If symbols do not display correctly change your browser character encoding to unicode CRUISE REPORT: P21 (Updated NOV 2011) HIGHLIGHTS CRUISE SUMMARY INFORMATION WOCE Section Designation P21 leg 1 P21 Leg 2 Expedition designation (ExpoCodes) 49NZ20090410 49NZ20090521 Chief Scientists Akihiko Murata/JAMSTEC Hiroshi Uchida/JAMSTEC Dates 2009-04-10 - 2009-05-19 2009-05-21 - 2009-06-19 Ship R/V Mirai R/V Mirai Ports of call Valparaiso, Chile - Papeete, Tahiti - Papeete, Tahiti Brisbane, Australia 15° 29.52'S Geographic Boundaries 153° 44.52'E 75° 09.86'W 24° 59.81'S Stations 140 117 Floats and drifters deployed 5 Argo floats 0 Moorings deployed or recovered 0 0 Recent Contact Information: Akihiko Murata Hiroshi Uchida akihiko.murata@jamstec.go.jp 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: +81-46-867-9455 WHP P21 REVISIT DATA BOOK Edited by Hiroshi Uchida (JAMSTEC) Akihiko Murata (JAMSTEC) Toshimasa Doi (JAMSTEC) WHP P21 REVISIT DATA BOOK March 25, 2011 Published Edited by Hiroshi Uchida (JAMSTEC), Akihiko Murata (JAMSTEC) and Toshimasa Doi (JAMSTEC) Published by © JAMSTEC, Yokosuka, Kanagawa, 2011 Japan Agency for Marine-Earth Science and Technology 2-15 Natsushima, Yokosuka, Kanagawa. 237-0061, Japan Phone +81-46-867-9474, Fax +81-46-867-9455 Printed by Aiwa Enterprise, Ltd. 3-22-4 Takanawa, Minato-ku, Tokyo 108-0074, Japan CONTENTS Preface M Fukasawa (JAMSTEC) Documents and station summary files 1. Cruise Narrative A. Murata, H. Uchida and K Sasaki (JAMSTEC) 2. Underway Measurements 2.1 Navigation and Bathymetry S. Okumura (GODI) et al., T Matsumoto (Univ. Ryukyu) et al. 2.2 Surface Meteorological Observation K Yoneyama (JAMSTEC) et al. 2.3 Thermo-Salinograph and Related Measurements Y Kumamoto (JAMSTEC) et al. 2.4 Underway pCO2 A. Murata (JAMSTEC) et al. 2.5 Acoustic Doppler Current Profiler S. Kouketsu (JAMSTEC) et al. 2.6 XCTD H. Uchida (JAMSTEC) et al. 3. Hydrographic Measurement Techniques and Calibrations 3.1 CTDO2 Measurements H. Uchida (JAMSTEC) et al. 3.2 Bottle Salinity T Kawano (JAMSTEC) et al. 3.3 Oxygen Y Kumamoto (JAMSTEC) et al. 3.4 Nutrients M Aoyama (MRI/JMA) et al. 3.5 Chlorofluorocarbons (CFCs) K Sasaki (JAMSTEC) et al. 3.6 Dissolved Inorganic Carbon (CT) A. Murata (JAMSTEC) et al. 3.7 Total Alkalinity (AT) .. A. Murata (JAMSTEC) et al. 3.8 pH (pHT) A. Murata (JAMSTEC) et al. 3.9 LADCP S. Kouketsu (JAMSTEC) et al. Figures (see PDF doc) Figure captions Station locations Bathymetry Surface wind Sea surface temperature Sea surface salinity ∆pCO2 Surface current Cross-sections Potential temperature CTD salinity Absolute salinity Density (σ0) Density (σ4) Density(γn) CTD oxygen Bottle sampled oxygen Silicate Nitrate Nitrite Phosphate Dissolved inorganic carbon (CT) Total alkalinity (AT) pH (pHT) CFC-11 CFC-12 CFC -113 Velocity Difference between WOCE and the revisit Potential temperature Salinity CTD oxygen CCHDO Data Processing Notes PREFACE P21 was the WOCE one time survey line located slightly in the south of the boundary between two gyre systems of the Equatorial Counter Current and the South Equatorial Current. In 1994, WOCE hydrographic observations were carried out by United States along the line. After this cruise, P21 was not revisited though there is a great possibility that repeat observations along this line could detect decadal or long-time scale variability of low latitudinal gyre system. In 2008, the research system of JAMSTEC was re-organized. As the result, Institute of Observational Research for Global Change (IORGC) and Frontier Research Center for Global Change (FRCGC) were merged to form a new research organization of Research Institute for Global Change (RIGC). The General Ocean Circulation Research Program of former IORGC, which had been the main driver of CLIVAR Carbon Repeat Hydrography (CCRH) in Japan, was also developed into the Ocean Climate Change Research Program of new RIGC including Argo Group of former IORGC and Ocean assimilation Group of former FRCGC together. P21 revisit cruise reported in this data book was the first CCRH cruise carried out under the new program of the Ocean Climate Change Research Program of RIGC. Also, it may be better to note here that this revisit-cruise was planned and proposed by bio-geochemical oceanographer in the program. One of distinct scientific outcomes from bio-geochemical researchers in the program was the discovery of the considerable acceleration in the CO2 up-taking ratio and rapid increase in CO2 accumulation of the South Pacific during these decades. P01, P02, P03, P10, P06 and P14 data were analyzed comprehensively but the Equator-ward extent of the CO2 related issues mentioned above were left to be examined. So, this is the biggest reason why P21 was selected to be revisited in spite of the fact that P21 was not included in the recommended repeat line in the strategy of the Global Ocean Ship-Based Hydrographic Investigation Program (GOSHIP). After OceanObs09 in Venice, quite a few discussions were held on the sustainability of ocean observation and many proposals were published. GOSHIP strategy, which had been discussed since 2008 and was adopted in 2010 finally, is one of answers to those discussions and proposals. The basic and important concept of the strategy is to maintain some of WOCE hydrographic lines by repeat observations along them as a strong tool of ocean monitoring to detect decadal changes in the global oceanic conditions especially in the Meridional Overturn Circulation System. We, ocean climate researchers in JAMSTEC, have carried out revisit cruises along eight WOCE one-time lines so far. However, as long as our activity concerns, P01 is the only line where we repeated observations twice. I strongly hope and believe that we will be able to have repeat observation along all of eight lines in near future to make the strategy of GO-SHIP real and effective. On the day of Japan Northern Territory* Masao Fukasawa Research Director of RIGC/JAMSTEC * On 7th February 1855, The Japan-Russia Treaty of Peace and Amity was ratified in which Etorofu, Kunashiri, Sikotan and Habomai islands are defined as Japan territory. 1 CRUISE NARRATIVE 1.1 HIGHLIGHT GHPO Section Designation: P21 Cruise code: MR09-01 Expedition Designation: 49NZ20090410 49NZ20090521 Chief Scientists and Affiliation: Leg.1: Akihiko Murata akihiko.murata@jamstec.go.jp Leg.2: Hiroshi Uchida huchida@jamstec.go.jp Leg.3: Kenichi Sasaki ksasaki@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: +81-46-867-9455 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: +81-46-867-9455 Ship: R/V Mirai Ports of Call: Leg 1: Valparaiso, Chile - Papeete, Tahiti Leg 2a: Papeete, Tahiti - Papeete, Tahiti Leg 2b: Papeete, Tahiti - Brisbane, Australia Leg 3: Brisbane, Australia - Moji, Japan Cruise Dates: Leg 1: April 10, 2009 - May 19, 2009 Leg 2a: May 21, 2009 - May 24, 2009 Leg 2b: May 25, 2009 - June 19, 2009 Leg 3: June 20, 2009 - July 3, 2009 Number of Stations: 257 stations for CTD/Carousel Water Sampler (Leg 1: 140, Leg 2a: 8, Leg 2b: 109) Geographic Boundaries (for hydrographic stations): 24° 59.81' S - 15° 29.52' S 153° 44.52' E - 75° 09.86' W Floats and Drifters Deployed: 5 Argo floats Mooring Deployed or Recovered Mooring: None 1.2 CRUISE SUMMARY (1) Station occupied A total of 257 stations was occupied using a Sea-Bird Electronics 36 position carousel equipped with 12 litter Niskin-X water sample bottles, a SBE 9/11plus equipped with SBE35 deep ocean standards thermometer, SBE43 oxygen sensor, AANDERAA Optode 3830 and 4330F oxygen sensors, JFE Alec RINKO oxygen sensor, Seapoint Sensors fluorometer, WET labs C-Star transmissometer, Benthos altimeter, and RDI ADCP. XCTDs were deployed at 23 stations. XMPs (eXpendable Microstructure Profiler) were also deployed at 3 stations. Cruise track and station location are shown in Figure 1.2.1. (2) Sampling and measurements Water samples were analyzed for salinity, oxygen, nutrients, CFC-11, -12, -113, total alkalinity, DIC, and pH. The sampling layers are coordinated as so-called staggered mesh. Samples for 14C, 13C, methane, nitrous oxide, carbonyl sulfide, chlorophyll a, PON, POC, 15N-nitrate, ammonia, and a biological study were also collected at the selected stations. The bottle depth diagram is shown in Figure 1.2.2. Underway pCO2, temperature, salinity, oxygen, surface current, bathymetry, and meteorological measurements were conducted along the cruise track. (3) Floats deployment Five ARGO floats were launched along the cruise track. The launched positions of the ARGO floats are listed in Table 1.2.1. Table 1.2.1: Launched positions of the ARGO floats. _______________________________________________________________________ Float ARGOS Date and time Date and time Location CTD S/N ID of reset (UTC) of launch (UTC) of launch station no. ----- ----- -------------- --------------- ----------- ----------- 4099 86536 2009/05/01 2009/05/01 16-45.21 S P21-080 18:45 20:03 105-20.41 W 4042 86510 2009/05/03 2009/05/03 16-44.51 S P21-087 08:16 09:15 107-19.90 W 4101 86537 2009/05/04 2009/05/04 16-45.05 S P21-095 05:54 06:35 109-59.34 W 4043 86511 2009/05/05 2009/05/05 16-44.99 S P21-099 04:05 04:52 112-41.19 W 4102 86538 2009/05/05 2009/05/05 16-45.33 S P21-102 18:37 19:37 114-40.55 W _______________________________________________________________________ Figure 1.2.2: Bottle depth diagram 1.3 LIST OF PRINCIPAL INVESTIGATOR AND PERSON IN CHARGE ON THE SHIP The principal investigator (PI) and the person in charge responsible for major parameters measured on the cruise 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 ON THE SHIP ----------- ------------------------------------ ----------------------------------- UNDERWAY ADCP Shinya Kouketsu (JAMSTEC) Shinya Okumura (GODI) (leg 1) skouketsu@jamstec.go.jp Satoshi Okumura (GODI) (leg 2) Souichiro Sueyoshi (GODI) (leg 3) Bathymetry Takeshi Matsumoto (Univ. of Ryukyus) Shinya Okumura (GODI) (leg 1) tak@sci.u-ryukyu.ac.jp Satoshi Okumura (GODI) (leg 2) Masao Nakanishi (Chiba Univ.) Souichiro Sueyoshi (GODI) (leg 3) nakanisi@earth.s.chiba-u.ac.jp Meteorology Kunio Yoneyama (JAMSTEC) Shinya Okumura (GODI) (leg 1) yoneyamak@jamstec.go.jp Satoshi Okumura (GODI) (leg 2) Souichiro Sueyoshi (GODI) (leg 3) T-S Yuichiro Kumamoto (JAMSTEC) Miyo Ikeda (MWJ) (leg 1, 2) kumamoto@jamtec.go.jp Fuyuki Shibata (MWJ) (leg 3) pCO2 Akihiko Murata (JAMSTEC) Minoru Kamata (MWJ) (leg 1, 2) akihiko.murata@jamstec.go.jp Yasuhiro Arii (MWJ) (leg 3) HYDROGRAPHY CTD/O2 Hiroshi Uchida (JAMSTEC) Kenichi Katayama (MWJ) (leg 1) huchida@jamstec.go.jp Tomoyuki Takamori (MWJ) (leg 2) XCTD Hiroshi Uchida (JAMSTEC) Shinya Okumura (GODI) (leg 1) huchida@jamstec.go.jp Satoshi Okumura (GODI) (leg 2) LADCP Shinya Kouketsu (JAMSTEC) Shinya Kouketsu (JAMSTEC) (leg 1) skouketsu@jamstec.go.jp Katsuro Katsumata (JAMSTEC) (leg 2) Salinity Takeshi Kawano (JAMSTEC) Tatsuya Tanaka (MWJ) (leg 1) kawanot@jamstec.go.jp Fujio Kobayashi (MWJ) (leg 2) Oxygen Yuichiro Kumamoto (JAMSTEC) Fuyuki Shibata (MWJ) (leg 1) kumamoto@jamstec.go.jp Miyo Ikeda (MWJ) (leg 2) Nutrients Michio Aoyama (MRI) Ayumi Takeuchi (MWJ) (leg 1) maoyama@mri-jma.go.jp Junji Matsushita (MWJ) (leg 2) DIC Akihiko Murata (JAMSTEC) Minoru Kamata (MWJ) akihiko.murata@jamstec.go.jp Alkalinity Akihiko Murata (JAMSTEC) Tomonori Watai (MWJ) (leg 1) akihiko.murata@jamstec.go.jp Yoshiko Ishikawa (MWJ) (leg 2) pH Akihiko Murata (JAMSTEC) Tomonori Watai (MWJ) (leg 1) akihiko.murata@jamstec.go.jp Yoshiko Ishikawa (MWJ) (leg 2) CFCs Kenichi Sasaki (JAMSTEC) Kenichi Sasaki (JAMSTEC) ksasaki@jamstec.go.jp ∆14C/δ13C Yuichiro Kumamoto (JAMSTEC) Yuichiro Kumamoto (JAMSTEC) kumamoto@jamstec.go.jp N2O/CH4 Osamu Yoshida (RGU) Osamu Yoshida (RGU) (leg 1) yoshida@rakuno.ac.jp Sakae Toyoda (TITECH) (leg 2) Biology Ken Furuya (UT) Taketoshi Kodama (UT) furuya@fs.a.u-tokyo.ac.jp FLOATS ARGO float Toshio Suga (JAMSTEC) Kenichi Katayama (MWJ) sugat@jamstec.go.jp ______________________________________________________________________________________ GODI Global Ocean Development Inc. JAMSTEC Japan Agency for Marine-Earth Science and Technology MRI Meteorological Research Institute, Japan Meteorological Agency MWJ Marine Works Japan, Ltd. RGU Rakuno Gakuen University TITECH Tokyo Institute of Technology UT The University of Tokyo 1.4 SCIENTIFIC PROGRAM AND METHODS (1) Nature and objectives of MR09-01 cruise project It is well known that climate changes of a timescale more than a decade are influenced by changes of oceanic conditions. Among a lot of oceanic changes, we focus on transport and accumulation of anthropogenic CO2 and heat in the ocean, both of which are important for global warming. Accordingly we are aimed at clarifying temporal changes of the transport and accumulation quantitatively. In doing so, we pay a special attention to water masses of the Southern Ocean's origin, which play an important role in transporting anthropogenic CO2 and heat into the ocean's interior. With this purpose, we have so far re-occupied historical observation lines, mainly in the Pacific Ocean. This cruise is a reoccupation of the hydrographic section called 'WHP-P21', which was observed by an ocean science group of United States of America (USA) in 1994 as a part of World Ocean Circulation Experiment (WOCE). The dataset is included in the data base of Climate Variability and Predictability (CLIVAR) and Carbon Hydrographic Data Office (http://whpo.ucsd.edW). We will compare physical and chemical properties along section WHP-P21 with those obtained in 1994 to detect and evaluate long-term changes of the marine environment in the Pacific. Reoccupations of the WOCE hydrographic sections are now in progress by international cooperation in ocean science community, under the framework of CLIVAR, which is as part of World Climate Research Programme (WCRP) and International Ocean Carbon Coordination Project (IOCCP). Our research is planned as a contribution to this international projects supported by World Meteorological Organization (WMO), International Council for Science (ICSU) / Scientific Committee on Oceanic Research (SCOR) and United Nations Educational, Scientific and Cultural Organization (UNESCO)/Intergovernmental Oceanographic Commission (IOC), and the results and data will be published by 2010 for worldwide use. The other purposes of this cruise are as follows: 1) to observe surface meteorological and hydrological parameters as a basic data of meteorology and oceanography such as studies on flux exchange, air-sea interaction and so on, 2) to observe sea bottom topography, gravity and magnetic fields along the cruise track to understand the dynamics of ocean plate and accompanying geophysical activities, 3) to observe biogeochemical parameters to study material (carbon, nitrate, etc) cycle in the ocean, 4) to observe greenhouse gases in the atmosphere and the ocean to study their cycle from bio-geochemical aspect, and 5) to estimate diapycnal diffusitivity in the deep ocean. (2) Cruise narrative R/V Mirai departed Valparaiso, Chile on April 10, 2009. The hydrographic cast was started at the station P21-29 on April 14, since permission of observation in the Peru's EEZ was not yet given. After the CTD station P21-33, R/V Mirai sailed towards the station P21-14 off Peru and waited for a few days in the Peru's EEZ. XCTDs were deployed at stations from P21-29 to P21-33 and the hydrographic cast was restarted at the station P21-41 on April 21. At Papeete, Tahiti on 21 May, 2009, 34 crews and scientists who came from Japan to embark on R/V Mirai by the same plane were not allowed to embark for 7 days, because one of the scientists developed a fever of 38°C and was suspected as a new type of flu. Therefore, we conducted 8 CTD stations without the 34 crews and scientists during leg 2a from 21 to 24 May. Then R/V Mirai departed Papeete again on May 25 and we conducted the rest of the hydrographic observations in leg 2b. R/V Mirai arrived at Brisbane, Australia on June 19, 2009. During leg 3 from June 20 to July 3, underway observations were conducted along the cruise track. 1.5 LIST OF CRUISE PARTICIPANTS Table 1.5.1(a): List of cruise participants for leg 1. __________________________________________________________________________________ NAME RESPONSIBILITY AFFILIATION ---------------------- ------------------------------------------- ------------- Akihiko Murata Chief scientist/carbon/water sampling RIGC/JAMSTEC Hiroshi Uchida CTD/water sampling RIGC/JAMSTEC Sinya Kouketsu LADCP/ADCP/water sampling RIGC/JAMSTEC Yuichiro Kumamoto DO/thermosalinograph/∆14C RIGC/JAMSTEC Kenichi Sasaki CFCs MIO/JAMSTEC Hirokatsu Uno CTD/water sampling MWJ Kenichi Katayama CTD/water sampling MWJ Shinsuke Toyoda CTD/water sampling MWJ Hiroyuki Hayashi CTD/water sampling MWJ Tatsuya Tanaka Salinity MWJ Akira Watanabe Salinity MWJ Fuyuki Shibata DO/water sampling MWJ Miyo Ikeda DO/water sampling MWJ Misato Kuwahara DO/water sampling MWJ Shinichiro Yokogawa Nutrients MWJ Ayumi Takeuchi Nutrients MWJ Kohei Miura Nutrients MWJ Kenichiro Sato Chief technologist/nutrients/water sampling MWJ Ai Ueda Water sampling MWJ Tetsuo Aoki Water sampling MWJ Rui Asakawa Water sampling MWJ Masashi Inose Water sampling MWJ Shinya Iwasaki Water sampling MWJ Masahiro Orui Water sampling MWJ Yuichi Sonoyama CFCs MWJ Katsunori Sagishima CFCs MWJ Shoko Tatamisashi CFCs MWJ Tomonori Watai pH/total alkalinity MWJ Ayaka Hatsuyama pH/total alkalinity MWJ Minoru Kamata DIC MWJ Yoshiko Ishikawa DIC MWJ Shinya Okumura Meteorology/geophysics/ADCP/XCTD GODI Ryo Kimura Meteorology/geophysics/ADCP/XCTD GODI Yosuke Yuki Meteorology/geophysics/ADCP/XCTD GODI Takuhei Shiozaki Biology/water sampling UT Satoshi Kitajima Biology/water sampling UT Taketoshi Kodama Biology/water sampling UT Hiroyuki Kurotori Biology/water sampling UT Osamu Yoshida CH4 and N2O/water sampling RGU Sho Imai CH4 and N2O/water sampling RGU Chiho Kubota CH4 and N2O/water sampling RGU Wolfgang Schneider CTD/water sampling COPAS Lorena Graciela Observer Peruvian Navy Marquez Ismodes __________________________________________________________________________________ COPAS Center for Oceanographic Research in the eastern South Pacific, University of Concepcion, Chile GODI Global Ocean Development Inc. JAMSTEC Japan Agency for Marine-Earth Science and Technology MIO Mutsu Institute of Oceanography MWJ Marine Works Japan, Ltd. RGU Rakuno Gakuen University RIGC Research Institute for Global Change UT The University of Tokyo Table 1.5.1(b): List of cruise participants for leg 2a. __________________________________________________________________________________ NAME RESPONSIBILITY AFFILIATION ---------------------- ------------------------------------------- ------------- Hiroshi Uchida Chief Scientist/CTD/water sampling RIGC/JAMSTEC Shinya Kouketsu LADCP/ADCP/water sampling RIGC/JAMSTEC Yuichiro Kumamoto DO/thermosalinograph /∆14C RIGC/JAMSTEC Toshimasa Doi LADCP/water sampling RIGC/JAMSTEC Katsuro Katsumata XMP/LADCP/water sampling RIGC/JAMSTEC Kenichi Sasaki CFCs MIO/JAMSTEC Hirokatsu Uno CTD/water sampling MWJ Kenichi Katayama CTD/water sampling MWJ Shinsuke Toyoda CTD/water sampling MWJ Hiroyuki Hayashi CTD/water sampling MWJ Tatsuya Tanaka Salinity MWJ Akira Watanabe Salinity MWJ Fuyuki Shibata DO/water sampling MWJ Miyo Ikeda DO/water sampling MWJ Misato Kuwahara DO/water sampling MWJ Shinichiro Yokogawa Nutrients MWJ Ayumi Takeuchi Nutrients MWJ Kohei Miura Nutrients MWJ Kenichiro Sato Chief technologist/nutrients/water sampling MWJ Ai Ueda Water sampling MWJ Yuichi Sonoyama CFCs MWJ Katsunori Sagishima CFCs MWJ Shoko Tatamisashi CFCs MWJ Tomonori Watai pH/total alkalinity MWJ Ayaka Hatsuyama pH/total alkalinity MWJ Minoru Kamata DIC MWJ Yoshiko Ishikawa DIC MWJ Shinya Okumura Meteorology/geophysics/ADCP/XCTD GODI Ryo Kimura Meteorology/geophysics/ADCP/XCTD GODI Yosuke Yuki Meteorology/geophysics/ADCP/XCTD GODI Takuhei Shiozaki Biology/water sampling UT Satoshi Kitajima Biology/water sampling UT Taketoshi Kodama Biology/water sampling UT Hiroyuki Kurotori Biology/water sampling UT Sho Imai CH4 and N2O/water sampling RGU Chiho Kubota CH4 and N2O/water sampling RGU Wolfgang Schneider CTD/water sampling COPAS Camillia Pauline Garae Observer DGMWR Harish Pratap Observer FMS __________________________________________________________________________________ DGMWR Department of Geology Mines and Water Resources, Vanuatu FMS Fiji Meteorological Services, Fiji Table 1.5.1(c): List of cruise participants for leg 