If symbols do not display correctly change your browser character encoding to unicode CRUISE REPORT: P10 (Updated Mar 2015) Highlights Cruise Summary Information Section Designation P10 leg 2 P10 leg 3 Expedition designation (ExpoCodes) 49NZ20111220 (MR11-08) 49NZ20120113 (MR11-08) Chief Scientists Akihiko Murata Yuichiro Kumamoto Dates 2011 Dec 20 - 2012 Jan 12 2012 Jan 13 - 2012 Feb 09 Ship R/V Mirai Ports of call Koror, Palau - Guam, USA Guam, USA - Sekinehama, JPN 43° N Geographic Boundaries 140° E 151° E 10° S Stations 69 43 Floats and drifters deployed 2 Argo Floats Moorings deployed or recovered 0 Contact Information: Ocean Climate Change Research Program • Research Institute for Global Change (RIGC) Japan Agency for Marine-Earth Science and Technology (JAMSTEC) 2-15 Natsushima, Yokosuka, Kanagawa, Japan 237-0061 Fax: +81-46-867-9835 • Email: murataa@jamstec.go.jp kumamoto@jamstec.go.jp WHP P10 REVISIT IN 2011 DATA BOOK Edited by Hiroshi Uchida (JAMSTEC), Akihiko Murata (JAMSTEC), Toshimasa Doi (JAMSTEC) WHP P10 Revisit in 2011 Towards Intl. Repeat Hydrography and Carbon Program WHP P10 REVISIT IN 2011 DATA BOOK March 20, 2014 Published Edited by Hiroshi Uchida (JAMSTEC), Akihiko Murata (JAMSTEC) and Toshimasa Doi (JAMSTEC) Published by © JAMSTEC, Yokosuka, Kanagawa, 2014 Japan Agency for Marine-Earth Science and Technology 2-15 Natsushima, Yokosuka, Kanagawa. 237-0061, Japan Phone +81-46-867-9474, Fax +81-46-867-9835 Printed by Aiwa Enterprise, Ltd. 3-22-4 Takanawa, Minato-ku, Tokyo 108-0074, Japan Contents Preface M. Fukasawa (JAMSTEC) Documents and station summary files 1 Cruise Narrative A. Murata and Y. Kumamoto (JAMSTEC) 2 Underway Measurements 2.1 Navigation 2.2 Swath Bathymetry T. Matsumoto (Univ. Ryukyu), N. Hirano (Tohoku Univ.) et al. 2.3 Surface Meteorological Observation K. Yoneyama (JAMSTEC) et al. 2.4 Thermo-Salinograph and Related Measurements H. Uchida (JAMSTEC) et al. 2.5 Underway pCO2 A. Murata (JAMSTEC) et al. 2.6 Shipboard ADCP S. Kouketsu (JAMSTEC) et al. 2.7 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 H. Uchida (JAMSTEC) et al. 3.3 Density H. Uchida (JAMSTEC) 3.4 Oxygen Y. Kumamoto (JAMSTEC) et al. 3.5 Nutrients M. Aoyama (MRI/JMA) et al. 3.6 Chlorofluorocarbons and Sulfur Hexafluoride K. Sasaki (JAMSTEC) et al. 3.7 Dissolved Inorganic Carbon (CT) A. Murata (JAMSTEC) et al. 3.8 Total Alkalinity (AT) A. Murata (JAMSTEC) et al. 3.9 pH A. Murata (JAMSTEC) et al. 3.10 Chlorophyll a O. Yoshida (Rakuno Gakuen Univ.), H. Uchida (JAMSTEC) et al. 3.11 LADCP S. Kouketsu (JAMSTEC) et al. Station Summary (see PDF version or data files) Figures Figure captions Station locations Bathymetry Surface wind Sea surface temperature, salinity, oxygen, chlorophyll a ΔpCO2 Surface current Cross-sections Potential temperature CTD salinity Absolute salinity Density (σ0) (EOS-80) Density (σ0) (TEOS-10) Density (σ4) (EOS-80) Density (σ4) (TEOS-10) Density (γn) CTD oxygen CTD chlorophyll a Bottle sampled dissolved oxygen Silicate Nitrate Nitrite Phosphate Dissolved inorganic carbon (CT) Total alkalinity (AT) pH (pHT) CFC-11 CFC-12 CFC-113 Velocity Difference between previous occupations and the revisit Potential temperature (2011-1993) (2011-2005) CTD Salinity (2011-1993) (2011-2005) CTD