15:33:50, 10 Dec. 2012
       15:16:20, 15 Dec. 2012
       16:07:00, 16 Dec. 2012
       16:07:05, 16 Dec. 2012
       20:50:55, 20 Dec. 2012

   ii) The following periods, navigation data was invalid due to GPS position 
       fix error.
       12:14:15, 22 Dec. 2012
       12:15:45, 22 Dec. 2012
       11:47:40, 28 Dec. 2012 - 11:52:40, 28 Dec. 2012
       12:39:25, 28 Dec. 2012 - 12:41:55, 28 Dec. 2012


Figure 2.1.1: Cruise Track of MR12-05 Leg 1.

Figure 2.1.2: Cruise Track of MR12-05 Leg 2.

Figure 2.1.3: Cruise Track of MR12-05 Leg 3.


2.2  Swath Bathymetry

(1) Personnel
        Takeshi Matsumoto    (University of      Principal investigator 
                              the Ryukyus):      (not on-board)
        Masao Nakanishi      (Chiba University): Principal investigator 
                                                 (not on-board)
        Souichiro Sueyoshi   (GODI)              -leg1, leg3-
        Koichi Inagaki       (GODI)              -leg1, leg3-
        Kazuho Yoshida       (GODI)              -leg2-
        Shinya Okumura       (GODI)              -leg2-
        Masanori Murakami    (GODI)              -leg2-
        Katsuhisa Maeno      (GODI)              -leg3-
        Ryo Kimura           (MIRAI Crew)        -leg1, leg2-
        Ryo Ohyama           (MIRAI Crew)        -leg3-


(2) Introduction

R/V MIRAI is equipped with a Multi narrow Beam Echo Sounding system (MBES), 
SEABEAM 3012 Upgraded Model (L3 Communications ELAC Nautik). The objective of 
MBES is collecting continuous bathymetric data along ship’s track to make a 
contribution to geological and geophysical investigations and global datasets.


(3) Data Acquisition

The “SEABEAM 3012 Upgrade Model” on R/V MIRAI was used for bathymetry mapping 
during the MR12-05 cruise from 5th November 2012 to 15th February 2013. To get 
accurate sound velocity of water column for ray-path correction of acoustic 
multibeam, we used Surface Sound Velocimeter (SSV) data to get the sea surface 
sound velocity (at 6.62m), and the deeper depth sound velocity profiles were 
calculated by temperature and salinity profiles from CTD and XCTD data by the 
equation in Del Grosso (1974) during this cruise.

Table 2.2.1 shows system configuration and performance of SEABEAM 3012Upgraded 
Model.


Table 2.2.1: System configuration and performance.

SEABEAM 3012 (12 kHz system)
———————————————————————————————————————————————————————————————————————————————
Frequency:              12 kHz
Transmit beam width:    1.6 degree
Transmit power:         20 kW
Transmit pulse length:  2 to 20 msec.
Receive beam width:     1.8 degree
Depth range:            100 to 11,000 m
Beam spacing:           0.5 degree athwart ship
Swath width:            150 degree (max)
                        120 degree to 4,500 m
                        100 degree to 6,000 m
                        90 degree to 11,000 m
Depth accuracy:         Within < 0.5% of depth or +/-1m, whichever is greater, 
                        over the entire swath. (Nadir beam has greater 
                        accuracy; typically within < 0.2% of depth or +/-1m, 
                        whichever is greater)


(4) Data processing

 i. Sound velocity correction

Each bathymetry data was corrected with a sound velocity profile calculated 
from the nearest CTD or XCTD data in the distance. The equation of Del Grosso 
(1974) was used for calculating sound velocity. The data correction was carried 
out using the HIPS software version 7.1 (CARIS, Canada).

ii. Editing and Gridding

Gridding for the bathymetry data were carried out using the HIPS. Firstly, the 
bathymetry data during ship’s turning was basically deleted, and spike noise of 
each swath data was removed. Then the bathymetry data was gridded by 
“Interpolate” function of the software with the parameters shown as Table 
2.2.2. Finally, interpolated data were exported as ASCII data, and converted to 
150m grid data using “xyz2grd” utility of GMT (Generic Mapping Tool) software.


Table 2.2.2: Parameters for interpolate of bathymetry data.

             BASE surface resolution:                      50m
             Interpolate matrix size:                      5 x 5
             Minimum number of neighbors for interpolate:  10



(5) Data Archives

Bathymetric data obtained during this cruise will be submitted to the Data 
Management Group (DMG) of JAMSTEC, and will be archived there.


(6) Remarks (Times in UTC)

1) The following periods, the observation was carried out.
          Leg1: 14:24, 06 Nov. 2012 - 13:05, 16 Nov. 2012
                04:28, 17 Nov. 2012 - 07:00, 25 Nov. 2012
          Leg2: 08:15, 28 Nov. 2012 - 07:00, 01 Jan. 2013
          Leg3: 02:35,  6 Jan. 2013 - 12:06, 13 Feb 2013.

2) The following periods, data acquisition was suspended due to the system 
   error and maintenance.
                12:22 - 13:12, 11 Dec. 2012
                07:12 - 09:02, 12 Dec. 2012
                08:06 - 08:31, 23 Jan. 2013

3) The following periods, navigation data was invalid due to GPS position fix 
   error.
                23:30:30 - 23:39:05, 22 Nov. 2012 (intermittently)
                11:47:37 - 11:52:42, 28 Dec. 2012
                12:39:23 - 12:41:55, 28 Dec. 2012



2.3  Surface Meteorological Observations


(1) Personnel
        Souichiro Sueyoshi   (GODI)              -leg1, leg3-
        Koichi Inagaki       (GODI)              -leg1, leg3-
        Kazuho Yoshida       (GODI)              -leg2-
        Shinya Okumura       (GODI)              -leg2-
        Masanori Murakami    (GODI)              -leg2-
        Katsuhisa Maeno      (GODI)              -leg3-
        Ryo Kimura           (MIRAI Crew)        -leg1, leg2-
        Ryo Ohyama           (MIRAI Crew)        -leg3-


(2) Objectives

Surface meteorological parameters are observed as a basic dataset of the 
meteorology. These parameters provide the temporal variation of the 
meteorological condition surrounding the ship.


(3) Methods

Surface meteorological parameters were observed during the MR12-05 cruise from 
5th November 2012 to 15th February 2013. In this cruise, we used two systems 
for the observation.

  i. MIRAI Surface Meteorological observation (SMet) system

     Instruments of SMet system are listed in Table 2.3.1 and measured 
     parameters are listed in Table 2.3.2. Data were collected and processed by 
     KOAC-7800 weather data processor made by Koshin-Denki, Japan. The data set 
     consists of 6-second averaged data.

 ii. Shipboard Oceanographic and Atmospheric Radiation (SOAR) measurement 
     system 

     SOAR system designed by BNL (Brookhaven National Laboratory, USA) 
     consists of major three parts.

     a) Portable Radiation Package (PRP) designed by BNL – short and long wave 
        downward radiation.

     b) Zeno Meteorological (Zeno/Met) system designed by BNL – wind, air 
        temperature, relative humidity, pressure, and rainfall measurement.

     c) Scientific Computer System (SCS) developed by NOAA (National Oceanic 
        and Atmospheric Administration, USA) – centralized data acquisition and 
        logging of all data sets.

SCS recorded PRP data every 6 seconds, Zeno/Met data every 10 seconds. 
Instruments and their locations are listed in Table 2.3.3 and measured 
parameters are listed in Table 2.3.4.

For the quality control as post processing, we checked the following sensors, 
before and after the cruise.

  i. Young Rain gauge (SMet and SOAR)

     Inspect of the linearity of output value from the rain gauge sensor to 
     change Input value by adding fixed quantity of test water.

 ii. Barometer (SMet and SOAR)

     Comparison with the portable barometer value, PTB220, VAISALA

iii. Thermometer (air temperature and relative humidity) ( SMet and SOAR )

     Comparison with the portable thermometer value, HMP41/45, VAISALA


(4) Preliminary results

Figs. 2.3.1, 2.3.2, and 2.3.3 show the time series of the following parameters;

     Wind (SMet)
     Air temperature (SMet)
     Relative humidity (SOAR)
     Precipitation (SOAR, rain gauge)
     Short/long wave radiation (SOAR)
     Pressure (SMet)
     Sea surface temperature (SMet)
     Significant wave height (SMet)


(5) Data archives

These meteorological data will be submitted to the Data Management Group (DMG) 
of JAMSTEC just after the cruise.


(6) Remarks (Times in UTC)

1) The following periods, observation was carried out.
      Leg1: 00:00, 05 Nov. 2012 to 15:00, 16 Nov. 2012
            03:00, 17 Nov. 2012 to 07:00, 25 Nov. 2012
      Leg2: 06:00, 28 Nov. 2012 to 07:00, 01 Jan. 2013
      Leg3: 02:00, 07 Jan. 2013 to 12:00, 13. Feb 2013
2) The following periods, navigation data of SMet data was invalid due to GPS 
   position fix error.
      Leg1: 23:30 - 23:39, 22 Nov. 2012 (intermittently)
      Leg2:  2:21, 18 Dec. 2012
            11:47 to 11:51, 28 Dec. 2012
            12:39 to 12:41, 28 Dec. 2012
3) The following periods, FRSR data acquisition was suspended to prevent damage 
   to the shadow-band from freezing.
      Leg2: 08:01, 08 Dec. 2012 to 20:45, 28 Dec. 2012
      Leg3: 19:20, 12 Jan. 2013 to 10:21, 08 Feb. 2013
4) The following time, SMet rain gauge amount values were increased because of 
   test transmitting for MF/HF radio.
      Leg1: 23:01 - 23:16, 11 Nov. 2012
      Leg2: 08:54, 06 Dec. 2012
            00:35, 18 Dec. 2012
            22:41, 25 Dec. 2012
      Leg3: 06:15, 24 Jan. 2013
            01:25, 13 Feb. 2013


Table 2.3.1: Instruments and installation locations of MIRAI Surface 
             Meteorological observation system.

Sensors                  Type       Manufacturer          Location (altitude from surface)
-----------------------  ---------  --------------------  --------------------------------
Anemometer               KE-500     Koshin Denki, Japan   foremast (24 m)
Tair/RH                  HMP45A     Vaisala, Finland
with 43408 Gill aspi-               R.M. Young, USA       compass deck (21 m)
rated radiation shield                                    starboard side and port side
Thermometer: SST         RFN1-0     Koshin Denki, Japan   4th deck (-1m, inlet -5m)
Barometer                Model-370  Setra System, USA     captain deck (13 m)
                                                          weather observation room
Rain gauge               50202      R. M. Young, USA      compass deck (19 m)
Optical rain gauge       ORG-815DR  Osi, USA              compass deck (19 m)
Radiometer (short wave)  MS-802     Eko Seiki, Japan      radar mast (28 m)
Radiometer (long wave)   MS-202     Eko Seiki, Japan      radar mast (28 m)
Wave height meter        WM-2       Tsurumi-seiki, Japan  bow (10 m)



Table 2.3.2: Parameters of MIRAI Surface Meteorological observation system.

Parameter                                 Units   Remarks
----------------------------------------  ------  -----------------------------
 1 Latitude                               degree
 2 Longitude                              degree
 3 Ship’s speed                           knot    Mirai log, DS-30 Furuno
 4 Ship’s heading                         degree  Mirai gyro, TG-6000, Tokimec
 5 Relative wind speed                    m/s     6sec./10min. averaged
 6 Relative wind direction                degree  6sec./10min. averaged
 7 True wind speed                        m/s     6sec./10min. averaged
 8 True wind direction                    degree  6sec./10min. averaged
 9 Barometric pressure hPa                        adjusted to sea surface level
                                                  6sec. averaged
10 Air temperature (starboard side)       degC    6sec. averaged
11 Air temperature (port side)            degC    6sec. averaged
12 Dewpoint temperature (starboard side)  degC    6sec. averaged
13 Dewpoint temperature (port side)       degC    6sec. averaged
14 Relative humidity (starboard side)             6sec. averaged
15 Relative humidity (port side)                  6sec. averaged
16 Sea surface temperature                degC    6sec. averaged
17 Rain rate (optical rain gauge)         mm/hr   hourly accumulation
18 Rain rate (capacitive rain gauge)      mm/hr   hourly accumulation
19 Down welling shortwave radiation       W/m2    6sec. averaged
20 Down welling infra-red radiation       W/m2    6sec. averaged
21 Significant wave height (bow)          m       hourly
22 Significant wave height (aft)          m       hourly
23 Significant wave period (bow)          second  hourly
24 Significant wave period (aft)          second  hourly


Table 2.3.3: Instruments and installation locations of SOAR system.

Sensors                  Type        Manufacturer     Location 
                                                      (altitude from surface)
-----------------------  ----------  ---------------  -----------------------
Zeno/Met
Anemometer               05106       R.M. Young, USA  foremast (25 m)
Tair/RH                  HMP45A      Vaisala, Finland
with 43408 Gill aspi-                R.M. Young, USA  foremast (23 m)
rated radiation shield 
Barometer                61302V      R.M. Young, USA
with 61002 Gill pressure port        R.M. Young, USA  foremast (23 m)
Rain gauge               50202       R.M. Young, USA  foremast (24 m)
Optical rain gauge       ORG-815DA   Osi, USA         foremast (24 m)

PRP
Radiometer (short wave)  PSP         Epply Labs, USA  foremast (25 m)
Radiometer (long wave)   PIR         Epply Labs, USA  foremast (25 m)
Fast rotating shadowband radiometer  Yankee, USA      foremast (25 m)


Table 2.3.4: Parameters of SOAR system.

Parameter                                 Units   Remarks
----------------------------------------  ------  --------------
1 Latitude                                degree  
2 Longitude                               degree
3 SOG                                     knot
4 COG                                     degree
5 Relative wind speed                     m/s
6 Relative wind direction                 degree
7 Barometric pressure                     hPa
8 Air temperature                         degC
9 Relative humidity                       
10 Rain rate (optical rain gauge)         mm/hr
11 Precipitation (capacitive rain gauge)  mm      reset at 50 mm
12 Down welling shortwave radiation       W/m2
13 Down welling infra-red radiation       W/m2
14 Defuse irradiance                      W/m2


Figure 2.3.1: Time series of surface meteorological parameters during the 
              MR12-05 leg1 cruise.

Figure 2.3.2: Time series of surface meteorological parameters during the 
              MR12-05 leg2 cruise.

Figure 2.3.3: Time series of surface meteorological parameters during the 
              MR12-05 leg3 cruise.


2.4  Thermo-Salinograph and Related Measurements
     October 8, 2014

(1) Personnel
       Hiroshi Uchida (JAMSTEC)
       Kanako Yoshida (MWJ) (Legs 1, 3)
       Misato Kuwahara (MWJ) (Legs 2, 3)
       Keitaro Matsumoto (MWJ) (Leg 2)

(2) Objectives

The objective is to collect sea surface salinity, temperature, dissolved 
oxygen, and fluorescence data continuously along the cruise track.

(3) Materials and methods

The Continuous Sea Surface Water Monitoring System (Marine Works Japan Co, 
Ltd.) has six sensors and automatically measures salinity, temperature, 
dissolved oxygen, and fluorescence in sea surface water every one minute. This 
system is located in the sea surface monitoring laboratory and connected to 
shipboard LAN system. Measured data along with time and location of the ship 
were displayed on a monitor and stored in a desktop computer. The sea surface 
water was continuously pumped up to the laboratory from about 5 m water depth 
and flowed into the system through a vinyl-chloride pipe. The flow rate of the 
surface seawater was controlled to be 1.2 L/min.

Software and sensors used in this system are listed below.

 i. Software
    Seamoni-kun Ver.1.30

ii. Sensors
    Temperature and conductivity sensor
       Model: SBE-45, SEA-BIRD ELECTRONICS, INC.
       Serial number: 4563325-0362
    Bottom of ship thermometer
       Model: SBE 38, SEA-BIRD ELECTRONICS, INC.
       Serial number: 3857820-0540
    Dissolved oxygen sensors
       Model: OPTODE 3835, Aanderaa Data Instruments, AS.
       Serial number: 985
       Model: RINKO-II, JFE Advantech Co. Ltd.
       Serial number: 0013
    Fluorometer
       Model: C3, TURNER DESIGNS
       Serial number: 2300123

(4) Data Processing and Quality Control

Data from the Continuous Sea Surface Water Monitoring System were processed as 
follows. Data gaps were linearly interpolated when the gap was ≤ 7 minutes. 
Spikes in the temperature and salinity data were removed using a median filter 
with a window of 3 scans (3 minutes) when difference between the original data 
and the median filtered data was larger than 0.1 ºC for temperature and 0.5 for 
salinity. Fluorometer data were low-pass filtered using a median filter with a 
window of 3 scans (3 minutes) to remove spikes. Raw data from the RINKO oxygen 
sensor and the fluorometer data were low-pass filtered using a Hamming filter 
with a window of 15 scans (15 minutes).

Salinity (S [PSU]), dissolved oxygen (O [μmol/kg]) and fluorescence (Fl [RFU]) 
data were corrected using the water sampled data. Details of the measurement 
methods are described in Sections 3.2, 3.4, and 3.8 for salinity, dissolved 
oxygen and chlorophyll-a, respectively. Corrected salinity (Scor), dissolved 
oxygen (Ocor), and estimated chlorophyll a (Chl-a) were calculated from 
following equations

      S   [PSU] = c  + c S + c t
       cor         0    1     2 

      O   [μmol/kg] = c  + c O + c T + c t
       cor             0    1     2     3

      Chl-a [μg/L] = c  + c Fl
                      0    1

where t is days from a reference time, T is temperature in ºC. The best fit 
sets of calibration coefficients (c0~c3) were determined by a least square 
technique to minimize the deviation from the water sampled data. The reference 
times were listed in Table 2.4.1. The calibration coefficients were listed in 
Table 2.4.2. Comparisons between the Continuous Sea Surface Water Monitoring 
System data and water sampled data are shown in from Figs. 2.4.1 to 2.4.9. For 
fluorometer data, water sampled data obtained at night [PAR (Photosynthetically 
Available Radiation) < 50 μE/(m2 sec), see Section 2.15] were used for the 
calibration, since sensitivity of the fluorometer to chlorophyll a is different 
at nighttime and daytime (Fig. 2.4.10). For leg 1, sensitivity of the 
fluorometer to chlorophyll a is also different at around Solomon Sea and other 
area. Therefore, slope (c1) of the calibration coefficients was changed for 
each area (Table 2.4.2). For latitude between 14ºS and 13ºS, chlorophyll a was 
estimated from weighted mean of the two equations as

      Chl-a = Chl-a f  + Chl-a f
                   1 1        2 2

      f = 1 – (latitude + 14)
       1

      f = 1 – f
       2       1

where Chl-a1 is chlorophyll a calculated by using the set of coefficients A, 
and Chl-a2 is chlorophyll a calculated by using the set of coefficients B 
(Table 2.4.2).


Table 2.4.1: Reference time used in the calibration equations for salinity and 
             dissolved oxygen.

                         Leg  Date        Time (UTC)
                         ---  ----------  ----------
                          1   2012/11/06  08:09
                          2   2012/11/28  06:00
                          3   2013/01/07  02:00


Table 2.4.2: Calibration coefficients for the salinity, dissolved oxygen, and 
             chlorophyll a.

      Leg               c           c             c             c
                         0           1             2             3
----------------  -------------  ---------  -------------  -------------
Salinity
       1          -8.264243e-04  1.000025   -3.094205e-06
       2          -4.901493e-04  1.000014   -8.007142e-08
       3           4.116161e-04  0.9999879   1.490024e-07
Dissolved oxygen
       1           8.682632e-03  0.9999764  -1.111354e-04  -3.665007e-05
       2           9.983204e-03  0.9999737  -1.391134e-04  -3.103317e-05
       3          -1.566883e-02  1.000044    2.854348e-04   8.284769e-06
Chlorophyll a
       1           5.352958e-02  0.1296275 (A: for latitude ≤ 14ºS or  latitude ≥ 5ºS)
                   5.352958e-02  0.3467123 (B: for latitude > 13ºS and latitude < 5ºS)
       2           0.1141853     5.968889e-02
       3           1.445487e-02  5.716477e-02


Figure 2.4.1:  Comparison between TSG salinity (green: before correction, red: 
               after correction) and sampled salinity for leg 1.

Figure 2.4.2:  Same as Fig. 2.4.1, but for leg 2.

Figure 2.4.3:  Same as Fig. 2.4.1, but for leg 3.

Figure 2.4.4:  Comparison between TSG oxygen (green: before correction, red: 
               after correction) and sampled oxygen for leg 1.

Figure 2.4.5:  Same as Fig. 2.4.4, but for leg 2.

Figure 2.4.6:  Same as Fig. 2.4.4, but for leg 3.

Figure 2.4.7:  Comparison between TSG fluorescence and sampled chlorophyll a for 
               leg 1. Black dots indicate the daytime data. For bottom panel, 
               blue or red dots indicate fluorescence and green dots indicate 
               water sampled chlorophyll a. Line indicates chlorophyll a 
               estimated from fluoremeter.

Figure 2.4.8:  Same as Fig. 2.4.7, but for leg 2.

Figure 2.4.9:  Same as Fig. 2.4.7, but for leg 3.

Figure 2.4.10: Diurnal variation of the chlorophyll a estimated from the 
               fluorometer. Water sampled chlorophyll a (blue and green dots) 
               does not show such diurnal variation.


2.5  Underway pCO2
     October 2, 2014

(1) Personnel
       Akihiko Murata    (JAMSTEC)
       Yoshiko Ishikawa  (MWJ)
       Tomonori Watai    (MWJ)
       Emi Deguchi       (MWJ)
       Atsushi Ono       (MWJ)
       Keisuke Tsubata   (MWJ)

(2) Introduction

According to the latest report from Intergovernmental Panel on Climate Change, 
concentrations of CO2 in the atmosphere have increased by 40% since pre-
industrial times owing to human activities such as burning of fossil fuels, 
deforestation, and cement production. It is evaluated that the ocean has 
absorbed about 30% of the emitted anthropogenic CO2. It is an urgent task to 
estimate as accurately as possible the absorption capacity of the oceans 
against the increased atmospheric CO2, and to clarify the mechanism of the CO2 
absorption, because the magnitude of future global warming depends on the 
levels of CO2 in the atmosphere.

The Southern Ocean is one of the regions where uncertainty of uptake of 
anthropogenic CO2 is large. In this cruise, therefore, we were aimed at 
quantifying how much anthropogenic CO2 is absorbed in the ocean interior of the 
Southern Ocean. For the purpose, we measured atmospheric and surface seawater 
partial pressures of CO2 (pCO2) along the WHP P14S and S04I lines at ~170°E and 
~60°S, respectively, in the Southern Ocean.

Apparatus and shipboard measurement

Continuous underway measurements of atmospheric and surface seawater pCO2 were 
made with the CO2 measuring system (Nippon ANS, Ltd) installed in the R/V Mirai 
of JAMSTEC. The system comprises of a non-dispersive infrared gas analyzer (Li-
COR LI-7000), an air-circulation module and a showerhead-type equilibrator. To 
measure concentrations (mole fraction) of CO2 in dry air (xCO2a), air sampled 
from the bow of the ship (approx. 30 m above the sea level) was introduced into 
the NDIR through a dehydrating route with an electric dehumidifier (kept at 
~2°C), a Perma Pure dryer (GL Sciences Inc.), and a chemical desiccant 
(Mg(ClO4)2). The flow rate of the air was 500 ml min–1. To measure surface 
seawater concentrations of CO2 in dry air (xCO2s), the air equilibrated with 
seawater within the equilibrator was introduced into the NDIR through the same 
flow route as the dehydrated air used in measuring xCO2a. The flow rate of the 
equilibrated air was 700 – 800 ml min–1. The seawater was taken by a pump from 
the intake placed at the approx. 4.5 m below the sea surface. The flow rate of 
seawater in the equilibrator was 400 – 500 ml min–1.