2b. __________________________________________________________________________________ NAME RESPONSIBILITY AFFILIATION ---------------------- ------------------------------------------- ------------- Hiroshi Uchida Chief scientist/CTD/water sampling RIGC/JAMSTEC Yuichiro Kumamoto DO/thermosalinograph/∆14C RIGC/JAMSTEC Toshimasa Doi LADCP/water sampling RIGC/JAMSTEC Katsuro Katsumata XMP/LADCP/water sampling RIGC/JAMSTEC Kenichi Sasaki CFCs MIO/JAMSTEC Fujio Kobayashi Salinity MWJ Akira Watanabe Salinity MWJ Miyo Ikeda DO/water sampling MWJ Misato Kuwahara DO/water sampling MWJ Masanori Enoki DO/water sampling MWJ Ayumi Takeuchi Nutrients MWJ Kohei Miura Nutrients MWJ Junji Matsushita Nutrients MWJ Satoshi Ozawa Chief technologist/CTD/water Sampling MWJ Ai Ueda Water sampling MWJ Yuichi Sonoyama CFCs MWJ Katsunori Sagishima CFCs MWJ Shoko Tatamisashi CFCs MWJ Yoshiko Ishikawa pH/total alkalinity MWJ Ayaka Hatsuyama pH/total alkalinity MWJ Minoru Kamata DIC MWJ Yasuhiro Arii DIC MWJ Tomoyuki Takamori CTD/water sampling MWJ Hiroshi Matsunaga CTD/water sampling MWJ Masayuki Fujisaki CTD/water sampling MWJ Shungo Oshitani CTD/water sampling MWJ Tatsuya Ando Water sampling MWJ Tomomi Watanabe Water sampling MWJ Kanako Yoshida Water sampling MWJ Mami Kawai Water sampling MWJ Hideki Yamamoto Water sampling MWJ Satoshi Okumura Meteorology/geophysics/ADCP/XCTD GODI Kazuho Yoshida Meteorology/geophysics/ADCP/XCTD GODI Harumi Ota Meteorology/geophysics/ADCP/XCTD GODI Takuhei Shiozaki Biology/water sampling UT Satoshi Kitajima Biology/water sampling UT Taketoshi Kodama Biology/water sampling UT Hiroyuki Kurotori Biology/water sampling UT Sho Imai CH4 and N2O/water sampling RGU Chiho Kubota CH4 and N2O/water sampling RGU Wolfgang Schneider CTD/water sampling COPAS Camillia Pauline Garae Observer DGMWR Harish Pratap Observer FMS Sakae Toyoda CH4 and N2O/water sampling TITECH Taku Watanabe CH4 and N2O/water sampling TITECH __________________________________________________________________________________ TITECH Tokyo Institute of Technology Table 1.5.1(d): List of cruise participants for leg 3. __________________________________________________________________________________ NAME RESPONSIBILITY AFFILIATION ---------------------- ------------------------------------------- ------------- Kenichi Sasaki Chief scientist MIO/JAMSTEC Fujio Kobayashi Technician MWJ Sinsuke Toyoda Technician MWJ Fuyuki Shibata Technician MWJ Sinichiro Yokogawa Technician MWJ Shoko Tatamisashi Technician MWJ Hideki Yamamoto Technician MWJ Nironori Sato Technician MWJ Yasuhiro Arii Technician MWJ Ryo Kimura Meteorology/geophysics/ADCP/XCTD GODI Soichiro Sueyoshi Meteorology/geophysics/ADCP/XCTD GODI Takuhei Shiozaki Biology UT Satoshi Kitajima Biology UT Taketoshi Kodama Biology UT Hiroyuki Kurotori Biology UT Taku Watanabe CH4 and N2O TITECH Sho Imai CH4 and N2O RGU Chiho Kubota CH4 and N2O RGU Hiroshi Furutani Air sampling ORI Jinyoung Jung Air sampling ORI __________________________________________________________________________________ ORI Ocean Research Institute, The University of Tokyo 2 UNDERWAY OBSERVATION 2.1 NAVIGATION AND BATHYMETRY September 9, 2009 2.1.1 Navigation (1) Personnel Shinya Okumura (GODI) : Leg 1 Satoshi Okumura (GODI) : Leg 2 Souichiro Sueyoshi (GODI) : Leg 3 Ryo Kimura (GODI) : Leg 1, Leg 3 Yousuke Yuuki (GODI) : Leg 1 Kazuho Yoshida (GODI) : Leg 2 Harumi Ota (GODI) : Leg2 (2) Overview of the equipment Ship's position, speed and course were provided by Radio Navigation System on R/V MIRAI. The system integrates GPS position, Log speed, Gyro heading and other basic data on a workstation. Ship's course and speed over ground are calculated from GPS position. The workstation clock is synchronized to reference clock using NTP (Network Time Protocol). Navigation data, called "SOJ data", is distributed to client computer every second, and recorded every 60 seconds. Navigation devices are listed below. 1. GPS receiver (2sets): Trimble DS-4000 9-channel receiver, the antennas are located on Navigation deck, port and starboard side. GPS position from each receiver is converted to the position of radar mast. 2. Doppler log: Furuno DS-30, which use three acoustic beam for current measurement 3. Gyrocompass: Tokimec TG-6000, sperry mechanical gyrocompass 4. Reference clock: Symmetricom TymServ2lOO, GPS time server 5. Workstation Hewlett-Packard ZX2000 running HP-UX ver.11.22 (3) Data period MR09-01 Leg 1: 17:58 UTC 09 Apr. 2009 to 23:59 UTC 19 May 2009 (UTC) MR09-01 Leg 2: 00:00 UTC 21 May 2009 to 02:00 UTC 19 Jun. 2009 (UTC) Figure 2.1.2: Cruise Track of MR09-01 Leg 2. Figure 2.1.3: Cruise Track of MR09-01 Leg 3. 2.1.2 Bathymetry (1) Personnel Takeshi Matsumoto (University of the Ryukyus) : Principal investigator/Not on-board Masao Nakanishi (Chiba University) : Principal investigator/Not on-board Shinya Okumura (GODI) : Leg1 Satoshi Okumura (GODI) : Leg2 Souichiro Sueyoshi (GODI) : Leg3 Ryo Kimura (GODI) : Leg1, Leg3 Yousuke Yuuki (GODI) : Leg1 Kazuho Yoshida (GODI) : Leg2 Harumi Ota (GODI) : Leg2 (2) Overview of the equipments R/V MIRAI equipped with a Multi Beam Echo Sounding system (MBES), SEABEAM 2112.004 (SeaBeam Instruments Inc.) The main objective of MBES survey is collecting continuous bathymetry data along ship's track to make a contribution to geological and geophysical investigations and global datasets. Data interval along ship's track was max 17 seconds at 6,000 m. 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 (6.2 m depth) sound velocity, and the deeper depth profiles were calculated using temperature and salinity profiles from the nearest CTD data by the equation in Mackenzie (1981). System configuration and performance of SEABEAM 2112.004, Frequency: 12 kHz Transmit beam width: 2 degree Transmit power: 20 kW Transmit pulse length: 3 to 20 msec. Depth range: 100 to 11,000 m Beam spacing: 1 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 ± 1 m, whichever is greater, over the entire swath. (Nadir beam has greater accuracy; typically within < 0.2% of depth or ± 1 m, whichever is greater) (3) Data Period MR09-01 Legl: P21-029 on 14 April 2009 to P21-033 on 16 April 2009, P21-014 on 17 April 2009 to P21-156 on 18 May 2009 MR09-01 Leg2: P21-157 on 21 May 2009 to P21-288 on 19 June 2009 MR09-01 Leg3: 20 June 2009 to 1 July 2009 (except for the territorial waters of Papua New Guinea) (4) Data processing i. Sound velocity correction The continuous bathymetry data are split into small areas around each CTD station. For each small area, the bathymetry data are corrected using a sound velocity profile calculated from the CTD data in the area. The equation of Mackenzie (1981) is used for calculating sound velocity. The data processing is carried out using "mbbath" command of MBsystem. ii. Editing and Gridding Gridding for the bathymetry data are carried out using the HIPS software version 6.1 Service Pack 2 (CARIS, Canada). Firstly, the bathymetry data during Ship's turning is basically removed before "BASE surface" is made. A spike noise of each swath data is also removed using "swath editor" and "subset editor". Then the bathymetry data are gridded by "Interpolate" function of the software with following parameters. BASE surface resolution: 50m Interpolate matrix size: 5 x 5 Minimum number of neighbors for interpolate: 10 Finally, raw data and interpolated data are exported as ASCII data, and converted to 150 m grid data using "xyz2grd" utility of GMT (Generic Mapping Tool) software. (5) Data Archive Bathymetry data obtained during this cruise was submitted to the Data Integration and Analysis Group (DIAG) of JAMSTEC, and archived there. (6) Tectonic history of the Pacific Plate The Pacific Plate is the largest oceanic lithospheric plate on the Earth. The Pacific Plate was born around 190 Ma, Middle Jurassic (Nakanishi et al., 1992). The tectonic history of the Pacific Plate has been exposed by many studies based on magnetic anomaly lineations. However, the tectonic history in some periods is still obscure because of lack of geophysical data. To reveal the entire tectonic history of the Pacific Plate from Middle Jurassic to the present, increase in geophysical data is indispensable. Identification of magnetic anomaly lineations has been the most common method for tectonic studies of oceanic plates. After improvement of the multi-narrow beam echo sounder, we become able to describe lineated abyssal hills for the tectonic studies in detail. Abyssal hills are related to the nature of the mid-ocean ridges at which they form (e.g. Goff et al., 1997). For example, abyssal hills heights and widths tend to correlate inversely with spreading rates. Abyssal hills also change morphology depending on crustal thickness and magma supply, factors which can vary within a single ridge segment and/or can vary from one ridge segment to another. Abyssal hills are therefore an off-axis indicator of mid-ocean ridge spreading history. We collected bathymetric data using SeaBeam 2112 during the cruise. Figures 2.1.4 and 2.1.5 show examples of abyssal hills. Figure 2.1.4 is the bathymetric map near the East Pacific Rise (EPR). The crest of the EPR has about 2600 m depth and about 350 m higher than its foot. The depth of the seafloor near the edges of Figure 2.1.4a is about 3500 m. Most of the abyssal hills have the similar strike as the EPR, but some have different strikes from the EPR. The height of abyssal hills is 50 m near the EPR and is more than 200 m around 114°W. Figure 2.1.5 is the bathymetric map of the seafloor south of the Manihiki Plateau and crosses the East Manihiki Scarp, which is a remarkably linear feature extending more than 700 km from the northeastern corner of the Manihiki plateau. Previous works (e.g., Viso et al., 2005; Downey et al., 2007) show the existence of the abyssal hills with an E-W strike in this area. The abyssal hills originate from the Pacific-Phoenix Ridge in the mid-Cretaceous. The abyssal hills with an E-W strike exist west of 164°W (Figure 2.1.5b). The height of the abyssal hills is -100 m. Several knolls with depression exist around 165°15'W. The height of the knolls is about 600 m. The abyssal hills east of the East Manihiki Scarp (EMS) have an NE-SW strike (Figure 2.1.5a, c). The height of abyssal hills is more than 100 m. The pattern of the abyssal hills near the EMS is similar to that around 2.5°S reported by Viso et al. (2005). They interpret these abyssal hills as intratransform spreading centers resulting from transtensional strain across the EMS. Thus, the abyssal hills east of the EMS in Figure 2.1.5(c) derive from the same mechanism. REFERENCES Downey, N.J., J.M. Stock, R.W. Clayton, and S.C. Cande (2007): History of the Cretaceous Osbourn spreading center, J. Geophys. Res., 112, B04102, doi:10.1029/2006JB004550. Goff, J.A., Y. Ma, A. Shah, J.R. Cochran, and J.-C. Sempere (1997): Stochastic analysis of seafloor morphology on the flank of the Southeast Indian Ridge: The influence of ridge morphology on the formation of abyssal hills, J. Geophys. Res., 102, 15,521-15,534. Mackenzie, K.V. (1981): Nine-term equation for the sound speed in the oceans, J. Acoust. Soc. Am., 70 (3), pp 807-812. Nakanishi, M., K. Tamaki, and K. Kobayashi (1992): A new Mesozoic isochron chart of the whole western Pacific Ocean: Paleomagnetic and tectonic implications, Geophys. Res. Lett., 19, 693-696. Searle, R. (1984): GLORIA survey of the East Pacific Rise Near 3.5°S: Tectonic and volcanic characteristics of a fast spreading mid-ocean rise, Tectonophysics, 101, 319-344. Viso, R.F., R.L. Larson, and R.A. Pockalny (2005): Tectonic evolution of the Pacific-Phoenix-Farallon triple junction in the South Pacific Ocean, Earth Planet Sci. Lett., 233, 179-194. Figure 2.1.4: Bathymetric Map around the East Pacific Rise. Contour interval is 50 m. Bathymetry is illuminated from the northwest. Red rectangles in (a) represent the areas of (b) and (c). Blue dotted lines represent abyssal hills. A blue line shows the crest of the East Pacific Rise. Figure 2.1.5: Bathymetric Map of the seafloor south of the Manihiki Plateau. Contour interval is 50 m. Bathymetry is illuminated from the northwest. Red rectangles in (a) represent the areas of (b) and (c). Yellow and blue dotted lines represent abyssal hills. EMS represents the East Manihiki Scarp. 2.2 SURFACE METEOROLOGICAL OBSERVATION January 13, 2010 (1) Personnel Kunio Yoneyama (JAMSTEC) Satoshi Okumura (GODI) Souichiro Sueyoshi (GODI) Shinya Okumura (GODI) Ryo Kimura (GODI) Kazuho Yoshida (GODI) Harumi Ota (GODI) Yousuke Yuuki (GODI) (2) Objective As a basic dataset that describes weather conditions during the cruise, surface meteorological observation was continuously conducted. (3) Methods There are two different surface meteorological measurement systems on board the R/V MIRAI. One is the MIRAI surface meteorological observation system (SMET), and the other is the Shipboard Oceanographic and Atmospheric Radiation measurement system (SOAR). Instruments of SMET are listed in Table 2.2.1. All SMET data were collected and processed by KOAC-7800 weather data processor made by Koshin Denki, Japan. Note that although SMET contains rain gauge, anemometer and radiometers in their system, we adopted those data from not SMET but SOAR due to the following reasons; 1) Since SMET rain gauge is located near the base of the mast, there is a possibility that its capture rate might be affected, 2) SOAR's anemometer has better starting threshold wind speed (1 m s-1) comparing to SMET's anemometer (2 m-1), and 3) SMET's radiometers record data with 10 W/m2 resolution while SOAR takes high resolution data of 1 W/m2. SOAR system was designed and constructed by the Brookhaven National Laboratory (BNL), USA, for an accurate measurement of solar radiation on the ship (cf. http://www.gim.bnl.gov/soarl). SOAR consist of 1) Portable Radiation Package (PRP) that measures short and long wave downwelling radiation, 2) Zen (meteorological system that measures pressure, air temperature, relative humidity, wind speed/direction and rainfall, and 3) Scientific Computer System (SCS) developed by the National Oceanic and Atmospheric Administration (NOAA), USA, for data collection, management, real-time monitoring, and so on. Information or sensors used here is listed in Table 2.2.2. Table 2.2.1: Instruments and locations of SMET. _____________________________________________________________________________________________ SENSOR PARAMETER MANUFACTURER/TYPE LOCATION/HEIGHT FROM SEA LEVEL ------------- ----------------- --------------------------- ------------------------------ Thermometer*1 air temperature Vaisala, Finland/HMP45A compass deck*2/21 m relative humidity Thermometer sea temperature Sea-Bird Electronics, Inc., 4th deck/-5 m USA/SBE3S*3 Barometer pressure Setra Systems Inc., USA/370 captain deck/13 m _____________________________________________________________________________________________ *1 Gill aspirated radiation shield 43408 made by R.M. Young, USA is attached. *2 There are two thermometers at starboard and port sides. *3 Sea surface temperature data were taken from EPCS surface water monitoring system. Table 2.2.2: Instruments and locations of SOAR. ________________________________________________________________________________________ SENSOR PARAMETER MANUFACTURER/TYPE LOCATION/HEIGHT FROM SEA LEVEL ---------- --------------------- --------------------- ------------------------------ Anemometer wind speed/direction R.M. Young, USA/05106 foremast/25 m Rain gauge rainfall accumulation R.M. Young, USA/50202 foremast/24 m Radiometer short wave radiation Eppley, USA/PSP foremast/24 m long wave radiation Eppley, USA/PIR foremast/24 m ________________________________________________________________________________________ (4) Data processing and data format All raw data were recorded every 6 seconds. Datasets produced here are 1-minute mean values (time stamp at the end of the average). These values are the simple mean of 8 samples, after removing maximum/minimum values from 10 samples to exclude singular/erroneous data. Liner interpolation onto missing values was applied only when their interval is less than 5 minutes. Since the thermometers are equipped on both starboard/port sides on the deck, we adopted air temperature/relative humidity data taken at upwind side. Dew point temperature was produced from relative humidity and air temperature data. Any adjustment to a certain height was not applied except pressure data to the sea level. Data are stored as ASCII format and contains following parameters. Time in UTC expressed as YYYYMMDDHHMM, time in Julian day (1.0000 = January 1, 0000Z), longitude (°E), latitude (°N), pressure (hPa), air temperature (°C), dew point temperature (°C), relative humidity (%), sea surface temperature (°C), zonal wind component (m/sec), meridional wind component (m/sec), precipitation (mm/hr), downwelling shortwave radiation (W/m2), and downwelling longwave radiation (W/m2). Missing values are expressed as "9999". (5) Data Quality To ensure the data quality, each sensor was calibrated as follows. Since there is a possibility for fine time resolution data sets to have some noises caused (generated) by turbulence, it is recommended to filter them out (ex. hourly mean) from this 1-minute mean data sets depending on the scientific purpose. T/RH sensor: Temperature and humidity probes were calibrated before/after the cruise by the manufacturer. Certificated accuracy of T/RH sensors are better than ± 0.2°C and ± 2%, respectively. We also checked T/RH values using another calibrated portable T/RH sensor (Vaisala, HIMP45A) before and after the cruise. The results are, Temperature (°C) Mean difference between T (SMET) and T (portable) is -0.08±0.17 (°C) at port side, -0.26±0.33 (°C) at starboard side. Relative Humidity (%) Mean difference between RH (SMET) and RH (portable) is 1.3±0.5 (%) at port side, 1.3± 1.6 (%) at starboard side. Sea surface temperature sensor: Temperature sensor was calibrated before the cruise at the manufacturer. Certificated accuracy is better than 0.002°C/year. Pressure sensor: Using calibrated portable barometer (Vaisala, Finland / PTB220, certificated accuracy is better than ± 0.1 hPa), pressure sensor was checked before/after the cruise. Mean difference of SMET pressure sensor and portable sensor is 0.06±0.05 hPa. Precipitation: Before the each leg, we checked the linearity of rain gauge value in response to water amount in the gauge. The results are as follows, and data have already been corrected using this relationship. ________________________________________________________ Leg-1 Leg-2 Leg-3 ------------------------------- ------ ------ ------ minimum input water volume (cc) 0.0 0.0 0.0 maximum input water volume (cc) 505.0 505.7 503.7 minimum measured value (mm) 0.47 0.25 0.47 maximum measured value (mm) 50.23 48.75 49.79 ________________________________________________________ Radiation sensors: Short wave and long wave radiometers were calibrated by the manufacturer, Remote Measurement and Research Company, USA, prior to the cruise (February 2009). (6) Data periods Leg-1 1300 UTC, April 10, 2009 - 0000 UTC, May 20, 2009 Leg-2 0100 UTC, May 21, 2009 - 0100 UTC, June 19, 2009 Leg-3 2300 UTC, June 19, 2009 - 2350 UTC, July 2, 2009 (7) Point of contact Kunio Yoneyama (yoneyamak@jamstec.go.jp) Research Institute for Global Change / JAMSTEC 2-15, Natsushima, Yokosuka 237-0061, Japan Figure 2.2.1: Time series of surface (a) air/sea temperature, (b) relative humidity, (c) precipitation, (d) pressure, (e) zonal and meridional wind components, and (e) short and long wave radiation for Leg-1. Day 100 corresponds to April 10, 2009. Figure 2.2.2: Same as Figure 2.2.1, but for Leg 2. Day 141 corresponds to May 21, 2009. Figure 2.2.3: Same as Figure 2.2.1, but for Leg 3. Day 171 corresponds to June 19, 2009. 