oxygen (2011-1993) (2011-2005) .sum, .sea, .wct and other data files CD-ROM on the back cover (see online data files) PREFACE At 14:46 on 11 March 2011, Japan was attacked by the huge catastrophe earthquake with magnitude of 9.0. The epicenter of the earthquake widely distributed along the Japan trench off the east coasts of Tohoku district. Unprecedented tragedies were brought about by the Tsunami which attacked the Pacific coast of eastern Japan twenty minutes after the earthquake. More than 18,000 people were killed or lost by this Tsunami. Moreover, the Fukushima First Nuclear Power Plant was destroyed by the Tsunami and considerable amount of radio nuclides were discharged from the power plant into the atmosphere and the ocean. Right after the earthquake, we, Research Institute for Global Change started to monitor and forecast the dispersion of the discharged radio nuclides off coast of Fukushima under the request from the Japanese government. It was very hard task for scientists in RIGC/JAMSTEC to conduct ocean monitoring and prediction, nevertheless, RIGC/JAMSTEC was expected to be deeply engaged in the task because RIGC is the only institute which has the ability to pursue the governmental requests. Facing the Fukushima Disaster brought about by the earthquake, RIGC/JAMSTEC changed the cruise plan for GO-SHIP hydrographic observation. As the result, RIGC/JAMSTEC decided to re-occupy P10 in the western North Pacific Ocean instead of I08N/I05E in the Indian Ocean since we believed this change of our plan made it possible for the world GO-SHIP community to build a data network on radio nuclides in the western North Pacific within three years together with US cruise along P02 in 2013 and RIGC/JAMSTEC cruise along P01 in 2014. The preparation for the original plan to re-occupy the line in the Indian Ocean had been proceeded under collaboration with Sri Lanka and India. Thus, here, I would like to express my heartfelt thanks to all those concerned in both countries for their kind acceptance of our sudden changes of the cruise at that time. The cruise along P10 was started on 20 December 2011 from Palau. Stations were set to reoccupy the stations which were observed in 2005 by IORGC, a predecessor of RIGC/JAMSTEC, namely 124 stations on the cruise track from Papua New Guinea to Hokkaido. We completed the cruise on 9 February 2012, however, bad weather and sea condition forced us to decrease the number of CTD/water sampling stations in the northern part of the cruise. Of course, this cruise was carried out as Japanese activity within the framework of GO-SHIP. On the other hand, we had our specific objective for this cruise that was to prepare data network for radio nuclides in the western North Pacific Ocean after the Fukushima Disaster. It was the reason why we placed larger priority on the northern part of P10 in the cruise. Now, the data including results from chemical analysis can be used by anyone through this data book and websites of JAMSTEC, CCHDO and CDIAC. Lastly, I would like to ask favors of all scientists to refer our data book as often as possible. Such reference from scientists proves the scientific importance of GO-SHIP and consequently helps RIGC/JAMSTEC to continue GO-SHIP activity. On