The CO2 measuring system was set to repeat the measurement cycle such as 4 
kinds of CO2 standard gases (Table 2.5.1), xCO2a (twice), xCO2s (7 times). This 
measuring system was run automatically throughout the cruise by a PC control.

Quality control

Concentrations of CO2 of the standard gases are listed in Table 2.5.1, which 
were calibrated after cruise by the JAMSTEC primary standard gases. The CO2 
concentrations of the primary standard gases were calibrated by the Scripps 
Institution of Oceanography, La Jolla, CA, USA.

In actual shipboard observations, the signals of NDIR usually reveal a trend. 
The trends were adjusted linearly using the signals of the standard gases 
analyzed before and after the sample measurements.

Effects of water temperature increased between the inlet of surface seawater 
and the equilibrator on xCO2s were adjusted based on Takahashi et al. (1993), 
although the temperature increases were slight, being ~0.3°C.

We checked values of xCO2a and xCO2s by examining signals of the NDIR by 
plotting the xCO2a and xCO2s as a function of sequential day, longitude, sea 
surface temperature and sea surface salinity.


Reference

Takahashi, T., J. Olafsson, J. G. Goddard, D. W. Chipman, and S. C. Southerland 
    (1993) Seasonal variation of CO2 and nutrients in the high-latitude surface 
    oceans: a comparative study, Global Biogeochem. Cycles, 7, 843 – 878.


Table 2.5.1: Concentrations of CO2 standard gases used during the Southern 
             Ocean cruise.

                    Cylinder no.  Concentrations (ppmv)
                    ------------  ---------------------
                      CRC00049           270.14
                      CRC00046           330.29
                      CRC00047           360.31
                      CRC00048           420.22



2.6  Shipboard ADCP
     September 30, 2014


(1) Personnel
       Shinya Kouketsu     (JAMSTEC)     :Principal Investigator
       Souichiro Sueyoshi  (GGODI)       -leg1, leg3-
       Koichi Inagaki      (GODI)        -leg1, leg3-
       Kazuho Yoshida      (GODI)        -leg2-
       Shinya Okumura      (GODI)        -leg2-
       Masanori Murakami   (GODI)        -leg2-
       Katsuhisa Maeno     (GODI)        -leg3-
       Ryo Kimura          (MIRAI Crew)  -leg1, leg2-
       Ryo Ohyama          (MIRAI Crew)  -leg3-


(2) Objective

To obtain continuous measurement of the current profile along the ship’s track.


(3) Methods

Upper ocean current measurements were made in the MR12-05 cruise, using the 
hull-mounted Acoustic Doppler Current Profiler (ADCP) system. For most of its 
operation the instrument was configured for water-tracking mode. Bottom-
tracking mode, interleaved bottom-ping with water-ping, was made to get the 
calibration data for evaluating transducer misalignment angle in the shallow 
water. The system consists of following components;

1) R/V MIRAI has installed vessel-mount ADCP (75 kHz “Ocean Surveyor”, Teledyne 
   RD Instruments). It has a phased-array transducer with single assembly and 
   creates 4 acoustic beams electronically.

2) For heading source, we use ship’s gyro compass (Tokimec, Japan), 
   continuously providing heading to the ADCP system directory. Also we have 
   Inertial Navigation System (PHINS, iXSEA) which provide highprecision 
   heading and attitude information are stored in “.N2R” data files.

3) DGPS system (Trimble SPS751 & StarFixXP) providing position fixes.

4) We used VmDas version 1.46.5 (TRDI) for data acquisition.

5) To synchronize time stamp of pinging with GPS time, the clock of the logging 
   computer is adjusted to GPS time every 8 minutes.

6) The sound speed at the transducer does affect the vertical bin mapping and 
   vertical velocity measurement, is calculated from temperature, salinity 
   (constant value; 35.0 psu) and depth (6.5 m; transducer depth) by equation 
   in Medwin (1975).

Data was configured for 8-m intervals starting 23-m below the surface. Every 
ping was recorded as raw ensemble data (.ENR). Also, 60 seconds and 300 seconds 
averaged data were recorded as short term average (.STA) and long term average 
(.LTA) data, respectively. Major parameters for the measurement (Direct 
Command) are shown in Table 2.6.1.


(4) Processed data

We corrected the misalignment of ADCP with the bottom track measurements and 
provided 9 sminutes averaged velocity profiles.


(5) Data archive

These data obtained in this cruise will be submitted to the Data Management 
Group (DMG) of JAMSTEC, and will be opened to the public via JAMSTEC home page.


(6) Remarks (Times in UTC)

1) The observation was carried out within following periods
   Leg1: 07:00, 05 Nov. 2012 - 15:00, 16 Nov. 2012
         03:00, 17 Nov. 2012 - 07:00, 25 Nov. 2012
   Leg2: 06:00, 28 Nov. 2012 - 07:00, 01 Jan. 2013
   Leg3: 02:00, 07 Jan. 2013 - 12:00, 13 Feb. 2013
2) RSSI (Echo Intensity) became weak deeper layers than 300m around southern  
   part of P14S line as shown in Fig 2.6-1. The following periods, we changed 
   temporally some of parameters (Depth cell size (WS), number of cells (WN) 
   and blanking distance (WF)) due to trying to improve of the state.
         01:30 - 01:44, 10 Dec. 2012 : WS;400[cm], WN;128, WF; 400[cm]
         01:45 - 02:51, 10 Dec. 2012 : WS;400[cm], WN;128, WF; 800[cm]
3) The following periods, navigation data was invalid due to GPS position fix 
   error.
   Leg1: 23:25:06 - 23:39:07, 22 Nov. 2012 (intermittently)
   Leg2: 11:47:39 - 13:41:46, 28 Dec. 2012


Table 2.6.1: Major parameters.

Bottom-Track Commands

BP = 000   Pings per Ensemble (almost over 1300m depth)
           Leg1: 01:19UTC 07 Nov. 2012 – 15:00UTC 16 Nov. 2012
                 03:00UTC 17 Nov. 2012 – 04:39UTC 17 Nov. 2012
                 06:48UTC 17 Nov. 2012 – 09:43UTC 18 Nov. 2012
                 10:59UTC 18 Nov. 2012 – 18:41UTC 22 Nov. 2012
                 20:56UTC 22 Nov. 2012 – 08:09UTC 23 Nov. 2012
                 09:16UTC 23 Nov. 2012 – 02:32UTC 23 Nov. 2012
           Leg2: 06:00UTC 28 Nov. 2012 – 02:31UTC 30 Nov. 2012
                 17:30UTC 30 Nov. 2012 – 20:54UTC 01 Dec. 2012
                 16:17UTC 03 Dec. 2012 – 07:00UTC 01 Jan. 2013
           Leg3: 17:43UTC 06 Jan. 2013 – 14:35UTC 06 Feb. 2013
                 05:15UTC 07 Feb. 2013 – 12:00UTC 13 Feb. 2013

BP = 001   Pings per Ensemble (almost less than 1300m depth)
           Leg1: 04:16UTC 05 Nov. 2012 – 01:19UTC 07 Nov. 2012
                 04:39UTC 17 Nov. 2012 – 06:47UTC 17 Nov. 2012
                 09:43UTC 18 Nov. 2012 – 10:59UTC 18 Nov. 2012
                 18:41UTC 22 Nov. 2012 – 20:56UTC 22 Nov. 2012
                 08:09UTC 23 Nov. 2012 – 09:16UTC 23 Nov. 2012
                 02:32UTC 23 Nov. 2012 – 07:00UTC 25 Nov. 2012
           Leg2: 02:32UTC 30 Nov. 2012 – 17:30UTC 30 Nov. 2012
                 20:54UTC 01 Dec. 2012 – 16:17UTC 03 Dec. 2012
           Leg3: 06:18UTC 05 Jan. 2013 – 17:43UTC 06 Jan. 2013
                 14:35UTC 06 Feb. 2013 – 05:15UTC 07 Feb. 2013
Environmental Sensor Commands

   EA = +04500   Heading Alignment (1/100 deg)
   EB = +00000   Heading Bias (1/100 deg)
   ED = 00065    Transducer Depth (0 - 65535 dm)
   EF = +001     Pitch/Roll Divisor/Multiplier (pos/neg) [1/99 - 99]
   EH = 00000    Heading (1/100 deg)
   ES = 35       Salinity (0-40 pp thousand)
   EX = 00000    Coord Transform (Xform:Type; Tilts; 3Bm; Map)
   EZ = 10200010 Sensor Source (C; D; H; P; R; S; T; U)
                 C (1): Sound velocity calculates using ED, ES, ET (temp.)
                 D (0): Manual ED
                 H (2): External synchro
                 P (0), R (0): Manual EP, ER (0 degree)
                 S (0): Manual ES
                 T (1): Internal transducer sensor
                 U (0): Manual EU

Timing Commands

   TE = 00:00:02.00  Time per Ensemble (hrs:min:sec.sec/100)
   TP = 00:02.00     Time per Ping (min:sec.sec/100)

Water-Track Commands

   WA = 255 False Target Threshold (Max) (0-255 count)
   WB = 1 Mode 1 Bandwidth Control (0=Wid, 1=Med, 2=Nar)
   WC = 120 Low Correlation Threshold (0-255)
   WD = 111 100 000 Data Out (V; C; A; PG; St; Vsum; Vsum^2;#G;P0)
   WE = 1000 Error Velocity Threshold (0-5000 mm/s)
   WF = 0800 Blank After Transmit (cm)
   WG = 001 Percent Good Minimum (0-100%)
   WI = 0 Clip Data Past Bottom (0 = OFF, 1 = ON)
   WJ = 1 Rcvr Gain Select (0 = Low, 1 = High)
   WM = 1 Profiling Mode (1-8)
   WN = 100 Number of depth cells (1-128)
   WP = 00001 Pings per Ensemble (0-16384)
   WS = 0800 Depth Cell Size (cm)
   WT = 000 Transmit Length (cm) [0 = Bin Length]
   WV = 0390 Mode 1 Ambiguity Velocity (cm/s radial)


Figure 2.6.1: Time series of Echo Intensity profile between P14S-26 and P14S-
              27.



2.7  XCTD
     May 6, 2013


(1) Personnel

       Hiroshi Uchida      (JAMSTEC)
       Souichiro Sueyoshi  (GODI)    (Legs 1 and 3)
       Koichi Inagaki      (GODI)    (Legs 1 and 3)
       Kazuho Yoshida      (GODI)    (Leg 2)
       Shinya Okumura      (GODI)    (Leg 2)
       Masanori Murakami   (GODI)    (Leg 2)
       Katsuhisa Maeno     (GODI)    (Leg 3)


(2) Objectives

In this cruise, XCTD (eXpendable Conductivity, Temperature and Depth profiler) 
measurements were carried out to evaluate the fall rate equation and 
temperature by comparing with CTD (Conductivity, Temperature and Depth 
profiler) measurements, and to substitute for CTD measurements.


(3) Instrument and Method

The XCTDs used were XCTD-1, XCTD-2 and XCTD-4 (Tsurumi-Seiki Co., Ltd., 
Yokohama, Kanagawa, Japan) with an MK-150N deck unit (Tsurumi-Seiki Co., Ltd.). 
The manufacturer’s specifications are listed in Table 2.7.1. In this cruise, 
the XCTD probes were deployed by using 8-loading automatic launcher or hand 
launcher (Tsurumi-Seiki Co., Ltd.). For comparison with CTD, XCTD was deployed 
at about 10 minutes after the beginning of the down cast of the CTD (999_C02, 
999_C03, P14S_25, S04_402, S04I_166, and S04I_167).

The fall-rate equation provided by the manufacturer was used to infer depth Z 
(m), Z = at – bt2, where t is the elapsed time in seconds from probe entry into 
the water, and a (terminal velocity) and b (acceleration) are the empirical 
coefficients (Table 2.7.2).


Table 2.7.1: Manufacturer’s specifications of XCTD-1, XCTD-2 and XCTD-4.

Parameter     Range                               Accuracy
------------  ----------------------------------  ---------------------------------
Conductivity   0 ~ 60 mS cm–1                     ±0.03 mS cm–1
Temperature   –2 ~ 35°C                           ±0.02°C
Depth          0 ~ 1000 m (for XCTD-1)            5 m or 2%, whichever is greater *
               0 ~ 1850 m (for XCTD-2 and XCTD-4)
———————————————————————————————————————————————————————————————————————————————————
* Depth error is shown in Kizu et al (2008).


Table 2.7.2: Manufacturer’s coefficients for the fall-rate equation.

      Model    a (terminal    b (acceleration,  e (terminal velocity
              velocity, m/s)        m/s2)            error, m/s)
      ------  --------------  ----------------  --------------------
      XCTD-1     3.42543          0.00047           not estimated
      XCTD-2     3.43898          0.00031             –0.0239
      XCTD-4     3.68081          0.00047             –0.0075


(4) Data Processing and Quality Control

The XCTD data were processed and quality controlled based on a method by Uchida 
et al. (2011). Differences between XCTD and CTD depths were shown in Fig. 
2.7.1. The terminal velocity error was estimated for the XCTD-2 and for the 
XCTD-4 (Table 2.7.2). Difference of temperature on pressure surfaces were 
examined by using side-by-side XCTD and CTD data (Fig. 2.7.2). The XCTD data 
were corrected for the depth error by using the estimated terminal velocities. 
Average thermal bias below 400 dbar was 0.009°C. Mean of the thermal biases of 
XCTD data estimated from four cruises was 0.015 ± 0.004°C (Table 2.7.3). The 
mean thermal bias (0.015°C) was corrected for the XCTD data obtained in this 
cruise. Difference of salinity on reference temperature surfaces were examined 
by using neighboring CTD data (Table 2.7.4). The estimated salinity biases were 
corrected for the XCTD data (Fig. 2.7.3) except for the XCTD data obtained at 
999_326 and 999_329, because neighboring CTD data was not available in this 
cruise.


Table 2.7.3: Thermal biases of the XCTD temperature data.

Cruise   Average thermal   Depth range       Source
            bias (°C)   
-------  ---------------  ------------  --------------------
MR09-01       0.016       >= 1100 dbar  Uchida et al. (2011)
KH-02-3       0.019       >= 1100 dbar  Uchida et al. (2011)
MR11-08       0.014       >= 1100 dbar  Uchida et al. (2013)
MR12-05       0.009       >=  400 dbar  This report
        Mean  0.015 ± 0.004


Table 2.7.4: Salinity biases of the XCTD data.

   XCTD   Salinity      Reference     Reference      Reference
 station    bias    temperature (°C)  salinity      CTD stations
--------  --------  ----------------  ---------  ------------------
999_C02    0.007          2.3          34.6251   999_C02
999_C03    0.018          2.3          34.6293   999_C03
P14S_25    0.001          0.9          34.7122   *1
S04_401    0.001          0.9          34.7122   *1
S04_402    0.001          0.9          34.7122   *1
S04_403   –0.006          0.9          34.7122   *1
S04_405   –0.009          0.9          34.7122   *1
S04_407   –0.009          0.9          34.7122   *1
S04_409    0.004          0.9          34.7122   *1
S04_411   –0.003          0.9          34.7122   *1
999_C04    0.017          1.2          34.7279   999_C04
S04I_166  –0.015          0.9          34.7065   S04I_166, S04I_167
S04I_167  –0.021          0.9          34.7065   S04I_166, S04I_167
—————————————————————————————————————————————————————————————————————————
*1: P14S_25, P14S_27, S04_50, S04_402, S04_404, S04_406, S04_408, S04_410



References

Kizu, S., H. Onishi, T. Suga, K. Hanawa, T. Watanabe, and H. Iwamiya (2008): 
    Evaluation of the fall rates of the present and developmental XCTDs. Deep-
    Sea Res I, 55, 571–586.

Uchida, H., K. Shimada, and T. Kawano (2011): A method for data processing to 
    obtain high-quality XCTD data. J. Atmos. Oceanic Technol., 28, 816–826. 
    Uchida, H., A. Murata, and T. Doi (2014): WHP P10 Revisit in 2011 Data 
    Book, 179 pp., JAMSTEC.


Figure 2.7.1: Differences between XCTD and CTD depths for XTD-2 and XCTD-4. 
              Differences were estimated with the same method as Uchida et al. 
              (2011). Standard deviation of the estimates (horizontal bars) and 
              the manufacturer’s specification for XCTD depth error (dotted 
              lines) are shown. The regressions for the XCTD-2 data (solid 
              line) and for the XCTD-4 data (broken line) are also shown.

Figure 2.7.2: Comparison between XCTD and CTD temperature profiles. (a) Mean 
              temperature files of CTD profiles with standard deviation (shade) 
              and (b) mean temperature difference with standard deviation 
              (shade) between the XCTD and CTD. Mean profiles were low-pass 
              filtered by a running mean with a window of 51 dbar.

Figure 2.7.3: Comparison of temperature-salinity profiles of CTD (red lines) 
              data used for the XCTD salinity bias estimation and salinity 
              bias-corrected XCTD (black lines) data.



2.8  Photosynthetically Available Radiation (PAR)
     May 6, 2013


(1) Personnel
 
    Hiroshi Uchida (JAMSTEC)


(2) Objectives

The PAR sensor is used to measure surface Photosynthetically Available 
Radiation (PAR) continuously along the cruise track for a study of primary 
production.


(3) Instrument and method

The PAR is measured by a PUV-510B (Biospherical Instruments Inc., San Diego, 
CA, USA) at one minute intervals. The PAR sensor was installed on the roof top 
of the anti-rolling system by looking upward. The PAR sensor was calibrated 
before the cruise by the K-Engineering Co., Ltd., Japan.

      Serial no.: 19209
      Date of calibration: September 28, 2012
      Slope: –6.220
      Offset: 0.000109 μE/(cm2 sec)


(4) Comparison with another PAR sensor

Data measured by a PUV-510B were compared with the data measured by another PAR 
sensor (Serial no.: 049, Satlantic LP, Halifax, NS, Canada) used in the CTD 
profiler measurement. The Satlantic’s PAR sensor was attached to the body of 
the surface PAR (PUV-510B) sensor and the PAR data were compared for four hours 
of daytime (2:54-6:53 [UTC], February 9, 2013) (Figure 2.8.1).


Figure 2.8.1: Comparison of two PAR sensors used for the surface PAR 
              measurement and the CTD profiler measurement.




3  Hydrographic Measurement Techniques and Calibrations


3.1  CTDO2 Measurements
     October 22, 2014


(1) Personnel

    Hiroshi Uchida (JAMSTEC)
    Shinsuke Toyoda (MWJ) (legs 1, 2)
    Satoshi Ozawa (MWJ) (leg 3)
    Tomohide Noguchi (MWJ) (leg 2)
    Tomoyuki Takamori (MWJ) (leg 2)
    Shungo Oshitani (MWJ) (leg 2)
    Naoko Miyamoto (MWJ) (leg 3)
    Hiroshi Matsunaga (MWJ) (leg 3)
    Takami Mori (MWJ) (leg 3)


(2) Winch arrangements

The CTD package was deployed by using 4.5 Ton Traction Winch System (Dynacon, 
Inc., Bryan, Texas, USA), which was installed on the R/V Mirai in April 2001 
(Fukasawa et al., 2004). Primary system components include a complete CTD 
Traction Winch System with up to 8000 m of 9.53 mm armored cable (Ocean Cable 
and Communications Co., Yokohama, Kanagawa, Japan).


(3) Overview of the equipment

The CTD system was SBE 911plus system (Sea-Bird Electronics, Inc., Bellevue, 
Washington, USA). The SBE 911plus system controls 36-position SBE 32 Carousel 
Water Sampler. The Carousel accepts 12-litre Niskin-X water sample bottles 
(General Oceanics, Inc., Miami, Florida, USA). The SBE 9plus was mounted 
horizontally in a 36-position carousel frame. SBE’s temperature (SBE 3) and 
conductivity (SBE 4) sensor modules were used with the SBE 9plus underwater 
unit. The pressure sensor is mounted in the main housing of the underwater unit 
and is ported to outside through the oil-filled plastic capillary tube. A 
modular unit of underwater housing pump (SBE 5T) flushes water through sensor 
tubing at a constant rate independent of the CTD’s motion, and pumping rate 
(3000 rpm) remain nearly constant over the entire input voltage range of 12-18 
volts DC. Flow speed of pumped water in standard TC duct is about 2.4 m/s. Two 
sets of temperature and conductivity modules were used. An SBE’s dissolved 
oxygen sensor (SBE 43) was placed between the primary conductivity sensor and 
the pump module. Auxiliary sensors, a Deep Ocean Standards Thermometer (SBE 
35), an altimeter (PSA-916T; Teledyne Benthos, Inc., North Falmous, 
Massachusetts, USA), two oxygen optodes (RINKO-III; JFE Alec Co., Ltd, Kobe 
Hyogo, Japan), two fluorometers (Seapoint sensors, Inc., Kingston, New 
Hampshire, USA), a transmissometer (C-Star Transmissometer; WET Labs, Inc., 
Philomath, Oregon, USA), and a Photosynthetically Active Radiation (PAR) sensor 
(Satlantic, LP, Halifax, Nova Scotia, Canada) were also used with the SBE 9plus 
underwater unit. To minimize rotation of the CTD package, a heavy stainless 
frame (total weight of the CTD package without sea water in the bottles is 
about 1000 kg) was used with an aluminum plate (54x 90 cm).


Summary of the system used in this cruise

Deck unit:
    SBE 11plus, S/N 0272 (leg 1, leg 2 stations from 001_1 to 076_1)
    SBE 11plus, S/N 0344 (leg 2 stations from 076_2 to 503_1, leg 3)
Under water unit:
    SBE 9plus, S/N 117457 (Pressure sensor: S/N 1027)
Temperature sensor:
    SBE 3plus, S/N 4815 (primary)
    SBE 3plus, S/N 1464 (secondary)
Conductivity sensor:
    SBE 4, S/N 2854 (leg 1 primary, legs 2 and 3 secondary)
    SBE 4, S/N 2435 (leg 1 secondary, legs 2 and 3 primary)
Oxygen sensor:
    SBE 43, S/N 2211 (legs 2 and 3)
    SBE 43, S/N 0949 (leg 3)
    JFE Advantech RINKO-III, S/N 0024 (foil batch no. 144002A) (primary)
    JFE Advantech RINKO-III, S/N 0079 (foil batch no. 160002A) (secondary: legs 
        1 and 2)
    JFE Advantech RINKO-III, S/N 0037 (foil batch no. 160005A) (secondary: leg 3)
Pump:
    SBE 5T, S/N 4598 (primary)
    SBE 5T, S/N 4595 (secondary)
Altimeter:
    PSA-916T, S/N 1100
Deep Ocean Standards Thermometer:
    SBE 35, S/N 0022
Fluorometer:
    Seapoint Sensors, Inc., S/N 3054 (measurement range: 0-5 ug/L)
    Seapoint Sensors, Inc., S/N 3497 (measurement range: 0-15 ug/L)
Transmissometer:
    C-Star, S/N CST-1363DR
PAR:
    Satlantic LP, S/N 0049
Carousel Water Sampler:
    SBE 32, S/N 0278
Water sample bottle:
    12-litre Niskin-X model 1010X (no TEFLON coating)


(4) Pre-cruise calibration

  i.  Pressure

The Paroscientific series 4000 Digiquartz high pressure transducer (Model 415K: 
Paroscientific, Inc., Redmond, Washington, USA) uses a quartz crystal resonator 
whose frequency of oscillation varies with pressure induced stress with 0.01 
per million of resolution over the absolute pressure range of 0 to 15000 psia 
(0 to 10332 dbar). Also, a quartz crystal temperature signal is used to 
compensate for a wide range of temperature changes at the time of an 
observation. The pressure sensor has a nominal accuracy of 0.015  FS (1.5 
dbar), typical stability of 0.0015  FS/month (0.15 dbar/month), and resolution 
of 0.001  FS (0.1 dbar). Since the pressure sensor measures the absolute value, 
it inherently includes atmospheric pressure (about 14.7 psi). SEASOFT subtracts 
14.7 psi from computed pressure automatically.

Pre-cruise sensor calibrations for linearization were performed at SBE, Inc.