2.3 THERMO-SALINOGRAPH AND RELATED MEASUREMENTS July 31, 2010 (1) Personnel Yuichiro Kumamoto (JAMSTEC) Miyo Ikeda (MWJ) Fuyuki Shibata (MWJ) Masanori Enoki (MWJ) Misato Kuwahara (MWJ) (2) Objective Our purpose is to obtain salinity, temperature, dissolved oxygen, and fluorescence data continuously in near-sea surface water during MR09-01 cruise. (3) Methods The Continuous Sea Surface Water Monitoring System (Nippon Kaiyo Co. Ltd.), including the thermosalinograph, has five sensors and automatically measures salinity, temperature, dissolved oxygen, and fluorescence in near-sea surface water every one minute. This system is located in the sea surface monitoring laboratory and connected to shipboard LAN system. Measured data, time, and location of the ship were stored in a data management PC (IBM NetVista 6826-CBJ). The near-surface water was continuously pumped up to the laboratory from about 4 m water depth and flowed into the system through a vinyl-chloride pipe. The flow rate of the surface seawater was adjusted to be 12 dm3/min except for a fluorometer (about 0.4 dm3/min). Specifications of the each sensor in this system are listed below. a) Temperature and salinity sensors SEACAT THERMOSALINOGRAPH Model: SBE-21, SEA-BIRD ELECTRONICS, INC. Serial number: 2126391-3126 Measurement range: Temperature -5 to +35°C (ITS-90), Salinity 0 to 7.0 5 m-1 Accuracy: Temperature 0.01°C 6month-1, Salinity 0.001 5 m-1 month-1 Resolution: Temperatures 0.001°C, Salinity0.0001 S a-1 b) Bottom of ship thermometer (RMT) Model: SBE 3S, SEA-BIRD ELECTRONICS, INC. Serial number: 032175 Measurement range: -5 to +35°C (ITS-90) Resolution: ±0.001°C Stability: 0.002°C year-1 c) Dissolved oxygen sensor Model: 2127A, HACH ULTRA ANALYTICS JAPAN, INC. Serial number: 61230 Measurement range: 0 to 14 ppm Accuracy: ± 1% at 5°C of correction range Stability: 1% month-1 d) Fluorometer Model: 10-AU-005, TURNER DESIGNS Serial number: 5562 FRXX Detection limit: 5 ppt or less for chlorophyll-a Stability: 0.5% month-1 of full scale e) Flow meter Model: EMARG2W, Aichi Watch Electronics LTD. Serial number: 8672 Measurement range: 0 to 30 1 min-1 Accuracy: ± 1% Stability: ± 1% day-1 (4) Measurements Periods of measurement, maintenance, and events during MR09-01 are listed in Table 2.3.1. Table 2.3.1: Events list of the thermo-salinograph during MR09-01 _________________________________________________________________________ System Date System Time [UTC] [UTC] Events Remarks ----------- ----------- -------------------------------- ------------- 09-Apr.-14 12:47 All the measurements started. Leg-1 start 09-Apr.-15 23:59 All the measurements stopped due 09-Apr.-21 00:00 to entering in the Peruvian EEZ. 09-Apr.-22 01:40 Lost of all the data due to re- 09-Apr.-22 02:04 boot of the data management PC. 09-May-18 07:06 All the measurements stopped. Leg-1 finish 09-May-21 20:18 All the measurements started. Leg-2a start 09-May-23 20:44 All the measurements stopped. Leg-2a finish 09-May-25 20:19 All the measurements started. Leg-2b start 09-Jun.-13 17:07 Lost of all the data due to error on program. 09-Jun.-13 17:18 Lost of all the data due to error on program. 09-Jun.-17 19:36 All the measurements stopped. Leg-2b finish 09-Jun.-20 10:01 All the measurements started. Leg-3 start 09-Jun.-23 22:59 Lost of all the data 09-Jun.-24 14:03 Lost of all the data 09-Jul.-01 04:23 All the measurements stopped. Leg-3 finish _________________________________________________________________________ (5) Calibrations We collected the surface seawater samples for salinity sensor calibration during Leg-1 and Leg-2 (Table 2.3.2). The seawater was collected approximately twice a day using a 250 ml brown grass bottle. The samples were stored in the sea surface monitoring laboratory and then measured using the Guildline 8400B at the end of the legs after all the measurements of the hydrocast bottle samples. Table 2.3.2: Comparison of the sensor salinity with the bottle salinity. _______________________________________________________________________________ Sensor Bottle Date Time salinity salinity Difference [UTC] [UTC] Latitude Longitude [PSS-78] [PSS-78] [Sen. - Bot.] --------- ----- ------------ ------------- -------- -------- ------------- 2009/4/14 13:48 16-44.97580S 078-42.43970W 35.4984 35.4950 0.0034 2009/4/14 21:56 16-45.17830S 079-19.83920W 35.5812 35.5769 0.0043 2009/4/15 8:56 16-44.40370S 080-39.63650W 35.5748 35.5725 0.0023 2009/4/15 22:04 16-40.73990S 080-59.80990W 35.4099 35.4083 0.0016 2009/4/21 8:19 16-44.92050S 080-25.69800W 35.4962 35.4981 -0.0019 2009/4/21 21:10 16-44.52540S 082-00.27190W 35.5029 35.5088 -0.0059 2009/4/22 10:00 16-44.93300S 082-59.85970W 35.5844 35.5889 -0.0045 2009/4/22 10:02 16-44.91210S 082-59.85080W 35.5842 35.5890 -0.0048 2009/4/22 21:29 16-45.09040S 083-40.05760W 35.5448 35.5507 -0.0059 2009/4/23 8:51 16-44.56640S 084-20.09390W 35.6529 35.6570 -0.0041 2009/4/23 21:08 16-45.11350S 085-19.65940W 35.5000 35.5058 -0.0058 2009/4/24 9:52 16-49.99990S 086-23.16600W 35.7428 35.7466 -0.0038 2009/4/24 21:11 16-44.71580S 087-40.33490W 35.7371 35.7444 -0.0073 2009/4/25 10:36 16-45.00120S 088-39.82020W 35.7708 35.7750 -0.0042 2009/4/25 10:38 16-45.00260S 088-39.84800W 35.7718 35.7744 -0.0026 2009/4/25 20:55 16-44.78260S 089-20.05120W 35.7637 35.7691 -0.0054 2009/4/26 10:09 16-44.73750S 090-08.14720W 35.7523 35.7574 -0.0051 2009/4/26 21:41 16-44.78340S 091-28.27440W 35.7917 35.7951 -0.0034 2009/4/27 9:19 16-44.80660S 092-49.23870W 35.8304 35.8362 -0.0058 2009/4/27 21:37 16-43.85810S 094-21.16550W 35.8251 35.8318 -0.0067 2009/4/28 9:21 16-45.33650S 095-47.60370W 35.8719 35.8724 -0.0005 2009/4/28 9:23 16-45.34400S 095-48.13740W 35.8679 35.8707 -0.0028 2009/4/28 21:52 16-44.73560S 097-20.31890W 35.8107 35.8161 -0.0054 2009/4/29 9:38 16-44.79350S 098-40.12210W 35.9412 35.9454 -0.0042 2009/4/29 22:07 16-44.05720S 100-00.30900W 36.0435 36.0471 -0.0036 2009/4/30 10:07 16-44.61130S 101-28.24690W 35.9749 35.9805 -0.0056 2009/4/30 10:09 16-44.62880S 101-28.76720W 35.9771 35.9820 -0.0049 2009/4/30 21:57 16-59.19030S 102-58.24090W 35.9857 35.9880 -0.0023 2009/5/1 11:09 16-45.46850S 104-00.09040W 36.0785 36.0822 -0.0037 2009/5/1 23:39 16-45.03880S 106-00.04450W 36.0361 36.0432 -0.0071 2009/5/2 11:08 16-44.97480S 106-54.64000W 36.0931 36.0988 -0.0057 2009/5/3 1:48 16-45.49220S 107-15.05250W 36.1222 36.1272 -0.0050 2009/5/3 10:31 16-44.96970S 107-37.76710W 36.1409 36.1453 -0.0044 2009/5/3 23:03 16-45.14510S 109-19.99040W 36.1931 36.1985 -0.0054 2009/5/3 23:04 16-45.14910S 109-19.98920W 36.1924 36.1974 -0.0050 2009/5/4 11:33 16-45.13740S 110-40.38760W 36.2194 36.2242 -0.0048 2009/5/4 23:32 16-45.29100S 112-00.07440W 36.1544 36.1630 -0.0086 2009/5/5 10:47 16-45.25910S 113-37.45760W 36.3165 36.3205 -0.0040 2009/5/5 21:52 16-45.46490S 115-13.33820W 36.2483 36.2538 -0.0055 2009/5/6 11:27 16-44.98470S 116-42.80650W 36.3767 36.3807 -0.0040 2009/5/6 23:06 16-45.17100S 118-25.21730W 36.2563 36.2622 -0.0059 2009/5/7 11:36 16-45.09820S 120-00.16570W 36.2863 36.2924 -0.0061 2009/5/7 11:38 16-45.10700S 120-00.17050W 36.2868 36.2924 -0.0056 2009/5/8 7:21 16-45.09310S 122-39.65920W 36.2948 36.3001 -0.0053 2009/5/8 11:20 16-44.85160S 122-57.81300W 36.3801 36.3857 -0.0056 2009/5/8 23:17 16-45.11080S 124-39.69490W 36.4907 36.4951 -0.0044 2009/5/9 10:59 16-45.02640S 126-00.21060W 36.3923 36.3965 -0.0042 2009/5/9 23:45 16-45.30990S 127-20.52890W 36.3225 36.3272 -0.0047 2009/5/10 12:35 16-45.01200S 129-05.41100W 36.3609 36.3641 -0.0032 2009/5/10 12:37 16-45.01500S 129-05.91430W 36.3552 36.3591 -0.0039 2009/5/11 2:11 16-45.46310S 130-39.68820W 36.3718 36.3788 -0.0070 2009/5/11 12:12 16-45.05740S 131-59.97770W 36.4767 36.4823 -0.0056 2009/5/12 2:21 16-45.29710S 133-20.19320W 36.3381 36.3432 -0.0051 2009/5/12 11:51 16-45.56450S 134-00.34900W 36.2077 36.2137 -0.0060 2009/5/13 11:58 16-45.31040S 136-39.87070W 36.4252 36.4293 -0.0041 2009/5/13 12:00 16-45.30590S 136-39.85740W 36.4246 36.4307 -0.0061 2009/5/13 17:28 16-44.96630S 137-20.15810W 36.3616 36.3693 -0.0077 2009/5/14 0:08 16-45.09200S 138-22.38950W 36.3073 36.3105 -0.0032 2009/5/14 12:56 16-44.92430S 140-02.89960W 36.3949 36.4020 -0.0071 2009/5/15 0:27 16-44.56690S 141-43.14970W 36.2809 36.2862 -0.0053 2009/5/15 14:26 17-18.00390S 143-01.90900W 36.2908 36.2964 -0.0056 2009/5/16 0:40 17-29.56580S 144-09.39550W 36.3152 36.3204 -0.0052 2009/5/16 14:32 17-29.82400S 145-44.07210W 36.3189 36.3234 -0.0045 2009/5/16 14:34 17-29.85300S 145-44.45950W 36.3190 36.3243 -0.0053 2009/5/17 1:06 17-29.80410S 146-55.62150W 36.3267 36.3310 -0.0043 2009/5/17 12:53 17-30.21460S 148-28.58790W 36.2912 36.2957 -0.0045 2009/5/18 2:28 17-30.00190S 149-10.30590W 36.2251 36.2292 -0.0041 2009/5/18 7:03 17-29.95660S 149-19.96200W 36.2223 36.2345 -0.0122 2009/5/22 0:57 17-29.84320S 150-05.34030W 36.1993 36.1916 0.0077 2009/5/22 13:27 17-29.91300S 151-16.85460W 36.1192 36.1159 0.0033 2009/5/23 1:14 17-30.41760S 152-43.27130W 36.038 36.0309 0.0071 2009/5/23 13:20 17-30.39290S 154-03.86520W 35.9694 35.9629 0.0065 2009/5/23 19:06 17-30.73690S 154-19.15890W 35.9772 35.9698 0.0074 2009/5/26 0:33 17-30.27460S 150-56.34070W 36.148 36.1428 0.0052 2009/5/26 7:46 17-28.15840S 152-47.88450W 36.0207 36.0145 0.0062 2009/5/26 7:48 17-28.15860S 152-48.39390W 36.0187 36.0123 0.0064 2009/5/27 2:22 17-29.71150S 155-39.65110W 35.935 35.9279 0.0071 2009/5/27 12:43 17-30.14850S 156-59.98330W 35.9856 35.9789 0.0067 2009/5/28 2:43 17-30.05130S 158-21.80860W 35.6579 35.6521 0.0058 2009/5/28 13:17 17-29.60850S 159-40.16600W 35.7293 35.7217 0.0076 2009/5/29 3:15 17-29.62850S 161-00.53220W 35.7593 35.7527 0.0066 2009/5/29 12:44 17-29.84780S 162-20.19010W 35.5213 35.5153 0.0060 2009/5/29 12:46 17-29.84070S 162-20.19980W 35.5218 35.5148 0.0070 2009/5/30 0:51 17-29.71710S 163-40.22410W 35.5298 35.5240 0.0058 2009/5/30 13:14 17-29.86090S 165-00.09660W 35.658 35.6523 0.0057 2009/5/31 2:37 17-29.50610S 166-20.56290W 35.3233 35.3168 0.0065 2009/5/31 12:34 17-29.75890S 167-19.39840W 35.2629 35.2559 0.0070 2009/6/1 2:10 17-30.02270S 168-57.87450W 35.1326 35.1238 0.0088 2009/6/1 2:12 17-30.01870S 168-58.38400W 35.1286 35.1222 0.0064 2009/6/1 13:19 17-30.12720S 169-57.96900W 35.6192 35.6121 0.0071 2009/6/2 2:06 17-30.09560S 171-19.29490W 35.3532 35.3447 0.0085 2009/6/2 13:53 17-29.47620S 172-09.08020W 35.3759 35.3695 0.0064 2009/6/3 2:19 17-29.86830S 172-39.93180W 35.3979 35.3921 0.0058 2009/6/3 13:42 17-29.76370S 172-59.95610W 35.4848 35.4781 0.0067 2009/6/4 1:57 17-29.15390S 174-53.24790W 35.1388 35.1300 0.0088 2009/6/4 2:00 17-29.24690S 174-54.02150W 35.1391 35.1312 0.0079 2009/6/4 14:06 17-29.84240S 176-29.21680W 35.4266 35.4206 0.0060 2009/6/5 1:48 17-45.08660S 178-15.00220W 35.5201 35.5144 0.0057 2009/6/5 14:08 18-24.86800S 179-39.44760W 35.0543 35.0458 0.0085 2009/6/6 4:37 18-25.14400S 178-19.77450E 34.7175 34.7105 0.0070 2009/6/6 15:05 18-34.43890S 177-15.01060E 34.8111 34.8052 0.0059 2009/6/7 3:07 17-49.80500S 176-20.13720E 34.8422 34.8366 0.0056 2009/6/7 3:09 17-49.80020S 176-20.14540E 34.8446 34.8362 0.0084 2009/6/7 14:51 17-49.96720S 174-30.44490E 34.7476 34.7396 0.0080 2009/6/8 3:29 17-50.20620S 172-57.74250E 34.7886 34.7854 0.0032 2009/6/8 16:16 17-50.03360S 171-00.02810E 34.8332 34.8284 0.0048 2009/6/9 3:14 17-49.98500S 169-39.81200E 34.8549 34.8498 0.0051 2009/6/9 14:51 18-08.76050S 168-35.87720E 34.8734 34.8673 0.0061 2009/6/9 14:54 18-08.72630S 168-35.86890E 34.8733 34.8673 0.0060 2009/6/10 3:33 18-28.98480S 167-48.94890E 34.8825 34.8751 0.0074 2009/6/10 15:10 18-41.83330S 167-18.97920E 34.668 34.6618 0.0062 2009/6/11 4:30 19-09.22850S 166-15.30210E 34.6166 34.6111 0.0055 2009/6/11 15:48 19-35.14790S 165-13.44460E 34.8688 34.8621 0.0067 2009/6/12 4:20 19-55.09680S 164-26.87740E 34.7665 34.7596 0.0069 2009/6/12 4:23 19-55.03730S 164-27.09530E 34.7686 34.7604 0.0082 2009/6/12 14:15 18-41.18910S 163-27.76470E 34.7966 34.7912 0.0054 2009/6/13 5:09 20-52.28470S 164-12.34210E 34.9014 34.8964 0.0050 2009/6/13 15:40 20-58.30450S 164-05.86780E 35.1654 35.1531 0.0123 2009/6/14 4:12 21-28.99900S 162-45.98240E 34.894 34.8870 0.0070 2009/6/14 15:44 22-05.92740S 161-12.07260E 35.2426 35.2314 0.0112 2009/6/15 4:55 22-43.07240S 159-39.05030E 35.2074 35.1999 0.0075 2009/6/15 4:57 22-43.07120S 159-39.05450E 35.2077 35.2009 0.0068 2009/6/15 15:44 23-15.94420S 158-15.27150E 35.2435 35.2369 0.0066 2009/6/16 4:18 23-52.07610S 156-43.12080E 35.3243 35.3164 0.0079 2009/6/16 16:06 24-20.93430S 155-30.04440E 35.2284 35.2212 0.0072 2009/6/17 5:24 24-46.82500S 154-19.41980E 35.437 35.4248 0.0122 2009/6/17 18:53 25-02.01130S 153-38.93560E 35.3601 35.3536 0.0065 _______________________________________________________________________________ 2.4 UNDERWAY pCO2 December 4, 2010 (1) Personnel Akihiko Murata (RIGC, JAMSTEC) Minoru Kamata (MWJ) Yoshiko Ishikawa (MWJ) Yasuhiro Arii (MWJ) (2) Introduction Concentrations of CO2 in the atmosphere are now increasing at a rate of 1.9 ppmv y-1 due to human activities such as burning of fossil fuels, deforestation, cement production, etc. It is an urgent task to estimate as accurately as possible the absorption capacity of the ocean against the increased atmospheric CO2, and to clarify the mechanism of the CO2 absorption, because the magnitude of the predicted global warming depends on the levels of CO2 in the atmosphere, and because the ocean currently absorbs 1/3 of the 6 Gt of carbon emitted into the atmosphere each year by human activities. In the P21 revisit cruise, we were aimed at quantifying how much anthropogenic CO2 is absorbed in the surface ocean in the Pacific. For the purpose, we measured pCO2 (partial pressures of CO2) in the atmosphere and in the surface seawater. (3) 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 (NDIR; BINOS® model 4.1, Fisher-Rosemount), 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 600 - 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 500 - 800 ml min-1. The CO2 measuring system was set to repeat the measurement cycle such as 4 kinds of CO2 standard gases (Table 2.4.1), xCO2a (twice), xCO2s (7 times). This measuring system was run automatically throughout the cruise by a PC control. (4) Quality control Concentrations of CO2 of the standard gases are listed in Table 2.4.1, which were calibrated by the JAMSTEC primary standard gases. The CO2 concentrations of the primary standard gases were calibrated by C.D. Keeling of the Scripps Institution of Oceanography, La Jolla, CA, USA. Since differences of concentrations of the standard gases between before and after the cruise were allowable (<0.1 ppmv), the averaged concentrations (Table 2.4.1) were adopted for the subsequent calculations. 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 Gordon and Jones (1973), although the temperature increases were slight, being -0.3°C. We checked values of xCO2a and xCO2s by examining signals of the NDIR on recorder charts, and by plotting the xCO2a and xCO2s as a function of sequential day, longitude, sea surface temperature and sea surface salinity. REFERENCE Gordon, L.I. and L.B. Jones (1973) The effect of temperature on carbon dioxide partial pressure in seawater. Mar. Chem., 1, 317-322. Table 2.4.1: Concentrations of CO2 standard gases used during MR09-01 cruise. ___________________________________ Cylinder no. Concentrations (ppmv) ------------ --------------------- CQC00742 270.22 CQC00739 330.43 CQC00740 360.04 CQC00741 420.32 ___________________________________ 2.5 ACOUSTIC DOPPLER CURRENT PROFILER (ADCP) November 1, 2010 (1) Personnel Shinya Kouketsu (JAMSTEC) Shinya Okumura (GODI) -leg1- Ryo Kimura (GODI) -leg1, 3- Yousuke Yuki (GODI) -leg1- Satoshi Okumura (GODI) -leg2- Kazuho Yoshida (GODI) -leg2- Harumi Ohta (GODI) -leg2- Souichiro Sueyoshi (GODI) -leg3- (2) Objective To obtain continuous measurement of the current profile along the ship's track. (3) Methods Upper ocean current measurements were made throughout MR09-01 cruise, using the hull mounted Acoustic Doppler Current Profiler (ADCP) system. For most of its operation, the instrument was configured for water-tracking mode recording. Bottom-tracking mode, interleaved bottom-ping with water-ping, was made in shallower water region to get the calibration data for evaluating transducer misalignment angle. The system consists of following components; 1) R/V MIRAI has installed the Ocean Surveyor for vessel-mount (acoustic frequency 75 kHz; Teledyne RD Instruments). It has a phased-array transducer with single ceramic assembly and creates 4 acoustic beams electronically. We mounted the transducer head rotated to a ship-relative angle of 45 degrees azimuth from the keel. 2) For heading source, we use ship's gyro compass (Tokimec, Japan), continuously providing heading to the ADCP system directory. Additionally, we have Inertial Navigation System (INS) which provide high-precision heading, attitude information, pitch and roll, are stored in ".N2R" data files with a time stamp. 3) GPS navigation receiver (Trimble D54000) provides position fixes. 4) We used VmDas version 1.4.2 (TRD Instruments) for data acquisition. 5) To synchronize time stamp of ping with GPS time, the clock of the logging computer is adjusted to GPS time every 1 minute. 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). The data was configured for 4 m processing bin, 4 m intervals and starting 20 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. We changed the major parameters, and showed the date and time that we changed command file. (4) Data processing We processed ADCP data as described below. ADCP-coordinate velocities were converted to the earth-coordinate velocities using the ship heading from the INU. The earth-coordinate currents were obtained by subtracting ship velocities from the earth-coordinate velocities. Corrections of the misalignment and scale factors were made using the bottom track data. The misalignment angle calculated was 0.15, the scale factor was 1.00. Figure 2.5.1. Cruise-averaged echo intensities. (5) Remarks The profile with had quality is included between 200 m in depth and 400 m while in this cruise corresponding to weak echo intensities (Fig. 2.5.1 causes of the weak echo intensity may be considered during data processing after cruise). 2.6 XCTD February 8, 2011 (1) Personnel Hiroshi Uchida (JAMSTEC) Leg 1 Shinya Okumura (GODI) Ryo Kimura (GODI) Yosuke Yuki (GODI) Leg 2 Satoshi Okumura (GODI) Kazuho Yoshida (GODI) Harumi Ota (GODI) (2) Objectives In this cruise, XCTD (expendable Conductivity, Temperature and Depth profiler) measurements were carried out to examine short-term changes in temperature and salinity profiles, and to evaluate fall rate equations by comparing with CTD (Conductivity, Temperature and Depth profiler) measurements and bottom topography measurements. (3) Instrument and Method The XCTDs used were XCTD-1 and XCTD-2 (Tsurumi-Seiki Co., Ltd., Yokohama, Kanagawa, Japan) with an MK-130 deck unit (Tsurumi-Seiki Co., Ltd.). The manufacturer's specifications are listed in Table 2.6.1. In this cruise, seven XCTD-1 probes and twenty-three XCTD-2 probes were deployed by using 8-loading automatic launcher (Tsurumi-Seiki Co., Ltd.) (Table 2.6.2). Ship's speed was slowed down to 3 knot during the XCTD-2 measurement. For the comparison with CTD, XCTD was deployed at about 5 minutes for XCTD-1 and at about 10 minutes for XCTD-2 after the beginning of the down cast of the CTD. Table 2.6.1: Manufacturer's specifications of XCTD-1 and XCTD-2. _________________________________________________________________________ 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) 5 m or 2%, whichever is greater * _________________________________________________________________________ * Depth error is shown in Kizu et al (2008). (4) Data Processing and Quality Control The XCTD data were processed and quality controlled based on a method by Uchida et al. (2011). Thermal bias (+0.016°C) of the XCTD data reported by Uchida et al. (2011) was not corrected. Depth error of the XCTD data was corrected by using the estimated terminal velocity error (-0.0428 m s-1) (Uchida et al., 2011). Salinity biases of the XCTD data were estimated by using temperature and salinity relationships in the deep ocean obtained from the post-cruise calibrated CTD data (Table 2.6.2). For the XCTD data of the station P21291, salinity bias could not be estimated because the maximum depth was too shallow to estimate the salinity bias. Vertical section of potential temperature is shown in Fig. 2.6.1 for stations between 29 and 33. Comparison with the CTD data shows short-term fluctuation in temperature between the observation periods 6 days apart. 