the memorial day after three years of the Tragic Earthquake and Tsunami Masao Fukasawa Research Director RIGC/JAMSTEC *Acronyum RIGC Research Institute for Global Change JAMSTEC Japan Agency for Marine-Earth Science and Technology GO-SHIP Global Ocean Ship-Based Hydrographic Investigation Program CCHDO CLIVAR and Carbon Hydrographic Data Office CDIAC Carbon Dioxide Information Analysis Center 1 Cruise Narrative Akihiko Murata (RIGC/JAMSTEC) Yuichiro Kumamoto (RIGC/JAMSTEC) 1.1 Highlight GHPO Section Designation: P10 Cruise code: MR11-08 Expedition Designation: 49NZ20111220 49NZ20120113 Chief Scientists and Affiliation: Leg 2: Akihiko Murata murataa@jamstec.go.jp Leg 3: Yuichiro Kumamoto kumamoto@jamstec.go.jp Ocean Climate Change Research Program Research Institute for Global Change (RIGC) Japan Agency for Marine-Earth Science and Technology (JAMSTEC) 2-15 Natsushima, Yokosuka, Kanagawa, Japan 237-0061 Fax: +81-46-867-9835 Ship: R/V Mirai Ports of Call: Leg 2: Koror, Palau – Guam, USA Leg 3: Guam, USA – Sekinehama, Japan Cruise Dates: Leg 2: December 20, 2011 – January 12, 2012 Leg 3: January 13, 2012 – February 9, 2012 Number of Stations: 102 stations for CTD/Carousel Water Sampler (Leg 2: 59, Leg 3: 43) Geographic Boundaries (for hydrographic stations): 10ºS - 43ºN 140ºE - 151ºE Floats and Drifters Deployed: 2 Argo floats Mooring Deployed or Recovered Mooring: None 1.2 Cruise Summary It is well known that climate changes of a timescale more than a decade are influenced by changes of oceanic conditions. Among various oceanic changes, we conducted shipboard observations focusing on storage and transport of anthropogenic CO2, heat and freshwater in the ocean, which are important for global warming and relevant climate changes. Our observation line (Figs. 1.2.1 and 1.2.2) is a meridional line, which is set in the western Pacific, and traverses the main subtropical gyre in the ocean. By occupying the observation line, we intended to clarify: (1) storage of anthropogenic CO2, distributions of dissolved oxygen, etc. in the subtropical gyre and the temporal changes, (2) temperature rise and transport of dissolved substances along the route of Circumpolar Deep Water, and (3) current degree of ocean acidification in the western Pacific. This study was conducted under the Global Ocean Ship-based Hydrographic Investigations Program (abbreviated as GO-SHIP, http://www.go-ship.org/). In addition to the objectives listed above, we were also aimed at elucidating dispersion of radioactive substances, released into the sea unfortunately from the Fukushima Dai-ichi nuclear power plant. During the 2nd leg, we could conduct hydrographic observations steadily. But during the 3rd leg, we had to give up some hydrographic casts due to big waves. Figure 1.2.1: Cruise track and hydrographic stations. 