    S/N 1027, 4 February 2011

The time drift of the pressure sensor is adjusted by periodic recertification 
corrections against a deadweight piston gauge (Model 480DA, S/N 23906; Piston 
unit, S/N 079K; Weight set, S/N 3070; Bundenberg Gauge Co. Ltd., Irlam, 
Manchester, UK). The corrections are performed at JAMSTEC, Yokosuka, Kanagawa, 
Japan by Marine Works Japan Ltd. (MWJ), Yokohama, Kanagawa, Japan, usually once 
in a year in order to monitor sensor time drift and linearity.

    S/N 1027, 23 August 2012
        slope = 1.00003946
        offset = –0.42611


 ii.  Temperature (SBE 3)

The temperature sensing element is a glass-coated thermistor bead in a 
stainless steel tube, providing a pressure-free measurement at depths up to 
10500 (6800) m by titanium (aluminum) housing. The SBE 3 thermometer has a 
nominal accuracy of 1 mK, typical stability of 0.2 mK/month, and resolution of 
0.2 mK at 24 samples per second. The premium temperature sensor, SBE 3plus, is 
a more rigorously tested and calibrated version of standard temperature sensor 
(SBE 3).

Pre-cruise sensor calibrations were performed at SBE, Inc.

    S/N 4815, 1 March 2012
    S/N 1464, 20 September 2012

Pressure sensitivities of SBE 3s were corrected according to a method by Uchida 
et al. (2007), for the following sensors.

    S/N 4815, –3.45974716e–7 [°C/dbar]
    S/N 1464, –7.75293156e–9 [°C/dbar]


iii.  Conductivity (SBE 4)

The flow-through conductivity sensing element is a glass tube (cell) with three 
platinum electrodes to provide in-situ measurements at depths up to 10500 
(6800) m by titanium (aluminum) housing. The SBE 4 has a nominal accuracy of 
0.0003 S/m, typical stability of 0.0003 S/m/month, and resolution of 0.00004 S/ 
m at 24 samples per second. The conductivity cells have been replaced to newer 
style cells for deep ocean measurements.

Pre-cruise sensor calibrations were performed at SBE, Inc.

    S/N 2854, 21 September 2012
    S/N 2435, 21 September 2012

The value of conductivity at salinity of 35, temperature of 15°C (IPTS-68) and 
pressure of 0 dbar is 4.2914 S/m.


 iv.  Oxygen (SBE 43)

The SBE 43 oxygen sensor uses a Clark polarographic element to provide in-situ 
measurements at depths up to 7000 m. The range for dissolved oxygen is 120  of 
surface saturation in all natural waters, nominal accuracy is 2  of saturation, 
and typical stability is 2  per 1000 hours.

Pre-cruise sensor calibration was performed at SBE, Inc.

    S/N 2211, 19 October 2012
    S/N 0949, 18 September 2012


  v.  Deep Ocean Standards Thermometer

Deep Ocean Standards Thermometer (SBE 35) is an accurate, ocean-range 
temperature sensor that can be standardized against Triple Point of Water and 
Gallium Melt Point cells and is also capable of measuring temperature in the 
ocean to depths of 6800 m. The SBE 35 was used to calibrate the SBE 3 
temperature sensors in situ (Uchida et al., 2007).

Pre-cruise sensor linearization was performed at SBE, Inc.

    S/N 0022, 4 March 2009

Then the SBE 35 is certified by measurements in thermodynamic fixed-point cells 
of the TPW (0.01°C) and GaMP (29.7646°C). The slow time drift of the SBE 35 is 
adjusted by periodic recertification corrections.

Pre-cruise sensor calibration was performed at SBE, Inc. From the end of 2011, 
the SBE has been applying a NIST correction to the fixed-point cells used for 
the calibration.

    S/N 0022, 6 March 2012 (slope and offset correction)
        Slope = 1.000012
        Offset = –0.000023

The time required per sample = 1.1x NCYCLES + 2.7 seconds. The 1.1 seconds is 
total time per an acquisition cycle. NCYCLES is the number of acquisition 
cycles per sample and was set to 4. The 2.7 seconds is required for converting 
the measured values to temperature and storing average in EEPROM.

 vi. Altimeter  Benthos PSA-916T Sonar Altimeter (Teledyne Benthos, Inc.) 
determines the distance of the target from the unit by generating a narrow beam 
acoustic pulse and measuring the travel time for the pulse to bounce back from 
the target surface. It is rated for operation in water depths up to 10000 m. 
The PSA-916T uses the nominal speed of sound of 1500 m/s.


vii. Oxygen optode (RINKO)

RINKO (JFE Alec Co., Ltd.) is based on the ability of selected substances to 
act as dynamic fluorescence quenchers. RINKO model III is designed to use with 
a CTD system which accept an auxiliary analog sensor, and is designed to 
operate down to 7000 m.

Data from the RINKO can be corrected for the time-dependent, pressure-induced 
effect by means of the same method as that developed for the SBE 43 (Edwards et 
al., 2010). The calibration coefficients, H1 (amplitude of hysteresis 
correction), H2 (curvature function for hysteresis), and H3 (time constant for 
hysteresis) were determined empirically as follows.

    H1 = 0.007 (for S/N 0024)
    H1 = 0.008 (for S/N 0079 and 0037)
    H2 = 5000 dbar
    H3 = 2000 seconds

Outputs from RINKO are the raw phase shift data. The RINKO can be calibrated by 
the Stern-Volmer equation, according to a method by Uchida et al. (2010):

    O2 (μmol/l) = [(V0 / V) – 1] / Ksv

where V is voltage, V0 is voltage in the absence of oxygen and Ksv is Stern-
Volmer constant. The V0 and the Ksv are assumed to be functions of temperature 
as follows.

    Ksv = C0 + C1 x T + C2x T2
    V0 = 1 + C3 x T
    V = C4 + C5 x Vb

where T is CTD temperature (°C) and Vb is raw output (volts). V0 and V are 
normalized by the output in the absence of oxygen at 0°C. The oxygen 
concentration is calculated using accurate temperature data from the CTD 
temperature sensor instead of temperature data from the RINKO. The pressure-
compensated oxygen concentration O2c can be calculated as follows.

                            1/3
    O   = O (1 + C p / 1000)
     2c    2      p

where p is CTD pressure (dbar) and Cp (0.013 for S/N0024) is the compensation 
coefficient. Since the sensing foil of the optode is permeable only to gas and 
not to water, the optode oxygen must be corrected for salinity. The salinity-
compensated oxygen can be calculated by multiplying the factor of the effect of 
salt on the oxygen solubility. The coefficients of the equation by García and 
Gordon (1992) were modified based on the laboratory experiment (Uchida et al., 
in prep.) and used for the compensation (B0 = –6.33568e–3, B1 = –6.84389e–3, B2 
= –1.18326e–2, B3 = –5.51960e–2, C0 = 3.40543e–6).

Pre-cruise sensor calibrations were performed at RIGC/JAMSTEC.

    S/N 0024, 21 May 2012
    S/N 0079, 21 May 2012
    S/N 0037, 18 September 2012


viii.  Fluorometer

The Seapoint Chlorophyll Fluorometer (Seapoint Sensors, Inc., Kingston, New 
Hampshire, USA) provides in-situ measurements of chlorophyll-a at depths up to 
6000 m. The instrument uses modulated blue LED lamps and a blue excitation 
filter to excite chlorophyll-a. The fluorescent light emitted by the 
chlorophyll-a passes through a red emission filter and is detected by a silicon 
photodiode. The low level signal is then processed using synchronous 
demodulation circuitry, which generates an output voltage proportional to 
chlorophyll-a concentration.


 ix. Transmissometer

The C-Star Transmissometer (WET Labs, Inc., Philomath, Oregon, USA) measures 
light transmittance at a single wavelength (650 nm) over a know path (25 cm). 
In general, losses of light propagating through water can be attributed to two 
primary causes: scattering and absorption. By projecting a collimated beam of 
light through the water and placing a focused receiver at a known distance 
away, one can quantify these losses. The ratio of light gathered by the 
receiver to the amount originating at the source is known as the beam 
transmittance. Suspended particles, phytoplankton, bacteria and dissolved 
organic matter contribute to the losses sensed by the instrument. Thus, the 
instrument provides information both for an indication of the total 
concentrations of matter in the water as well as for a value of the water 
clarity.

Light transmission Tr (in ) and beam attenuation coefficient cp are calculated 
from the sensor output (V in volt) as follows. 

    Tr = c0 + c1 V
    cp = – (1 / 0.25) ln(Tr / 100)

The pre-cruise calibration coefficients were determined by using the data 
obtained in the R/V Mirai MR12-02 cruise.

 
x.  PAR
   
Satlantic’s Photosynthetically Active Radiation (PAR) sensors provide highly 
accurate measurements of PAR (400 – 700 nm) for a wide range of aquatic and 
terrestrial applications. The ideal spectral response for a PAR sensor is one 
that gives equal emphasis to all photons between 400 – 700 nm. Satlantic PAR 
sensors use a high quality filtered silicon photodiode to provide a near equal 
spectral response across the entire wavelength range of the measurement.

Pre-cruise sensor calibration was performed at Satlantic, LP.

    S/N 0049, 22 January 2009


(5)  Data collection and processing

  i. Data collection

CTD system was powered on at least 20 minutes in advance of the data 
acquisition to stabilize the pressure sensor and was powered off at least two 
minutes after the operation in order to acquire pressure data on the ship’s 
deck. The package was lowered into the water from the starboard side and held 
10 m beneath the surface in order to activate the pump. After the pump was 
activated, the package was lifted to the surface and lowered at a rate of 1.0 
m/s to 200 m (or 300 m when significant wave height was high) then the package 
was stopped to operate the heave compensator of the crane. The package was 
lowered again at a rate of 1.2 m/s to the bottom. For the up cast, the package 
was lifted at a rate of 1.1 m/s except for bottle firing stops. As a rule, the 
bottle was fired after waiting from the stop for 30 seconds and the package was 
stayed at least 5 seconds for measurement of the SBE 35 at each bottle firing 
stops. For depths where vertical gradient of water properties were expected to 
be large, the bottle was exceptionally fired after waiting from the stop for 60 
seconds to enhance exchanging the water between inside and outside of the 
bottle (depths ≤ 500 dbar for station from C01_1 to C03_1, depths ≤ 100 dbar 
for station from 063_1 to 068_1, depths ≤ 200 dbar for station from C04_1 to 
073_1, depths ≤ 250 dbar for station from 074_1 to 166_1). At 200 m (or 300 m) 
from the surface, the package was stopped to stop the heave compensator of the 
crane. Water samples were collected using a 36-bottle (or 12-bottles) SBE 32 
Carousel Water Sampler with 12-litre Niskin-X bottles. Before a cast taken 
water for CFCs, the bottle frame and Niskin-X bottles were wiped with acetone.

    Data acquisition software
        SEASAVE-Win32, version 7.22

 ii.  Data collection problems

(a) Miss trip and miss fire

Niskin bottles did not trip correctly at the following stations.

    Miss     trip Miss fire
    None     None

(b) Noise of the primary temperature and conductivity sensors

Data quality for the primary temperature and conductivity sensors were bad at 
the following stations, so that data from the secondary temperature and 
conductivity sensors were used.

    Down cast profile data: 015_1, 123_1, 126_1
    Up cast bottle data: 064_1, 123_1, 124_1, 134_1

(c) Noise of the transmissometer

Data quality of the down cast of the transmissometer was bad at the following 
stations, so that data from the up cast was used.

    135_1: from surface to bottom
    145_1: pressure deeper than 1000 dbar
    148_1: pressure deeper than 3600 dbar

(d) Over range of the fluorometer

Over range of the primary fluorometer (measurement range: 0-5 ug/L) were 
frequently occurred. Therefore, the secondary fluorometer (measurement range: 
0-15 ug/L) was basically used for the dataset. However, the primary fluorometer 
was used for stations from 149_1, because the secondary fluorometer was drifted 
in time from station 149_1.

(e) Winch trouble

The CTD package was stopped relatively for a long time due to a mechanical 
problem of the winch system at 502 dbar of up cast for station 004_1 (50 
minutes) and at 2780 dbar of up cast for station 056_1 (25 minutes).

(f) RS-232C communications timeout

Communications timeout of RS-232C was occurred at following stations. The fuse 
of the CTD deck unit blew due to unknown reason.

    076_1: 2888 dbar of up cast: Deck unit was replaced after the cast.
    088_2: 3125 dbar of up cast: The end connection to the armored cable was 
           reprocessed.
    130_1: 4085 dbar of down cast: The cast was aborted


iii.  Data processing

SEASOFT consists of modular menu driven routines for acquisition, display, 
processing, and archiving of oceanographic data acquired with SBE equipment. 
Raw data are acquired from instruments and are stored as unmodified data. The 
conversion module DATCNV uses instrument configuration and calibration 
coefficients to create a converted engineering unit data file that is operated 
on by all SEASOFT post processing modules. The following are the SEASOFT and 
original software data processing module sequence and specifications used in 
the reduction of CTD data in this cruise.

    Data processing software

      SBEDataProcessing-Win32, version 7.22

DATCNV converted the raw data to engineering unit data. DATCNV also extracted 
bottle information where scans were marked with the bottle confirm bit during 
acquisition. The duration was set to 4.4 seconds, and the offset was set to 0.0 
second. The hysteresis correction for the SBE 43 data (voltage) was applied for 
both profile and bottle information data.

TCORP (original module, version 1.1) corrected the pressure sensitivity of the 
SBE 3 for both profile and bottle information data.

RINKOCOR (original module, version 1.0) corrected the time-dependent, pressure-
induced effect (hysteresis) of the RINKO for both profile data.

RINKOCORROS (original module, version 1.0) corrected the time-dependent, 
pressure-induced effect (hysteresis) of the RINKO for bottle information data 
by using the hysteresis-corrected profile data.

BOTTLESUM created a summary of the bottle data. The data were averaged over 4.4 
seconds (or 1 second for the bottle fired without stop).

ALIGNCTD converted the time-sequence of sensor outputs into the pressure 
sequence to ensure that all calculations were made using measurements from the 
same parcel of water. For a SBE 9plus CTD with the ducted temperature and 
conductivity sensors and a 3000-rpm pump, the typical net advance of the 
conductivity relative to the temperature is 0.073 seconds. So, the SBE 11plus 
deck unit was set to advance the primary and the secondary conductivity for 
1.73 scans (1.75/24 = 0.073 seconds). Oxygen data are also systematically 
delayed with respect to depth mainly because of the long time constant of the 
oxygen sensor and of an additional delay from the transit time of water in the 
pumped plumbing line. This delay was compensated by 6 seconds advancing the SBE 
43 oxygen sensor output (voltage) relative to the temperature data. Delay of 
the RINKO data was also compensated by 1 second advancing sensor output 
(voltage) relative to the temperature data. Delay of the transmissometer data 
was also compensated by 2 seconds advancing sensor output (voltage) relative to 
the temperature data.

WILDEDIT marked extreme outliers in the data files. The first pass of WILDEDIT 
obtained an accurate estimate of the true standard deviation of the data. The 
data were read in blocks of 1000 scans. Data greater than 10 standard 
deviations were flagged. The second pass computed a standard deviation over the 
same 1000 scans excluding the flagged values. Values greater than 20 standard 
deviations were marked bad. This process was applied to pressure, temperature, 
conductivity, SBE 43, and RINKO output.

CELLTM used a recursive filter to remove conductivity cell thermal mass effects 
from the measured conductivity. Typical values used were thermal anomaly 
amplitude alpha = 0.03 and the time constant 1/beta = 7.0.

FILTER performed a low pass filter on pressure with a time constant of 0.15 
seconds. In order to produce zero phase lag (no time shift) the filter runs 
forward first then backwards.

WFILTER performed as a median filter to remove spikes in fluorometer and 
transmissometer data. A median value was determined by 49 scans of the window.

SECTIONU (original module, version 1.1) selected a time span of data based on 
scan number in order to reduce a file size. The minimum number was set to be 
the start time when the CTD package was beneath the sea-surface after 
activation of the pump. The maximum number was set to be the end time when the 
depth of the package was 1 dbar below the surface. The minimum and maximum 
numbers were automatically calculated in the module.

LOOPEDIT marked scans where the CTD was moving less than the minimum velocity 
of 0.0 m/s (traveling backwards due to ship roll).

DESPIKE (original module, version 1.0) removed spikes of the data. A median and 
mean absolute deviation was calculated in 1-dbar pressure bins for both down- 
and up-cast, excluding the flagged values. Values greater than 4 mean absolute 
deviations from the median were marked bad for each bin. This process was 
performed 2 times for temperature, conductivity, SBE 43, and RINKO output.

DERIVE was used to compute oxygen (SBE 43).

BINAVG averaged the data into 1-dbar pressure bins. The center value of the 
first bin was set equal to the bin size. The bin minimum and maximum values are 
the center value plus and minus half the bin size. Scans with pressures greater 
than the minimum and less than or equal to the maximum were averaged. Scans 
were interpolated so that a data record exist every dbar.

DERIVE was re-used to compute salinity, potential temperature, and density 
(sq).

SPLIT was used to split data into the down cast and the up cast. Remaining 
spikes in the CTD data were manually eliminated from the 1-dbar-averaged data. 
The data gaps resulting from the elimination were linearly interpolated with a 
quality flag of 6. Especially for the transmissometer data, relatively large 
data gaps were linearly interpolated for depth range of 257-563 dbar of station 
135_1, 177-182 dbar of station 141_1, and 1794-1849 dbar of station 145_1.


(6) Post-cruise calibration

  i. Pressure

The CTD pressure sensor offset in the period of the cruise was estimated from 
the pressure readings on the ship deck. For best results the Paroscientific 
sensor was powered on for at least 20 minutes before the operation. In order to 
get the calibration data for the pre- and post-cast pressure sensor drift, the 
CTD deck pressure was averaged over first and last one minute, respectively. 
Then the atmospheric pressure deviation from a standard atmospheric pressure 
(14.7 psi) was subtracted from the CTD deck pressure to check the pressure 
sensor time drift. The atmospheric pressure was measured at the captain deck 
(20 m high from the base line) and sub-sampled one-minute interval as a 
meteorological data. Time series of the CTD deck pressure is shown in Fig. 
3.1.1. The CTD pressure sensor offset was estimated from the deck pressure. 
Mean of the pre- and the post-casts data over the whole period gave an 
estimation of the pressure sensor offset (–0.01 dbar) from the pre-cruise 
calibration. The post-cruise correction of the pressure data is not deemed 
necessary for the pressure sensor.

 
Figure 3.1.1: Time series of the CTD deck pressure. Atmospheric pressure 
              deviation (magenta dots) from a standard atmospheric pressure was 
              subtracted from the CTD deck pressure. Blue and green dots 
              indicate pre- and post-cast deck pressures, respectively. Red 
              dots indicate averages of the pre- and the post-cast deck 
              pressures.

 
 ii.  Temperature

The CTD temperature sensors (SBE 3) were calibrated with the SBE 35 under the 
assumption that discrepancies between SBE 3 and SBE 35 data were due to 
pressure sensitivity, the viscous heating effect, and time drift of the SBE 3, 
according to a method by Uchida et al. (2007).

Post-cruise sensor calibration for the SBE 35 was performed at SBE, Inc.

S/N 0022, 3 September 2013 (2nd step: fixed point calibration)

    Slope = 1.000006
    Offset = 0.000187

Offset of the SBE 35 data from the pre-cruise calibration was estimated to be 
smaller than 0.2 mK. So the postcruise correction of the SBE 35 temperature 
data was not deemed necessary for the SBE 35.

The CTD temperature was preliminary calibrated as Calibrated temperature = T – 

                        (c0x P + c1x t + c2 )

where T is CTD temperature in °C, P is pressure in dbar, t is time in days from 
pre-cruise calibration date of the CTD temperature and c0, c1, and c2 are 
calibration coefficients. The coefficients were determined using the data for 
the depths deeper than 950 dbar.

The primary temperature data were basically used for the post-cruise 
calibration. The secondary temperature sensor was also calibrated and used 
instead of the primary temperature data when the data quality of the primary 
temperature data was bad. The calibration coefficients are listed in Table 
3.1.1. The results of the post-cruise calibration for the CTD temperature are 
summarized in Table 3.1.2 and shown in from Fig. 3.1.2 to Fig. 3.1.6.


Table 3.1.1: Calibration coefficients for the CTD temperature sensors.

              Serial 
         Leg  number  c0(°C/dbar)  c1 (°C/day)  c2 (°C)  Station
         ---  ------  -----------  -----------  -------  -------
          1    4815        -            -        0.0009  
          2    4815   –1.54321e–8   2.87072e-5  –0.0071   ~025
                       1.72901e-8  –8.25355e-6   0.0035    026~
          2    1464    9.52754e-8   7.92269e-5  –0.0057   ~025
                       1.09093e-7  –3.12326e-6   0.0011    026~
          3    4815   –4.63955e-9   3.34095e-6   0.0001  
          3    1464    7.28496e-8   1.32368e-5  –0.0006 
 

Table 3.1.2: Difference between the CTD temperature and the SBE 35 after the 
             post-cruise calibration. Mean and standard deviation (Sdev) are 
             calculated for the data below and above 950 dbar. Number of data 
             used is also shown. 

             Leg  Serial  Pressure ≥ 950 dbar    Pressure < 950 dbar 
                  number  Number  Mean  Sdev     Number  Mean  Sdev
                          (mK)    (mK)                   (mK)  (mK)
             ---  ------  ------  ----  ----     ------  ----  ----
              1   4815      18     0.0   0.5        45    1.2  6.9
              2   4815    1056     0.0   0.2      1295    0.4  5.3
              2   1464    1054     0.0   0.2      1306   –0.0  4.8
              3   4815    1010    –0.0   0.2      1246    0.3  4.7
              3   1525    1002     0.0   0.3      1251   –0.6  4.4


Figure 3.1.2: Difference between the CTD temperature (primary) and the SBE 35 
              for leg 1. Blue and red dots indicate before and after the post-
              cruise calibration using the SBE 35 data, respectively. Lower two 
              panels show histogram of the difference after the calibration.

Figure 3.1.3: Same as Fig. 3.1.2, but for leg2.

Figure 3.1.4: Same as Fig. 3.1.2, but for secondary temperature sensor for leg 2.

Figure 3.1.5: Same as Fig. 3.1.2, but for leg 3.

Figure 3.1.6: Same as Fig. 3.1.2, but for secondary temperature sensor for leg 3.


iii.  Salinity

The discrepancy between the CTD conductivity and the conductivity calculated 
from the bottle salinity data with the CTD temperature and pressure data is 
considered to be a function of conductivity, pressure and time. The CTD 
conductivity was calibrated as

Calibrated conductivity = c0 x C + c1 x P + c2 x C x P + c3 x t + c4

where C is CTD conductivity in S/m, P is pressure in dbar, t is time in days 
from 14 April 2009 and c0, c1, c2, c3 and c4 are calibration coefficients. The 
best fit sets of coefficients were determined by a least square technique to 
minimize the deviation from the conductivity calculated from the bottle 
salinity data.

The primary conductivity data created by the software module ROSSUM were 
basically used after the post-cruise calibration for the temperature data. The 
secondary conductivity sensor was also calibrated and used instead of the 
primary conductivity data when the data quality of the primary temperature or 
conductivity data was bad. The coefficients were determined for each leg. The 
calibration coefficients are listed in Table 3.1.3. The results of the post-
cruise calibration for the CTD salinity are summarized in Table 3.1.4 and shown 
in from Fig. 3.1.7 to Fig. 3.1.11.


Table 3.1.3: Calibration coefficients for the CTD conductivity sensors.