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., accepted. Table 2.6.2: Serial number and probe type of the XCTD. Water depth, ship intake temperature (SST) and salinity (SSS; not corrected), and maximum pressure for the XCTD data are shown. Salinity offset applied to the XCTD data and reference salinity estimated from the CTD data are also shown. __________________________________________________________________________________ Serial Max Salinity Reference number Depth SST SSS pressure offset salinity Station (type) [m] [°C] [PSU] [dbar] [PSU] [PSU] ------- ------------- ----- ------ ------ -------- -------- --------------- Leg 1 29_1* 08112315 (2) 3798 23.759 35.444 187‡ - NA 29_2* 08112312 (2) 3816 23.725 35.430 1967 0.009 34.6215 @ 2.5°C 30_1* 08112308 (2) 4462 24.249 35.432 1967 0.021 34.6215 @ 2.5°C 31_1* 08112304 (2) 4441 24.815 35.497 1913 0.022 34.6215 @ 2.5°C 32_1* 08112309 (2) 4713 23.453 35.480 1917 0.007 34.6215 @ 2.5°C 33_1* 08112306 (2) 4442 23.787 35.538 1967 0.014 34.6215 @ 2.5°C 41_1 03022164 (1) 4659 23.975 35.456 1036 0.023 34.5219 @ 4.5°C 41_2 08112305 (2) 4659 23.977 35.455 1967 0.007 34.6215 @ 2.5°C 34_1 08112307 (2) 4536 24.030 35.505 1967 0.012 34.6215 @ 2.5°C 34_2 07022711 (1)# 4537 24.029 35.505 1037 0.000 34.5219 @ 4.5°C 42_1 03022159 (1) 4558 23.544 35.584 1037 -0.017 34.5219 @ 4.5°C 42_2 08112310 (2) 4572 23.547 35.585 1967 0.015 34.6215 @ 2.5°C 96_1 03022156 (l) 3732 25.612 36.217 1036 ?0.005 34.5219 @ 4.5°C 96_2 08112311 (2) 3751 25.610 36.218 1967 0.007 34.6215 @ 2.5°C 97_1 03022162 (l) 3462 25.592 36.166 1037 0.012 34.5219 @ 4.5°C 97_2 08112313 (2) 3453 25.591 36.166 1967 0.010 34.6215 @ 2.5°C 98_1 03022157 (l) 3287 25.649 36.149 1037 0.002 34.5219 @ 4.5°C 98_2 08112314 (2) 3297 25.659 36.162 1967 0.010 34.6215 @ 2.5°C 145_1 08112319 (2) 1505 28.117 36.244 1464 0.007 34.5665 @ 3.0°C 146_1 08112316 (2) 1530 27.918 36.291 1520 0.020 34.5665 @ 3.0°C 151_1 08112322 (2) 1531 28.009 36.315 1518 0.005 34.5665 @ 3.0°C 156_1 03022155 (l) 943 28.339 36.223 943 0.008 34.4726 @ 4.5°C Leg 2 205_1 08112325 (2) 1365 28.097 35.430 1356 0.014 34.4781 @ 3.5°C 206_1 08112317 (2) 1484 27.978 35.548 1470 0.037 34.5512 @ 3.0°C 209_1 08112318 (2) 1924 27.032 35.260 1286‡ 0.008 34.4911 @ 3.5°C 213_1 08112327 (2) 991 26.979 35.232 985 0.016 34.4238 @ 4.5°C 221_1 08112320 (2) 1883 26.466 34.783 1911 -0.004 34.6094 @ 2.5°C 250_1 08112321 (2) 1716 25.045 34.938 1700 0.013 34.5710 @ 3.0°C 266_1 08112324 (2) 1638 24.094 34.950 1631 -0.001 34.5860 @ 3.0°C 268_1 08112323 (2) 1562 23.496 35.227 1551 0.014 34.5860 @ 3.0°C __________________________________________________________________________________ * Not for simultaneous measurements with CTD ‡ Failure of measurements due to noise or lost contact # Relatively large (about 30 minutes) time difference between CTD and XCTD measurements Figure 2.6.1: Vertical sections of potential temperature measured by CTD (left) and XCTD (right). 3 Hydrographic Measurement Techniques and Calibrations 3.1 CTDO2 MEASUREMENTS February 16, 2010 (1) Personnel Hiroshi Uchida (JAMSTEC) Wolfgang Schneider (University of Concepcion, Chile) Leg 1 and leg 2a Kenichi Katayama (MWJ) Shinsuke Toyoda (MWJ) Hirokatsu Uno (MWJ) Hiroyuki Hayashi (MWJ) Leg 2b Tomoyuki Takamori (MWJ) Hiroshi Matsunaga (MWJ) Masayuki Fujisaki (MWJ) Shungo Oshitani (MWJ) Satoshi Ozawa (MWJ) (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 (Rochester Wire & Cable). (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), three oxygen optodes (Oxygen Optode 3830 and 4330F; Aanderaa Data Instruments AS, Bergen, Norway, and a prototype of RINKO-III; JFE Alec Co., Ltd, Kobe Hyogo, Japan), a fluorometer (Seapoint sensors, Inc., Kingston, New Hampshire, USA), and a transmissometer (C-Star Transmissometer; WET Labs, Inc., Philomath, Oregon, USA) were also used with the SBE 9plus underwater unit. To minimize motion 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 (54 x 90 cm). SUMMARY OF THE SYSTEM USED IN THIS CRUISE Deck unit: SBE 11plus, S/N 0272 Under water unit: SBE 9plus, S/N 79511 (Pressure sensor: S/N 0677) Temperature sensor: SBE 3plus, S/N 4815 (primary) SBE 3, S/N 1525 (secondary) Conductivity sensor: SBE 4, S/N 2854 (primary) SBE 4, S/N 1203 (secondary: stations from P21_14_1 to P21_86_1) SBE 4, S/N 3261 (secondary: stations from P21_87_1 to P21_288_1) Oxygen sensor: SBE 43, S/N 0394 (stations from P21_14_1 to P21_76_1) SBE 43, S/N 0330 (stations from P21_X18_1 to P21_288_1) AANDERAA Oxygen Optode 3830, S/N 612 (foil batch no. 1707) AANDERAA Oxygen Optode 4330E S/N 143 (foil batch no. 2808F) JFE Alec RINKO-III, S/N 006 (foil batch no. 131002A) 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 0045 Fluorometer: Seapoint Sensors, Inc., S/N 3054 Transmissometer: C-Star, S/N CST-207RD Carousel Water Sampler: SBE 32, S/N 0391 Water sample bottle: 12-litre Niskin-X model 1010X (no TEFLON coating) * without Oxygen Optode 4330E fluorometer, and transmissometer at station P21_200_1 (4) Pre-cruise calibration i. Pressure The Paroscientific series 4000 Digiquartz high pressure transducer (Model 415K-187: 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 0677, 4 May 2007 The time drift of the pressure sensor is adjusted by periodic recertification corrections against a dead-weight piston gauge (Model 480DA, S/N 23906; 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 0677, 9 December 2008 slope = 0.99977580 offset = -0.02383 Result of the pre-cruise pressure sensor calibration against the dead-weight piston gauge is shown in Fig. 3.1.1. Figure 3.1.1: Difference between the dead-weight piston gauge and the CTD pressure. The calibration line (black line) is also shown. 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, 26 November 2008 S/N 1525, 25 November 2008 Pressure sensitivity of SBE 3 was corrected according to a method by Uchida et al. (2007), for the following sensor. S/N 4815, -3.45974716e-7 [°C/dbar] S/N 1525, 5.92243e-9 [°C/dbar] Time drift of the SBE 3 temperature sensors based on the laboratory calibrations is shown in Fig. 3.1.2. Figure 3.1.2: Time drift of SBE 3 temperature sensors based on laboratory calibrations. 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. Pre-cruise sensor calibrations were performed at SBE, Inc. S/N 2954, 25 November 2008 (new cell preventing a stress concentration) S/N 1203, 12 December 2008 (new cell preventing a stress concentration) S/N 3261, 17 December 2008 (new cell preventing a stress concentration) 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 in. 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 calibrations were performed at SBE, Inc. S/N 0394, 20 December 2008 S/N 0330, 20 December 2008 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 0045, 27 October 2002 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. S/N 0045, 23 December 2008 (slope and offset correction) The time required per sample = 1.1 x 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. When using the SBE 911 system with SBE 35, the deck unit receives incorrect signal from the under water unit for confirmation of firing bottle #16. In order to correct the signal, a module (Yoshi Ver. 1; EMS Co. Ltd., Kobe, Hyogo, Japan) was used between the under water unit and the deck unit. Time drift of the SBE 35 based on the fixed point calibrations is shown in Fig. 3.1.3. Figure 3.1.3: SBE35 time drift based on laboratory fixed point calibrations (triple point of water, TPW and gallium melt point, GaMP) performed by SBE, Inc. 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 (a) Oxygen Optode 3830 Oxygen Optode 3830 (Aanderaa Data Instruments AS) is based on the ability of selected substances to act as dynamic fluorescence quenchers. In order to use with the SBE 911plus CTD system, an analog adaptor (3966) is connected to the oxygen optode (3830). The analog adaptor is packed into titanium housing made by Alec Electronics Co., Ltd. The sensor is designed to operate down to 6000 m. The range for dissolved oxygen is 120% of surface saturation in all natural waters, nominal accuracy is less than 8 µM or 5% of saturation which ever is greater and setting time (63%) is shorter than 25 seconds. (b) Oxygen Optode 4330F Oxygen Optode 4330F (Aanderaa Data Instruments AS) is based on the ability of selected substances to act as dynamic fluorescence quenchers. In order to use with the SBE 911plus CTD system, an analog adaptor (3966) with titanium housing for Oxygen Optode 3975 is connected to the oxygen optode (4330F). The sensor is designed to operate down to 6000 m. The range for dissolved oxygen is 150% of surface saturation in all natural waters, nominal accuracy is less than 8 µM or 5% of saturation which ever is greater and setting time (63%) is shorter than 8 seconds. (c) 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. Outputs from Optode 3830 and RINKO are the raw phase shift data. Raw phase shift data for Optode 4330F can be back calculated from the outputs (oxygen concentration and temperature). The optode oxygen can be calibrated by the Stern-Volmer equation, according to a method by Uchida et al. (2008) with slight modification: O2 (µmol/l) = [(V0 / V)2 - 1] / KSV where V is voltage, V0 is voltage in the absence of oxygen and KSV is Stern-Volmer constant. The VO and the KSV are assumed to be functions of temperature as follows. KSV = C0 + C1 x T + C2 x 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 temperature data from the first responding CTD temperature sensor instead of temperature data from slow responding optode temperature sensor. The pressure-compensated oxygen concentration O2c can be calculated as follows. O2c = O2 (1 + Cpp / 1000)1/3 where p is CTD pressure (dbar) and Cp 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 (Garcia and Gordon, 1992). Garcia and Gordon (1992) have recommended the use of the solubility coefficients derived from the data of Benson and Krause. The calibration coefficients were preliminary determined by using the bottle oxygen data obtained in this cruise, and used during the cruise. 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 over a know path. 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. (5) Data collection and processing i. Data collection CTD system was powered on at least 20 minutes in advance of the data acquisition 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 is 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. At each bottle firing stops, the bottle was fired after waiting from the stop for 30 seconds (20 seconds from station P21_23_1) and the package was stayed at least 5 seconds for measurement of the SBE 35. 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 SBE 32 Carousel Water Sampler with 12-litre Niskin-X bottles. Before a cast taken water for CFCs, the 36-bottle frame and Niskin-X bottles were wiped with acetone. Data acquisition software SEASAVE-Win32, version 7.18c ii. Data collection problems (a) Temperature and conductivity sensors Since differences of temperature-salinity relationship calculated from the secondary sensors between downcast and upcast were larger than that calculated from the primary sensors, the secondary conductivity sensor S/N 1203 was replaced with the conductivity sensor S/N 3261 after the station P21_86_1. However, the differences were still larger than that calculated from the primary sensors. The results suggest that the secondary temperature sensor S/N 1525 may have a pressure hysteresis relatively larger than the primary temperature sensor. At the station P21161, the primary temperature and conductivity data were noisy probably due to jellyfish in the primary TC duct. Therefore, the second cast P21_16_2 was carried out. At the station P21261, the primary temperature and conductivity data were noisy probably due to jellyfish in the primary TC duct. Since the second cast was not carried out, the secondary temperature and conductivity data must be used for this station. (b) SBE43 oxygen sensor Since differences between downcast and upcast profiles near the surface gradually became large, the SBE43 oxygen sensor S/N 0394 was replaced with the oxygen sensor S/N 0330 after the station P21_76_1. (c) Miss trip and miss fire Niskin bottles did not trip correctly at the following stations. Miss trip Miss fire ----------- ------------ P21331, #13 P21611, #14 P21181, #13 P21691, #15 P21361, #15 P211771, #21 P211851, #21 P211881, #21 P212551, #33 (d) Problem of the Niskin bottle #13 Discrepancies between CTD salinity and bottle sampled salinity data for the bottle #13 (about 3000 dbar) were slightly larger (about 0.001) than that obtained from neighboring bottles during leg 1. Bottle salinity data were obtained from a different bottle at the same depth of following stations, and were compared with the bottle salinity data obtained from the bottle #13. Bottle #2 of P21471 Bottle #3 of P211311, P211321, P211331, P211351, P211371 Bottle #9 of P211361 Mean difference with standard error between CTD salinity and bottle salinity data are -0.0021 ± 0.0002 and -0.0013 ± 0.0001 for the bottle #13 and for the duplicate bottles, respectively. Salinity data from bottle #13 were significantly smaller than the other bottles probably due to slight leakage, although leak was not found for the bottle #13 at the water sampling. Therefore, the Niskin bottle #13 (S/N X12013) was replaced with the Niskin bottle S/N X12014 after the station P21_141_1, and the bottle flags of #13 for stations from P21_29_1 to P21_141_1 were set to 7 (unknown problem). For the other water sampling parameters, significant difference was not detected for the duplicate bottle comparison (#2 and #13) at the station P21471. (e) Errors of bottle sampled oxygen data from nitrites During the determination of dissolved oxygen by using the Winkler method, errors from nitrites were introduced at the time the solution was made acidic with sulfuric acid (Wetzel and Gene, 2000). Therefore, the bottle sampled oxygen data were corrected when the nitrite concentration was high (> 0.5 µmol/kg) as follows and used for the CTD oxygen calibration. O2c, = O2- 0.25 NO2 If the nitrite concentration was higher than 5 µmol/kg, the bottle sampled oxygen data was not used, because the error was significantly greater than 0.25 NO2. (f) Other incidents of note At the station P21_200_1, Oxygen Optode 4330F, fluorometer, and transmissometer were removed from the CTD system, because the maximum pressure (6500 dbar) for the cast was beyond the proof pressure of these sensors (6000 m). To gain more observation time, the bottle was fired after waiting from the stop for 20 seconds at each bottle firing stops from station P21_23_1. Immediately after the bottle firing stop, water around the instruments can be contaminated by the wake effect (Uchida et al., 2007). Although the wake effect is usually large within the first 20 seconds of the stop, the data may somewhat contaminated by the wake effect. At the station P21_97_1, the cast was aborted at 285 dbar of the down cast due to a bad condition of the winch system, and the second cast P21_97_2 was carried out. At the station P21_118_1, the cast was aborted at 54 dbar of the down cast due to a mistake of the parameter setting for the LADCP, and the second cast P21_118_2 was carried out. 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 acquisition software SEASOFT-Win32, version 7.18c 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. 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 5 seconds advancing 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. 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 and SBE 43 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, Optode 3830, 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. OPTBACKCAL (original module, version 1.0) calculated raw phase shift data of the Optode 4330F from the Optode 4330F outputs (oxygen concentration and temperature data). For bottle information data, this module was applied before applying the module BOTTLESUM. DERIVE was re-used to compute salinity, potential temperature, and density (σθ). 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. (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. 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. 3.1.4. The CTD pressure sensor offset was estimated from the deck pressure obtained above. Mean of the pre- and the post-casts data over the whole period gave an estimation of the pressure sensor offset from the pre-cruise calibration. Mean residual pressure between the dead-weight piston gauge and the calibrated CTD data at 0 dbar of the pre-cruise calibration was subtracted from the mean deck pressure. Estimated mean offset of the pressure data is listed in Table 3.1.1. The post-cruise correction of the pressure data is not deemed necessary for the pressure sensor. Figure 3.1.4: Time series of the CTD deck pressure. Black dot indicates atmospheric pressure anomaly. Blue and green dots indicate pre- and post-cast deck pressures, respectively. Red dot indicates an average of the pre- and the post-cast deck pressures. Table 3.1.1: Offset of the pressure data. Mean and standard deviation are calculated from time series of the average of the pre- and the post-cast deck pressures. _________________________________________________________ Mean deck Standard Residual Estimated Number pressure deviation pressure offset of cast [dbar] [dbar] [dbar] [dbar] ----- ------- --------- --------- -------- --------- Leg 1 140 0.02 0.03 0.13 -0.11 Leg 2 117 0.02 0.02 0.13 -0.11 _________________________________________________________ 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. SIN 0045, 19 August 2009 (2nd step: fixed point calibration) Slope = 1.000013 Offset = -0.001173 Offset of the SBE 35 data from the pre-calibration was estimated to be smaller than 0.1 mK for temperature smaller than 4.5C. So the post-cruise 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 - (c0 x P + c1 x 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 1950 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 for the station P21_26_1. The number of data used for the calibration and the mean absolute deviation from the SBE 35 are listed in Table 3.1.2 and the calibration coefficients are listed in Table 3.1.3. The results of the post-cruise calibration for the CTD temperature are summarized in Table 3.1.4 and shown in Figs. 3.1.6 and 3.1.7. Table 3.1.2: Number of data used for the calibration (pressure ≥ 1950 dbar) and mean absolute deviation between the CTD temperature and the SBE 35. _________________________________________________________________________ Leg Serial number Number Mean absolute deviation Note --- ------------- ------ ----------------------- -------------------- 1 4815 1315 0.l mK 1 1525 1315 0.1 mK for station P21_26_1 2 4815 834 0.1 mK 2 1525 834 0.1 mK Not used _________________________________________________________________________ Table 3.1.3: Calibration coefficients for the CTD temperature sensors. ______________________________________________________ Leg Serial number c0 (°C/dbar) c1 (°C/day) c2 (°C) --- ------------- ------------ ----------- ------- 1 4815 1.03996e-8 2.23793e-6 -0.0000 1 1525 -7.61078e-9 1.76847e-6 0.0005 2 4815 -4.16502e-8 3.67354e-7 -0.0003 2 1525 1.76844e-8 -1.01065e-5 0.0024 ______________________________________________________ Table 3.1.4: 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 1950 dbar Number of data used is also shown. _____________________________________________________ Pressure ≥ 1950 dbar Pressure < 1950 dbar -------------------- --------------------- Serial Mean Sdev Mean Sdev number Number (mK) (mK) Number (mK) (mK) ------ ------ ----- ---- ------ ---- ---- Leg 1 4815 1315 -0.01 0.2 2647 -0.03 8.7 1525 1315 -0.01 0.2 2647 0.46 9.8 Leg 2 4815 834 -0.00 0.3 2171 -0.42 4.8 1525 834 -0.02 0.5 2171 -0.00 5.2 _____________________________________________________ Figure 3.1.5: Difference between the CTD temperature and the SBE 35. 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. Results from the primary temperature sensor (S/N 4815) are shown. Figure 3.1.6: Same as Fig. 3.1.5, but for the secondary temperature sensor (S/N 1525). 