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) Kazuho Yoshida (GODI) (leg 2) skouketsu@jamstec.go.jp Katsuhisa Maeno (GODI) (lge 3) Bathymetry Takeshi Matsumoto (U of Ryukyus) Kazuho Yoshida (GODI) (leg 2) tak@sci.u-ryukyu.ac.jp Katsuhisa Maeno (GODI) (leg 3) Naoto Hirano (Tohoku Univ.) nhirano@cneas.tohoku.ac.jp Meteorology Kunio Yoneyama (JAMSTEC) Kazuho Yoshida (GODI) (leg 2) yoneyamak@jamstec.go.jp Katsuhisa Maeno (GODI) (leg 3) T-S Hiroshi Uchida (JAMSTEC) Miyo Ikeda (MWJ) (leg 2) huchida@jamtec.go.jp Misato Kuwahara (MWJ) (leg 3) pCO2 Akihiko Murata (JAMSTEC) Yoshiko Ishikawa (MWJ) murataa@jamstec.go.jp Hydrography CTD/O2 Hiroshi Uchida (JAMSTEC) Shinsuke Toyoda (MWJ) (leg 2) huchida@jamstec.go.jp Kenichi Katayama (MWJ) (leg 3) XCTD Hiroshi Uchida (JAMSTEC) Katsuhisa Maeno (GODI) huchida@jamstec.go.jp LADCP Shinya Kouketsu (JAMSTEC) Shinya Kouketsu (JAMSTEC) (leg 2) skouketsu@jamstec.go.jp Katsuro Katsumata (JAMSTEC) (leg 3) Salinity Hiroshi Uchida (JAMSTEC) Fujio Kobayashi (MWJ) (leg 2) huchida@jamstec.go.jp Tatsuya Tanaka (MWJ) (leg 3) Density Hiroshi Uchida (JAMSTEC) Hiroshi Uchida (JAMSTEC) huchida@jamstec.go.jp Oxygen Yuichiro Kumamoto (JAMSTEC) Miyo Ikeda (MWJ) (leg 2) kumamoto@jamstec.go.jp Misato Kuwahara (MWJ) (leg 3) Nutrients Michio Aoyama (MRI) Minoru Kamata (MWJ) maoyama@mri-jma.go.jp DIC Akihiko Murata (JAMSTEC) Yoshiko Ishikawa (MWJ) murataa@jamstec.go.jp Alkalinity Akihiko Murata (JAMSTEC) Tomonori Watai (MWJ) murataa@jamstec.go.jp pH Akihiko Murata (JAMSTEC) Tomonori Watai (MWJ) murataa@jamstec.go.jp CFCs Ken’ichi Sasaki (JAMSTEC) Ken’ichi Sasaki (JAMSTEC) ksasaki@jamstec.go.jp Δ14C/δ13C Yuichiro Kumamoto (JAMSTEC) Yuichiro Kumamoto (JAMSTEC) kumamoto@jamstec.go.jp 134Cs/137Cs Yuichiro Kumamoto (JAMSTEC) Yuichiro Kumamoto (JAMSTEC) kumamoto@jamstec.go.jp Tritium Tatsuo Aono (NIRS) t_aono@nirs.go.jp Iodine-129 Shigeyoshi Otosaka (JAEA) otosaka.shigeyoshi@jaea.go.jp Chlorophyll a Osamu Yoshida (RGU) Osamu Yoshida (RGU) (leg 2) yoshida@rakuno.ac.jp Hiroshi Uchida (JAMSTEC) (leg 3) Hiroshi Uchida (JAMSTEC) huchida@jamstec.go.jp N2O/CH4 Osamu Yoshida (RGU) Osamu Yoshida (RGU) (leg 2) yoshida@rakuno.ac.jp Yuki Okazaki (RGU) (leg 3) PFCs Nobuyasu Yamashita (AIST) nob.yamashita@aist.go.jp Plankton Minoru Kitamura (JAMSTEC) Minoru Kitamura (JAMSTEC) kitamura@jamstec.go.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. NIRS National Institute of Radiological Sciences JAEA Japan Atomic Energy Agency RGU Rakuno Gakuen University AIST National Institute of Advanced Industrial Science and Technology 1.4 List of Cruise Participants Table 1.4.1: List of cruise participants for leg 2. Name Responsibility Affiliation ------------------- ------------------------------------------ ------------ Akihiko Murata Chief Scientist/CTD/water sampling RIGC/JAMSTEC Yuichiro Kumamoto DO/radionuclides RIGC/JAMSTEC Hiroshi Uchida CTD/density/water sampling RIGC/JAMSTEC Shinya Kouketsu LADCP/ADCP/water sampling RIGC/JAMSTEC Kazuhiko Hayashi Water sampling RIGC/JAMSTEC Ken’ichi Sasaki CFCs MIO/JAMSTEC Moyap Kilepak Observer U. of PNG Benjamin Malai Observer NWS/PNG Osamu Yoshida CH4 and N2O/water sampling RGU Yuki Okazaki CH4 and N2O/water sampling RGU Shinichi Oikawa CH4 and N2O/water sampling RGU Hikari Shimizu CH4 and N2O/water sampling RGU Satoshi Ozawa Chief technologist/CTD/water sampling MWJ Hirokatsu Uno CTD/water sampling MWJ Fujio Kobayashi Salinity MWJ Kenichi Kato CTD/water sampling MWJ Shinsuke Toyoda CTD/water sampling MWJ Hiroki Ushiromura Salinity MWJ Shungo Oshitani CTD/water sampling MWJ Kenichiro Sato Nutrients MWJ Minoru Kamata Nutrients MWJ Masanori Enoki Nutrients MWJ Tomonori Watai pH/total