Leg  Serial       c0           c1          c2            c3          c4       Station
     Number  [S/(m dbar)]   (1/dbar)   [S/(m day)]     (S/m)
---  ------  ------------  ----------  -----------  -----------  -----------  -------
 1    2854   –7.70527e–5   1.39303e–6  –4.83208e–7  –4.97522e–5   5.04388e–4
 2    2435    1.31818e–4   4.00954e–7  –1.14786e–7  –6.09242e–6  –5.06603e–4
 2    2854    1.02000e–4   1.61048e–7  –4.41938e–8  –4.80557e–6  –4.38375e–4
 3    2435    3.18511e–4   1.06019e–6  –3.37484e–7  –2.48779e–5  –1.11175e–3   ~110
              2.04845e–4   5.84160e–7  –1.79325e–7  –4.40484e–6  –8.93388e–4    111~
 3    2854    1.96052e–4   8.09425e–7  –2.62172e–7  –3.45533e–5  –6.80743e–4
              8.92585e–5  –9.12391e–8   3.75737e–8  –7.47841e–7  –5.49522e–4


Table 3.1.4: Difference between the CTD salinity and the bottle salinity after 
             the post-cruise calibration. Mean and standard deviation (Sdev) 
             (in 10–3) are calculated for the data below and above 950 dbar. 
             Number of data used is also shown. 


             Leg  Serial  Pressure ≥ 950 dbar    Pressure < 950 dbar 
                  number  Number  Mean  Sdev     Number  Mean  Sdev
             ---  ------  ------  ----  ----     ------  ----  ----
              1    2854      18    0.1   0.3        39    1.3   7.5
              2    2435     989    0.0   0.4      1156   –0.5   3.6
              2    2854     987   –0.0   0.4      1167   –0.2   3.6
              3    2435    1006   –0.0   0.4      1225   –0.0   5.5
              3    2854     996   –0.0   0.4      1230    0.1   5.8


Figure 3.1.7:  Difference between the CTD salinity (primary) and the bottle 
               salinity for leg 1. Blue and red dots indicate before and after 
               the post-cruise calibration, respectively. Lower two panels show 
               histogram of the difference after the calibration.

Figure 3.1.8:  Same as Fig. 3.1.7, but for leg 2.

Figure 3.1.9:  Same as Fig. 3.1.7, but for secondary salinity data for leg 2.

Figure 3.1.10: Same as Fig. 3.1.7, but for leg 3.

Figure 3.1.11: Same as Fig. 3.1.7, but for secondary salinity data for leg 3.


 iv.  Oxygen

The RINKO oxygen optode (S/N 0024) was calibrated and used as the CTD oxygen 
data, since the RINKO has a fast time response. The pressure-hysteresis 
corrected RINKO data was calibrated by the modified Stern-Volmer equation, 
basically according to a method by Uchida et al. (2010) with slight 
modification:

    [O2] (μmol/l) = [(V0 / V)1.2 – 1] / Ksv
    Ksv = C0 + C1 x T + C2 x T2
    V0 = 1 + C3 x T
    V = C4 + C5 x Vb + C6 x t + C7 x t x Vb

where Vb is the RINKO output (voltage), V0 is voltage in the absence of oxygen, 
T is temperature in °C, and t is exciting time (days) integrated from the first 
CTD cast for each leg. Time drift of the RINKO output was corrected. The 
calibration coefficients were determined by minimizing the sum of absolute 
deviation with a weight from the bottle oxygen data. The revised quasi-Newton 
method (DMINF1) was used to determine the sets.

The post-cruise calibrated temperature and salinity data were used for the 
calibration. The calibration coefficients are listed in Table 3.1.5. The 
results of the post-cruise calibration for the RINKO oxygen are summarized in 
Table 3.1.6 and shown in from Fig. 3.1.12 to Fig. 3.1.14.


Table 3.1.5: Calibration coefficients for the RINKO oxygen sensors.

Leg       c0           c1           c2            c3            c4          c5
---  -----------  -----------  -----------  ------------  ------------  -----------
 1   4.733362e-3  1.729522e-4  2.164708e-6  -1.431144e-3  -7.402308e-2  3.205825e-1
 2   5.644516e-3  2.046661e-4  2.784686e-6  -3.090264e-3  -0.1119851    0.3162570
 3   4.729148e-3  2.002866e-4  3.871103e-6   8.659935e-4  -9.234123e-2  0.3306834


Table 3.1.5: Continue.

                        Leg       c6           c7
                        ---  ------------  -----------
                         1         -            -
                         2   -1.036494e-4  2.598641e-4
                         3   -2.497366e-4  2.824747e-4


Table 3.1.6: Difference between the RINKO oxygen and the bottle ooxygen after 
             the post-cruise calibration. Mean and standard deviation (Sdev) 
             are calculated for the data below and above 950 dbar. Number of 
             data used is also shown.

        Leg  Serial  Pressure ≥ 950 dbar      Pressure < 950 dbar 
             number  Number  Mean  Sdev       Number  Mean  Sdev
                             [μmol/kg]                 [μmol/kg]
        ---  ------  ------  ----  ----       ------  ----  ----
         1    0024      52   0.00  0.11          40   0.02  0.45
         2    0024     987  –0.01  0.29        1157   0.09  1.00
         3    0024    1009  –0.04  0.29        1245  –0.02  0.90


Figure 3.1.12: Difference between the CTD oxygen and the bottle oxygen for leg 
               1. Blue and red dots indicate before and after the post-cruise 
               calibration, respectively. Lower two panels show histogram of 
               the difference after the calibration.

Figure 3.1.13: Same as Fig. 3.1.12, but for leg 2.

Figure 3.1.14: Same as Fig. 3.1.12, but for leg 3.



  v.  Fluorometer

The CTD fluorometer (FLUOR in μg/L) was calibrated by comparing with the bottle 
sampled chlorophyll-a as

             FLUORc = c0 + c1 x FLUOR + c2 x ln (c3 x FLUOR + 1)

where c0, c1, c2 and c3 are calibration coefficients (Fig. 3.1.15). The CTD 
fluorometer data is slightly noisy so that the up cast profile data which was 
averaged over one decibar agree with the bottle sampled data better than the 
discrete CTD fluorometer data obtained at bottle-firing stop. Therefore, the 
CTD fluorometer data at water sampling depths extracted from the up cast 
profile data were compared with the bottle sampled chlorophyll-a data. The 
bottle sampled data obtained at dark condition [PAR (Photosynthetically 
Available Radiation) < 50 μE/(m2 sec)] were used for the calibration, since 
sensitivity of the fluorometer to chlorophyll a is different at nighttime and 
daytime (see Section 2.4). The calibration coefficients are listed in Table 
3.1.7. The results of the post-cruise calibration for the fluorometer are 
summarized in Table 3.1.8.


Table 3.1.7: Calibration coefficients for the CTD fluorometer.

      Sensor                   c0          c1         c2         c3
      ------------------  -----------  --------   ----------  --------
      Secondary (leg 1)   –0.0245343   0.953320   0.0           0.0
      Secondary           –7.51097e–2  0.234395   5.43321e–2  107.923
       (legs 2 and 3 [for stations 88_2 ~ 148_1])
      Primary             –0.127043    0.246599   8.41309e–2  61.0197
       (leg 3 [for stations 149_1 ~ 166_1])


Table 3.1.8: Difference between the CTD fluorometer and the bottle chlorophyll-
             a after the post-cruise calibration. Mean, standard deviation 
             (Sdev), and number of data used are shown. Data obtained at 
             daytime are also used in this calculation.

                        Number     Mean      Sdev
                        ------  ---------  ---------
                          178   0.03 μg/L  0.10 μg/L


Figure 3.1.15: Comparison of the CTD fluorometer and the bottle sampled 
               chlorophyll-a. The regression lines are also shown.


 vi.  Transmissometer

The transmissometer (Tr in ) is calibrated as

      Tr = (V–Vd) / (Vr–Vd) x 100

wehre V is the measured signal (voltage), Vd is the dark offset for the 
instrument, and Vr is the signal for clear water. Vd can be obtained by 
blocking the light path. Vd and Vair, which is the signal for air, were 
measured on deck before each cast after wiping the optical windows with 
ethanol. Vd was constant (0.0012) during the cruise. Vr is estimated from the 
measured maximum signal in the deep ocean at each cast. Since the 
transmissometer drifted in time (Fig. 3.1.16), Vr is expressed as

      Vr = c0 + c1xt

where t is time (in days) from the first cast for each leg, and c0, c1, and c2 
are calibration coefficients.

The calibration coefficients are listed in Table 3.1.9.


Table 3.1.9: Calibration coefficients for the CTD transmissometer.

       Leg     c0         c1        Vd              Note
       ---  -------  -----------  ------  --------------------------
        1   4.79000       –       0.0012  estimated from station C01
        2   4.78998  –1.05177e–3  0.0012  for stations 001~068
            4.77840  –1.05177e–3  0.0012  for stations C04~074
            4.75812  –1.05177e–3  0.0012  for stations 075~503
        3   4.72956  –1.66124e–3  0.0012 


Figure 3.1.16: Time series of an output signal (voltage) from transmissometer 
               at on deck before CTD casts (Vair) and deep ocean (Vdeep) for 
               leg 2 (upper panel) and leg 3 (lower panel). The black solid 
               line indicates the modeled signal in the deep clear ocean.


vii.  PAR

The PAR sensor was calibrated with an offset correction. The offset was 
estimated from the data measured in the deep ocean during the cruise. The 
corrected data (PARc) is calculated from the raw data (PAR) as follows:

      PARc [μE m–2 s–1] = PAR – 0.046.


References

Edwards, B., D. Murphy, C. Janzen and N. Larson (2010): Calibration, response, 
    and hysteresis in deep-sea dissolved oxygen measurements, J. Atmos. Oceanic 
    Technol., 27, 920–931.

Fukasawa, M., T. Kawano and H. Uchida (2004): Blue Earth Global Expedition 
    collects CTD data aboard Mirai, BEAGLE 2003 conducted using a Dynacon CTD 
    traction winch and motion-compensated crane, Sea Technology, 45, 14–18.

García, H. E. and L. I. Gordon (1992): Oxygen solubility in seawater: Better 
    fitting equations. Limnol. Oceanogr., 37 (6), 1307–1312.

Uchida, H., G. C. Johnson, and K. E. McTaggart (2010): CTD oxygen sensor 
    calibration procedures, The GOSHIP Repeat Hydrography Manual: A collection 
    of expert reports and guidelines, IOCCP Rep., No. 14, ICPO Pub. Ser. No. 
    134.

Uchida, H., K. Ohyama, S. Ozawa, and M. Fukasawa (2007): In situ calibration of 
    the Sea-Bird 9plus CTD thermometer, J. Atmos. Oceanic Technol., 24, 1961–
    1967.



3.2  Bottle Salinity
     October 2, 2014


(1) Personnel

    Hiroshi Uchida (JAMSTEC)
    Tatsuya Tanaka (MWJ) (Legs 1 and 2)
    Hiroki Ushiromura (MWJ) (Leg 3)
    Tamami Ueno (MWJ) (Leg 3)
    Keisuke Tsubata (MWJ) (Leg 2)


(2) Objectives

Bottle salinities were measured to calibrate CTD salinity data.


(3) Instrument and Method

Salinity measurement was conducted basically based on a method by Kawano 
(2010).

 i. Salinity Sample Collection

The bottles in which the salinity samples were collected and stored were 250 ml 
Phoenix brown glass bottles with screw caps. Each bottle was rinsed three times 
with sample water and was filled to the shoulder of the bottle. The caps were 
also thoroughly rinsed. Salinity samples were stored more than 24 hours in the 
same laboratory as the salinity measurement was made.

ii. Instruments and Methods

Salinity of water samples was measured with two salinometers (Autosal model 
8400B; Guildline Instruments Ltd., Ontario, Canada; S/N 62556 for leg 1 and S/N 
62827 for legs 2 and 3), which was modified by adding an peristaltic-type 
intake pump (Ocean Scientific International Ltd., Hampshire, UK) and two 
platinum thermometers (Guildline Instruments Ltd., model 9450). One thermometer 
monitored an ambient temperature and the other monitored a salinometer’s bath 
temperature. The resolution of the thermometers was 0.001°C. The measurement 
system was almost same as Aoyama et al. (2002). The salinometer was operated in 
the air-conditioned laboratory of the ship at a bath temperature of 24°C.

The ambient temperature varied from approximately 20 to 24°C, while the bath 
temperature was stable and varied within ±0.002°C. A measure of a double 
conductivity ratio of a sample was taken as a median of 31 readings. Data 
collection was started after 10 seconds and it took about 10 seconds to collect 
31 readings by a personal computer. Data were sampled for the sixth and seventh 
filling of the cell. In case where the difference between the double 
conductivity ratio of this two fillings was smaller than 0.00002, the average 
value of the two double conductivity ratios was used to calculate the bottle 
salinity with the algorithm for practical salinity scale, 1978 (UNESCO, 1981). 
When the difference was grater than or equal to the 0.00003, we measured 
another additional filling of the cell. In case where the double conductivity 
ratio of the additional filling did not satisfy the criteria above, we measured 
other additional fillings of the cell within 10 fillings in total. In case 
where the number of fillings was 10 and those fillings did not satisfy the 
criteria above, the median of the double conductivity ratios of five fillings 
were used to calculate the bottle salinity.

The measurement was conducted about from 6 to 23 hours per day and the cell was 
cleaned with soap after the measurement for each day. A total of about 5700 
water samples were measured during the cruise.

 
(4) Results

 i. Standard Seawater

Standardization control was set to 688 (leg 1), 509 (leg 2), and 514 (leg 3). 
The value of STANDBY was 5197±0001 (leg 1), 5432±0002 (leg 2), and 5438±0002 
(leg 3), and that of ZERO was 0.00000 or -0.00001 for all legs. We used IAPSO 
Standard Seawater batch P154 whose conductivity ratio is 0.99990 (double 
conductivity ratio is 1.99980) as the standard for salinity measurement. We 
measured 8 (leg 1), 98 (leg 2), and 115 (leg 3) bottles of the Standard 
Seawater during the cruise. Histories of double conductivity ratio measurement 
of the Standard Seawater are shown in Figs. 3.2.1 (leg 1), 3.2.2 (leg 2), and 
3.2.3 (leg 3).

Time drift of the salinometer was corrected by using the Standard Seawater 
measurements. For leg 1, offset of the salinometer was estimated from the 
average of the Standard Seawater measurement for each day because number of 
data was small. For legs 2 and 3, linear time drift of the salinometer was 
estimated from the Standard Seawater measurement by using the least square 
method (thin black lines in Figs. 3.2.2 and 3.2.3). For leg 2, linear time 
drift was calculated for two periods before and after December 15, 2013, 
because tendency of the time drift was changed during the cruise. The average 
of double conductivity ratio was 1.99980 and the standard deviation was 
0.00001, which is equivalent to 0.0002 in salinity after the time drift 
correction.

Figure 3.2.1: History of double conductivity ratio measurement of the Standard 
              Seawater (P154) during leg1. Horizontal and vertical axes 
              represents date and double conductivity ratio, respectively. Blue 
              dots indicate raw data and red dots indicate corrected data.

Figure 3.2.2. Same as Fig. 3.2.1, but for leg 2.

Figure 3.2.3. Same as Fig. 3.2.1, but for leg 3.


 ii. Sub-Standard Seawater 

We also used sub-standard seawater which was deep-sea water filtered by pore 
size of 0.45 μm and stored in a 20 liter cubitainer made of polyethylene and 
stirred for at least 24 hours before measuring. It was measured every 6 samples 
in order to check the possible sudden drift of the salinometer. During the 
whole measurements, there was no detectable sudden drift of the salinometer.

iii. Replicate Samples 

We took 12 (leg 1), 419 (leg 2), and 437 (leg 3) pairs of replicate samples 
during the cruise. Histograms of the absolute difference between replicate 
samples are shown in Figs. 3.2.4 (leg 1), 3.2.5 (leg 2), and 3.2.6 (leg 3). The 
root-mean-squares of the absolute deference were 0.00015 (leg 1), 0.00018 (leg 
2), and 0.00020 (leg 3).

Figure 3.2.4: Histogram of the absolute difference between replicate samples 
              for leg 1. Horizontal axis is absolute difference in salinity and 
              vertical axis is frequency.

Figure 3.2.5. Same as Fig. 3.2.4, but for leg 2.

Figure 3.2.6. Same as Fig. 3.2.4, but for leg 3.

 

References

Aoyama, M., T. Joyce, T. Kawano and Y. Takatsuki (2002): Standard seawater 
    comparison up to P129. Deep- Sea Research, I, Vol. 49, 1103-1114.

Kawano (2010): Salinity. The GO-SHIP Repeat Hydrography Manual: A collection of 
    Expert Reports and Guidelines, IOCCP Report No. 14, ICPO Publication Series 
    No. 134, Version 1.

UNESCO (1981): Tenth report of the Joint Panel on Oceanographic Tables and 
    Standards. UNESCO Tech. Papers in Mar. Sci., 36, 25 pp.








3.3  Density
     September 30, 2014


(1) Personnel

    Hiroshi Uchida (JAMSTEC)


(2) Objectives
 
The objective of this study is to collect absolute salinity (also called 
“density salinity”) data, and to evaluate an algorithm to estimate absolute 
salinity provided along with TEOS-10 (the International Thermodynamic Equation 
of Seawater 2010) (IOC et al., 2010).

 
(3) Materials and methods

Seawater densities were measured during the cruise with an oscillation-type 
density meter (DMA 5000M, serial no. 80570578, Anton-Paar GmbH, Graz, Austria) 
with a sample changer (Xsample 122, serial no. 80548492, Anton-Paar GmbH). The 
sample changer was used to load samples automatically from up to ninetysix 12-
mL glass vials. AC power was supplied to the density meter through a frequency 
conversion AC power supply unit (AA500F, Takasago, Ltd., Japan).

The water samples were collected in 100-mL aluminum bottles (Mini Bottle Can, 
Daiwa Can Company, Japan). The bottles were stored at room temperature (~23 ºC) 
upside down. The bottles were warmed up in a water bath (~30 ºC) for about one 
hour before measurement. The water sample was filled in a 12-mL glass vial and 
the glass vial was sealed with Parafilm M (Pechiney Plastic Packaging, Inc., 
Menasha, Wisconsin, USA) immediately after filling. Densities of the samples 
were measured at 20 ºC by the density meter two times for each bottle and 
averaged to estimate the density. When the difference between the two 
measurements was greater than 0.002, additional measurements were conducted 
until two samples satisfying the above criteria were obtained.

Time drift of the density meter was monitored by periodically measuring the 
density of ultra-pure water (Milli-Q water, Millipore, Billerica, 
Massachusetts, USA) prepared from Yokosuka (Japan) tap water in October 2012. 
The true density at 20 ºC of the Milli-Q water was estimated to be 998.2042 kg 
m–3 from the isotopic composition (δD = –8.76 ‰, δ18O = –56.86 ‰) and 
International Association for the Properties of Water and Steam (IAPWS)-95 
standard. An offset correction was applied to the measured density by using the 
Milli-Q water measurements (ρMilli-Q) with a slight modification of the density 
dependency (Uchida et al., 2011). The offset (ρoffset) of the measured density 
(ρ) was estimated from the following equation:

   ρ       = (ρ       – 998.2042) – (ρ – 998.2042) x 0.000241 [kg m–3].
    offset     Milli-Q

The offset correction was verified by measuring Reference Material for Density 
in Seawater (prototypes Dn-RM1 [100 ml PFA bottle sealed with double aluminum 
bags], Reference Material for Nutrients in Seawater (RMNS) lot BF (Kanso 
Technos Co., Ltd.), and International Association of the Physical Sciences of 
the Ocean (IAPSO) Standard Seawater (SSW) (Ocean Scientific International Ltd., 
Havant, UK) batch P154 along with the Milli-Q water.

Density salinity can be back calculated from measured density and temperature 
(20 ºC) with TEOS-10.

 
(4) Results

Results of density measurements of the Reference Material for Density in 
Seawater (Dn-RM1, RMNS, and IAPSO SSW) were shown in Table 3.3.1 and Table 
3.3.2. Mean densities of the Dn-RM1 were similar for legs 2 and 3, except for 
the results on January 15 and February 2, 2013 (Table 3.3.2). Density of Dn-RM1 
measured at first, middle and last of the series of the measurement of sea 
water samples drifted in time (–0.0004 kg/ m3/hour) for the results on January 
15 and biased (about +0.0196 kg/m3) for the results on February 2. Therefore, 
densities measured on these days were corrected by a time drift correction for 
January 15 and offset correction for February 2 to match the mean density of 
the Dn-RM1 with the average (1024.2605 kg/ m3) for leg 3.

A total of 26 pairs of replicate samples were measured. The root-mean square of 
the absolute difference of replicate samples was 0.0016 g/kg. The measured 
density salinity anomalies (δSA) are shown in Fig. 3.3.1. The measured δSA well 
agree with calculated δSA from Pawlowicz et al. (2011) which exploits the 
correlation between δSA and nutrient concentrations and carbonate system 
parameters based on mathematical investigation using a model relating 
composition, conductivity and density of arbitrary seawaters.


Table 3.3.1: Result of density measurements of the Reference Material for 
             Density in Seawater (prototype Dn-RM1).

Date        Stations          Mean density of  Note
            (sample no.)      Dn-RM1 (kg/m3)
----------  ----------------  ---------------  --------------------------------
Leg 2
2012/12/04  (001,004)           1024.2608
2012/12/06  011                 1024.2626
2012/12/08  018                 1024.2618
2012/12/10  023,027             1024.2624
2012/12/11  404                 1024.2603
2012/12/15  053                 1024.2605
2012/12/17  059                 1024.2604
2012/12/19  064                 1024.2634
2012/12/23  071                 1024.2632
2012/12/25  078                 1024.2618
2012/12/27  085                 1024.2631
2012/12/28  081,083,087,501     1024.2621      bottles #7,9-36 for station 501
2012/12/30  501,503             1024.2611      bottles #1,8 for station 501
                       Average: 1024.2618 ± 0.0011 (n = 13)

Leg 3
2013/01/15  090                 1024.2566*     1024.2600 after drift correction
2013/01/16  094                 1024.2593
2013/01/18  100                 1024.2604
2013/01/19  104                 1024.2610
2013/01/21  111,116             1024.2618
2013/01/23  123                 1024.2607
2013/01/25  128                 1024.2631
2013/01/28  133                 1024.2597
2013/01/30  none                1024.2598
2013/01/31  146,151             1024.2606
2013/02/02  156                 1024.2801*     1024.2601 after bias correction
                                               bottles #1,17-30,32,33,35,36
2013/02/03 162,156,166          1024.2589      bottles #31,34 for station 156
                       Average: 1024.2605 ± 0.0012 (n = 10: exclude data 
                                                    labeled by asterisk)


Table 3.3.2: Comparison of density measurement of the Reference Material for 
             Nutrients in Seawater (lot BF) and IAPSO SSW (batch 154).

Date        Reference  Density [kg/m3]  Note
----------  ---------  ---------------  ----
Leg 2
2012/12/04  RMNS BF    1024.4815
2012/12/06  RMNS BF    1024.4832
2012/12/08  RMNS BF    1024.4824
2012/12/30  RMNS BF    1024.4838
              Average: 1024.4827 ± 0.0010
2012/12/08  SSW  P154  1024.7631
2012/12/08  SSW  P154  1024.7640
2012/12/10  SSW  P154  1024.7642
2012/12/15  SSW  P154  1024.7618
2012/12/23  SSW  P154  1024.7631
2012/12/28  SSW  P154  1024.7640
              Average: 1024.7634 ± 0.0009
Leg 3
2013/01/16  SSW  P154  1024.7626
2013/01/21  SSW  P154  1024.7645
2013/01/31  SSW  P154  1024.7622
              Average: 1024.7631 ± 0.0012


Figure 3.3.1: Vertical distribution of density salinity anomaly measured by the 
              density meter. Absolute Salinity anomaly estimated from nutrients 
              and carbonate parameters (Pawlowicz et al., 2011) are also shown 
              for comparison.

 
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.