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 c are calibration coefficients. The best fit sets of coefficients were determined by a weighted least square technique to minimize the deviation from the conductivity calculated from the bottle salinity data. The revised quasi-Newton method (FORTRAN subroutine DMINF1 from the Scientific Subroutine Library II, Fujitsu Ltd., Kanagawa, Japan) was used to determine the sets. The weight was given as a function of pressure as Weight = min100, exp{log(100) x P / PR}] where PR is threshold of the pressure (950 dbar). When pressure is large (small), the weight is large (small) at maximum (minimum) value of 100 (1). The primary conductivity data created by the software module ROSSUM were basically used after the post-cruise calibration for the temperature data. For the station P21_26_1, the secondary conductivity data was used, because the primary conductivity data was not able to be used for the station. Data from the station P21_14_1 to P21_27_1 were used for the calibration of the secondary conductivity. The coefficients were determined for each leg. The calibration coefficients are listed in Table 3.1.5. The results of the post-cruise calibration for the CTD salinity are summarized in Table 3.1.6 and shown in Fig. 3.1.7. Table 3.1.5: Calibration coefficients for the CTD conductivity sensors. _____________________________________________________________________________________ Number c0 c1 [S/(m dbar)] c2 (1/dbar) c3 [S/(m day)] c4 (S/m) Note ------ -------- --------------- ----------- -------------- ----------- -------- Leg 1 3743 1.00015 3.00883e-8 -9.60863e-8 4.24710e-6 -4.86614e-4 S/N 2854 330 0.999985 1.87529e-7 -6.74291e-8 5.33449e-5 -9.41355e-5 S/N 1203 Leg 2 2849 1.00021 -3.50016e-8 5.62948e-9 -1.22961e-6 -4.63040e-4 S/N 2854 _____________________________________________________________________________________ Table 3.1.6: Difference between the CTD salinity and the bottle salinity after the post-cruise calibration. Mean and standard deviation (Sdev) (in 10) are calculated for the data below and above 950 dbar. Number of data used is also shown. ____________________________________________________________ Pressure ≥ 950 dbar Pressure < 950 dbar ------------------- ------------------- Leg (Serial no.) Number Mean Sdev Number Mean Sdev ---------------- ------ ----- ---- ------ ---- ---- Leg 1 (2854) 1933 -0.02 0.42 1810 0.15 5.57 Leg 1 (1203) 163 -0.00 0.40 167 0.13 3.20 Leg 2 (2854) 1347 0.00 0.39 1502 0.05 4.58 ____________________________________________________________ Figure 3.1.7: Difference between the CTD salinity and the bottle salinity. Blue and red dots indicate before and after the post-cruise calibration, respectively. Lower two panels show histogram of the difference after the calibration. Results from the primary conductivity sensor (S/N 2854) are shown. iv. Oxygen The RINKO oxygen optode was calibrated and used as the CTD oxygen data, since the RINKO has a fast time response. However, the time-dependent, pressure-induced effect on the sensing foil was large for the RINKO, as was observed for the SBE 43. Data from the RINKO was corrected for the time-dependent, pressure-induced effect by means of the same method as that developed for the SBE 43 (Sea-Bird Electronics, 2009). The calibration coefficients, H1 (amplitude of hysteresis correction), H2 (curvature function for hysteresis), and H3 (time constant for hysteresis) were determined empirically as: H1 = 0.0065 H2 = 5000 dbar H3 = 2000 seconds. Difference between the up and down cast oxygen was quite small for the pressure-hysteresis corrected RINKO data (Fig. 3.1.8). The pressure-hysteresis corrected RINKO data was calibrated by the Stern-Volmer equation, basically according to a method by Uchida et al. (2008) with modification: [O2] (µmol/l) = [(V0 / V)2 - 1] / KSV and 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. Time drift of the RINKO output was corrected. The pressure-compensation coefficient (Cp) was estimated to be 0.058. The coefficient for the V0 (C3 = -0.00076) was estimated from laboratory experiments on August 6, 2009. The remaining seven coefficients (C0, C1, C2, C4, C5, C6, and C7) 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 weight was given as a function of pressure as Weight = min[20, exp{log(20) x P / PR}], when [O2] ≥ 5 µmol/kg Weight = 20, when [O2] < 5 µmol/kg, where PR is threshold of the pressure (950 dbar). The post-cruise calibrated temperature and salinity data were used for the calibration. The coefficients were determined for some groups of the CTD stations. The calibration coefficients are listed in Table 3.1.7. The results of the post-cruise calibration for the RINKO oxygen are summarized in Table 3.1.8 and shown in Fig. 3.1.9. Figure 3.1.8: Difference between the up and down cast oxygen profiles from RINKO, SBE 43, Optode 4330E and Optode 3830. (a) mean and (b) standard deviation calculated from all CTD data. Table 3.1.7: Calibration coefficients for the RINKO oxygen sensor. ________________________________________________________________________________________________ Group C0 C1 C2 C4 C5 C6 C7 ----- ----------- ---------- ------------ ----------- --------- ------------ ------------ Leg 1 A 6.689376e-3 1.762279e-4 4.882030e-6 8.338279e-2 0.2267409 -4.196177e-3 3.326666e-3 B 6.782221e-3 1.365800e-4 6.972649e-6 7.467877e-2 0.2304436 -2.522455e-3 2.283958e-3 C 6.422881e-3 2.150534e-4 2.960990e-6 8.887120e-2 0.2285794 -7.967244e-5 8.759761e-4 D 6.707974e-3 2.692866e-4 1.586005e-6 7.623816e-2 0.2298613 -1.307925e-4 8.577014e-4 E 7.702781e-3 3.032778e-4 3.319508e-6 3.659057e-2 0.2395650 -3.795239e-4 5.390385e-4 F 8.815933e-3 3.357220e-4 4.934811e-6 2.385302e-2 0.2267504 -1.456302e-3 1.483800e-3 Leg 2 G 8.751177e-3 3.336450e-4 4.553403e-6 -4.679584e-2 0.2673914 2.997944e-3 -9.971862e-4 H 8.835125e-3 3.345906e-4 5.044742e-6 1.583165e-2 0.2399865 -9.708137e-4 6.960351e-4 ________________________________________________________________________________________________ Group of CTD stations A: 291-331, B: 141-281, C: 411-681, D: 691-861, E: 871-1481, F: 1491-1561, G: 1641-1721, H: 1731-2881 Figure 3.1.9: Difference between the RINKO oxygen and the bottle oxygen after the post-cruise calibration. Lower two panels show histogram of the difference. Table 3.1.8: Difference between the RINKO oxygen and the bottle oxygen 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. _________________________________________________________________ Pressure ≥ 950 dbar Pressure < 950 dbar ---------------------------- ---------------------------- Leg Number Mean Sdev Number Mean Sdev (µmol/kg) (µmol/kg) (µmol/kg) (µmol/kg) ----- ------ --------- --------- ------ --------- --------- Leg 1 2023 0.00 0.24 1781 0.07 1.67 Leg 2 1357 0.01 0.28 1507 0.03 0.52 _________________________________________________________________ (8) Estimation of tripped depth for the bottle #13 of stations P21_33_1 and P21_18_1 True tripped depths for the following miss tripped bottles were estimated by using post-cruise calibrated CTD salinity and oxygen data compared to the bottle sampled salinity and oxygen data (Table 3.1.9). Table 3.1.9: Estimated pressure of tripped depth for miss tripped bottles. The CTD temperature, salinity and oxygen data at the estimated pressure are also shown. _________________________________________________________________________ Estimated pressure (dbar) Bottle ----------------------------- CTDTMP CTDSAL CTDOXY by CTDSAL by CTDOXY Average (ITS-90) (PSS-78) (µmol/kg) ----------- --------- --------- ------- -------- -------- --------- P21_33_1#13 2403.0 2388.6 2395.8 1.9394 34.6628 134.45 P21_18_1#13 762.2 763.2 762.7 5.6999 34.5179 28.86 _________________________________________________________________________ REFERENCES 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. Garcia, H.E. and L.I. Gordon (1992): Oxygen solubility in seawater: Better fitting equations. Limnol. Oceanogr., 37 (6),1307-1312. Sea-Bird Electronics (2009): SBE 43 dissolved oxygen (DO) sensor - hysteresis corrections, Application note no. 64-3, 7 pp. 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. Uchida, H., T. Kawano, I. Kaneko, and M. Fukasawa (2008): In situ calibration of optode-based oxygen sensors, J. Atmos. Oceanic Technol., 25,2271-2281. Wetzel, R.G. and G.E. Likens (2000): Limnological Analysis, 429 pp., Springer, New York, USA. 3.2 BOTTLE SALINITY September 9, 2009 (1) Personnel Takeshi Kawano (JAMSTEC) Fujio Kobayashi (MWJ) Tatsuya Tanaka (MWJ) Akira Watanabe (MWJ) Kenichi Katayama (MWJ) (2) Objectives Bottle salinities were measured to compare with CTD salinities for calibrating CTD salinities and for identifying leaking bottles. (3) Instrument and Method i. Salinity Sample Collection The bottles in which the salinity samples are collected and stored are 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 12 hours in the same laboratory as the salinity measurement was made. ii. Instruments and Method The salinity analysis was carried out on Guildline Autosal salinometer model 8400B (S/N 62556), which was modified by adding an Ocean Scientific International Ltd. peristaltic-type sample intake pump and two Guildline platinum thermometers model 9450. One thermometer monitored an ambient temperature and the other monitored a 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. An ambient temperature varied from approximately 20°C to 24°C, while a bath temperature is very stable and varied within ± 0.002°C on rare occasion. A measure of a double conductivity ratio of a sample is 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 is smaller than 0.00002, the average value of the two double conductivity ratios is used to calculate the bottle salinity with the algorithm for practical salinity scale, 1978 (UNESCO 1981). If the difference is grater than or equal to the 0.00003, we measure another additional filling of the cell. In case where the double conductivity ratio of the additional filling does not satisfy the criteria above, we measure other additional fillings of the cell within 10 fillings in total. In case where the number of fillings is 10 and those fillings do not satisfy the criteria above, the median of the double conductivity ratios of five fillings are used to calculate the bottle salinity. The measurement was conducted about from 12 to 20 hours per day and the cell was cleaned with soap after the measurement of the day. We measured more than 8,500 samples in total. (4) Preliminary Result i. Standard Seawater Leg1 and Leg2a Standardization control was set to 649 during Leg1 and Leg2a. The value of STANDBY was 5491 ± 0002 and that of ZERO was 0.00000 ± 0.00001. We used IAPSO Standard Seawater batch P150 which conductivity ratio was 0.99978 (double conductivity ratio is 1.99956) as the standard for salinity. We measured 219 bottles of P150 during routine measurement. Fig.3.2.1 shows the history of double conductivity ratio of the Standard Seawater batch P150 during Legl and Leg2a. Drifts were calculated by fitting data from P150 to the equation obtained by the least square method (solid lines). Correction for the double conductivity ration of the sample was made to compensate for the drift. After correction, the average of double conductivity ratio became 1.99956 and the standard deviation was 0.00001, which is equivalent to 0.0002 in salinity. Figure 3.2.1: History of Double conductivity ratio of P150 during Leg1 and Leg2a. X and Y axes represents date and double conductivity ratio, respectively. Blue diamond is raw data and red rectangular is corrected data. Figure 3.2.2: History of Double conductivity ratio of P150 during Leg2b. X and Y axes represents date and double conductivity ratio, respectively. Blue diamond is raw data and red rectangular is corrected data. Leg2b As the drift of this salinometer had been significant, the re-standardization was done on 27 May, and standardization control was set to 652 during Leg2b. The value of STANDBY was 5492 ± 0001 and that of ZERO was .00000 ± 0.00001. We used IAPSO Standard Seawater batch P150 which conductivity ratio was 0.99978 (double conductivity ratio is 1.99956) as the standard for salinity. We measured 137 bottles of P150 during routine measurement. Fig.3.2.2 shows the history of double conductivity ratio of the Standard Seawater batch P150 during Leg2b. Drifts were calculated by fitting data from P150 to the equation obtained by the least square method (solid lines). Correction for the double conductivity ration of the sample was made to compensate for the drift. After correction, the average of double conductivity ratio became 1.99956 and the standard deviation was 0.00001, which is equivalent to 0.0002 in salinity. ii. Sub-Standard Seawater We also used sub-standard seawater which was deep-sea water filtered by pore size of 0.45 micrometer and stored in a 20 liter cubitainer made of polyethylene and stirred for at least 24 hours before measuring. It was measured every six 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 Leg1 We took 819 pairs of replicate during Legl. Fig.3.2.3 shows the histogram of the absolute difference between replicate samples. There was 1 bad measurement of replicate samples. Excluding these bad measurements, the standard deviation of the absolute deference of 818 pairs of replicate samples was 0.00023 in salinity. Figure 3.2.3: The histogram of the absolute difference between replicate samples in Leg1. X axis is absolute difference in salinity and Y axis is frequency. Figure 3.2.4: The histogram of the absolute difference between replicate samples in Leg2. X axis is absolute difference in salinity and Y axis is frequency. Leg2 We took 613 pairs of replicate during Leg2. Fig.3.2.4 shows the histogram of the absolute difference between replicate samples. There was 1 bad measurement of replicate samples. Excluding these bad measurements, the standard deviation of the absolute deference of 612 pairs of replicate samples was 0.00019 in salinity. (5) Further data quality check All the data will be checked once again in detail with other parameters such as dissolved oxygen and nutrients. 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. UNESCO (1981): Tenth report of the Joint Panel on Oceanographic Tables and Standards. UNESCO Tech. Papers in Mar. Sci., 36, 25 pp. 3.3 OXYGEN July 31, 2010 (1) Personnel Yuichiro Kumamoto (JAMSTEC) Miyo Ikeda (MWJ) Fuyuki Shibata (MWJ) Masanori Enoki (MWJ) Misato Kuwahara (MWJ) (2) Objectives Dissolved oxygen is one of good tracers for the ocean circulation. Recent studies indicated that the oxygen minimum layers in the tropical region have expanded (Stramma et al., 2008). Climate models predict a decline in oceanic dissolved oxygen concentration and a consequent expansion of the oxygen minimum layers under the global warming, which results mainly from decreased interior advection and ongoing oxygen consumption by remineralization. The mechanism of the decrease, however, is still unknown. During MR09-01, we measured dissolved oxygen concentration from surface to bottom layers at all the hydrocast stations along approximately 18°S in the tropical South Pacific. These stations reoccupied the WOCE Hydrographic Program (WHP) P21 stations in 1994. Our purpose is to evaluate temporal change in dissolved oxygen concentration in the tropical South Pacific between the 1994 and 2009. (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) CSK standard of potassium iodate: Lot T5K3592, Wako Pure Chemical Industries Ltd., 0.0100N (4) Instruments Burette for sodium thiosulfate and potassium iodate: APB-510 manufactured by Kyoto Electronic Co. Ltd. / 10 cm3 of titration vessel Detector: Automatic photometric titrator, DOT-01 manufactured by Kimoto Electronic Co. Ltd. (5) Seawater sampling Following procedure is based on an analytical method, entitled by "Determination of dissolved oxygen in sea water by Winkler titration", 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 automatically by sodium thiosulfate solution whose molarity was determined by standard solution of potassium iodate (see section 7). 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-1 and DOT-2. Dissolved oxygen concentration (µmol/kg-1) was calculated by the sample temperature during the sampling, CTD salinity, flask volume, and the titrant concentration and volume corrected with burette-volume calibration. When we measured suboxic samples (oxygen concentration less than about 40 µmol/kg-1), titration procedure was adjusted manually. In case of anoxic sample measurements (oxygen concentration less than about 6 µmol/kg-1), titration volume of sodium thiosulfate titrant was not corrected with the burette-volume calibration. (7) Standardization Concentration of sodium thiosulfate titrant (ca. 0.025M) was determined by potassium iodate solution. Pure potassium iodate (Lot TSK3592, Wako Pure Chemical Industries Ltd., 99.96±0.01%) 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 3.3.1). Error (C.V.) of the standardization was 0.02±0.01%, or c.a. 0.05 µmol/kg-1. (8) Determination of the blank The oxygen in the pickling reagents 1(0.5 cm3) and 11(0.5 cm3) was assumed to be 3.8 x 108 mol (Murray et al., 1968). The blank due to other than oxygen 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 3.3.1). The averaged blank values for DOT-1 and DOT-2 were -0.002±0.001 (S.D., n=27) and -0.000±0.001 (S.D., n=27) cm3, respectively. The blank determined here can cancel a sum of errors due to oxidants or reductants in the reagents, differences between the measured end-point and the equivalence point, and oxidation of iodide to iodate with the atmospheric O2 during the titration. However, blank due to redox species other than oxygen in seawater sample, called "seawater blank", still remains in the Winkler oxygen concentration. Table 3.3.1: Results of the standardization and the blank determinations during MR09-01. ___________________________________________________________________________________________________ KIO3 standard Na2S2O3 DOT-1 DOT-2 Date # -------------- ------------ ------------- ------------- Stations (UTC) ID No. E.P. blank E.P. blank --------- -- -------------- ------------ ----- ------ ----- ------ ------------------------ 2009/4/13 20081203-11-02 20080704-2-1 3.957 -0.001 3.957 -0.001 029,030,031,032,040,033 2009/4/18 20081203-11-03 20080704-2-1 3.958 0.001 3.959 0.003 - 2009/4/18 11 20081203-11-04 20080704-2-2 3.958 -0.002 3.957 -0.002 - 2009/4/21 20081203-11-05 20080704-2-2 3.956 -0.001 3.956 0.001 041,034,042,035 2009/4/22 20081203-11-07 20080704-3-1 3.960 -0.002 3.960 -0.001 043,036,044,037,045,038, 046,039 --------------------------------------------------------------------------------------------------- 2009/4/24 20081203-12-02 20080704-3-1 3.962 -0.002 3.962 -0.001 047,X19,049,050 2009/4/25 20081203-12-03 20080704-3-2 3.961 -0.002 3.964 0.001 054,051,055,056,053,057, 058,059,060,061,062,063, 064,065 2009/4/26 20081203-12-04 20080704-3-2 3.962 -0.002 3.961 0.000 052 2009/4/28 12 20081203-12-06 20080704-4-1 3.963 -0.002 3.962 0.000 066,067,068,069,070,071, 072,073,074,075,076,X18, 077,078 2009/5/1 20081203-12-08 20080704-4-2 3.963 -0.002 3.964 -0.001 079,080,085,086,087,088, 089,090,095,096,097-2, 098,099,100 2009/5/5 20081203-12-10 20080704-5-1 3.964 -0.002 3.964 0.000 101,102,103,104,105,106 --------------------------------------------------------------------------------------------------- 2009/5/6 20081203-13-01 20080704-5-1 3.962 -0.001 3.962 0.000 107,108,109,110,111,112, 113,114 2009/5/8 20081203-13-02 20080704-5-2 3.965 -0.002 3.964 -0.001 115,116,117,118,119,120, 121,122,123,124,125,126, 127 2009/5/11 13 20081203-13-04 20080704-6-1 3.964 -0.001 3.964 0.000 128,129,130,X17,131,132, 133,134,135,136,137 2009/5/14 20081203-13-06 20080704-6-2 3.964 -0.002 3.964 -0.001 138,139,140,141,142,143, 144,145,146,147,148,149, 150,151,152 2009/5/16 20081203-13-08 20080704-7-1 3.963 -0.001 3.965 0.000 153,154,155,160,159,158, 157,156 --------------------------------------------------------------------------------------------------- 2009/5/21 20081203-14-01 20080704-7-2 3.963 -0.003 3.965 -0.003 164,165,X16,167,168,169, 170,171,172 2009/5/26 20081203-14-03 20080704-8-1 3.968 -0.001 3.971 0.001 173,174,175,176,177,178, 179,180,181,182,183 2009/5/29 14 20081203-14-05 20080704-8-2 3.968 -0.001 3.969 -0.001 184,185,186,187,188,189, 190,191,192 2009/6/1 20081203-14-07 20080704-9-1 3.965 -0.001 3.965 -0.001 193,194,195,196,197,198, 199,200,201,203,204,205 2009/6/3 20081203-14-09 20080704-9-2 3.965 -0.002 3.966 0.000 206,207,208,209,210,211, 212,213 --------------------------------------------------------------------------------------------------- 2009/6/5 20081203-15-01 20080704-9-2 3.963 -0.002 3.964 0.000 214,215,216,217,218,220, 221,222 2009/6/6 20081203-15-03 20080704-10-1 3.975 -0.001 3.976 0.001 223,224,225,226,227,228, 15 229,230,231,232,233 2009/6/9 20081203-15-05 20080704-10-2 3.977 -0.001 3.978 0.002 234,235,236,237,238,239, 240,241,243,244,245,246 2009/6/10 20081203-15-07 20080704-11-1 3.965 -0.001 3.965 0.000 247,248,249,250,251,252, 253,255,254 --------------------------------------------------------------------------------------------------- 2009/6/13 20081204-16-01 20080704-11-2 3.967 -0.002 3.968 0.000 