3.4  Oxygen
     September 29, 2014


(1) Personnel

    Yuichiro Kumamoto (Japan Agency for Marine-Earth Science and Technology)
    Misato Kuwahara (Marine Works Japan Co. Ltd)
    Kanako Yoshida (Marine Works Japan Co. Ltd)
    Keitaro Matsumoto (Marine Works Japan Co. Ltd)
    TakuhiroOsumi (Marine Works Japan Co. Ltd)


(2) Objectives

Dissolved oxygen is one of good tracers for the ocean circulation. Climate 
models predict a decline in oceanic dissolved oxygen concentration and a 
consequent expansion of the oxygen minimum layers under global warming 
conditions, which results mainly from decreased interior advection and ongoing 
oxygen consumption by remineralization. The mechanism of the decrease, however, 
is still unknown. During MR12-05 cruise, we measured dissolved oxygen 
concentration from surface to bottom layers at all the hydrocast stations in 
the western Pacific and Southern Oceans. Most of the stations reoccupied the 
WOCE Hydrographic Program P14S and S4 stations in the 1990s. Our purpose is to 
evaluate temporal change in dissolved oxygen concentration in the western 
Pacific and Southern Oceans between the 1990s and 2012/13.


(3) Reagents

    Pickling Reagent I: Manganous chloride solution (3M)
    Pickling Reagent II: Sodium hydroxide (8M) / sodium iodide solution (4M)
    Sulfuric acid solution (5M)
    Sodium thiosulfate (0.025M)
    Potassium iodate (0.001667M): Wako Pure Chemical Industries, Ltd., 
        volumetric standard, reference material for iodometry, Lot No.EPR3227, 
        Purity: 99.96±0.01%
    CSK standard of potassium iodate: Lot DCE2131, Wako Pure Chemical 
        Industries Ltd., 0.0100N


(4) Instruments

    Burette for sodium thiosulfate and potassium iodate;
    APB-620 and APB-510 manufactured by Kyoto Electronic Co. Ltd. / 10 cm3 of 
        titration vessel
    Detector; Automatic photometric titrator, DOT-01X manufactured by Kimoto 
        Electronic Co. Ltd.


(5) Seawater sampling

Following procedure is based on a determination method in the WHP Operations 
Manual (Dickson, 1996). Seawater samples were collected from 12-liters Niskin 
sampler bottles attached to the CTD-system. Seawater for bottle oxygen 
measurement was transferred from the Niskin sampler bottle to a volume 
calibrated glass flask (ca. 100 cm3). Three times volume of the flask of 
seawater was overflowed. Sample temperature was measured by a thermometer 
during the overflowing. Then two reagent solutions (Reagent I, II) of 0.5 cm3 
each were added immediately into the sample flask and the stopper was inserted 
carefully into the flask. The sample flask was then shaken vigorously to mix 
the contents and to disperse the precipitate finely throughout. After the 
precipitate has settled at least halfway down the flask, the flask was shaken 
again to disperse the precipitate. The sample flasks containing pickled samples 
were stored in a laboratory until they were titrated.


(6) Sample measurement

At least two hours after the re-shaking, the pickled samples were measured on 
board. A magnetic stirrer bar and 1 cm3 sulfuric acid solution were added into 
the sample flask and stirring began. Samples were titrated by sodium 
thiosulfate solution whose molarity was determined by potassium iodate 
solution. Temperature of sodium thiosulfate during titration was recorded by a 
thermometer. We measured dissolved oxygen concentration using two sets of the 
titration apparatus, named DOT-7 and DOT-8. Dissolved oxygen concentration 
(μmol kg-1) was calculated by the sample temperature during the sampling, 
bottle salinity, flask volume, and titrated volume of the sodium thiosulfate 
solution. When the bottle salinity data is flagged to be 3 (questionable), 4 
(bad), or 5 (missing), CTD salinity (primary) data is referred in the 
calculation alternatively.


(7) Standardization

Concentration of sodium thiosulfate titrant (ca. 0.025M) was determined by 
potassium iodate solution. Pure potassium iodate was dried in an oven at 130°C. 
1.7835 g potassium iodate weighed out accurately was dissolved in deionized 
water and diluted to final volume of 5 dm3 in a calibrated volumetric flask 
(0.001667M). 10 cm3 of the standard potassium iodate solution was added to a 
flask using a volume-calibrated dispenser. Then 90 cm3 of deionized water, 1 
cm3 of sulfuric acid solution, and 0.5 cm3 of pickling reagent solution II and 
I were added into the flask in order. Amount of titrated volume of sodium 
thiosulfate (usually 5 times measurements average) gave the molarity of the 
sodium thiosulfate titrant. Table 3.4.1 shows result of the standardization 
during this cruise. Coefficient of variation (C.V.) for the standardizations 
was 0.02±0.01  (n = 67), c.a. 0.05 μmol kg-1.


(8) Determination of the blank

The oxygen in the pickling reagents I (0.5 cm3) and II (0.5 cm3) was assumed to 
be 3.8x 10-8 mol (Murray et al., 1968). The blank from the presence of redox 
species apart from oxygen in the reagents (the pickling reagents I, II, and the 
sulfuric acid solution) was determined as follows. 1 and 2 cm3 of the standard 
potassium iodate solution were added to two flasks respectively. Then 100 cm3 
of deionized water, 1 cm3 of sulfuric acid solution, and 0.5 cm3 of pickling 
reagent solution II and I each were added into the two flasks in order. The 
blank was determined by difference between the two times of the first (1 cm3 of 
KIO3) titrated volume of the sodium thiosulfate and the second (2 cm3 of KIO3) 
one. The results of 3 times blank determinations were averaged (Table 3.4.1). 
The averaged blank values for DOT-7 and DOT-8 were 0.003±0.001 (standard 
deviation, S.D., n=34) and 0.001±0.001 (S.D., n=33) cm3, respectively.


(9) Replicate sample measurement

From a routine CTD cast at all the stations, a pair of replicate samples was 
collected at four layers of 25, 400, 1500, and 3500 dbars. In order to estimate 
uncertainty including instrumental error, one and the other of the replicate 
sample pair were measured using DOT-7 and DOT-8, respectively. The total number 
of the replicate sample pairs in good measurement (flagged 2) was 550 (Fig. 
3.4.1). The standard deviation of the replicate measurement was 0.09 μmol kg-1 
calculated by a procedure (SOP23) in DOE (1994). The results of the replicate 
measurements are not included in the data sheet.


(10) Duplicate sample measurement

During the leg-1 duplicate samples were taken from 36 Niskin bottles at 
stations C01 and C02 (Table 3.4.2). One and the other of the duplicate sample 
pair were measured using DOT-7 and DOT-8, respectively, in order to estimate 
uncertainty depends on the apparatus. The standard deviation of the duplicate 
measurements at the stations C01 and C02 were calculated to be 0.12 and 0.07 
μmol kg-1, respectively, which were equivalent with that of the replicate 
measurements (see section 9).


(11) CSK standard measurements

The CSK standard is a commercial potassium iodate solution (0.0100 N) for 
analysis of dissolved oxygen. We titrated the CSK standard solutions (Lot 
DCE2131) against our KIO3 standards as samples before and during the cruise 
(Table 3.4.3). A good agreement among them confirms that concentration of the 
KIO3 standards did not change between preparation of the standards onshore and 
the sample measurements on board.

(12) Quality control flag assignment

Quality flag values were assigned to oxygen measurements using the code defined 
in Table 0.2 of WHP Office Report WHPO 91-1 Rev.2 section 4.5.2 (Joyce et al., 
1994). Measurement flags of 2 (good), 3 (questionable), 4 (bad), and 5 
(missing) have been assigned (Table 3.4.4). For the choice between 2, 3, or 4, 
we basically followed a flagging procedure as listed below:

   a. Bottle oxygen concentration at the sampling layer was plotted against 
      sampling pressure. Any points not lying on a generally smooth trend were 
      noted.
   b. Difference between bottle oxygen and CTD oxygen was then plotted against 
      sampling pressure. If a datum deviated from a group of plots, it was 
      flagged 3.
   c. Vertical sections against pressure and potential density were drawn. If a 
      datum was anomalous on the section plots, datum flag was degraded from 2 
      to 3, or from 3 to 4.
   d. If there was problem in the measurement, the datum was flagged 4.
   e. If the bottle flag was 4 (did not trip correctly), a datum was flagged 4 
      (bad). In case of the bottle flag 3 (leaking) or 5 (unknown problem), a 
      datum was flagged based on steps a, b, c, and d.


(13) Results

A notable decrease (increase) in dissolved apparent oxygen utilization (oxygen) 
on density surfaces was found near the bottom (Fig. 3.4.2). The increase 
appears due to density decrease of near-bottom water, which can be explained by 
a change in the mixing ratio of bottom water from near the Ad´elie Depresion 
(Ad´elie Land Bottom Water (ALBW), higher oxygen) with that from the more 
distant Ross Sea (Ross Sea Bottom Water (RSBW), lower oxygen): an increased 
contribution of ALBW and a decreased contribution of RSBW. This change might be 
associated with a decrease in the RSBW supply following an earlier ice-calving 
event in the polynya region. Oxygen rich and dense bottom water observed in 
1995/96 in troughs near 130oE disappeared in 2012/13, which also might reflect 
changes in bottom water production along the coast, possibly in Mertz and 
Dibble Polynyas.

 

References

Dickson, A. (1996) Determination of dissolved oxygen in sea water by Winkler 
    titration, in WHPO Pub. 91-1 Rev. 1, November 1994, Woods Hole, Mass., USA.

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.

Joyce, T., and C. Corry, eds., C. Corry, A. Dessier, A. Dickson, T. Joyce, M. 
    Kenny, R. Key, D. Legler, R. Millard, R. Onken, P. Saunders, M. Stalcup 
    (1994) Requirements for WOCE Hydrographic Programme Data Reporting, WHPO 
    Pub. 90-1 Rev. 2, May 1994 Woods Hole, Mass., USA.

Katsumata, K., H. Nakano, and Y. Kumamoto (in press) Dissolved oxygen change 
    and freshening of Antarctic Bottom Water along 62oS in the Australian-
    Antarctic Basin between 1995/96 and 2012/13, Deep-Sea Res. II.

Murray, C.N., J.P. Riley, and T.R.S. Wilson (1968) The solubility of oxygen in 
    Winkler reagents used for determination of dissolved oxygen, Deep-Sea Res., 
    15, 237-238.


Table 3.4.1: Results of the standardization (End point, E.P.) and the blank 
             determinations (cm3).

Date             KIO3  No.                       DOT-7        DOT-8      
            ——————————————————  Na2S2O3 No.  ————————————  ————————————  Stations
(UTC)       #       ID No.                    E.P.  blank   E.P.  blank
----------  --  --------------  -----------  -----  -----  -----  -----  ------------------------
2012/11/06  03  20120417-03-03  20120615-16  3.970  0.003  3.964  0.002  C01,C02,C03
2012/12/04      20120417-03-11  20120615-16  3.972  0.003  3.967  0.001  008-011
2012/12/06      20120417-03-09  20120615-17  3.969  0.004  3.965  0.001  012-022
2012/12/09      20120417-03-06  20120615-17  3.967  0.002  3.963  0.001  023-027,402,404,406
2012/12/11      20120417-03-10  20120615-18  3.968  0.003  3.964 -0.001  408,410,050-054

2012/12/14  04  20120419-04-01  20120615-18  3.966  0.001  3.962  0.002  055-062
2012/12/16      20120419-04-09  20120615-19  3.969  0.002  3.965  0.001  063-068,C04,069-071
2012/12/21      20120419-04-07  20120615-19  3.966  0.002  3.962  0.001  072-078
2012/12/23      20120419-04-08  20120615-20  3.968  0.002  3.964  0.001  079-085
2012/12/25      20120419-04-03  20120615-20  3.966  0.003  3.962  0.002  086-088,501,502,503
2013/01/08      20120419-04-05  20120615-21  3.970  0.003  3.966  0.001  088-091
2013/01/14      20120419-04-06  20120615-21  3.970  0.002  3.966  0.002  092-102
2013/01/17      20120419-04-02  20120615-22  3.970  0.002  3.967  0.000  103-116

2013/01/20  05  20120419-05-01  20120615-22  3.969  0.003  3.966  0.000  117-122
2013/01/21      20120419-05-02  20120615-23  3.970  0.002  3.966  0.001  123-130,140,139 ,138,137
2013/01/25      20120419-05-03  20120615-23  3.969  0.004  3.966  0.003  136,135,134 ,131,132,133
2013/01/27      20120419-05-05  20120615-24  3.975  0.002  3.971  0.000  141-150
2013/01/29      20120419-05-04  20120615-24  3.970  0.001  3.967  0.000  151-158
2013/02/01      20120419-05-07  20120615-25  3.967  0.002  3.962  0.001  162-165,167,166


Figure 3.4.1: Oxygen difference between measurements of a replicate pair 
              against oxygen concentration.


Table 3.4.2: Results of duplicate sample measurements.

                Leg  Stns  Pressure   Niskins   Apparatus   Oxygen
                            (dbar)                         [umol/kg]
           ---  ---  ----  --------  ---------  ---------  ---------
             1   1   C01    2001.9   18 X12J18    DOT-8     107.29
             2   1   C01    2001.6   17 X12J17    DOT-8     107.42
             3   1   C01    2001.2   16 X12J16    DOT-8     107.41
             4   1   C01    2001.1   15 X12J15    DOT-8     107.56
             5   1   C01    2001.0   14 X12J14    DOT-8     107.48
             6   1   C01    2000.8   13 X12J13    DOT-8     107.45
             7   1   C01    2000.5   12 X12J12    DOT-8     107.45
             8   1   C01    2000.6   11 X12J11    DOT-8     107.47
             9   1   C01    2000.4   10 X12J10    DOT-8     107.34
            10   1   C01    2000.6    9 X12J09    DOT-7     107.23
            11   1   C01    2000.4    8 X12J08    DOT-7     107.16
            12   1   C01    2000.4    7 X12J07    DOT-7     107.23
            13   1   C01    2000.6    6 X12J06    DOT-7     107.21
            14   1   C01    2000.4    5 X12J05    DOT-7     107.27
            15   1   C01    2000.6    4 X12J04    DOT-7     107.18
            16   1   C01    2001.1    3 X12J03    DOT-7     107.32
            17   1   C01    2000.4    2 X12J02    DOT-7     107.38
            18   1   C01    2001.0    1 X12J01    DOT-7     107.33
            19   1   C02    2003.6   36 X12J36    DOT-8     110.46
            20   1   C02    2003.2   35 X12J35    DOT-8     110.35
            21   1   C02    2003.5   34 X12J34    DOT-8     110.43
            22   1   C02    2003.8   33 X12J33    DOT-8     110.51
            23   1   C02    2003.3   32 X12J32    DOT-8     110.51
            24   1   C02    2003.3   31 X12J31    DOT-8     110.47
            25   1   C02    2003.2   30 X12J30    DOT-8     110.43
            26   1   C02    2003.1   29 X12J29    DOT-8     110.50
            27   1   C02    2002.7   28 X12J28    DOT-8     110.44
            28   1   C02    2002.5   27 X12J27    DOT-7     110.43
            29   1   C02    2003.0   26 X12J26    DOT-7     110.36
            30   1   C02    2002.8   25 X12J25    DOT-7     110.41
            31   1   C02    2002.3   24 X12J24    DOT-7     110.34
            32   1   C02    2002.1   23 X12J23    DOT-7     110.40
            33   1   C02    2002.4   22 X12J22    DOT-7     110.31
            34   1   C02    2002.4   21 X12J21    DOT-7     110.41
            35   1   C02    2001.6   20 X12J20    DOT-7     110.30
            36   1   C02    2001.4   19 X12J19    DOT-7     110.34


Table 3.4.3: Results of the CSK standard (Lot DCE2131) measurements.

Date (UTC)    KIO3 ID No.           DOT-1                  -            Remarks
——————————  ——————————————  ————————————————————  ————————————————————  —————————————
                            Conc. (N)  error (N)     -          -    
                            ---------  --------- 
2012/4/25   20120419-04-10  0.010004   0.000002      -          -       Onshore lab.
2012/4/25   20120419-05-10  0.010011   0.000004      -          -       Onshore lab.

                                    DOT-7                 DOT-8
                            ————————————————————  ————————————————————  
                            Conc. (N)  error (N)  Conc. (N)  error (N)
                            ---------  ---------  ---------  ---------
2012/10/6   20120417-03-01  0.009997   0.000004   0.010000   0.000003   MR12-E03
2012/12/14  20120419-04-01  0.009996   0.000003   0.009999   0.000004   MR12-05 Leg-2
2013/01/20  20120419-05-01  0.010012   0.000004   0.010009   0.000004   MR12-05 Leg-3


Table 3.4.4: Summary of assigned quality control flags.

                     Flag  Definition
                     ----  --------------------  ----
                      2    Good                  5657
                      3    Questionable             4
                      4    Bad 0
                      5    Not report (missing)     0
                                          Total  5661


Figure 3.4.2: Differences in apparent oxygen utilization (AOU, μmol kg-1) on 
              density surfaces along WHP-S4 line between 1995/96 and 2012/13 
              (Katsumata et al., in press).





3.5  Nutrients
     January 6, 2015


(1) Personnel

    Michio AOYAMA (Meteorological Research Institute /
             Japan Meteorological Agency, Principal Investigator)

    LEG 2
       Minoru KAMATA (Department of Marine Science, Marine Works Japan Ltd.)
       Yasuhiro ARII (Department of Marine Science, Marine Works Japan Ltd.)
       Kohei MIURA (Department of Marine Science, Marine Works Japan Ltd.)
    LEG 3
       Minoru KAMATA (Department of Marine Science, Marine Works Japan Ltd.)
       Masanori ENOKI (Department of Marine Science, Marine Works Japan Ltd.)
       Elena HAYASHI (Department of Marine Science, Marine Works Japan Ltd.)


(2) Objectives

The objectives of nutrients analyses during the R/V Mirai MR12-05 cruise, WOCE 
P14S, S04 and S04I revisited cruise in 2012/2013, in the Southern Ocean are as 
follows;

- Describe the present status of nutrients concentration with excellent 
  comparability.
- The determinants are nitrate, nitrite, silicate and phosphate.
- Study the temporal and spatial variation of nutrients concentration based on 
  the previous high quality experiments data of WOCE previous P14S, S04 and 
  S04I cruises in 1993 and 2005, GEOSECS, IGY and so on.
- Study of temporal and spatial variation of nitrate: phosphate ratio, so 
  called Redfield ratio.
- Obtain more accurate estimation of total amount of nitrate, silicate and 
  phosphate in the interested area.
- Provide more accurate nutrients data for physical oceanographers to use as 
  tracers of water mass movement.


(3) Summary of nutrients analysis

We made 142 QuAAtro 2-HR runs for the samples at 145 stations in MR12-05. The 
total amount of layers
of the seawater sample reached up to 4292 for MR12-05. We made duplicate 
measurement at all layers.


(4) Instrument and Method

(4.1) Analytical detail using QuAAtro 2-HR systems (BL-Tech)

Nitrate + nitrite and nitrite were analyzed according to the modification 
method of Grasshoff (1970). The sample nitrate was reduced to nitrite in a 
cadmium tube inside of which was coated with metallic copper. The sample 
streamed with its equivalent nitrite was treated with an acidic, sulfanilamide 
reagent and the nitrite forms nitrous acid which reacted with the sulfanilamide 
to produce a diazonium ion. N-1-Naphthylethylenediamine added to the sample 
stream then coupled with the diazonium ion to produce a red, azo dye. With 
reduction of the nitrate to nitrite, both nitrate and nitrite reacted and were 
measured; without reduction, only nitrite reacted. Thus, for the nitrite 
analysis, no reduction was performed and the alkaline buffer was not necessary. 
Nitrate was computed by difference.

The silicate method was analogous to that described for phosphate. The method 
used was essentially that of Grasshoff et al. (1983), wherein silicomolybdic 
acid was first formed from the silicate in the sample and added molybdic acid; 
then the silicomolybdic acid was reduced to silicomolybdous acid, or 
"molybdenum blue" using ascorbic acid as the reductant. The analytical methods 
of the nutrients, nitrate, nitrite, silicate and phosphate, during this cruise 
were same as the methods used in (Kawano et al. 2009).

The phosphate analysis was a modification of the procedure of Murphy and Riley 
(1962). Molybdic acid was added to the seawater sample to form phosphomolybdic 
acid which was in turn reduced to phosphomolybdous acid using L-ascorbic acid 
as the reductant.

The details of modification of analytical methods used in this cruise are also 
compatible with the methods described in nutrients section in GO-SHIP repeat 
hydrography manual (Hydes et al., 2010). The flow diagrams and reagents for 
each parameter are shown in Figures 3.5.1 to 3.5.4.

(4.2) Nitrate Reagents

Imidazole (buffer), 0.06 M (0.4  w/v)
Dissolve 4 g imidazole, C3H4N2, in ca. 1000 ml DIW; add 2 ml concentrated HCl. 
After mixing, 1 ml Triton(R) X-100 (50  solution in ethanol) is added.

Sulfanilamide, 0.06 M (1  w/v) in 1.2 M HCl
Dissolve 10 g sulfanilamide, 4-NH2C6H4SO3H, in 900 ml of DIW, add 100 ml 
concentrated HCl. After mixing, 2 ml Triton(R)X-100 (50 f solution in ethanol) 
is added.

N-1-Napthylethylene-diamine dihydrochloride, 0.004 M (0.1 f w/v)
Dissolve 1 g NEDA, C10H7NHCH2CH2NH2•2HCl, in 1000 ml of DIW and add 10 ml 
concentrated HCl. After mixing, 1 ml Triton(R)X-100 (50 f solution in ethanol) 
is added. 
Stored in a dark bottle.


Figure 3.5.1: NO3 + NO2 (1ch.) Flow diagram.


(4.3) Nitrite Reagents

Sulfanilamide, 0.06 M (1  w/v) in 1.2 M HCl
Dissolve 10 g sulfanilamide, 4-NH2C6H4SO3H, in 900 ml of DIW, add 100 ml 
concentrated HCl. After mixing, 2 ml Triton(R)X-100 (50  solution in ethanol) 
is added.

N-1-Napthylethylene-diamine dihydrochloride, 0.004 M (0.1  w/v)
Dissolve 1 g NEDA, C10H7NHCH2CH2NH2•2HCl, in 1000 ml of DIW and add 10 ml 
concentrated HCl. After mixing, 1 ml Triton(R)X-100 (50 f solution in ethanol) 
is added. This reagent was stored in a dark bottle.


(4.4) Silicate Reagents

Molybdic acid, 0.06 M (2  w/v)
Dissolve 15 g disodium Molybdate (VI) dihydrate, Na2MoO4•2H2O, in 980 ml DIW, 
add 8 ml concentrated H2SO4. After mixing, 20 ml sodium dodecyl sulphate (15  
solution in water) is added.

Oxalic acid, 0.6 M (5  w/v)
Dissolved 50 g oxalic acid anhydrous, HOOC: COOH, in 950 ml of DIW.

Ascorbic acid, 0.01 M (3  w/v)
Dissolved 2.5g L (+)- ascorbic acid, C6H8O6, in 100 ml of DIW. This reagent was 
freshly prepared before every measurement.


Figure 3.5.3: SiO2 (3ch.) Flow diagram.


(4.5) Phosphate Reagents

Stock molybdate solution, 0.03 M (0.8  w/v)
Dissolved 8 g disodium molybdate(VI) dihydrate, Na2MoO4•2H2O, and 0.17 g 
antimony potassium tartrate, C8H4K2O12Sb2•3H2O, in 950 ml of DIW and added 50 
ml concentrated H2SO4.

Mixed Reagent
Dissolved 1.2 g L (+)-ascorbic acid, C6H8O6, in 150 ml of stock molybdate 
solution. After mixing, 3 ml sodium dodecyl sulphate (15  solution in water) 
was added in leg 3 of this cruise, 4 mL sodium dodecyl sulphate (15% solution 
in water) was added in leg 2 because to reduce relatively noisy signals. This 
reagent was freshly prepared before every measurement.

Reagent for sample dilution
Dissolved sodium chloride, NaCl, 10 g in ca. 950 ml of DIW, added 50 ml acetone 
and 4 ml concentrated H2SO4. After mixing, 5 ml sodium dodecyl sulphate (15  
solution in water) was added.


Figure 3.5.4: PO4 (4ch.) Flow diagram.


(4.6) Sampling procedures

Sampling of nutrients followed that oxygen, salinity and trace gases. Samples 
were drawn into two of virgin 10 ml polyacrylates vials without sample drawing 
tubes. These were rinsed three times before filling and vials were capped 
immediately after the drawing. The vials were put into water bath adjusted to 
ambient temperature, 24 ± 2 ºC, in about 30 minutes before use to stabilize the 
temperature of samples in MR12-05.

No transfer was made and the vials were set an auto sampler tray directly. 
Samples were analyzed after collection basically within 24 hours in MR12-05.


(4.7) Data processing

Raw data from QuAAtro 2-HR was treated as follows:
- Checked baseline shift.
- Checked the shape of each peak and positions of peak values taken, and then 
  changed the positions of peak values taken if necessary.
- Carry-over correction and baseline drift correction were applied to peak 
  heights of each samples followed by sensitivity correction.
- Baseline correction and sensitivity correction were done basically using 
  liner regression.
- Loaded pressure and salinity from CTD data to calculate density of seawater.
- Calibration curves to get nutrients concentration were assumed second order 
  equations.


(5) Nutrients standards

(5.1) Volumetric laboratory ware of in-house standards

All volumetric glass ware and polymethylpentene (PMP) ware used were 
gravimetrically calibrated. Plastic volumetric flasks were gravimetrically 
calibrated at the temperature of use within 0 to 4 K.

Volumetric flasks

Volumetric flasks of Class quality (Class A) are used because their nominal 
tolerances are 0.05  or less over the size ranges likely to be used in this 
work. Class A flasks are made of borosilicate glass, and the standard solutions 
were transferred to plastic bottles as quickly as possible after they are made 
up to volume and well mixed in order to prevent excessive dissolution of 
silicate from the glass. High quality plastic (polymethylpentene, PMP, or 
polypropylene) volumetric flasks were gravimetrically calibrated and used only 
within 0 to 4 K of the calibration temperature.

The computation of volume contained by glass flasks at various temperatures 
other than the calibration temperatures were done by using the coefficient of 
linear expansion of borosilicate crown glass.

Because of their larger temperature coefficients of cubical expansion and lack 
of tables constructed for these materials, the plastic volumetric flasks were 
gravimetrically calibrated over the temperature range of intended use and used 
at the temperature of calibration within 0 to 4 K. The weights obtained in the 
calibration weightings were corrected for the density of water and air 
buoyancy.

Pipettes and pipettors

All pipettes have nominal calibration tolerances of 0.1  or better. These were 
gravimetrically calibrated in order to verify and improve upon this nominal 
tolerance.

(5.2) Reagents, general considerations

Specifications

For nitrate standard, “potassium nitrate 99.995 suprapur®” provided by Merck, 
CAS No. : 7757-91-1, was used.

For nitrite standard, “sodium nitrite” provided by Wako, CAS No. : 7632-00-0, 
was used. The assay of nitrite salts was determined according JIS K8019 were 
98.73 . We use that value to adjust the weights taken.

For the silicate standard, we use “Silicon standard solution SiO2 in NaOH 0.5 
mol/l CertiPUR®” provided by Merck, CAS No. : 1310-73-2, of which lot number is 
HC097572 is used. The silicate concentration is certified by NIST-SRM3150 with 
the uncertainty of 0.5 . Factor of HC097572 was signed 1.000, however we 
reassigned the factor as 0.976 from the result of comparison among RMNS in 
MR11-E02 cruise. A history of assigned factor of Merck solutions are shown in 
Table 3.5.1.

For phosphate standard, “potassium dihydrogen phosphate anhydrous 99.995 
suprapur®” provided by Merck, CAS No. : 7778-77-0, was used.


Table 3.5.1: A history of assigned factor of Merck solutions.

       Lot             Factor  Date         Reference
       --------------  ------  -----------  -----------------------
       Merck OC551722  1.001   2006/5/24
       Merck HC623465  1.000  
       Merck HC751838  0.998   2007/4/13
       Merck HC814662  0.999   2008/8/27
       Merck HC074650  0.975  
       Merck HC097572  0.976   MR11-E02     RMNS_BA, AY, BD, BE, BF
                               (2011/06/20)


Ultra pure water

Ultra pure water (MilliQ water) freshly drawn was used for preparation of 
reagents, standard solutions and for measurement of reagent and system blanks.

Low-Nutrient Seawater (LNSW)

Surface water having low nutrient concentration was taken and filtered using 
0.45 μm pore size membrane filter. This water is stored in 20 liter cubitainer 
with paper box. The concentrations of nutrient of this water were measured 
carefully in August 2012.

Treatment of silicate standard due to high alkalinity

Since the silicon standard solution Merck CertiPUR® is in NaOH 0.5 mol/l, we 
need to dilute and neutralize to avoid make precipitation of MgOH2 etc. When we 
make B standard, silicon standard solution is diluted by factor 12 with pure 
water and neutralized by HCl 1.0 mol/l to be about 7. After that B standard 
solution is used to prepare C standards.

(5.3) Concentrations of nutrients for A, B and C standards

Concentrations of nutrients for A, B and C standards are set as shown in Table 
3.5.2. The C standard is prepared according recipes as shown in Table 3.5.3. 
All volumetric laboratory tools were calibrated prior the cruise as stated in 
chapter (i). Then the actual concentration of nutrients in each fresh standard 
was calculated based on the ambient, solution temperature and determined 
factors of volumetric lab. wares.

The calibration curves for each run were obtained using 6 levels, C-1, C-2, C-
3, C-4, C-5 and C-6.


Table 3.5.2: Nominal concentrations of nutrients for A, B and C standards.

                    A      B   C-1  C-2  C-3  C-4  C-5  C-6
                  -----  ----  ---  ---  ---  ---  ---  -----
        NO3(μM)   22500   900   BS   BU   BT   BD   BF   45
        NO2(μM)    4000    20   BS   BU   BT   BD   BF    1.0
        SiO2(μM)  36000  2160   BS   BU   BT   BD   BF  105
        PO4(μM)    3000    60   BS   BU   BT   BD   BF    3.0


Table 3.5.3: Working calibration standard recipes.

        C Std.  B-1 Std.  B-2 Std.
         C-6     25 ml     25 ml
        ————————————————————————————————————————————————————
        B-1 Std.: Mixture of nitrate, silicate and phosphate
        B-2 Std.: Nitrite
        
(5.4) Renewal of in-house standard solutions

In-house standard solutions as stated in (iii) were renewed as shown in Table 
3.5.4 (a) to (c).


Table 3.5.4(a): Timing of renewal of in-house standards.

          NO3, NO2, SiO2, PO4                 Renewal
       ---------------------------  ----------------------------
             A-1 Std. (NO3)               maximum 1 month
             A-2 Std. (NO2)               maximum 1 month
             A-3 Std. (SiO2)        commercial prepared solution
             A-4 Std. (PO4)               maximum 1 month
                B-1 Std.
       (mixture of NO3, SiO2, PO4)            8 days
              B-2 Std. (NO2)                  8 days


Table 3.5.4(b): Timing of renewal of in-house standards.

           Working standards                  Renewal
       ---------------------------  ----------------------------
                C-6 Std.
      (mixture of B-1 and B-2 Std.)          24 hours


Table 3.5.4(c): Timing of renewal of in-house standards for reduction 
                estimation.

           Reduction estimation               Renewal
       ---------------------------  ----------------------------
          D-1 Std.(3600 μM NO3)               8 days
                43 μM NO3               when C Std. renewed
                39 μM NO2               when C Std. renewed


(6) Reference material of nutrients in seawater

To get the more accurate and high quality nutrients data to achieve the 
objectives stated above, huge numbers of the bottles of the reference material 
of nutrients in seawater (hereafter RMNS) are prepared (Aoyama et al., 2006, 
2007, 2008, 2009). In the previous worldwide expeditions, such as WOCE cruises, 
the higher reproducibility and precision of nutrients measurements were 
required (Joyce and Corry, 1994). Since no standards were available for the 
measurement of nutrients in seawater at that time, the requirements were 
described in term of reproducibility. The required reproducibility was 1 , 1 to 
2 , 1 to 3  for nitrate, phosphate and silicate, respectively. Although 
nutrient data from the WOCE one-time survey was of unprecedented quality and 
coverage due to much care in sampling and measurements, the differences of 
nutrients concentration at crossover points are still found among the 
expeditions (Aoyama and Joyce, 1996, Mordy et al., 2000, Gouretski and Jancke, 
2001). For instance, the mean offset of nitrate concentration at deep waters 
was 0.5 μmol kg–1 for 345 crossovers at world oceans, though the maximum was 
1.7 μmol kg–1 (Gouretski and Jancke, 2001). At the 31 crossover points in the 
Pacific WHP one-time lines, the WOCE standard of reproducibility for nitrate of 
1  was fulfilled at about half of the crossover points and the maximum 
difference was 7  at deeper layers below 1.6 ºC in potential temperature 
(Aoyama and Joyce, 1996).

During the period from 2003 to 2010, RMNS were used to keep comparability of 
nutrients measurement among the 8 cruises of CLIVAR project (Sato et al., 
2010), MR10-05 cruise for Arctic research (Aoyama et al., 2010) and MR10-06 
cruise for “Change in material cycles and ecosystem by the climate change and 
its feedback” (Aoyama et al., 2011).


(6.1) RMNSs for this cruise

RMNS lots BS, BU, BT, BD and BF, which cover full range of nutrients 
concentrations in the Southern Ocean are prepared. 82 sets of BS, BU, BT, BD 
and BF are prepared.

One hundred seventy bottles of RMNS lot BV are prepared for MR12-05. Lot BV was 
used all stations. These RMNS assignment were completely done based on random 
number. The RMNS bottles were stored at a room in the ship, REAGENT STORE, 
where the temperature was maintained around 15 – 33 ºC.


(6.2) Assigned concentration for RMNSs

We assigned nutrients concentrations for RMNS lots BS, BU, BT, BD, BV, and BF 
as shown in Table 3.5.5.


Table 3.5.5: Assigned concentration of RMNSs.

                                                 unit: μmol kg–1
                   Nitrate  Phosphate  Silicate      Nitrite
                   -------  ---------  --------  ---------------
            BS*      0.07     0.063      1.61         0.02
            BU*      3.96     0.378     20.27         0.07
            BT*     18.18     1.318     40.94         0.47
            BD*     29.82     2.191     64.30         0.05
            BV**    35.32     2.541     99.55         0.06
            BF***   41.39     2.809    149.71†        0.02
        ——————————————————————————————————————————————————————————————
          * The values are assigned for this cruise on 27 July 2011.
         ** The values are assigned for this cruise on 4 April 2009 
            (Table 3.4.4 in WHP P21 REVISIT DATA BOOK).
        *** The values are assigned for this cruise on 21 August 2012.
          † This value is changed for MR12-05 cruise.
        
        
(6.3) The homogeneity of RMNSs

The homogeneity of lot BV used in MR12-05 cruise and analytical precisions are 
shown in Table 3.5.6. These are for the assessment of the magnitude of 
homogeneity of the RMNS bottles those are used during the cruise. As shown in 
Table 3.5.6 and Figures 3.5.5 to 3.5.7, homogeneity of RMNS lot BV for nitrate, 
phosphate and silicate are the same magnitude of analytical precision derived 
from fresh raw seawater in January 2009.


Table 3.5.6: Homogeneity of lot BV derived from simultaneous 298 samples 
             measurements and analytical precision onboard R/V Mirai in MR12-05.

                            Nitrate  Phosphate  Silicate
                            -------  ---------  --------
                              CV%       CV%        CV%
                 BV          0.13      0.19       0.15
                 Precision   0.10      0.16       0.11
                 BV: N=298   


Figure 3.5.5: Time series of RMNS-BV of nitrate for MR12-05.

Figure 3.5.6: Time series of RMNS-BV of phosphate for MR12-05.

Figure 3.5.7: Time series of RMNS-BV of silicate for MR12-05.


(6.4) Comparability of RMNSs during the periods from 2003 to 2011

Cruise-to-cruise comparability has examined based on the results of the 
previous results of RMNSs measurements obtained among cruises and RMNS 
international comparison experiments in 2003 and 2009. The uncertainties for 
each value were obtained similar method described in 7.1 in this chapter at the 
measurement before each cruise and inter-comparison study, shown as precruise 
and intercomparison, and mean of uncertainties during each cruise, only shown 
cruise code, respectively. As shown in Table 3.5.7, the nutrients 
concentrations of RMNSs were in good agreement among the measurements during 
the period from 2003 to 2011. For the silicate measurements, we show lot 
numbers and chemical company names of each cruise/measurement in the footnote. 
As shown in Table 3.5.7, there shows less comparability among the measurements 
due to less comparability among the standard solutions provided by chemical 
companies in the silicate measurements.


Table 3.5.7(a): Comparability for nitrate.

                                                                             unit: μmol kg–1
Cruise                                    RM Lots
—————————————————————————————————————————————————————————————————————————————————————————————
            BS    unc.   BU     unc.   BT     unc.   BD     unc.    BV    unc.    BF    unc.
          -----  -----  -----  -----  -----  -----  -----  -----  -----  -----  -----  -----
                                          Nitrate
—————————————————————————————————————————————————————————————————————————————————————————————
MR07-04                                                                         41.34  0.083
MR10-05                                             29.80  0.097
MR10-06                                             29.81  0.053                41.41  0.036
MR11-02                                             29.83  0.047                41.39  0.058
MR11-03                               18.11  0.073  29.80  0.053                41.39  0.051
MR11-05                               18.04  0.025  29.89  0.073                41.40  0.075
MR11-08    0.10  0.031   3.97  0.031  18.19  0.054  29.85  0.082                41.45  0.082
MR12-E03   0.08  0.012   3.97  0.017  18.23  0.030  29.86  0.054  
MR12-05    0.07  0.011   3.96  0.012  18.19  0.039  29.82  0.043  35.37  0.046  41.40  0.042
       
       
Table 3.5.7(b): Comparability for Phosphate.

                                                                             unit: μmol kg–1
Cruise                                    RM Lots
—————————————————————————————————————————————————————————————————————————————————————————————
            BS    unc.   BU     unc.   BT     unc.   BD     unc.   BV     unc.   BF     unc.
          -----  -----  -----  -----  -----  -----  -----  -----  -----  -----  -----  -----
                                         Phosphate
—————————————————————————————————————————————————————————————————————————————————————————————
MR07-04                                                                         2.803  0.006
MR10-05                                             2.184  0.011
MR10-06                                             2.182  0.006                2.807  0.007
MR11-02                                             2.187  0.003                2.810  0.006
MR11-03                               1.316  0.011  2.187  0.004                2.815  0.007
MR11-05                               1.313  0.009  2.183  0.007                2.808  0.007
MR11-08   0.064  0.010  0.377  0.007  1.317  0.010  2.190  0.011                2.821  0.009
MR12-E03  0.070  0.007  0.385  0.006  1.331  0.007  2.211  0.007  
MR12-05   0.063  0.003  0.377  0.003  1.319  0.004  2.190  0.004  2.524  0.005  2.818  0.005


Table 3.5.7(c): Comparability for Silicate.

                                                                             unit: μmol kg–1
Cruise                                    RM Lots
—————————————————————————————————————————————————————————————————————————————————————————————
            BS    unc.   BU     unc.   BT     unc.   BD     unc.    BV    unc.    BF    unc.
          -----  -----  -----  -----  -----  -----  -----  -----  -----  -----  ------  ----
                                          Silicate
—————————————————————————————————————————————————————————————————————————————————————————————
MR07-04*                                                                        150.69  1.02
MR10-05                                             64.40  0.10
MR10-06                                             64.47  0.07                 150.40  0.17
MR11-02                                             64.40  0.11                 150.12  0.33
MR11-03                               40.97  0.16   64.43  0.11                 150.14  0.16
MR11-05                               40.96  0.09   64.40  0.07                 150.18  0.13
MR11-08†   1.46  0.15   20.24  0.13   41.02  0.16   64.38  0.19                 149.97  0.32
MR12-E03   1.61  0.04   20.25  0.08   40.89  0.12   64.11  0.18
MR12-05    1.58  0.08   20.23  0.07   40.88  0.10   64.13  0.13   99.50  0.15   149.64  0.26
—————————————————————————————————————————————————————————————————————————————————————————————
List of lot numbers: *: Merck HC623465; †: HC097572


(7) Quality control

(7.1) Precision of nutrients analyses during the cruise

Precision of nutrients analyses during the cruise was evaluated based on the 9 
to 11 measurements, which are measured every 10 to 12 samples, during a run at 
the concentration of C-6 std. Summary of precisions are shown in Table 3.5.8 
and Figures 3.5.8 to 3.5.10, the precisions for each parameter are generally 
good considering the analytical precisions during the Mirai cruses conducted in 
2009 − 2012. During this cruise, analytical precisions were 0.10% for nitrate, 
0.16% for phosphate and 0.11  for silicate in terms of median of precision, 
respectively.


Table 3.5.8: Summary of precision based on the replicate analyses.

                         Nitrate  Phosphate  Silicate
                           CV        CV         CV 
                         -------  ---------  --------
                Median    0.10      0.11       0.16
                Mean      0.10      0.11       0.18
                Maximum   0.23      0.24       0.40
                Minimum   0.04      0.03       0.08
                N         144       144        144


Figure 3.5.8: Time series of precision of nitrate for MR12-05.

Figure 3.5.9: Time series of precision of phosphate for MR12-05.

Figure 3.5.10: Time series of precision of silicate for MR12-05.


(7.2) Carry over

We also summarize the magnitudes of carry over throughout the cruise. These are 
small enough within acceptable levels as shown in Table 3.5.9 and Figures 
3.5.11 – 3.5.13.


Table 3.5.9: Summary of carry over throughout MR12-05 cruise.

                         Nitrate  Phosphate  Silicate
                           CV        CV         CV 
                         -------  ---------  --------
                Median    0.14      0.20       0.34
                Mean      0.14      0.20       0.39
                Maximum   0.23      0.37       0.95
                Minimum   0.03      0.08       0.01
                N         144       144        144


Figure 3.5.11. Time series of carryover of nitrate for MR12-05.

Figure 3.5.12. Time series of carryover of phosphate for MR12-05.

Figure 3.5.13. Time series of carryover of silicate for MR12-05.


(7.2) Estimation of uncertainty of phosphate, nitrate and silicate 
      concentrations

Empirical equations, eq. (1), (2) and (3) to estimate uncertainty of 
measurement of phosphate, nitrate and silicate are used based on measurements 
of 72 sets of RMNSs during the this cruise. These empirical equations are as 
follows, respectively.

Phosphate Concentration Cp in μmol kg–1:

      Uncertainty of measurement of phosphate (%) = 0.05668 + 0.3158 / Cp --- (1)

   where Cp is phosphate concentration of sample.

Nitrate Concentration Cn in μmol kg–1:

      Uncertainty of measurement of nitrate (%) = 0.09216 + 1.0861 / Cn --- (2)

   where Cn is nitrate concentration of sample.

Silicate Concentration Cs in μmol kg–1:

      Uncertainty of measurement of silicate (%) = 0.06383 + 7.436 / Cs --- (3)

   where Cs is silicate concentration of sample.



(8) Problems/improvements occurred and solutions


(8.1)

During this cruise we observed relatively large carryover of phosphate 
measurement especially in leg 3 as shown in Figure 3.5.12. We washed assemblies 
and a flow cell of phosphate channel a few times in leg 3, however relatively 
large carry over did not changed.

We also found that carry over correction on the raw data was considered only 
“High to Low”. An equation of carry over correction is as below

A(i)corrected = A(i) – A(i–1) x k --- (4)

where A(i) is absorbance of sample I, k is carry over coefficient. Although 
this carryover correction method is adopted in AACE software ver 6.07, this 
might make systematic underestimate on the nutrient concentration. A magnitude 
might depend a gradient of nutrient concentration and in case of phosphate it 
is estimated to be about 0.002 μmol kg–1 at 0.005 μmol kg–1 m–1.


(8.2)

After the cruise, we found that LNSW concentration used in this cruise did not 
determined appropriately, especially for phosphate. We overestimate about 0.03 
μmol kg–1. Therefore we corrected these overestimation and decided to report 
phosphate concentration x.xx μmol kg–1 NOT x.xxx μmol kg–1 considering the 
larger uncertainty of phosphate concentration of seawater samples.



References

Aminot, A. and Kerouel, R. 1991. Autoclaved seawater as a reference material 
    for the determination of nitrate and phosphate in seawater. Anal. Chim. 
    Acta, 248: 277–283.

Aminot, A. and Kirkwood, D.S. 1995. Report on the results of the fifth ICES 
    intercomparison exercise for nutrients in sea water, ICES coop. Res. Rep. 
    Ser., 213.

Aminot, A. and Kerouel, R. 1995. Reference material for nutrients in seawater: 
    stability of nitrate, nitrite, ammonia and phosphate in autoclaved samples. 
    Mar. Chem., 49: 221–232.

Aoyama M., and Joyce T.M. 1996, WHP property comparisons from crossing lines in 
    North Pacific. In Abstracts, 1996 WOCE Pacific Workshop, Newport Beach, 
    California.

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

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

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

Aoyama, M., Nishino, S., Nishijima, K., Matsushita, J., Takano, A., Sato, K., 
    2010a. Nutrients, In: R/V Mirai Cruise Report MR10-05. JAMSTEC, Yokosuka, 
    pp. 103–122.

Aoyama, M., Matsushita, J., Takano, A., 2010b. Nutrients, In: MR10-06 
    preliminary cruise report. JAMSTEC, Yokosuka, pp. 69–83

Gouretski, V.V. and Jancke, K. 2001. Systematic errors as the cause for an 
    apparent deep water property variability: global analysis of the WOCE and 
    historical hydrographic data・REVIEW ARTICLE, Progress In Oceanography, 48: 
    Issue 4, 337–402.

Grasshoff, K., Ehrhardt, M., Kremling K. et al. 1983. Methods of seawater 
    anylysis. 2nd rev. Weinheim: VerlagChemie, Germany, West.

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

Joyce, T. and Corry, C. 1994. Requirements for WOCE hydrographic programmed 
    data reporting. WHPO Publication, 90-1, Revision 2, WOCE Report No. 67/91.

Kawano, T., Uchida, H. and Doi, T. WHP P01, P14 REVISIT DATA BOOK, (Ryoin Co., 
    Ltd., Yokohama, 2009).

Kirkwood, D.S. 1992. Stability of solutions of nutrient salts during storage. 
    Mar. Chem., 38 : 151-164.

Kirkwood, D.S. Aminot, A. and Perttila, M. 1991. Report on the results of the 
    ICES fourth intercomparison exercise for nutrients in sea water. ICES coop. 
    Res. Rep. Ser., 174.

Mordy, C.W., Aoyama, M., Gordon, L.I., Johnson, G.C., Key, R.M., Ross, A.A., 
    Jennings, J.C. and Wilson. J. 2000. Deep water comparison studies of the 
    Pacific WOCE nutrient data set. Eos Trans-American Geophysical Union. 80 
    (supplement), OS43.

Murphy, J., and Riley, J.P. 1962. Analyticachim. Acta 27, 31–36.

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

Uchida, H. and Fukasawa, M. WHP P6, A10, I3/I4 REVISIT DATA BOOK Blue Earth 
    Global Expedition 2003 1, 2, (Aiwa Printing Co., Ltd., Tokyo, 2005).


3.6  Chlorofluorocarbons and Sulfur Hexafluoride
     February 1, 2015

(1) Personnel

    Ken’ichi Sasaki (MIO, JAMSTEC)
    Hironori Sato (MWJ)
    Hideki Yamamoto (MWJ)
    Katsunori Sagishima (MWJ)
    Shoko Tatamisashi (MWJ)
    Masahiro Ohrui (MWJ)

(2) Objectives
    
Chlorofluorocarbons (CFCs) and sulfur hexafluoride (SF6) are man – made stable 
gases. These gases can slightly dissolve in sea surface water by air-sea gas 
exchange and then are spread into the ocean interior. These dissolved gases 
could be used as transient chemical tracers for the ocean circulation. We 
measured concentrations of three chemical species of CFCs, CFC-11 (CCl3F), CFC-
12 (CCl2F2) and CFC-113 (C2Cl3F3), and SF6 in seawater on board.