260,261,262,263,264,265, 266,267,268,269,270,271, 16 272,273,274,275,276 2009/6/16 20081204-16-03 20080704-12-1 3.966 -0.002 3.967 0.000 277,278,279,280,281,282, 283,285,287,286,288 ___________________________________________________________________________________________________ # Batch number of the KIO3 standard solution (9) Replicate sample measurement Replicate samples were taken from every CTD cast. Total amount of the replicate sample pairs of good measurement (flagged 2) was 656. The standard deviation of the replicate measurement was 0.09 µmol kg-1 that was calculated by a procedure (SOP23) in DOE (1994). The replicate measurements depended on neither measurement date nor sampling depth (Fig.3.3.1). Each set of "good" data from replicate sample pairs were averaged and then flagged 2 (see section 12). Figure 3.3.1: Differences ((µmol kg-1)2) of replicate sample pairs against the Julian days (a) and sampling depth (b). (10) Duplicate sample measurement Duplicate samples were taken from 27 CTD casts during this cruise. The standard deviation of the duplicate measurements was calculated to be 0.07 µmol kg-1 which was equivalent with that of the replicate measurements (0.09 µmol kg-1). We concluded that the precision of our oxygen measurement through this cruise, including errors from the seawater sampling, pickling, and the Winkle titration, were about 0.1 µmol kg-1. (11) CSK standard measurements The CSK standard is a commercial potassium iodate solution (0.0100 N) for analysis of dissolved oxygen. Before the cruise, we titrated the CSK standard solutions (Lot TSK3592) against all the six batch series (#11-#16) of our KIO3 standard solution (see section 7) which had been prepared for this cruise. In addition, the CSK solution was also measured at the beginning, mid, and end of the cruise. The results of the CSK are shown in Table 3.3.2. A good agreement among them confirms that there was no systematic shift in our oxygen analyses on board. We also confirmed that there was not difference in the results between the current (TSK3592) and former (EWL3818) batches of the CSK standard solutions which were applied to this cruise and previous ones in 2007 (MR07-04 and MR07-06), respectively. This agreement indicates comparability in the oxygen data between 2007 and 2009. Table 3.3.2: Results of the CSK standard (Lot TSK3592) measurements. _____________________________________________________________________________________ DOT-3 - Date (UTC) KIO3 ID No. -------------------- -------------------- Remarks Conc. (N) error (N) - - ---------- -------------- --------- --------- --------- --------- ------------- 2008/12/08 20081203-11-12 0.010000 0.000002 - - before cruise 2008/12/08 20081203-12-12 0.010001 0.000002 - - before cruise 2008/12/08 20081203-13-12 0.010001 0.000002 - - before cruise 2008/12/08 20081203-14-12 0.009999 0.000002 - - before cruise 2008/12/08 20081203-15-12 0.009999 0.000002 - - before cruise 2008/12/09 20081203-16-12 0.010001 0.000003 - - before cruise DOT-1 DOT-2 Date (UTC) KIO3 ID No. -------------------- -------------------- Remarks Conc. (N) error (N) Conc. (N) error (N) ---------- -------------- --------- --------- --------- --------- ------------- 2009/04/10 20081203-11-01 0.010003 0.000002 0.010008 0.000001 MR09-01 Leg-1 2009/05/18 20081203-13-09 0.010008 0.000001 0.010003 0.000003 MR09-01 Leg-1 2009/06/18 20081204-16-04 0.010005 0.000007 0.010002 0.000002 MR09-01 Leg-2 _____________________________________________________________________________________ (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 3.3.3). The replicate data were averaged and flagged 2 if both of them were flagged 2. If either of them was flagged 3 or 4, a datum with "younger" flag was selected. Thus we did not use flag of 6 (see section 9). For the choice between 2, 3, or 4, we basically followed a flagging procedure as listed below: a. Bottle oxygen concentration was plotted against sampling pressure. Any points not lying on a generally smooth trend were noted. b. Difference between the 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 transections 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 7 (unknown problem), a datum was flagged based on steps a, b, c, and d. Table 3.3.3: Summary of assigned quality control flags. ___________________________________ Flag Definition ---- ---------------------- ---- 2 Good 6319 3 Questionable 30 4 Bad 29 5 Not reported (missing) 0 Total 6378 ___________________________________ 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 seawater; 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. 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. Stramma, L., G.C. Johnson, J. Sprintall, and V. Mohrholz (2008): Expanding Oxygen-Minimum Zones in the Tropical Oceans, Science, 320, 655-668. 3.4 NUTRIENTS September 1, 2010 (1) Personnel Michio Aoyama (Meteorological Research Institute/Japan Meteorological Agency, Principal Investigator) LEG 1 Ayumi Takeuchi (Department of Marine Science, Marine Works Japan Ltd.) Shinichiro Yokogawa (Department of Marine Science, Marine Works Japan Ltd.) Kohei Miura (Marine Works Japan Ltd.) LEG 2 Junji Matsushita (Department of Marine Science, Marine Works Japan Ltd.) Ayumi Takeuchi (Department of Marine Science, Marine Works Japan Ltd.) Kohei Miura (Marine Works Japan Ltd.) (2) Objectives The objectives of nutrients analyses during the R/V Mirai MR0901 cruise, WOCE P21 revisited cruise in 2009, in the North Pacific are as follows; • Describe the present status of nutrients concentration with excellent comparability. • The determinants are nitrate, nitrite, phosphate and silicate. • Study the temporal and spatial variation of nutrients concentration based on the previous high quality experiments data of WOCE previous P21 cruises in 1994, 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, phosphate and silicate 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 233 TRAACS800 runs for the samples at 243 stations in MR0901. The total amount of layers of the seawater sample reached up to 6369 for MR0901. We made duplicate measurement at all layers. (4) Instrument and Method (4.1) Analytical detail using TRAACS 800 systems (BRAN+LUEBBE) The phosphate analysis is a modification of the procedure of Murphy and Riley (1962). Molybdic acid is added to the seawater sample to form phosphomolybdic acid which is in turn reduced to phosphomolybdous acid using L-ascorbic acid as the reductant. Nitrate + nitrite and nitrite are analyzed according to the modification method of Grasshoff (1970). The sample nitrate is reduced to nitrite in a cadmium tube inside of which is coated with metallic copper. The sample stream with its equivalent nitrite is treated with an acidic, sulfanilamide reagent and the nitrite forms nitrous acid which reacts with the sulfanilamide to produce a diazonium ion. N-1-Naphthylethylene-diamine added to the sample stream then couples with the diazonium ion to produce a red, azo dye. With reduction of the nitrate to nitrite, both nitrate and nitrite react and are measured; without reduction, only nitrite reacts. Thus, for the nitrite analysis, no reduction is performed and the alkaline buffer is not necessary. Nitrate is computed by difference. The silicate method is analogous to that described for phosphate. The method used is essentially that of Grasshoff et al. (1983), wherein silicomolybdic acid is first formed from the silicate in the sample and added molybdic acid; then the silicomolybdic acid is reduced to silicomolybdous acid, or "molybdenum blue," using ascorbic acid as the reductant. The analytical methods of the nutrients during this cruise are same as the methods used in (Kawano et al. 2009). We, though, changed the rate of NED in channel 2 from WHT/WHT to RED/RED to increase stability of the analysis. We also made slight change in NED regent that we add Triton(R) X-100 as shown in (4.3) Nitrite Regents. The flow diagrams and reagents for each parameter are shown in Figures 3.4.1 to 3.4.4. (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 1.2M 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 2HC1, 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 3.4.1: 1ch. (NO3+NO2) Flow diagram (4.3) Nitrite Reagents Sulfanilamide, 0.06 M (1% w/v) in 1.2 M HC1 Dissolve l0g sulfanilamide, 4-NH2C6H4SO3H, in 900 ml of DIW, add 100 ml concentrated HC1. 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 2HC1, in 1000 ml of DIW and add 10 ml concentrated HC1. After mixing, 1 ml Triton(R)X-100 (50%f solution in ethanol) is added. Stored in a dark bottle. Figure 3.4.2: 2ch. (NO2) Flow diagram (4.4) Silicate Reagents Molybdic acid, 0.06 M (2% w/v) Dissolve 15 g Disodium Molybdate(VI) Dihydrate, Na2MoO4 2H20, 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) Dissolve 50 g Oxalic Acid Anhydrous, HOOC: COOH, in 950 ml of DIW. Ascorbic acid, 0.01 M (3% w/v) Dissolve 2.5 g L (+)-Ascorbic Acid, C6H806, in 100 ml of DIW. Stored in a dark bottle and freshly repaired before every measurement. Figure 3.4.3: 3ch. (5i02) Flow diagram. (4.5) Phosphate Reagents Stock molybdate solution, 0.03 M (0.8% w/v) Dissolve 8 g Disodium Molybdate(VI) Dihydrate, Na2MoO4 2H2O, and 0.17 g Antimony Potassium Tartrate, C8H4K2O12Sb2 3H20, in 950 ml of DIW and add 50 ml concentrated H2S04. Mixed Reagent Dissolve 0.8 g L (+)-Ascorbic Acid, C6H8O6, in 100 ml of stock molybdate solution. After mixing, 2 ml sodium dodecyl sulphate (15% solution in water) is added. Stored in a dark bottle and freshly prepared before every measurement. Reagent for sample dilution Dissolve Sodium Hydrate, NaC1, 10 g in ca. 950 ml of DIW, add 50 ml Acetone and 4 ml concentrated H25O4. After mixing, 5 ml sodium dodecyl sulphate (15% solution in water) is added. Figure 3.4.4: 4ch. (PO4) Flow diagram. (4.6) Sampling procedures Sampling of nutrients followed that oxygen, trace gases and salinity. 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 are put into water bath adjusted to ambient temperature, 25 ± 1°C, in 10 to 20 minutes before use to stabilize the temperature of samples in MR0901. No transfer was made and the vials were set an auto sampler tray directly. Samples were analyzed after collection basically within 17 hours in MR0901. (4.7) Data processing Raw data from TRAACS800 were treated as follows; • Check baseline shift. • Check the shape of each peak and positions of peak values taken, and then change 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. • Load 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 phosphate standard, "potassium dihydrogen phosphate anhydrous 99.995 suprapur" provided by Merck, CAS No. 7778-77-0, was used. For nitrite standard, "sodium nitrate" provided by Wako, CAS No. 7632-00-0, was used. And assay of nitrite was determined according JIS K8019 and assays of nitrite salts were 98.04%. 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 HC75 1838 is used. The silicate concentration is certified by NIST-SRM3 150 with the uncertainty of 0.5%. Ultra pure water Ultra pure water (MilliQ water) freshly drawn was used for preparation of reagents, higher concentration standards 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 gm 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 Jul2008. (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 3.4.1. The C standard is prepared according recipes as shown in Table 3.4.2. 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-S and C-6. For the 10 stations from station 233 to station 245, we used only five levels, from C-1 to C-5 because silicate concentration of C-6 for these stations might be higher rather than target concentration. For the 19 runs, we used only five levels because nutrients concentration of one of the RMs was outliter. Table 3.4.1: Nominal concentrations of nutrients for A, B and C standards. ___________________________________________________ A B C-1 C-2 C-3 C-4 C-S C-6 ----- ---- --- --- --- --- --- --- NO3(µM) 45000 900 AS BJ AX BE AZ 55 NO2(µM) 4000 20 AS BJ AX BE AZ 1.2 SiO2(µM) 36000 2880 AS BJ AX BE AZ 170 PO4(µM) 3000 60 AS BJ AX BE AZ 3.6 ___________________________________________________ Table 3.4.2: Working calibration standard recipes. ________________________________ C Std. B-1 Std. B-2 Std. ------ -------- ---------- C-6 30m1 30m1 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 3.4.3(a) to (c). Table 3.4.3(a): Timing of renewal of in-house standards. _________________________________________________________ NO3, NO2, Si02, P04 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 3.4.3(b): Timing of renewal of in-house standards. _________________________________________________ C Std. Renewal -------------------------------------- -------- C-6 Std. (mixture of B-1 and B-2 Std.) 24 hours _________________________________________________ Table 3.4.3(c): Timing of renewal of in-house standards. ___________________________________________ Reduction estimation Renewal -------------------- --------------------- D-1 Std.(7200µM NO3) when A-1 Std. renewed 43/µM NO3 when C Std. renewed 47/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). In the previous world wide 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°C in potential temperature (Aoyama and Joyce, 1996). (6.1) RMNSs for this cruise RMNS lots AS, BJ, AX, BE and AZ, which cover full range of nutrients concentrations in the western North Pacific Ocean are prepared. 160 sets of AS, BJ, AX, BE and AZ are prepared. Three hundred ten bottles of RMNS lot BI and 200 bottles of RMNS lot AV are prepared for MR09Oi. Lot BI was used at 99 stations from 14 to 120 and lot AV was used at 158 stations from 121 to 288, respectively. 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 24°C. (6.2) Assigned concentration for RMNSs We assigned nutrients concentrations for RMNS lots AS, BJ, AX, BE, AZ, BI and AV as shown in Table 3.4.4. Table 3.4.4: Assigned concentration of RMNSs. unit: µmol kg-1 ___________________________________________ Nitrate Phosphate Silicate Nitrite ------- --------- -------- ------- AS* 0.11 0.077 1.58 0.02 BJ* 7.74 0.628 31.04 0.02 AX** 21.42 1.619 58.06 0.35 BE* 36.70 2.662 99.20 0.03 42.36 3.017 133.93 0.03 BI* 41.36 2.576 147.51 0.02 AV** 33.36 2.516 154.14 0.10 ___________________________________________ * The value in the Table is result of mea- surement on 6 January, 2009. ** The value in the Table is result of mea- surement on 7 October, 2007. (6.3) The homogeneity of RMNSs The homogeneity of lot AV and AZ used in MR0901 cruise and analytical precisions are shown in Table 3.4.5. These are for the assessment of the magnitude of homogeneity of the RMNS bottles those are used during the cruise. As shown in Table 3.4.5 homogeneity of RMNS lot AV and AZ for nitrate, phosphate and silicate are the same magnitude of analytical precision derived from fresh raw seawater in January 2009. Table 3.4.5: Homogeneity of lot AV and AZ derived from simultaneous 297 samples measurements and analytical precision onboard R/V Mirai in MR0901. _________________________________________________ Nitrate Phosphate Silicate CV% CV% CV% ------- --------- -------- AV 0.09 0.12 0.08 AZ 0.13 0.15 0.08 Precision 0.08 0.10 0.07 AV: N=297 AZ: N=244 _________________________________________________ We can see history of homogeneity of several lots of RMNS as shown in Table 3.4.6. The homogeneity of phosphate in old lots such as lot AH and K were relatively larger than those of recent lots, BI and BC. The homogeneities of nitrate and silicate, we also see progress from lot K to recent lots. Table 3.4.6: History of homogeneity of lot BI and previous lots derived from simultaneous 30 samples measurements and analytical precision onboard R/V Mirai in January 2009. _______________________________________ Nitrate Phosphate Silicate CV% CV% CV% ------- --------- -------- BI 0.19 0.21 0.08 BC* 0.22 0.32 0.19 AH* 0.39 0.83 0.13 K* 0.3 1.0 0.2 Precision 0.18 0.14 0.07 _______________________________________ * Table 3.4.5 in WHP P01, P14 REVISIT DATA BOOK (Kawano et al. 2009) (6.4) Comparability of RMNSs during the periods from 2003 to 2009 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 3.4.7, the nutrients concentrations of RMNSs were in good agreement among the measurements during the period from 2003 to 2009. For the silicate measurements, we show lot numbers and chemical company names of each cruise / measurement in the footnote. As shown in Table 3.4.7, there shows less comparability among the measurements due to less comparability among the standard solutions provided by chemical companies in the silicate measurements. Table 3.4.7 (a): Comparability for nitrate. NITRATE µmol kg-1 RM Lots _______________________________________________________________________________________________________________________________ Cruise / Lab. | AH | unc. | AZ | unc. | BA | unc. | AX | unc. | AV | unc. | BC | unc. | BE | unc. ----------------------- | ----- | ---- | ----- | ---- | ---- | ---- | ----- | ---- | ----- | ---- | ----- | ---- | ----- | ---- 2003 | | | | | | | | | | | | | | 2003intercomp_repeorted | 35.23 | 0.06 | | | | | 21.39 | | | | | | | MR03-K04 Legl | 35.25 | | | | | | | | | | | | | MR03-K04 Leg2 | 35.37 | | | | | | | | | | | | | MR03-K04 Leg4 | 35.37 | | | | | | | | | | | | | MR03-K04 Leg5 | 35.34 | | | | | | | | | | | | | 2005 | | | | | | | | | | | | | | MR05-02 | | | 42.30 | | 0.07 | 0.02 | 21.45 | 0.07 | 33.35 | 0.06 | 40.70 | 0.06 | | MR05-05_1 precruise | 35.65 | 0.05 | 42.30 | 0.10 | 0.07 | 0.00 | 21.41 | 0.01 | 33.41 | 0.02 | 40.76 | 0.03 | | MR05-05_1 | | | 42.33 | | 0.07 | 0.01 | 21.43 | 0.05 | 33.36 | 0.05 | 40.73 | 0.85 | | MR05-05_2 precruise | | | 42.33 | | 0.08 | 0.00 | 21.39 | 0.02 | 33.36 | 0.05 | 40.72 | 0.03 | | MR05-05_2 | | | 42.34 | | 0.07 | 0.01 | 21.44 | 0.05 | 33.36 | 0.05 | 40.73 | 0.06 | | MR05-05_3 precruise | | | 42.35 | | 0.06 | 0.00 | 21.49 | 0.01 | 33.39 | 0.01 | 40.79 | 0.01 | | MR05-05_3 | | | 42.36 | | 0.07 | 0.01 | 21.44 | 0.04 | 33.37 | 0.05 | 40.75 | 0.05 | | 2006 | | | | | | | | | | | | | | 2006intercomp | | | 42.24 | 0.04 | 0.04 | 0.00 | 21.40 | 0.02 | 33.32 | 0.03 | 40.63 | 0.04 | | 2003intercomp_revisit | 35.40 | 0.03 | | | | | | | | | | | | 2007 | | | | | | | | | | | | | | MR07-04_1 precruise | 35.74 | 0.03 | | | 0.07 | 0.00 | 21.59 | 0.02 | 33.49 | 0.03 | 40.83 | 0.03 | | MR07-04_2 precruise | 35.80 | 0.01 | | | 0.08 | 0.00 | 21.60 | 0.01 | 33.47 | 0.01 | 40.92 | 0.02 | | MR07-04 | | | | | 0.08 | 0.01 | 21.41 | 0.06 | 33.38 | 0.05 | 40.77 | 0.05 | | MR07-06_1 precruise | 35.61 | 0.02 | | | 0.07 | 0.00 | 21.44 | 0.01 | 33.43 | 0.02 | 40.79 | 0.02 | | MR07-06_2 precruise | 35.61 | 0.04 | | | 0.06 | 0.00 | 21.43 | 0.02 | 33.54 | 0.04 | 40.79 | 0.05 | | MR07-06_1 | | | | | 0.08 | 0.01 | 21.44 | 0.03 | 33.41 | 0.05 | 40.81 | 0.04 | | MR07-06_2 | | | | | 0.09 | 0.01 | 21.44 | 0.03 | 33.39 | 0.06 | 40.81 | 0.04 | | 2008 | | | | | | | | | | | | | | 2008intercomp_report | | | | | 0.08 | 0.00 | 21.44 | 0.02 | | | | | | 2006intercomp_revisit | | | 42.27 | 0.04 | 0.07 | 0.00 | 21.47 | 0.02 | 33.34 | 0.03 | | | | 2003intercomp_revisit | 35.35 | 0.04 | | | | | | | | | | | | 2009 | | | | | | | | | | | | | | MR09-01_0 precruise | | | 42.36 | 0.02 | 0.07 | 0.00 | 21.43 | 0.01 | 33.42 | 0.02 | 40.81 | 0.02 | 36.70 | 0.02 MR09-01_1 | | | 42.42 | 0.06 | 0.11 | 0.01 | 21.51 | 0.04 | 33.53 | 0.04 | 40.82 | 0.11 | 36.74 | 0.04 MR09-01_2 | | | 42.43 | 0.05 | | | 21.54 | 0.03 | 33.53 | 0.03 | | | 36.74 | 0.03 INSS stability test_1 | 35.76 | 0.22 | | | 0.08 | 0.01 | 21.49 | 0.02 | 33.45 | 0.03 | | | | ________________________________________________________________________________________________________________________________ Table 3.4.7 (b): Comparability for phosphate. PHOSPATE µmol kg-1 RM Lots _____________________________________________________________________________________________________________________________________ Cruise / Lab. | AH | unc. | AZ | unc. | BA | unc. | AX | unc. | AV | unc. | BC | unc. | BE | unc. --------------------- | ----- | ----- | ----- | ----- | ----- | ----- | ----- | ----- | ----- | ----- | ----- | ----- | ----- | ---- 2003 | | | | | | | | | | | | | | 2003intercomp | 2.141 | 0.001 | | | | | | | | | | | | MRO3-K04 Leg1 | 2.110 | | | | | | | | | | | | | MR03-K04 Leg2 | 2.110 | | | | | | | | | | | | | MR03-K04 Leg4 | 2.110 | | | | | | | | | | | | | MR03-K04 Leg5 | 2.110 | | | | | | | | | | | | | 2005 | | | | | | | | | | | | | | MR05-02 | | | 3.010 | | 0.061 | 0.010 | 1.614 | 0.008 | 2.515 | 0.008 | 2.778 | 0.010 | | MR05-05_1 precruise | 2.148 | 0.006 | 3.020 | 0.010 | 0.045 | 0.000 | 1.620 | 0.001 | 2.517 | 0.002 | 2.781 | 0.002 | | MR05-05_1 | | | 3.016 | | 0.063 | 0.007 | 1.615 | 0.006 | 2.515 | 0.007 | 2.778 | 0.033 | | MR05-05_2 precruise | | | 3.015 | | 0.066 | 0.000 | 1.608 | 0.001 | 2.510 | 0.001 | 2.784 | 0.002 | | MR05-05_2 | | | 3.018 | | 0.064 | 0.005 | 1.614 | 0.004 | 2.515 | 0.005 | 2.782 | 0.006 | | MR05-05_3 precruise | | | 3.020 | | 0.060 | 0.000 | 1.620 | 0.001 | 2.517 | 0.002 | 2.788 | 0.002 | | MR05-05_3 | | | 3.016 | | 0.061 | 0.004 | 1.618 | 0.005 | 2.515 | 0.004 | 2.779 | 0.008 | | 2006 | | | | | | | | | | | | | | 2006intercomp | | | 3.018 | 0.002 | 0.071 | 0.000 | 1.623 | 0.001 | 2.515 | 0.001 | 2.791 | 0.001 | | 2003intercomp_revisit | 2.141 | 0.001 | | | | | | | | | | | | 2007 | | | | | | | | | | | | | | MR07-04_1 precruise | 2.140 | 0.002 | | | 0.062 | 0.000 | 1.620 | 0.001 | 2.512 | 0.002 | 2.782 | 0.002 | | MR07-04_2 precruise | 2.146 | 0.002 | | | 0.056 | 0.000 | 1.620 | 0.001 | 2.517 | 0.002 | 2.788 | 0.002 | | MR07.04_2 precruise | 2.146 | 0.002 | | | 0.056 | 0.000 | 1.620 | 0.001 | 2.517 | 0.002 | 2.788 | 0.002 | | MR07.04 | | | | | 0.066 | 0.004 | 1.617 | 0.005 | 2.513 | 0.004 | 2.781 | 0.007 | | MR07.06_1 precruise | 2.144 | 0.001 | | | 0.066 | 0.000 | 1.617 | 0.001 | 2.517 | 0.001 | 2.790 | 0.001 | | MR07.06_2 precruise | 2.146 | 0.002 | | | 0.067 | 0.000 | 1.620 | 0.001 | 2.517 | 0.002 | 2.789 | 0.002 | | MR07.06_1 | | | | | 0.064 | 0.004 | 1.620 | 0.003 | 2.515 | 0.003 | 2.783 | 0.005 | | MR07.06_2 | | | | | 0.066 | 0.004 | 1.619 | 0.005 | 2.515 | 0.003 | 2.785 | 0.006 | | 2008 | | | | | | | | | | | | | | 2008intercomp_report | | | | | 0.068 | 0.000 | 1.615 | 0.005 | | | | | | 2006intercomp_revisit | | | 3.014 | 0.008 | 0.065 | 0.000 | 1.627 | 0.005 | 2.513 | 0.007 | | | | 2003intercomp_revisit | 2.131 | 0.006 | | | | | | | | | | | | 2009 | | | | | | | | | | | | | | MR09-01_0 precruise | | | 3.017 | 0.001 | 0.074 | 0.000 | 1.619 | 0.001 | 2.520 | 0.001 | 2.790 | 0.001 | 2.662 | 0.001 MR09-01_1 | | | 3.019 | 0.005 | 0.072 | 0.002 | 1.623 | 0.004 | 2.528 | 0.003 | 2.783 | 0.004 | 2.668 | 0.005 MR09-01_2 | | | 3.018 | 0.004 | | | 1.625 | 0.003 | 2.527 | 0.003 | | | 2.668 | 0.003 INSS stability test_1 | 2.134 | 0.008 | | | 0.069 | 0.001 | 1.606 | 0.001 | 2.512 | 0.003 | | | | _____________________________________________________________________________________________________________________________________ Table 3.4.7 (C): Comparability for silicate. SILICATE µmol kg-1 RM Lots ____________________________________________________________________________________________________________________________________ Cruise / Lab. | AH | unc. | AZ | unc. | BA | unc. | AX | unc. | AV | unc. | BC | unc. | BE | unc. ----------------------- | ------ | ---- | ------ | ---- | ---- | ---- | ----- | ---- | ------ | ---- | ------ | ---- | ----- | ---- 2003 | | | | | | | | | | | | | | 2003mtercomp * | 130.51 | 0.20 | | | | | | | | | | | | MRO3-K04 Leg1 ** | 132.01 | | | | | | | | | | | | | MR03-K04 Leg2 ** | 132.26 | | | | | | | | | | | | | MR03-K04 Leg4 ** | 132.28 | | | | | | | | | | | | | MR03-K04 Leg5 ** | 132.19 | | | | | | | | | | | | | 2005 | | | | | | | | | | | | | | MR05-02# | | | 133.69 | | 1.61 | 0.05 | 58.04 | 0.11 | 153.92 | 0.19 | 155.93 | 0.19 | | MR05-05_1 precruise## | 132.49 | 0.13 | 133.77 | 0.02 | 1.51 | 0.00 | 58.06 | 0.03 | 153.97 | 0.09 | 15.65 | 0.09 | | MR05-05_1## | | | 133.79 | | 1.59 | 0.07 | 58.01 | 0.12 | 154.01 | 0.26 | 156.08 | 0.36 | | MR05-05_2 precruise## | | | 133.78 | | 1.58 | 0.00 | 57.97 | 0.04 | 154.07 | 0.09 | 156.21 | 0.10 | | MR05-05_2## | | | 133.88 | | 1.59 | 0.06 | 58.00 | 0.09 | 154.05 | 0.16 | 156.14 | 0.15 | | MR05-05_3 precruise## | | | 134.02 | | 1.57 | 0.00 | 58.05 | 0.05 | 154.07 | 0.14 | 156.11 | 0.14 | | MR05-05_3## | | | 133.79 | | 1.60 | 0.05 | 57.98 | 0.09 | 153.98 | 0.18 | 156.08 | 0.13 | | 2006 | | | | | | | | | | | | | | 2006intercomp$ | | | 133.83 | 0.07 | 1.64 | 0.00 | 58.20 | 0.03 | 154.16 | 0.08 | 156.31 | 0.08 | | 2003intercomp_revisit$ | 132.55 | 0.07 | | | | | | | | | | | | 2007 | | | | | | | | | | | | | | MR07-04_1 precruise$$ | 133.38 | 0.06 | | | 1.61 | 0.00 | 58.46 | 0.03 | 154.82 | 0.07 | 156.98 | 0.07 | | MR07-04_2 precruise$$ | 133.15 | 0.12 | | | 1.69 | 0.00 | 58.44 | 0.05 | 154.87 | 0.14 | 156.86 | 0.14 | | MRO7-04$$ | | | | | 1.62 | 0.07 | 58.11 | 0.11 | 154.45 | 0.21 | 156.62 | 0.48 | | MRO7-06_1 precruise$$ | 133.02 | 0.09 | | | 1.64 | 0.00 | 58.50 | 0.04 | 155.06 | 0.11 | 156.33 | 0.11 | | MRO7-06_2 precruise$$ | 132.70 | 0.07 | | | 1.56 | 0.00 | 58.25 | 0.03 | 154.39 | 0.08 | 156.57 | 0.08 | | MRO7-06_1$$ | | | | | 1.61 | 0.04 | 58.13 | 0.08 | 154.48 | 0.13 | 156.64 | 0.08 | | MRO7-06_2$$ | | | | | 1.58 | 0.07 | 58.04 | 0.10 | 154.38 | 0.16 | 156.61 | 0.13 | | 2008 | | | | | | | | | | | | | | 2008intercomp‡ | | | | | 1.64 | 0.00 | 58.17 | 0.05 | | | | | | 2006intercomp_re‡ | | | 134.11 | 0.11 | 1.65 | 0.00 | 58.26 | 0.05 | 154.36 | 0.12 | | | | 2003intercomp_re‡ | 132.11 | 0.11 | | | | | | | | | | | | 2009 | | | | | | | | | | | | | | MR09-01_0 precruise‡ | | | 133.93 | 0.04 | 1.57 | 0.00 | 58.06 | 0.02 | 154.23 | 0.05 | 156.16 | 0.05 | 99.20 | 0.03 MR09-01_1‡ | | | 133.97 | 0.11 | 1.34 | 0.11 | 58.15 | 0.08 | 154.48 | 0.09 | 155.89 | 0.13 | 99.24 | 0.08 MR09-01_2‡ | | | 133.96 | 0.11 | | | 58.19 | 0.08 | 154.42 | 0.12 | | | 99.23 | 0.08 INSS stability test_1‡‡ | 132.40 | 0.35 | | | 1.69 | 0.02 | 58.18 | 0.02 | 154.43 | 0.09 | | | | ____________________________________________________________________________________________________________________________________ List of lot numbers: *: Kanto 306F9235; **: Kanto 402F9041; #: Kanto 507F9205; ##: Kanto 609F9157; $: Merck 0C551722; $$: Merck HC623465; ‡: Merck HC751838; ‡‡: HC814662 (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 13 samples, during a run at the concentration of C-6 std. There is exception for the number of the measurements that are used to evaluate analytical precision of silicate at 10 runs from stations 233 to 245 where we evaluate analytical precision based on 6 to 8 measurements. Summary of precisions are shown as shown in Table 3.4.8 and Figures 3.4.5 to 3.4.7, the precisions for each parameter are generally good considering the analytical precisions estimated from the simultaneous analyses of 14 samples in January 2009 as shown in Table 3.4.6. Analytical precisions previously evaluated were 0.18% for nitrate, 0.14% for phosphate and 0.08% for silicate, respectively. During this cruise, analytical precisions were 0.08% for nitrate, 0.10% for phosphate and 0.07% for silicate in terms of median of precision, respectively. Then we can conclude that the analytical precisions for nitrate, phosphate and silicate were maintained throughout this cruise. The time series of precision are shown in Figures 3.4.5 to 3.4.7. Table 3.4.8: Summary of precision based on the replicate analyses. _____________________________________ Nitrate Phosphate Silicate CV% CV% CV% ------- --------- -------- Median 0.08 0.10 0.07 Mean 0.08 0.10 0.08 Maximum 0.18 0.17 0.14 Minimum 0.02 0.04 0.02 N 265 265 263 _____________________________________ Figure 3.4.5: Time series of precision of nitrate for MR0901. Figure 3.4.6: Time series of precision of phosphate for MR0901 Figure 3.4.7: Time series of precision of silicate for MR0901. (7.2) Carry over We can also summarize the magnitudes of carry over throughout the cruise. These are small enough within acceptable levels as shown in Table 3.4.10. Table 3.4.10: Summary of carry over through out MR0901 cruise. _____________________________________ Nitrate Phosphate Silicate CV% CV% CV% ------- --------- -------- Median 0.21 0.24 0.20 Mean 0.21 0.23 0.20 Maximum 0.38 0.53 0.33 Minimum 0.03 0.01 0.03 N 237 237 237 _____________________________________ (7.3) Dilution for shallower samples by lot AZ. We decided to dilute 41 samples from shallower layers as shown Table 3.4.11 due to higher nitrite concentration which exceed 2 µmol kg-1. We add 5.060 ml of lot AZ to 0.504 ml of sample. Therefore, uncertainties of the nutrients concentration of diluted samples were larger compared with non-diluted samples. Table 3.4.11: Summary of diluted samples. ________________________________________ Station Pressure (dbar) ------- ------------------------------- 29 10, 50, 100, 150, 200, 250, 280 30 10, 50, 100, 150, 200, 250, 300 31 10, 50, 100, 150, 200, 250, 330 32 150, 200, 250, 280 35 280 40 150, 200, 250, 300 41 250,280 43 250,300 46 200,250 51 100 67 100 68 100 143 150 144 150 ________________________________________ (7.4) Possible concentration change of lot AV We found that nutrients concentrations of RM-AV were about 0.5% higher rather than those we assigned before cruise as shown in Table 3.4.4. The reasons of this increase are not clear yet, it might occur depend on the storage history of this RM-AV (8) Problems/improvements occurred and solutions. No problem occurred during this cruise. REFERENCES Aminot, A. and R. Kerouel (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 D.S. Kirkwood (1995): Report on the results of the fifth ICES intercomparison exercise for nutrients in sea water, ICES coop. Res. Rep. Set, 213. Aminot, A. and R. Kerouel (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 T.M. Joyce (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, 9lpp, Tsukuba, Japan. Aoyama, M., B. Susan, D. Minhan, D. Hideshi, I.G. Louis, H. Kasai, K. Roger, K. Nurit, M. Doug, A. Murata, N. Nagai, H. Ogawa, H. Ota, H. Saito, K. Saito, T. Shimizu, H. Takano, A. Tsuda, K. Yokouchi, and Y. Agnes (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, E.S. Braga, S.C. Coverly, E. Czobik, I. Dahllof, M.H. Dai, G.O. Donnell, C. Engelke, G.C. Gong, G.-H. Hong, D.J. Hydes, M.M. Jin, H. Kasai, R. Kerouel, Y. Kiyomono, M. Knockaert, N. Kress, K.A. Krogslund, M. Kumagai, S. Leterme, Y. 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. Gouretski, V.V. and K. Jancke (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., M. Ehrhardt, K. Kremling et al. (1983): Methods of seawater analysis. 2nd rev. Weinheim: Verlag Chemie, Germany, West. Joyce, T. and C. Corry (1994): Requirements for WOCE hydrographic programmed data reporting. WHPO Publication, 90-1, Revision 2, WOCE Report No. 67/91. Kawano, T., H. Uchida and T. Doi (2009): WHP P01, P14 REVISIT DATA BOOK, (Ryoin Co., Ltd., Yokohama). Kirkwood, D.S. (1992): Stability of solutions of nutrient salts during storage. Mar. Chem., 38: 151-164. Kirkwood, D.S., A. Aminot and M. Perttila (1991): Report on the results of the ICES fourth intercomparison exercise for nutrients in sea water. ICES coop. Res. Rep. Set, 174. Mordy, C.W, M. Aoyama, L.I. Gordon, G.C. Johnson, R.M. Key, A.A. Ross, J.C. Jennings and J. Wilson (2000): Deep water comparison studies of the Pacific WOCE nutrient data set. Eos Trans-American Geophysical Union. 80 (supplement), 0S43. Murphy, J. and J.P. Riley (1962): Analytica chim. Acta 27, 31-36. Uchida, H. and M. Fukasawa (2005): WHP P6, A10, 13/14 REVISIT DATA BOOK Blue Earth Global Expedition 2003 1, 2, (Aiwa Printing Co., Ltd., Tokyo). 3.5 CHLOROFLUOROCARBONS (CFCs) July 31, 2010 (1) Personnel Ken'ichi Sasaki (MIO, JAMSTEC) Katsunori Sagishima (MWJ) Yuichi Sonoyama (MWJ) Shoko Tatamisashi (MWJ) Hideki Yamamoto (MWJ) (2) Introduction Chlorofluorocarbons (CFCs) are completely man-made compounds that are chemically and biologically stable gasses in the environment. The CFCs have accumulated in the atmosphere since 1930's (Walker et al., 2000) and the atmospheric CFCs can slightly dissolve in sea surface water by air-sea gas exchange. The dissolved CFCs concentrations in sea surface water should have changed year by year and then penetrate into the ocean interior by water circulation. Three chemical species of CFCs, namely CFC-11 (CC13F), CFC-12 (CC12F2) and CFC-113 (CPA), dissolved in seawater are useful as the transient tracers for the ocean circulation with times scale on the order of several decades. In these cruises, we determined concentrations of CFCs dissolved in seawater on board. (3) Apparatus Dissolved CFCs were measured by a typical method modified from the original design of Bullister and Weiss (1988). A developed purging and trapping system was attached to gas chromatograph (GC-14B: Shimadzu Ltd) having an electron capture detector (ECD-14: Shimadzu Ltd). Cold trap columns were "1/16 stainless steel tubing packed with 5 cm of 100/120 mesh Porapak T. A pre-column and a main columns were Silica Plot capillary column [i.d.: 0.53 mm, length: 8 m, film thickness: 6 gm] and a complex capillary column (Pola Bond-Q lid.: 0.53 mm, length: 7 m, film thickness: 10 gm] followed by Silica Plot Ii. d.: 0.53 mm, length: 22 m, film thickness: 6 gm]), respectively. (4) Shipboard measurement (4.1) Sampling Before every CTD cast, the water sampler was cleaned by diluted acetone to remove any oils which could cause contaminations of CFCs. Seawater sub-samples were collected from 12 litter Niskin bottles into 250 ml glass bottles. The bottles had been filled with pure nitrogen gas before the sampling. The two times bottle volumes of seawater sample were overflowed. The bottles filled with seawater were kept in water bathes roughly controlled on the sample temperature. The CFC concentrations were determined within 12 hrs. In order to confirm CFC concentrations of standard gases and their stabilities and also to check CFC saturation levels in sea surface water with respect to overlying air, CFC mixing ratios in the background air were periodically analyzed. Air samples were continuously led into the Environmental Research Laboratory using 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 samples were collected from the flowing air into a 200 ml glass cylinder attached on the cock during running ship form a station to next station. Average mixing ratios of the atmospheric CFC-11, CFC-12 and CFC113 are 242.6 ± 6.3 ppt, 530.4 ± 7.6 ppt, and 76.2 ± 5.4 ppt, respectively. (4.2) Analysis Constant volume of sample water (50 ml) was taken into the purging & trapping system. Dissolved CFCs were extracted by nitrogen gas purge. The sample gases were dried by magnesium perchlorate desiccant and concentrated on a trap column cooled to c -45°C. Following 8 minutes extraction, the trap column was isolated by valve switching and heated electrically to 140°C within 1.5 minutes to desorb CFCs. The trap column was connected to GC and CFCs led into the pre-column. The gasses were roughly separated on the pre-column. When required compounds were eluted, the pre-column was switched onto cleaning line and flushed back by counter flow of pure nitrogen gas. The compounds which were sent onto main column were separated further and detected by an electron capture detector (ECD). Retention times of compounds were around 1.5, 4.5 and 11.5 minutes for CFC-12, -11 and -113, respectively. Temperature of an analytical column and a detector was 95 and 240°C. Pure nitrogen gas (99.99995) was further purified by a molecular sieve 13X gas filter and was used for analyses. Mass flow rates of nitrogen gas were 10, 27, 20 and 120 ml/min for carrier, detector make up, back flush and sample purging gasses, respectively. Gas loops whose volumes were 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 analysis using large loop (10 ml) were performed more frequently to monitor change in the detector sensitivity. The standard gasses had been made by Japan Fine Products co. ltd. Standard gas cylinder numbers used in cruises were listed in Table 3.5.1. Cylinder of CPB30524 was used as reference gas. Precise mixing ratios of the standard gasses were calculated by gravimetric data. The standard gases used in this cruise have not been calibrated to SIO scale standard gases yet because SIO scale standard gasses is hard to obtain due to legal difficulties for CFCs import into Japan. The data will be corrected as soon as possible when we obtain the standard gasses. (5) Quality control (5.1) Main problems on the shipboard analysis A large and broad peak was interfered determining CFC-113 peak area for samples collected from surface layer (several hundred meters depth). Retention time of the interfering peak was around 3% shorter than that of CFC-113. The peak of compound interfering CFC-113 determination could not be completely separated from the peak of CFC-113 by our analytical condition. We tried to split these peaks on chromatogram analysis and give flag "4". In the case of the interfering peak completely covering the CFC-113 peak, we could not determine CFC-113 peak area and give flag "5". (5.2) Blanks CFCs concentrations in deep water which was one of oldest water masses in the ocean were low but not zero for CFC-11 and -12. Average concentrations of CFC-11, 12 in the deep water were 0.003 ± 0.001, 0.008 ± 0.001 pmol kg-1 (n= -1500), respectively. These values were assumed as sampling blanks which was contaminations from Niskin bottle and/or during sub-sampling and were subtracted from all data. Significant blank was not found in CFC-113 measurements. (5.3) Precisions The analytical precisions were estimated from replicate sample analyses (610 pairs for CFC-12, 609 pairs for CFC-11 and 401 pairs for CFC-113). The replicate samples were basically collected from two or three sampling depths which is around 100, 400 and 600 m depths in every stations. Precisions of CFCs are less than ± 0.010 pmol kg-1 or 0.6% for CFC-11 (whichever is greater), ± 0.006 pmol kg-1 or 0.8% for CFC-12 (whichever is greater), and ± 0.010 pmol kg-1 for CFC-113, respectively. REFERENCES Bullister, J.L and R. E Weiss (1998): Determination of CC13F and CC12F2 in seawater and air. Deep Sea Research, 35, 839-853. Table 3.5.1: Standard gas cylinder list. _________________________________________ CFC Concentrations (pptv). Cylinder No. --------------------------- CFC-11 CFC-12 CFC-113 ------------ ------ ------ ------- CPBO3O13 300 159 30.1 CPB19294 299 159 30.1 CPB28545 293 163 29.9 CPB30524 300 159 30.2 _________________________________________ 3.6 DISSOLVED INORGANIC CARBON (CT) December 4, 2010 (1) Personnel Akihiko Murata (RIGC/JAMSTEC) Minoru Kamata (MWJ) Yoshiko Ishikawa (MWJ) Yasuhiro Arii (MWJ) (2) Objectives Concentrations of CO2 in the atmosphere are now increasing at a rate of 1.9 ppmv y-1 due to human activities such as burning of fossil fuels, deforestation, cement production, etc. 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 the predicted global warming depends on the levels of CO2 in the atmosphere, and because the ocean currently absorbs 1/3 of the 6 Gt of carbon emitted into the atmosphere each year by human activities. In the cruise (MR09-01, revisit of WOCE P21 line) using the R/V Mirai, we were aimed at quantifying how much anthropogenic CO2 is absorbed in the Pacific Ocean. For the purpose, we measured CO2-system properties such as dissolved inorganic carbon (CT), total alkalinity (AT), pH and underway pCO2. In this section, we describe data on CT obtained in the cruise in detail. (3) Apparatus Measurements of CT were made with two total CO2 measuring systems (systems-A and -B; Nippon ANS, Inc.), which are slightly different from each other. The systems comprise of a seawater dispensing system, a CO2 extraction system and a coulometer (Model 5012, UIC Inc.). The seawater dispensing system has an auto-sampler (6 ports), which takes seawater from a 300 ml borosilicate glass bottle and dispenses the seawater to a pipette of nominal 21 ml volume by a PC control. The pipette is kept at 20°C by a water jacket, where water from a water bath set at 20°C is circulated. CO2 dissolved in a seawater sample is extracted in a stripping chamber of a CO2 extraction system by adding phosphoric acid (10% v/v). 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 a 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 fit at the bottom of the stripping chamber. The CO2 stripped in the stripping chamber is carried by the nitrogen gas (140 ml min-1 for the systems A and B) to the coulometer through a dehydrating module. For the system A, the module consists of two electric dehumidifiers (kept at 1 -2°C) and a chemical desiccant (Mg(ClO4)2). For the system B, it consists of three electric dehumidifiers with a chemical desiccant. (4) Shipboard measurement (4.1) Sampling 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 the 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 4°C in a refrigerator until analysis. A few hours just before analysis, the seawater samples were kept at 20°C in a water bath. (4.2) Analysis 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 kg-1). 