(3) Apparatuses

Measurement of CFCs and SF6 were made with three gas chromatographs attached 
with purging and trapping systems (modified from the original design of 
Bullister and Weiss (1988)). Two of them were SF6/ CFCs simultaneous analyzing 
systems (System A & B). Another one was CFCs analyzing system (System D). These 
purging and trapping systems were developed in JAMSTEC.

(3.1) SF6/CFCs simultaneous analyzing systems (System A &B)

Cold trap columns are 30 cm length stainless steel tubing packed the section of 
5 cm with 100/120 mesh Porapak T and followed by the section of 5 cm of 100/120 
mesh Carboxen 1000. Outer diameters of the main and focus trap columns are 1/8” 
and 1/16”, respectively.

Each gas chromatograph (GC-14B, Shimadzu LTD) has two electron capture 
detectors, ECD1 and ECD2 (both ECDs: ECD-14, Shimadzu LTD). A pre-column is 
Silica Plot capillary column [i.d.: 0.32 mm, length: 10 m, film thickness: 4 
μm]. There are two main analytical columns. Main column 1 (MC1) is MS 5A packed 
column [1/16” OD, 10 cm length stainless steel tubing packed the section of 7 
cm with 80/100 mesh Molecular Sieve 5A] followed by Gas Pro capillary column 
[i.d.: 0.32 mm, length: 35 m] connected up to ECD1 for SF6 and CFC-12. Main 
column 2 (MC2) is Silica Plot capillary column [i.d.: 0.32 mm, length: 30 m, 
film thickness: 4 μm] connected up to ECD2 for CFC-11 and CFC-113.

(3.2) CFCs System (System D)

Cold trap column is 1/16” stainless steel tubing packed with 5 cm of 100/120 
mesh Porapak T.

A Gas chromatograph (GC-14B, Shimadzu LTD) in this system has single ECD (ECD-
14, Shimadzu LTD). A pre column is Silica Plot capillary column [i.d.: 0.53 mm, 
length: 6 m, film thickness: 6 μm]. A main column is Pola Bond-Q capillary 
column [i.d.: 0.53 mm, length: 9 m, film thickness: 10 μm] followed by Silica 
Plot capillary column [i. d.: 0.53 mm, length: 18 m, film thickness: 6 μm].

 
(4) Shipboard measurements

(4.1) Sampling

The marine water sampler was cleaned by diluted acetone before every CTD cast. 
Seawater sub-samples were collected from 12 litter Niskin bottles to 450 ml of 
glass bottles. The sub-sampling bottles were filled by pure nitrogen gas before 
sub-sampling. Two times of the bottle volumes of seawater sample were 
overflowed. The bottles filled by seawater samples were kept in thermostatic 
water bath (7ºC). The CFC and SF6 concentrations were determined within 24 
hours.

In order to confirm stabilities of standard gases and to check saturation 
levels of CFCs and SF6 in sea surface water, mixing ratios of CFCs and SF6 in 
background air collected on high sea were periodically analyzed. Air sample was 
continuously led into the Environmental Research Laboratory of R/V MIRAI by 10 
mm OD Dekaron tubing. The end of the tubing was put on a head of the Compass 
Deck and another end was connected onto an air pump in the laboratory. The 
tubing was relayed by a T-type union which had a small stop cock. Air sample 
was collected from the continuously flowing air into a 200 ml glass syringe 
attached on the cock. Average mixing ratios of the atmospheric CFC-11, CFC-12, 
CFC-113, and SF6 were 229.7 ± 11.7 ppt, 525.4 ± 5.9 ppt, 71.0 ± 3.2 (n ~ 140), 
and 7.60 ± 0.22 ppt (n ~ 90), respectively.

(4.2) Analyses

(4.2.1) SF6/CFCs simultaneous analyses (System A &B)

Constant volume of sample water (200 ml) was taken into a sample loop. The 
aliquot was send into stripping chamber and dissolved gases were extracted by 
pure nitrogen gas purging for 8 minutes. The gaseous sample was dried by 
magnesium perchlorate desiccant and concentrated on a main trap column cooled 
to –80ºC. Stripping efficiencies were frequently confirmed by re-stripping of 
surface layer samples and more than 98 of dissolved SF6 and CFCs were extracted 
on the first purge. Following purging & trapping, the main trap column was 
isolated and heated to 170ºC for 1 minute. The desorbed gases were sent onto 
focusing trap cooled to –80ºC for 30 sec and then the trap was isolated. 
Gaseous sample on the focusing trap were desorbed by heating to170ºC for 1 
minute and led into the pre-column. Sample gases were roughly separated in the 
pre-column. When SF6 and CFC-12 were sent onto MC1 (and CFC-11 and CFC-113 
still remain on the pre-column), main columns were switched (pre-column was 
followed by MC2 and another carrier gas line was connected up to MC1). SF6 and 
CFC-12 were further separated and detected by the ECD1. CFC-11 and CFC-113 led 
onto MC 2 were detected by ECD2. When CFC-113 eluted from pre-column onto MC 2, 
the pre-column was switched onto another line and remaining compounds on the 
pre-column were back flushed. Temperature of the analytical column and ECD was 
95 and 300°C. Mass flow rates of nitrogen gas were 5, 32, 6 and 220 ml/min for 
carrier gases, detector make up gases, back flush gas and seawater sample 
purging, respectively. Gas loops whose volumes were 0.05, 0.15, 0.3, 1, 3 and 
10 ml were used for introducing standard gases into the analytical system. 
Calibration curves were made every several days and standard gas analyses using 
largest loop (10 ml) were performed more frequently to monitor change in the 
detector sensitivity.

(4.2.2) CFCs analyses (System D)

These systems were somewhat simple compared with the system A & B. Volume of 
water sample loop was 50 ml. Gas extraction time was for 8 minutes. Cooling and 
heating temperatures of trap column were –50 and 140ºC, respectively. There was 
not focusing trap in the system. Stripping efficiencies were more than 99.5 % 
of dissolved CFCs on the first purge. Temperatures of the analytical column and 
ECD were 95 and 240°C. Mass flow rates of nitrogen gas were 10, 27, 15 and 120 
ml/min for carrier, detector make up, back flush and seawater sample purging 
gases, respectively. There were three gas loops whose volumes were 1, 3 and 10 
ml, respectively.

(4.2.3) Standard gases

The standard gasses had been made by Japan Fine Products co. ltd. Standard gas 
cylinder numbers used in this cruise were listed in Table 3.6.1. Cylinder of 
CPB15651 was used as reference gas. Precise mixing ratios of CFCs/SF6 in the 
standard gases were calculated by gravimetric data. The standard gases have not 
been calibrated to SIO scale standard gases yet because SIO scale standard 
gasses were hard to obtain due to legal difficulties for CFCs import into 
Japan. The data would be corrected as soon as possible when we obtained the SIO 
scale standard gases.


(5) Quality control

(5.1) Blanks

Blanks (from sub-sampling and analytical systems) are confirmed by several 
analyses of CFC free water which is made from deep water purging by moist 
nitrogen gas in a glass chamber (10 L). Concentrations of CFC-11 and CFC-12 in 
the CFC free water are 0.015 ± 0.009, 0.005 ± 0.004 pmol kg–1 (n = 3), 
respectively. These values are close to previous blanks (0.011 ± 0.003 and 
0.005 ± 0.002 pmol kg–1 for CFC-11 and CFC 12, respectively) estimated from a 
number of analyses (N ≈ 700) of deep water in the North Pacific in 2011 (Sasaki 
et al., 2014). Blank values in this cruise are assumed as equivalent to the 
previously estimated blanks and were subtracted from all data. Significant CFC-
113 and SF6 were not detected in the CFC free water.

(5.2) Major problems

Sensitivities of detectors on the System B were dramatically varied during 
seawater sample analysis for stations P14S-001,-003,-012, -015, -018, -020, -
023, S04-404. A number of measurements for these stations are flagged ‘4’ 
because it is too difficult to define adequate correction factors for the 
sensitivity variations.

(5.3) Precisions

The analytical precisions were estimated from replicate sample analyses (N ~ 
530 pairs for CFC-12, CFC-11, and CFC-113, and 340 pairs for SF6 measurements). 
The replicate samples were collected from four sampling depths which were 
around 50, 600, 1300, and 4000 m depths in every station. Precisions were 
estimated as better than ±0.002 pmol kg–1 or 1 for CFC-11, ±0.004 pmol kg–1 or 
1 for CFC-12, ±0.002 pmol kg–1 or 5 for CFC-113 , and ±0.030 fmol kg–1 or 6% 
for SF6(whichever is greater), respectively.

 
(6) References

Bullister, J.L and Weiss, R.F., Determination of CCl3F and CCl2F2 in seawater 
    and air. Deep Sea Research, 35, 839-853 (1988).

Sasaki, K., K. Sagishima, S. Tatamisashi, H. Sato, and M. Orui, 
    Chlorofluorocarbons and Sulfur Hexafluoride, WHP P10 Revisit in 2011 Data 
    Book, H. Uchida et al. (Eds.), JAMSTEC, Yokosuka, Kanagawa, Japan, 72–75 
    (2014).


Table 3.6.1: Standard gas cylinder list (Japan Fine Products co. ltd.).

    Cylinder No.  Base  CFC-11  CFC-12  CFC-113  SF6       remarks
                        —————————————————————————————
                         ppt     ppt     ppt     ppt
    ———————————————————————————————————————————————————————————————————
      CPB26845    Air    1304    649     130     9.99  SF6/CFC, Leg 2
      CPB25863    Air    1301    649     130    10.00  SF6/CFC, Leg 2,3
      CPB17252    Air    1304    652     130     9.93  SF6/CFC, Leg 3
      CPB30572    Air    1301    651     130     9.98  SF6/CFC, Leg 3
      CPB07911    N2      302    159      30.0   0.0   CFC, Leg 2,3
      CPB15651    N2      299    159      30.2   0.0   CFC, Reference
   
  
3.7  Carbon Items (CT, AT and pH)
     December 19, 2014

(1) Personnel
 
    Akihiko Murata (JAMSTEC)
    Yoshiko Ishikawa (MWJ)
    Tomonori Watai (MWJ)
    Emi Deguchi (MWJ)
    Atsushi Ono (MWJ)
    Keisuke Tsubata (MWJ)

(2) Objectives

According to the latest report from Intergovernmental Panel on Climate Change, 
concentrations of CO2 in the atmosphere have increased by 40% since pre-
industrial times owing to human activities such as burning of fossil fuels, 
deforestation, and cement production. It is evaluated that the ocean has 
absorbed about 30% of the emitted anthropogenic CO2. It is an urgent task to 
estimate as accurately as possible the absorption capacity of the oceans 
against the increased atmospheric CO2, and to clarify the mechanism of the CO2 
absorption, because the magnitude of future global warming depends on the 
levels of CO2 in the atmosphere.

The Southern Ocean is one of the regions where uncertainty of uptake of 
anthropogenic CO2 is large. In this cruise, therefore, we were aimed at 
quantifying how much anthropogenic CO2 is absorbed in the ocean interior of the 
Southern Ocean. For the purpose, we measured CO2-system parameters such as 
dissolved inorganic carbon (CT), total alkalinity (AT) and pH mainly along the 
WHP P14S and S04I lines at ~170°E and ~60°S, respectively, in the Southern 
Ocean.

(3) Apparatus

 i. CT

Measurement of CT was made with two total CO2 measuring systems (called as 
Systems C and D, respectively; Nippon ANS, Inc.), which were slightly different 
from each other. The systems comprised of a seawater dispensing system, a CO2 
extraction system and a coulometer. In this cruise, we used a same type (Model 
3000, Nippon ANS) of coulometers, for Systems C and D, respectively. Each of 
the two systems had almost a same specification as follows:

The seawater dispensing system has an auto-sampler (6 ports), which dispenses 
seawater from a 300 ml borosilicate glass bottle into a pipette of about 15 ml 
volume by PC control. The pipette is kept at 20°C by a water jacket, in which 
water from a water bath set at 20°C is circulated. CO2 dissolved in a seawater 
sample is extracted in a stripping chamber of the CO2 extraction system by 
adding phosphoric acid (~ 10 v/v) of about 2 ml. The stripping chamber is 
approx. 25 cm long and has a fine frit at the bottom. The acid is added to the 
stripping chamber from the bottom of the chamber by pressurizing an acid bottle 
for a given time to push out the right amount of acid. The pressurizing is made 
with nitrogen gas (99.9999). After the acid is transferred to the stripping 
chamber, a seawater sample kept in a pipette is introduced to the stripping 
chamber by the same method as in adding an acid. The seawater reacted with 
phosphoric acid is stripped of CO2 by bubbling the nitrogen gas through a fine 
frit at the bottom of the stripping chamber. The CO2 stripped in the chamber is 
carried by the nitrogen gas (flow rates is 140 ml min-1) to the coulometer 
through a dehydrating module. The modules of Systems C and D consist of two 
electric dehumidifiers (kept at ~4°C) and a chemical desiccant (Mg(ClO4)2).

The measurement sequence such as system blank (phosphoric acid blank), 1.865 
CO2 gas in a nitrogen base, sea water samples (6) is programmed to repeat. The 
measurement of 1.865 CO2 gas is made to monitor response of coulometer 
solutions purchased from UIC, Inc. or laboratory-made.

ii. AT

Measurement of AT was made based on spectrophotometry using a custom-made 
system (Nippon ANS, Inc.). The system comprises of a water dispensing unit, an 
auto-burette (765 Dosimat, Metrohm), and a spectrophotometer (Carry 50 Bio, 
Varian), which are automatically controlled by a PC. The water dispensing unit 
has a water-jacketed pipette and a water-jacketed titration cell. The 
spectrophotometer has a waterjacketed quartz cell, length and volume of which 
are 8 cm and 13 ml, respectively. To circulate sample seawater between the 
titration and the quartz cells, PFA tubes are connected to the cells.

A seawater of approx. 42 ml is transferred from a sample bottle (borosilicate 
glass bottle; 130 ml) into the water-jacketed (25 ºC) pipette by pressurizing 
the sample bottle (nitrogen gas), and is introduced into the water-jacketed (25 
ºC) titration cell. The seawater is circulated between the titration and the 
quartz cells by a peristaric pump to rinse the route. Then, Milli-Q water is 
introduced into the titration cell, and is circulated in the route twice to 
rinse the route. Next, a seawater of approx. 42 ml is weighted again by the 
pipette, and is transferred into the titration cell. The weighted seawater is 
introduced into the quartz cell. Then, for seawater blank, absorbances are 
measured at three wavelengths (750, 616 and 444 nm). After the measurement, an 
acid titrant, which is a mixture of approx. 0.05 M HCl in 0.65 M NaCl and 
bromocresol green (BCG) is added (about 2.1 ml) into the titration cell. The 
seawater + acid titrant solution is circulated for 6 minutes between the 
titration and the quartz cells, with stirring by a stirring tip and bubbling by 
wet nitrogen gas in the titration cell. Then, absorbances at the three 
wavelengths are measured.

Calculation of AT is made by the following equation:

                         A =(−[H+]  V  + M  V )/V  ,
                          T       T  SA   A  A   S

where MA is the molarity of the acid titrant added to the seawater sample, 
[H+]T is the total excess hydrogen ion concentration in the seawater, and VS, 
VA and VSA are the initial seawater volume, the added acid titrant volume, and 
the combined seawater plus acid titrant volume, respectively. [H+]T is 
calculated from the measured absorbances based on the following equation (Yao 
and Byrne, 1998):

pH = -log[H+]  = 4.2699+0.002578(35-S)+log((R-0.00131)/(2.3148-0.1299R))-log(1 0.001005S),
  T          T

where S is the sample salinity, and R is the absorbance ratio calculated as:

                       R = (A   -A   )/(A   -A   ) ,
                             616  750    444  750 

where Ai is the absorbance at wavelength i nm.

The HCl in the acid titrant is standardized on land. The concentrations of BCG 
were estimated to be approx.: 
                                     -6
                              2.0 x 10  M 
in the sample seawater.

iii. pH

Measurement of pH was made by a pH measuring system (Nippon ANS, Inc.). For the 
detection of pH, spectrophotometry was adopted. The system comprises of a water 
dispensing unit and a spectrophotometer (Bio 50 Scan, Varian). For an 
indicator, m-cresol purple (2 mM) was used.

Seawater is transferred from borosilicate glass bottle (300 ml) to a sample 
cell in the spectrophotometer. The length and volume of the cell are 8 cm and 
13 ml, respectively, and the sample cell is kept at 25.00 ± 0.05 ºC in a 
thermostated compartment. First, absorbance of seawater only is measured at 
three wavelengths (730, 578 and 434 nm). Then the indicator is injected and 
circulated for about 4 minutes to mix the indicator and seawater sufficiently. 
After the pump is stopped, the absorbance of seawater + indicator is measured 
at the same wavelengths. The pH is calculated based on the following equation 
(Clayton and Byrne, 1993):

                              ⎛    A1/A2 - 0.00691   ⎞
               pH = pK  + log ⎜----------------------⎟
                      2       ⎝2.2220 - 0.1331(A1/A2)⎠
                             
where A1 and A2 indicate absorbance at 578 and 434 nm, respectively, and pK2 is 
calculated as a function of water temperature and salinity.

 
(4) Shipboard measurement

(4.1) Sampling

 i. CT

All seawater samples were collected from depth with 12 liter Niskin bottles 
basically at every other stations. The seawater samples for CT were taken with 
a plastic drawing tube (PFA tubing connected to silicone rubber tubing) into a 
300 ml borosilicate glass bottle. The glass bottle was filled with seawater 
smoothly from the bottom following a rinse with a seawater of 2 full, bottle 
volumes. The glass bottle was closed by a stopper, which was fitted to the 
bottle mouth gravimetrically without additional force.

At a chemical laboratory on ship, a headspace of approx. 1 of the bottle volume 
was made by removing seawater with a plastic pipette. A saturated mercuric 
chloride of 100 μl was added to poison seawater samples. The glass bottles were 
sealed with a greased (Apiezon M, M&I Materials Ltd) ground glass stopper and 
the clips were secured. The seawater samples were kept at 5°C in a refrigerator 
until analysis. A few hours just before analysis, the seawater samples were 
kept at 20°C in a water bath.

 ii. AT

All seawater samples were collected from depth using 12 liter Niskin bottles 
basically at every other stations. The seawater samples for AT were taken with 
a plastic drawing tube (PFA tubing connected to silicone rubber tubing) into 
borosilicate glass bottles of 130 ml. The glass bottle was filled with seawater 
smoothly from the bottom after rinsing it with a seawater of half a or a full 
bottle volume. A few hours before analysis, the seawater samples were kept at 
25°C in a water bath.

iii. pH

All seawater samples were collected from depth with 12 liter Niskin bottles 
basically at every other stations. The seawater samples for pH were taken with 
a plastic drawing tube (PFA tubing connected to silicone rubber tubing) into a 
300 ml borosilicate glass bottle, which was the same as used for CT sampling. 
The glass bottle was filled with seawater smoothly from the bottom following a 
rinse with a sea water of 2 full, bottle volumes. The glass bottle was closed 
by a stopper, which was fitted to the bottle mouth gravimetrically without 
additional force.  A few hours just before analysis, the seawater samples were 
kept at 25°C in a water bath.

 (4.2) Analysis

 i. CT

At the start of each leg, we calibrated the measuring systems by blank and 5 
kinds of Na2CO3 solutions (nominally 500, 1000 1500, 2000, 2500 μmol/L). As it 
was empirically known that coulometers do not show a stable signal (low 
repeatability) with fresh (low absorption of carbon) coulometer solutions. 
Therefore we measured 2% CO2 gas repeatedly until the measurements became 
stable. Then we started the calibration.

The measurement sequence such as system blank (phosphoric acid blank), 2 CO2 
gas in a nitrogen base, seawater samples (6) was programmed to repeat. The 
measurement of 2 CO2 gas was made to monitor response of coulometer solutions 
(from UIC, Inc. or in-house made). For every renewal of coulometer solutions, 
certified reference materials (CRMs, batch 121, certified value = 2039.26 μmol 
kg-1) provided by Prof. A. G. Dickson of Scripps Institution of Oceanography 
were analyzed. In addition, in-house reference materials (RM) (batch QRM Q23 
and Q26 for leg 2 and leg 3, respectively) were measured at the initial, 
intermediate and end times of a coulometer solution’s lifetime.

The preliminary values were reported in a data sheet on the ship. Repeatability 
and vertical profiles of CT based on raw data for each station helped us check 
performances of the measuring systems.

In the cruise, we finished all the analyses for CT on board the ship. As we 
used two systems, we had not encountered such a situation as we had to abandon 
the measurement due to time limitation.

 ii. AT

We analyzed reference materials (RM), which were produced for CT measurement by 
JAMSTEC, but were efficient also for the monitor of AT measurement. In 
addition, certified reference materials (CRM, batches 121, certified value = 
2225.01 μmol kg-1) were also analyzed periodically to monitor systematic 
differences of measured AT. The reported values of AT were set to be traceable 
to the certified value of the batch 121.

The preliminary values were reported in a data sheet on ship. Repeatability 
calculated from replicate samples and vertical profiles of AT based on raw data 
for each station helped us check performance of the measuring system.

In the cruise, we finished all the analyses for AT on board the ship. We did 
not encounter so serious problems as we had to give up the analyses.

iii. pH

For an indicator solution, m-cresol purple (2 mM) was used. The indicator 
solution was produced on board a ship, and retained in a 1000 ml DURAN® 
laboratory bottle. We renewed an indicator solution 3 times when the headspace 
of the bottle became large, and monitored pH or absorbance ratio of the 
indicator solution by another spectrophotometer (Carry 50 Scan, Varian) using a 
cell with a short path length of 0.5 mm. In most indicator solutions, the 
absorbance ratios of the indicator solution were kept mostly between 1.4 and 
1.6 by adding acid or alkali solution appropriately.

It is difficult to mix seawater with an indicator solution sufficiently under 
no headspace condition. However, by circulating the mixed solution with a 
peristaltic pump, a well-mixed condition came to be attained rather shortly, 
leading to a rapid stabilization of absorbance. We renewed a TYGON® tube of a 
peristaltic pump periodically, when a tube deteriorated.

Absorbances of seawater only and seawater + indicator solutions were measured 
11 times each, and the last value was used for the calculation of pH.

The preliminary values of pH were reported in a data sheet on the ship. 
Repeatability calculated from replicate samples and vertical profiles of pH 
based on raw data for each station helped us check performance of the measuring 
system.

We finished all the analyses for pH on board the ship. We did not encounter so 
serious a problem as we had to give up the analyses.

 (5) Quality control

 i. CT

We conducted quality control of the data after return to a laboratory on land. 
With calibration factors, which had been determined on board a ship based on 
blank and 5 kinds of Na2CO3 solutions, we calculated CT of CRM (batches 121), 
and plotted the values as a function of sequential day, separating legs and the 
systems used. There were no statistically-significant trends of CRM 
measurements.

The repeatability of measurements was estimated to be 0.6 μmol kg-1, which was 
calculated from 274 differences of replicate measurements.

 ii. AT

Temporal changes of AT, which originate from analytical problems, were 
monitored by measuring AT of CRM. We found no abnormal measurements during the 
cruises.

The repeatability of measurements was estimated to be 0.6 μmol kg-1, which was 
calculated from 211 differences of replicate measurements.

iii. pH

It is recommended that correction for pH change resulting from addition of 
indicator solutions is made (Dickson et al., 2007). To check the perturbation 
of pH due to the addition, we measured absorbance ratios by doubling the volume 
of indicator solutions added to a same seawater sample. We corrected absorbance 
ratios based on an empirical method (Dickson et al., 2007), although the 
perturbations were small. Figure 3.7.1 illustrates a perturbation of absorbance 
ratios by adding indicator solutions for leg 2 in MR12-05 cruise. For leg 3, 
the tendency was not significant statistically. Thus for correction, a value of 
6.3364x10-5 was subtracted from the measured values. The reported values, which 
are the total scale, were set to the values at 25°C by the CO2 system 
calculation using data for pH and CT with K1 and K2 from Mehrbach et al. (1973) 
refit by Dickson and Millero (1987).

The repeatability of measurements was estimated to be 0.0005 pH unit, which was 
calculated from 318 differences of replicate measurements.

During the cruise, we measured in-house TRIS buffers to monitor performance of 
the measuring system. Different lots of TRIS buffers were used for legs 2 and 3 
of MR12-05. Averaged differences between measured and calculated pH of the TRIS 
buffers were 0.0089 ± 0.0011 (n=37) and 0.0140 ± 0.0012 (n=36) for legs 2 and 
3, respectively. From these results, we decided to correct measured values of 
pH by subtracting 0.0089 and 0.0140 from the measured values for each cruise.

After correction, we evaluated accuracy of pH values by comparing the corrected 
values with those computed from measured CT and AT. Averaged differences 
(corrected – computed) were 0.0059 ± 0.0054 and -0.0019 ± 0.0056 for legs 2 and 
3, respectively.



References

Clayton T. D. and R. H. Byrne (1993) Spectrophotometric seawater pH 
    measurements: total hydrogen ion concentrtaion scale calibration of 
    m-cresol purple and at-sea results. Deep-Sea Research 40, 2115-2129.

Dickson A. G. and F. J. Millero (1987) A comparison of the equilibrium 
    constants for the dissociation of carbonic acid in seawater media, Deep-Sea 
    Research, 34, 1733–1743.

Dickson, A. G., C. L. Sabine and J. R. Christian eds. (2007), Guide to best 
    practices for ocean CO2 measurements, PICES Special Publication 3, 191 pp.

Mehrbach, C., C. H. Culberson, J. E. Hawley and R. M. Pytkowicz (1973) 
    Measurement of the apparent dissociation constants of carbonic acid in 
    seawater at atmospheric pressure. Limnology and Oceangography, 18, 897-907.

Yao, W. and R. B. Byrne (1998) Simplified seawater alkalinity analysis: Use of 
    linear array spectrometers. Deep-Sea Research 45, 1383-1392.

 
Figure 3.7.1: Perturbation of absorbance ratios by adding indicator. The line 
              was determined by the method of least squares.


3.8  Chlorophyll a
     May 10, 2013

(1) Personnel

    Hiroshi Uchida  (JAMSTEC)
    Osamu Yoshida   (Rakuno Gakuen University) (Leg 3)
    Haruka Tamada   (Rakuno Gakuen University) (Leg 3)
    Yuko Kanayama   (Rakuno Gakuen University) (Leg 3)
    Okura Shinozaki (Rakuno Gakuen University) (Leg 3)
    Kanako Yoshida  (MWJ) (Legs 1, 3)
    Hideki Yamamoto (MWJ) (Leg 2)

(2) Objectives

Chlorophyll a is one of the most convenient indicators of phytoplankton stock, 
and has been used extensively for the estimation of phytoplankton abundance in 
various aquatic environments. In this study, we investigate horizontal and 
vertical distribution of phytoplankton. The chlorophyll a data is also used for 
calibration of fluorometers used in the surface water monitoring and the CTD 
profiler measurements.

(3) Instrument and Method

Seawater samples were collected in 500 or 250 ml brown Nalgene bottles without 
head-space. The whole sampled water were gently filtrated by low vacuum 
pressure (<0.02 MPa) through Whatman GF/F filter (diameter 25 mm) in the dark 
room. Whole volume of each sampling bottle was precisely measured in advance. 
Phytoplankton pigments were immediately extracted in 7 ml of N,N-
dimethylformamide (DMF) after filtration and then, the samples were stored at –
20°C under the dark condition to extract chlorophyll a for more than 24 hours. 
Fluorescence of the extracted samples was measured by the Turner fluorometer 
(10-AU- 005, TURNER DESIGNS) which was previously calibrated against a pure 
chlorophyll a (Sigma-Aldrich Co., LLC). We applied the fluorometric “Non-
acidification method” (Welschmeyer, 1994).

(4) Results

Chlorophyll a data obtained during the cruise are shown in Fig. 3.8.1. To 
estimate measurement precision, 20 pairs of replicate samples were obtained 
from hydrographic casts during leg 3. Ten pairs of the replicate samples were 
collected in 500 ml and 250 ml bottles. Difference between samples collected in 
500 ml and 250 ml was small (≤ 0.02 μg/L). Standard deviation from 20 pairs of 
the replicate samples was 0.018 μg/L, although absolute difference was smaller 
than 0.01 μg/L for 16 pairs of the replicate samples.

 
Figure 3.8.1: Vertical distribution of chlorophyll a obtained from hydrographic 
              casts (closed circles) and surface water monitoring system (open 
              circles).

 
Reference

Welschmeyer, N. A. (1994): Fluorometric analysis of chlorophyll a in the 
    presence of chlorophyll b and pheopigments. Limnor. Oceanogr., 39, 1985-1992.



3.9  LADCP
     September 30, 2014


(1) Personnel

    Shinya Kouketsu   (JAMSTEC)
    Hiroshi Uchida    (JAMSTEC)
    Katsuro Katsumata (JAMSTEC)
    Toshimasa Doi     (JAMSTEC)


(2) Overview of the equipment

An acoustic Doppler current profiler (ADCP) was integrated with the CTD/RMS 
package. The lowered ADCP (LADCP), Workhorse Monitor WHM300 (Teledyne RD 
Instruments, San Diego, California, USA), which has 4 downward facing 
transducers with 20-degree beam angles, rated to 6000 m. The LADCP makes direct 
current measurements at the depth of the CTD, thus providing a full profile of 
velocity. The LADCP was powered during the CTD casts by a 50.4 volts expendable 
Alkali battery pack. The LADCP unit was set for recording internally prior to 
each cast. After each cast the internally stored observed data was uploaded to 
the computer on-board. By combining the measured velocity of the sea water and 
bottom with respect to the instrument, and shipboard navigation data during the 
CTD cast, the absolute velocity profile can be obtained (e.g., Visbeck, 2002).

The instrument used in this cruise was Teledyne RD Instruments, WHM300(S/N 
183240).


(3) Data collection

In this cruise, data were collected with the following configuration.

    Bin size: 4 m
    Number of bins: 25
    Pings per ensemble: 1
    Ping interval: 1 sec


(4) Data collection problems

Echo intensities are sufficiently high along the section (Fig. 3.9.1), except 
at the stations of 9. Since the weak echo were observed for all the beams, the 
weakness was not due to the instrument problem.


Figure 3.9.1: Cast-averaged echo intensities at the first bin. Red, blue, green 
              and orange denote beam 1, 2, 3, and 4 respectively.


(4) Data process

Vertical profiles of velocity are obtained by the inversion method (Visbeck, 
2002). Since the first bin from LADCP is influenced by the turbulence generated 
by CTD frame, the weight for the inversion is set to 0.1. GPS navigation data 
and the bottom-track data are used in the calculation of the reference 
velocities. Shipboard ADCP data averaged for 9 minute are also included in the 
calculation. The CTD data are used for the sound speed and depth calculation. 
The directions of velocity are corrected using the magnetic deviation estimated 
with International Geomagnetic reference field data.

However, the inversion method doesn’t work well due to no-good velocity data 
due to the instrument problems as well as weak echo intensity at deep layers.



Reference

Visbeck, M. (2002): Deep velocity profiling using Lowered Acoustic Doppler 
    Current Profilers: Bottom track and inverse solutions. J. Atmos. Oceanic 
    Technol., 19, 794-807.








3.10  Expendable Microstructure Profiler
      September 30, 2014

(1) Personnel

Katsuro Katsumata (JAMSTEC)

(2) Objectives
 
Turbulence mixing in the ocean has been a diffi cult quantity to measure 
directly despite its important role in the ocean energy budget and general 
circulation dynamics. Recent improvements on materials such as optic fi bre and 
on sensors such as high precision shear probes now enable the measurement using 
expendable microstructure profi lers (XMP).

(3) Apparatus

XMP probe and its tow frame were manufactured by Rockland Scientific 
International, Canada. The expendable sensor has a cylindrical shape with a 
length of about 152 cm and a diameter of 18 cm. Two shear sensors, one 
temperature sensor, a pressure sensor, and an accelerometer are mounted on the 
deeper tip of the cylinder. The tail is fringed with plastic drag brushes to 
stabilise its drop rate.

The shear sensors measure the shear at a 2.5x10-3 s-1 rms resolution. Least 
squares fit of the shear spectrum to the Nasmyth theoretical curve yields an 
estimate of the turbulent kinetic energy dissipation rate. The instrument 
oscillation is measured by the accelerometer and corrected during the spectrum 
estimation

R/V Mirai's A-frame was used to deploy the prove attached to the tow frame. The 
prove was released underwater. The measured data were transmitted to a computer 
in a laboratory through an optic fibre. Twlelve kilometre of the fibre on a 
spool was used and the fibre freely came off the spool as the prove descended 
underwater. The fall rate was about 0.8 m/s initially but slowed down to less 
than 0.5 m/s at 2000 dbar as more fi bre was dragged in the water. The fi bre 
spool was mounted underwater (about 10 m depth) in a tow frame which was towed 
from the stern of the vessel. The vessel travelled no faster than 2 knots 
relative to water.

The turbulent kinetic energy dissipation rate є was estimated by

              __
          15   2
      ε = -- vu   ,
          2    z  

where v is the kinematic molecular viscosity of water and uz is the vertical 
derivative of the horizontal velocity and the overbar denotes a spatial or 
ensemble averaging. Detailed description of the principle and sensors can lsbe 
found in Lueck et al. (2002).

 
(4) Deployments

Six probes were deployed at six different CTD stations right after the CTD 
cast. Two were deployed within an area where, at the time of writing, a problem 
was detected in foreign clearance request documents, hence the data are not 
disclosed. The details of other deployments are shown below. The year is 2012.


      S/N  Latitude    Longitude    Depth   Start (UT)   End (UT)
      ---  ----------  -----------  ------  -----------  ------------
      30   58-01.52°S  173-59.97°E  5201 m  6 Dec 13:06  6 Dec 14:47
      31   58-30.33°S  173-58.98°E  5005 m  6 Dec 20:42  7 Dec 00:11
      28   62-45.99°S  172-12.97°E  4264 m  9 Dec 05:34  9 Dec 05:37
      26   63-59.72°S  171-07.46°E  2557 m  9 Dec 20:55  9 Dec 22:23


(5) Results

The realtime pressure reading indicated that Serial Number (SN) 31 and 26 
survived to the sea bottom. SN 30 and 28 lost connection at about 2500 dbar and 
30 dbar, respectively. Fig. 3.10.1 shows the vertical distribution of the eddy 
kinetic energy dissipation rate, tentatively estimated by quick_look_XMP.m in 
the ODAS library. The method for estimating the dissipation rate follows that 
of Lueck et al. (2002).



References

Lueck, R.G., F. Wolk, and H. Yamazaki (2002) Oceanic Velocity Microstructure 
    Measurements in the 20th Century. Journal of Oceanography 58, 153-174.


Figure 3.10.1: Kinetic energy dissipation rate estimated at intervals of 100-
               300 dbar, 200-400 dbar and so forth using quick_look_XMP.m in 
               the ODAS library. Out of two sensors, the one which produced 
               smaller dissipation estimate was plotted.



Water sample parameters:

                                                     Mnemonic for
     Number  Parameter                     Mnemonic    expected error
     ------  ----------------------------  --------  ----------------
        1    Salinity                      SALNTY
        2    Oxygen                        OXYGEN
        3    Silicate                      SILCAT    SILUNC *1
        4    Nitrate                       NITRAT    NRAUNC *1
        5    Nitrite                       NITRIT    NRIUNC *1
        6    Phosphate                     PHSPHT    PHPUNC *1
        7    Freon-11                      CFC-11
        8    Freon-12                      CFC-12
       12    14Carbon                      DELC14    C14ERR
       13    13Carbon                      DELC13    C13ERR
       20    Ratio of O18 to O16           O18/O16
       22    137Cesium                     CS-137    CS137ER *2
       23    Total carbon                  TCARBN
       24    Total alkalinity              ALKALI
       26    pH                            PH
       27    Freon-113                     CFC113
       28    Carbon tetrachloride          CCL4
       31    Methane                       CH4
       33    Nitrous oxide                 N2O
       34    Chlorophyll-a                 CHLORA
       37    Biogenic sulfur compounds     DMS
       40    Particulate organic carbon    PO14C
       42    Abundance of bacteria         BACT
       47    Plutonium                     PLUTO     PLUTOER *2
       64    Incubation
       81    Particulate organic matter    POM
       82    15N-Nitrate                   15NO3
       83    Particulate inorganic matter  PIM
       89    134Cesium                     CS-134    CS134ER
       90    Perfluoroalkyl substances     PFAS
       91    Iodine-129                    I-129
       92    Density salinity              DNSSAL
       93    Sulfur hexafluoride           SF6
       94    Isoprene
       95    Pigment
       96    Chlorophyll-a isotope


Figure captions

Figure 1:  Station locations for WHP P14S, S04I revisit in 2012 cruise with 
           bottom topography.

Figure 2:  Bathymetry measured by Multi Narrow Beam Echo Sounding system.

Figure 3:  Surface wind measured at 25 m above sea level. Wind data is averaged 
           over 6-hour.

Figure 4:  (a) Sea surface temperature (°C), (b) sea surface salinity (psu), 
           (c) sea surface oxygen (μmol/kg), and (d) sea surface chlorophyll a 
           (mg/m3) measured by the Continuous Sea Surface Water Monitoring 
           System.

Figure 5:  Difference in the partial pressure of CO2 between the ocean and the 
           atmosphere, ΔpCO2.

Figure 6:  Surface current at 100 m depth measured by ship board acoustic 
           Doppler current profiler (ADCP).

Figure 7:  Potential temperature (°C) cross sections calculated by using CTD 
           temperature and salinity data calibrated by bottle salinity 
           measurements. Vertical exaggeration of the 0-6500 m section is 
           1000:1, and expanded section of the upper 1000 m is made with a 
           vertical exaggeration of 2500:1, except for short meridional 
           sections (38°E, 53°E). For the short sections, vertical exaggeration 
           of the 0-6500 m and 0-1000 m section are 250:1 and 625:1, 
           respectively.

Figure 8:  CTD salinity (psu) cross sections calibrated by bottle salinity 
           measurements. Vertical exaggeration is same as Fig. 7.

Figure 9:  Absolute salinity (g/kg) cross sections calculated by using CTD 
           salinity data. Vertical exaggeration is same as Fig. 7.

Figure 10: Density (upper: σ0, lower: σ4) (kg/m3) cross sections calculated by 
           using CTD temperature and salinity data. Vertical exaggeration of 
           the 0-1500 m and 1500-6500 m section are 2500:1 and 1000:1, 
           respectively, except for short meridional sections (38°E, 53°E). For 
           the short sections, vertical exaggeration of the 0-1500 m and 1500-
           6500 m section are 250:1 and 625:1, respectively. (a) EOS- 80 and 
           (b) TEOS-10 definition.

Figure 11: Neutral density (γn) (kg/m3) cross sections calculated by using CTD 
           temperature and salinity data. Vertical exaggeration is same as Fig. 7.

Figure 12: CTD oxygen (μmol/kg) cross sections. Vertical exaggeration is same 
           as Fig. 7.

Figure 13: CTD chlorophyll a (μg/L) cross sections. Vertical exaggeration of 
           the upper 1000 m section is same as Fig. 7.

Figure 14: CTD beam attenuation coefficient (m–1) cross sections. Vertical 
           exaggeration is same as Fig. 7.

Figure 15: Bottle sampled dissolved oxygen (μmol/kg) cross sections. Data with 
           quality flags of 2 were plotted. Vertical exaggeration is same as 
           Fig. 7.

Figure 16: Silicate (μmol/kg) cross sections. Data with quality flags of 2 were 
           plotted. Vertical exaggeration is same as Fig. 7.

Figure 17: Nitrate (μmol/kg) cross sections. Data with quality flags of 2 were 
           plotted. Vertical exaggeration is same as Fig. 7.

Figure 18: Nitrite (μmol/kg) cross sections. Data with quality flags of 2 were 
           plotted. Vertical exaggeration of the upper 1000 m section is same 
           as Fig. 7.

Figure 19: Phosphate (μmol/kg) cross sections. Data with quality flags of 2 
           were plotted. Vertical exaggeration is same as Fig. 7.

Figure 20: Dissolved inorganic carbon (μmol/kg) cross sections. Data with 
           quality flags of 2 were plotted. Vertical exaggeration is same as 
           Fig. 7.

Figure 21: Total alkalinity (μmol/kg) cross sections. Data with quality flags 
           of 2 were plotted. Vertical exaggeration is same as Fig. 7.

Figure 22: pH cross sections. Data with quality flags of 2 were plotted. 
           Vertical exaggeration is same as Fig. 7.

Figure 23: CFC-11 (pmol/kg) cross sections. Data with quality flags of 2 were 
           plotted. Vertical exaggeration is same as Fig. 7.

Figure 24: CFC-12 (pmol/kg) cross sections. Data with quality flags of 2 were 
           plotted. Vertical exaggeration is same as Fig. 7.

Figure 25: CFC-113 (pmol/kg) cross sections. Data with quality flags of 2 were 
           plotted. Vertical exaggeration is same as Fig. 7.

Figure 26: SF6 (fmol/kg) cross sections. Data with quality flags of 2 were 
           plotted. Vertical exaggeration is same as Fig. 7.

Figure 27: Cross sections of current velocity (cm/s) normal to the cruise track 
           measured by LADCP (eastward or northward is positive). Vertical 
           exaggeration is same as Fig. 7.

Figure 28: Difference in potential temperature (°C) between results from the 
           WOCE cruise in 1995/96 and the revisit in 2012/13. Red and blue 
           areas show areas where potential temperature increased and decreased 
           in the revisit cruise, respectively. On white areas differences in 
           temperature do not exceed the detection limit of 0.002°C. Vertical 
           exaggeration is same as Fig. 7.

Figure 29: Same as Fig. 28, but for salinity (psu). CTD salinity data with SSW 
           batch correction1 were used. On white areas differences in salinity 
           do not exceed the detection limit of 0.002 psu.

Figure 30: Same as Fig. 28, but for dissolved oxygen (μmol/kg). CTD oxygen data 
           were used. On white areas differences in dissolved oxygen do not 
           exceed the detection limit of 2 μmol/kg.

Figure 31: Same as Fig. 30, but for bottle sampled dissolved oxygen (μmol/kg).




Note
1. As for the traceability of SSW to Kawano’s value (Kawano et al., 2006), the 
   offset for the batches P108 (WOCE S04P), P114 (WOCE P14S), P123 (WOCE S04), 
   P124 (WOCE I09S), P125 (WOCE S04I) and P155 (the revisit) are 0.0017, 
   0.0020, 0.0007, 0.0006, 0.0002 and 0.0001, respectively. The offset values 
   for the recent batches are listed in Table A1 (Uchida et al., in 
   preparation).




Table A1: SSW batch to batch differences from P145 to P157 (Uchida et al., in 
          preparation). The difference of P145 is reevaluated.

Batch  Production    K15     Sp        Batch to batch difference (x10–3)
no.    date                          Mantyla’s standard  Kawano’s standard
-----  ----------  -------  -------  ------------------  -----------------
P145   2004/07/15  0.99981  34.9925          –2.3              –1.0
P146   2005/05/12  0.99979  34.9917          –2.8              –1.5
P147   2006/06/06  0.99982  34.9929          –1.9              –0.6
P148   2006/10/01  0.99982  34.9929          –1.3               0.0
P149   2007/10/05  0.99984  34.9937          –0.6               0.7
P150   2008/05/22  0.99978  34.9913          –0.6               0.7
P151   2009/05/20  0.99997  34.9984          –1.7              –0.4
P152   2010/05/05  0.99981  34.9926          –1.3               0.0
P153   2011/03/08  0.99979  34.9918          –0.9               0.4
P154   2011/10/20  0.99990  34.9961          –0.7               0.6
P155   2012/09/19  0.99981  34.9925          –1.2               0.1
P156   2013/07/23  0.99984  34.9937          –0.9               0.4
P157   2014/05/15  0.99985  34.9941          –2.0              –0.7



Reference

Kawano, T., M. Aoyama, T. Joyce, H. Uchida, Y. Takatsuki and M. Fukasawa 
    (2006): The latest batch-to-batch difference table of standard seawater and 
    its application to the WOCE onetime sections, J. Oceanogr., 62, 777–792.




CCHDO Data Processing Notes

Leg 3 (449NZ20130106)

Date       2013-11-05
Data Type  BTL/CTD
Action     Submitted
Summary    to go online
Name       Hiroshi Uchida
Note       Documents will be submitted later. 


Date       2013-11-07
Data Type  CTD
Action     Website Update
Summary    Available under 'Files as received'
Name       CCHDO Staff
Note       The following files are now available online under 'Files as 
           received', unprocessed by the CCHDO.  49NZ20130106_ct1.zip


Date       2013-11-07
Data Type  SUM
Action     Website Update
Summary    Available under 'Files as received'
Name       CCHDO Staff
Note       The following files are now available online under 'Files as 
           received', unprocessed by the CCHDO.  49NZ20130106_sum.txt             


Date       2014-03-13
Data Type  CTD_SUM
Action     Website Update
Summary    CTD and SUM files online
Name       Carolina Berys
Note       =========================================== 
           S04I 2013 49NZ20130106 processing - CTD/SUM 
           ===========================================  
           2014-03-13  
           C Berys  
           .. contents:: :depth: 2  
          
           Submission 
           ==========  
           
           ==================== ============ ========== ========= ==== 
           filename             submitted by date       data type id   
           ==================== ============ ========== ========= ==== 
           49NZ20130106_ct1.zip cchdo_admin  2013-11-07 CTD       1095 
           49NZ20130106_sum.txt cchdo_admin  2013-11-07 SUM       1095 
           ==================== ============ ========== ========= ====  
           
           Parameters 
           ----------  
           49NZ20130106
           _ct1.zip 
           ~~~~~~~~~~~~~~~~~~~~ 
           - CTDPRS [1]_ 
           - CTDTMP [1]_ 
           - CTDSAL [1]_ 
           - CTDOXY [1]_ 
           - XMISS [1]_ [3]_ 
           - FLUOR [1]_ [3]_ 
           - XMISSCP [3]_ 
           - PAR [1]_ [3]_  
          
           .. [1] parameter has quality flag column 
           .. [2] parameter only has fill values/no reported measured data 
           .. [3] not in WOCE bottle file 
           .. [4] merged, see merge_  
           
           Process 
           =======  
           Changes 
           -------  
           
           49NZ20130106_ct1.zip 
           ~~~~~~~~~~~~~~~~~~~~ 
           - Comma removed from units line and data lines 
           - added END_DATA  
           
           49NZ20130106_sum.txt 
           ~~~~~~~~~~~~~~~~~~~~ 
           - none  
           
           .. _merge:  
           
           Merge 
           ----- 
           - none  
           
           Conversion 
           ----------  
           
           ======================= ==================== ======================== 
           file                    converted from       software                 
           ======================= ==================== ======================== 
           18HU19990627_nc_ctd.zip 18HU19990627_ct1.csv hydro 0.8.0-110-g7da02f9 
           ======================= ==================== ========================  
           
           All converted files opened in JOA with no apparent problems.  
           
           Directories 
           =========== 
           :working directory:   
           /data/co2clivar/southern/s04/s04i_49NZ20130106/original/2014.03.13_CTD_SUM_CBG 
           :cruise directory:   
           /data/co2clivar/southern/s04/s04i_49NZ20130106  
           
           Updated Files Manifest 
           ====================== 
           ======================= =================== 
           file                    stamp               
           ======================= =================== 
           49NZ20130106_nc_ctd.zip 20130515JAMSTECRIGC 
           49NZ20130106su.txt                          
           49NZ20130106_ct1.zip    20130515JAMSTECRIGC 
           ======================= ===================