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.). For every renewal of coulometer solutions, certified reference materials (CRMs, batch 92 and a small number of batch 79) provided by Prof. A.G. Dickson of Scripps Institution of Oceanography were analyzed. In addition, in-house reference materials (RM) (batch QRM Q20 and Q19 for systems A and B, 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. (5) Quality control 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 92 and 79), 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. Based on the averages of CT of CRM, we re-calculated the calibration factors so that measurements of seawater samples become traceable to the certified value of batches 92. We did use the measured results of batch 79 because of a small number of measurements. Temporal variations of RM measurements for one coulometer solution are shown in Fig. 3.6.1. From this figure, it is evident that RM measurements had a linear trend of ~3 to ~7 µmol kg-1, implying that measurements of seawater samples also have the trend. The trend was also found in temporal changes of 2% CO2 gas measurements. The trend seems to be due to "cell age" change (Johnson et al., 1998) of a coulometer solution. Considering the trends, we adjusted measurements of seawater samples so as to be traceable to the certified value of batch 92. Finally we surveyed vertical profiles of C1. In particular, we examined whether systematic differences between measurements of the systems A and B existed or not. Then taking other information of analyses into account, we determined a flag of each value of C1. The average and standard deviation of absolute values of differences of CT analyzed consecutively were 0.8 and 0.7 µmol kg-1 (n=211), and 0.6 and 0.6 µmol kg-1 (n= 165), for legs 1 and 2, respectively. The combined values were 0.7 and 0.7 µmol kg-1 (n=376). REFERENCE Johnson, K.M., A.G. Dickson, G. Eischeid, C. Goyet, P Guenther, R.M. Key, F.J. Millero, D. Purkerson, C.L. Sabine, R.G. Schottle, D.W.R. Wallace, R.J. Wilke and C.D. Winn (1998): Coulometric total carbon dioxide analysis for marine studies: assessment of the quality of total inorganic carbon measurements made during the US Indian Ocean CO2 survey 1994-1996, Mar. Chem., 63, 21-37. Figure 3.6.1: Distributions of RM measurements as a function of sequential day for Stns. 279 and 282 during MR09-01. 3.7 TOTAL ALKALINITY (AT) December 4, 2010 (1) Personnel Akihiko Murata (RIGC/JAMSTEC) Tomonori Watai (MWJ) Yoshiko Ishikawa (MWJ) Ayaka Hatsuyama (MWJ) (2) Objectives Concentrations of CO2 in the atmosphere are now increasing at a rate of 1.9 ppmv y-1 due to human activities such as burning of fossil fuels, deforestation, cement production, etc. 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 the predicted global warming depends on the levels of CO2 in the atmosphere, and because the ocean currently absorbs 1/3 of the 6 Gt of carbon emitted into the atmosphere each year by human activities. In the cruise (MR09-01, revisit of WOCE P21 line) using the R/V Mirai, we were aimed at quantifying how much anthropogenic CO2 is absorbed in the Pacific Ocean. For the purpose, we measured CO2-system properties such as dissolved inorganic carbon (CT), total alkalinity (AT), pH and underway pCO2. In this section, we describe data on AT obtained in the cruise in detail. (3) Apparatus 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 water-jacketed 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°C) pipette by pressurizing the sample bottle (nitrogen gas), and is introduced into the water-jacketed (25°C) 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 same 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 HC1 in 0.65 M NaCl and bromocresol green (BCG) is added (approx. 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 again. Calculation of AT was made by the following equation: A(T) = (-[H+](T)V(SA) + M(A)V(A))/V(S), where M(A) 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 V(S), V(A) and V(SA) 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(T)= -log[H+](T)= 4.2699+ 0.002578(35-S)+ log((R-0.00131)/(2.3148-0.1299R))-log(1-0.001005S), where S is the sample salinity, and R is the absorbance ratio calculated as: R =(A(616)-A(750))/(A(444)-A(750)), where Ai is the absorbance at wavelength i nm. The HCl in the acid titrant was standardized (0.049983 M, 0.049982 M) on land. (4) Shipboard measurement (4.1) Sampling 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. (4.2) Analysis 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 92, certified value = 2201.91 µmol kg-1, respectively) were also analyzed periodically to monitor systematic differences of measured A1 The reported values of AT were set to be traceable to the certified value of the batch 92. The preliminary values were reported in a data sheet on the 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. However, we experienced some malfunctions of the system during the cruise, which are listed in the followings: At the early stage of the 1st leg, we found malfunction of the instrument such as showing different AT values by different quantities of acid titrant added. The malfunction was attributed to the light source of spectrophotometer. After the light source was changed to a new one, the malfunction was resolved. (5) Quality control Temporal changes of AT, which originate from analytical problems, were monitored by measuring AT of CRM. We found no abnormal measurements during the cruises. After making the measured values of AT comparable to CRM, we examined vertical profiles of AT. Then taking other information of analyses into account, we determined a flag of each value of AT. The average and standard deviation of absolute values of differences of AT analyzed consecutively were 0.5 and 0.5 µmol kg-1 (n = 200), and 0.6 and 0.5 µmol kg-1 (n = 165) for legs 1 and 2, respectively. The combined values were calculated to be 0.5 and 0.5 µmol kg-1 (n = 365). REFERENCE Yao, W. and R. H. Byrne (1998): Simplified seawater alkalinity analysis: Use of linear array spectrometers. Deep- Sea Research 145, 1383-1392. 3.8 pH (pH(T)) December 10, 2010 (1) Personnel Akihiko Murata (RIGC/JAMSTEC) Tomonori Watai (MWJ) Yoshiko Ishikawa (MWJ) Ayaka Hatsuyama (MWJ) (2) Objectives Concentrations of CO2 in the atmosphere are now increasing at a rate of 1.9 ppmv y-1 due to human activities such as burning of fossil fuels, deforestation, cement production, etc. 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 the anticipated global warming depends on the levels of CO2 in the atmosphere, and because the ocean currently absorbs 1/3 of the 6 Gt of carbon emitted into the atmosphere each year by human activities. In the cruises (MR09-01, revisit of WOCE P21 line) using the R/V Mirai, we were aimed at quantifying how much anthropogenic CO2 is absorbed in the Pacific Ocean. For the purpose, we measured CO2-system properties such as dissolved inorganic carbon (CT), total alkalinity (AT), pH and underway pCO2. In this section, we describe data on pH obtained in the cruise in detail. (3) Apparatus Measurement of pH was made by a pH measuring system (Nippon ANS, Inc.), which adopts spectrophotometry. The system comprises of a water dispensing unit and a spectrophotometer (Carry 50 Scan, Varian). 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 was kept at 25.00 ± 0.05°C in a thermostated compartment. First, absorbances of seawater only are measured at three wavelengths (730, 578 and 434 nm). Then an indicator is injected and circulated for about 4 minutes. to mix the indicator and seawater sufficiently. After the pump is stopped, the absorbances of seawater + indicator are measured at the same wavelengths. The pH is calculated based on the following equation (Clayton and Byrne, 1993): ⎛ A(1)/A(2)-0.00691 ⎞ pH= pK(2)+log ⎜ -------------------------- ⎟ (1), ⎝ 2.2220 - 0.1331(A(1)/A(2)) ⎠ where A1 and A2 indicate absorbances at 578 and 434 nm, respectively, and pK(2) is calculated as a function of water temperature and salinity. (4) Shipboard measurement (4.1) Sampling 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 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 (Eq. 1). 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. However, we sometimes experienced malfunctions of the system during the cruise. (5) Quality control It is recommended that correction for pH change resulting from addition of indicator solutions is made (DOE, 1994). 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 (DOE, 1994), although the perturbations were small. Figure 3.8.1 illustrates an example of perturbation of absorbance ratios by adding indicator solutions. We surveyed vertical profiles of pH. In particular, we examined whether systematic differences between before and after the renewal of indicator solutions existed or not. Then taking other information of analyses into account, we determined a flag of each value of pH. 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, K2 from Mehrbach et al. (1973) refit by Dickson and Millero (1987). The average and standard deviation of absolute values of differences of pH analyzed consecutively were 0.0005 and 0.0004 pH unit (n = 266), and 0.0004 and 0.0004 pH unit (n = 205) for legs 1 and 2, respectively. The combined values were 0.0004 and 0.0004 pH unit (n = 471). REFERENCES Clayton T.D. and R.H. Byrne (1993): Spectrophotometric seawater pH measurements: total hydrogen ion concentration scale calibration of m-cresol purple and at-sea results. Deep-Sea Research, 40, 2115-2129. Dickson A.G. and E.J. Millero (1987): A Comparison of the equilibrium constants for the dissociation of carbonic acid in seawater media. Deep-Sea Research, 34, 1733-1743. 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 & C. Goyet, eds. (unpublished manuscript). 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 Oceanography, 18, 897-907. Figure 3.8.1: Perturbation of absorbance ratios by adding indicator solutions. The line was determined by the method of least squares. 3.9 LADCP November 1, 2010 (1) Personnel Shinya Kouketsu (JAMSTEC) Hiroshi Uchida (JAMSTEC) Katsurou 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 WHIM300 (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 rechargeable Ni-Cd 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 as follows. Teledyne RD Instruments, WHIM300 S/N 11853 (CPU firmware vet 50.32, vet 50.35, with pressure sensor) S/N 8484 (CPU firmware vet 50.32, vet 50.35) S/N 1512 (CPU firmware vet 50.35) (3) Data collection In this cruise, data were collected with the following configuration. Bin size: 8 m Number of bins: 14 Pings per ensemble: 1 Ping interval: 1 sec At the following stations, the CTD cast was carried out without the LADCP, because maximum pressure was beyond the pressure-proof of the LADCP (6000 m). Station P21-200 (4) Data collection problems We changed the instruments many times due to various troubles. The log of changing instruments is as follows. Station P21-120: from S/N 11853 (firmware vet 50.32) to S/N 8484 (firmware vet 50.32) Station P21-132: from S/N 8484 (firmware vet 50.32) to S/N 8484 (firmware vet 50.35) Station P21-141: from S/N 8484 (firmware vet 50.35) to S/N 11853 (firmware vet 50.35) Station P21-174: from S/N 11853 (firmware vet 50.35) to S/N 1512 (firmware vet 50.35) Station P21-181: from S/N 1512 (firmware vet 50.35) to S/N 11853 (firmware vet 50.35) Station P21-182: from S/N 11853 (firmware vet 50.35) to S/N 1512 (firmware vet 50.35) Until the Station 120, data recording was intermittently stopped during a cast due to the firmware (ver. 50.32) bug. Because the beam 2 of S/N 8484 became weak at the Station 139, we changed instruments from 5/ N 8484 to S/N 11853. The beam 2 of the instrument (S/N 11853) also didn't work well at the Station 173 and the instrument was changed to S/N 1512. Since the beam 3 of the instrument (S/N 1512) became weak at the Station 180, we tried the S/N 11853 again at the Station 181 to compare the echo intensities. Since the instrument of S/N 1512 worked better than S/N 11853, the S/N 1512 was used after the Station 182 (see Fig. 3.9.1). Figure 3.9.1: Cast-averaged echo intensities at 31 bin. (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 1 minutes 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. So we added a cast flag for each profile. The flag of 5 means that data files for one cast were divided into small files due to firmware bugs provided form RDI. The flag of 6 means that 3 beam solutions were included in the cast. 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. Water sample parameters: ______________________________________________________________ Mnemonic for Number Parameter Mnemonic expected error ------ ---------------------------- -------- -------------- 1 Salinity SALNTY 2 Oxygen OXYGEN 3 Silicate SILCAT SILUNC 4 Nitrate NITRAT NRAUNC 5 Nitrite NITRIT NRIUNC 6 Phosphate PHSPHT PHPUNC 7 Freon-11 CFC-l1 8 Freon-12 CFC-12 12 14Carbon OELC14 C14ERR 13 13Carbon OELC13 C13ERR 23 Total carbon TCARBN 24 Total alkalinity ALKALI 26 pH PH 27 Freon-113 CFC113 28 Carbon Tetrachloride CCL4 30 Ammonia NN4 31 Methane CH4 33 Nitrous oxide N2O 34 Chlorophyll a CHLORA 41 Particulate Organic Nitrogen PON 42 Abundance of bacteria BACT 47 Plutonium PLUTO PLOTOER 48 Primary Productivity 64 Incubation 82 15N-Nitrate 15MO3 86 Flowcytometry 88 Nitrogen Fixation DIAZO ______________________________________________________________ REFERENCES Aminot, A. and D.S. Kirkwood (1995): Report on the results of the fifth ICES intercomparison exercise for nutrients in sea water, ICES coop. Res. Rep. Set, 213. Aminot, A. and R. Kerouel (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 R. Kerouel (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 T.M. Joyce (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, 9l pp, Tsukuba, Japan. Aoyama, M., B. Susan, D. Minhan, D. Hideshi, I.G. Louis, H. Kasai, K. Roger, K. Nurit, M. Doug, A. Murata, N. Nagai, H. Ogawa, H. 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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., T. Joyce, T. Kawano and Y. Takatsuki (2002): Standard seawater comparison up to P129. Deep-Sea Research, I, Vol. 49, 1103-1114. Clayton T.D. and R.H. Byrne (1993): Spectrophotometric seawater pH measurements: total hydrogen ion concentration scale calibration of m-cresol purple and at-sea results. Deep-Sea Research, 40, 2115-2129. Dickson A.G. and E.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. (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 seawater; version 2. A.G. 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FIGURE CAPTIONS Figure 1: Station locations for WHP P21 revisit cruise with bottom topography based on Smith and Sandwell (1997). 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 1-hour and plotted every 1 degree in latitude or longitude. Figure 4: Sea surface temperature (SST). Temperature data is averaged over 1-hour. Figure 5 Sea surface salinity (SSS). Salinity data is averaged over 1-hour. Figure 6 Difference in the partial pressure of CO2 between the ocean and the atmosphere, ∆pCO2 Figure 7 Surface current at 100 m depth measured by ship board acoustic Doppler current profiler (ADCP). Figure 8: Potential temperature (°C) cross section calculated by using CTD temperature and salinity data calibrated by bottle salinity measurements. Vertical exaggeration of the 0-6500 m section is 1000:1. Expanded section of the upper 1000 m is made with a vertical exaggeration of 2500:1. Figure 9: CTD salinity (psu) cross section calibrated by bottle salinity measurements. Vertical exaggeration is same as Figure 8. Figure 10: Absolute salinity (g/kg) cross section calculated by using CTD salinity data. Vertical exaggeration is same as Figure 8. Figure 11: Density (σ0 ) (kg/m3) cross section calculated by using CTD temperature and salinity data. Vertical exaggeration is same as Figure 8. Figure 12: Same as Figure 11 but for σ4 (kg/m3). Figure 13: Neutral density γn (kg/m3) cross section calculated by using CTD temperature and salinity data. Vertical exaggeration is same as Figure 8. Figure 14: Cross section of CTD oxygen (µmol/kg). Vertical exaggeration is same as Figure 8. Figure 15: Cross section of bottle sampled dissolved oxygen (µmol/kg). Data with quality flags of 2 were plotted. Vertical exaggeration is same as Figure 8. Figure 16: Silicate (µmol/kg) cross section. Data with quality flags of 2 were plotted. Vertical exaggeration is same as Figure 8. Figure 17: Nitrate (µmol/kg) cross section. Data with quality flags of 2 were plotted. Vertical exaggeration is same as Figure 8. Figure 18: Nitrite (µmol/kg) cross section. Data with quality flags of 2 were plotted. Vertical exaggeration of the upper 1000 m section is same as Figure 8. Figure 19: Phosphate (µmol/kg) cross section. Data with quality flags of 2 were plotted. Vertical exaggeration is same as Figure 3. Figure 20: Dissolved inorganic carbon (µmol/kg) cross section. Data with quality flags of 2 were plotted. Vertical exaggeration is same as Figure 8. Figure 21: Total alkalinity (µmol/kg) cross section. Data with quality flags of 2 were plotted. Vertical exaggeration is same as Figure 8. Figure 22: pH cross section. Data with quality flags of 2 were plotted. Vertical exaggeration is same as Figure 8. Figure 23: CFC-11 (pmol/kg) cross section. Data with quality flags of 2 were plotted. Vertical exaggeration is same as Figure 8. Figure 24: CFC-12 (pmol/kg) cross section. Data with quality flags of 2 were plotted. Vertical exaggeration is same as Figure 8. Figure 25: CFC-113 (pmol/kg) cross section. Data with quality flags of 2 were plotted. Vertical exaggeration is same as Figure 8. Figure 26: Cross section of current velocity (cm/s) normal to the cruise track measured by LADCP (northward is positive). Figure 27: Difference in potential temperature (°C) between results from WOCE (from March to June 1994) and the revisit cruise (from April to June 2009). 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 Figure 8. Figure 28: Difference in salinity (psu) between results from WOCE and the revisit cruise. Red and blue areas show areas where salinity increased and decreased in the revisit cruise, respectively. 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. Vertical exaggeration is same as Figure 8. Figure 29: Difference in dissolved oxygen (µmol/kg) between results from WOCE and the revisit cruise. Red and blue areas show areas where salinity increased and decreased in the revisit cruise, respectively. CTD oxygen data were used. On white areas differences in dissolved oxygen do not exceed the detection limit of 2 µmol/kg. Vertical exaggeration is same as Figure 8. Note 1. As for the traceability of SSW to Mantyla's value, the offset for the batches P123 (WOCE P21) and P150 (the revisit cruise) are -0.0006 and -0.0005, respectively (Kawano et al, 2006; T. Kawano, personal communication, 2009). REFERENCES 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. Smith, W. H. F. and D. T. Sandwell (1997): Global seafloor topography from satellite altimetry and ship depth soundings, Science, 277, 1956-1962. CCHDO DATA PROCESSING NOTES EVENT DATE CONTACT DATA TYPE EVENT SUMMARY ---------- --------------- ----------------- -------------- ------------------------- 2010-05-27 Uchida, Hiroshi CTD/SUM Submitted Data are public Exchange & WOCE files submitted/Public 2010-08-12 Berys, Carolina CTD/BTL/SUM Website Update added to "as received" ArchiveHLY031bottledata.xls bottle file submitted by Jerry Kappa on 2010-03- 24 and HLY031CTDO.zip CTD files submitted by Kelly Falkner on 2010-04-08 available under 'Preliminary/Unprocessed', unprocessed by CCHDO. 49NZ20090410_wct_without_peru.zip CTD files in WOCE format, 49NZ20090410_ct1_without_peru.zip CTD files in Exchange format, and 49NZ20090410_sum_without_peru.txt station summary file submitted by Uchida Hiroshi on 2010-05-27, and MR09-01_leg1-3_all.pdf cruise report submitted by Jerry Kappa on 2010-08-12 available under 'Preliminary/Unprocessed', unprocessed by CCHDO. 2010-08-12 Fields, Justin Cruise Report Website Update added to "as received" 2011-09-19 Uchida, Hiroshi BTL/Cruise Report Submitted Ready to go online 55