alkalinity MWJ Yoshiko Ishikawa DIC/pCO2 MWJ Miyo Ikeda DO MWJ Ayaka Hatsuyama pH/total alkalinity MWJ Hatsumi Aoyama DIC/pCO2 MWJ Masahiro Orui CFCs MWJ Makoto Takada Water sampling/radionuclides MWJ Katsunori Sagishima CFCs MWJ Shoko Tatamisashi CFCs MWJ Kanako Yoshida DO MWJ Yuki Miyajima DO MWJ Elena Hayashi Water sampling MWJ Tatsuya Ando Water sampling MWJ Hitomi Takahashi Water sampling MWJ Mizuho Yasui Water sampling MWJ Daiki Hayashi Water sampling MWJ Yusuke Ogiwara Water sampling MWJ Satoshi Okumura Chief technologist /meteorology/ geophysics/ADCP/XCTD GODI Kazuho Yoshida Meteorology/geophysics/ADCP/XCTD GODI Ryo Kimura Meteorology/geophysics/ADCP/XCTD GODI GODI Global Ocean Development Inc. JAMSTEC Japan Agency for Marine-Earth Science and Technology RIGC Research Institute for Global Change MIO Mutsu Institute of Oceanography MWJ Marine Works Japan, Ltd. RGU Rakuno Gakuen University PNG Papua New Guinea NWS National Weather Service Table 1.4.2: List of cruise participants for leg 3. Name Responsibility Affiliation Yuichiro Kumamoto Chief scientist/DO/radionuclides RIGC/JAMSTEC Hiroshi Uchida CTD/density/water sampling RIGC/JAMSTEC Katsuro Katsumata XMP/LADCP/water sampling RIGC/JAMSTEC Toshimasa Doi LADCP/water sampling RIGC/JAMSTEC Kazuhiko Hayashi Water sampling RIGC/JAMSTEC Ken’ichi Sasaki CFCs MIO/JAMSTEC Minoru Kitamura Plankton BGS/JAMSTEC Eric Cruz Plankton net dragging/water sampling NMFS/NOAA Nobuyoshi Yamashita PFCs AIST Yuki Okazaki CH4 and N2O/water sampling RGU Shinichi Oikawa CH4 and N2O/water sampling RGU Hikari Shimizu CH4 and N2O/water sampling RGU Yoshiko Ishikawa Chief technologist /DIC/pCO2 MWJ Hideki Yamamoto Water sampling/radionuclides MWJ Toru Idai CTD/water sampling MWJ Kenichi Katayama CTD/water sampling MWJ Naoko Miyamoto CTD/water sampling MWJ Tatsuya Tanaka Salinity MWJ Tamami Ueno Salinity MWJ Kenichiro Sato Nutrients MWJ Minoru Kamata Nutrients MWJ Tomonori Watai pH/total alkalinity MWJ Yasuhiro Arii Nutrients MWJ Misato Kuwahara DO MWJ Hatsumi Aoyama DIC/pCO2 MWJ Makoto Takada DIC/pCO2 MWJ Shinichiro Yokokawa DO MWJ Katsunori Sagishima CFCs MWJ Shoko Tatamisashi CFCs MWJ Hironori Sato DO MWJ Kanako Yoshida DO MWJ Takami Mori CTD/water sampling MWJ Yasumi Yamada pH/total alkalinity MWJ Elena Hayashi Water sampling MWJ Tatsuya Ando Water sampling MWJ Rie Muranaka Water sampling MWJ Shihomi Saito Water sampling MWJ Emi Deguchi Water sampling MWJ Erina Matsumoto Water sampling MWJ Katsuhisa Maeno Chief technologist /meteorology/ GODI geophysics/ADCP/XCTD Asuka Doi Meteorology/geophysics/ADCP/XCTD GODI Kazuho Yoshida Meteorology/geophysics/ADCP/XCTD GODI Toshimitsu Goto Meteorology/geophysics/ADCP/XCTD GODI BGS Institute of Biogeosciences NMFS/NOAA National Marine Fisheries Service, National Oceanic and Atmospheric Administration 2 UNDERWAY MEASUREMENTS 2.1 Navigation February 5, 2014 (1) Personnel Kazuho Yoshida (GODI) -leg1, leg2- Ryo Kimura (GODI) -leg1, leg2- Satoshi Okumura (GODI) -leg2- Katsuhisa Maeno (GODI) -leg3- Asuka Doi (GODI) -leg3- Toshimitsu Goto (GODI) -leg3- Ryo Ohyama (MIRAI Crew) -leg1, leg2, leg3- (2) System description Ship’s position and velocity were provided by Radio Navigation System on R/V Mirai. This system integrates GPS position, log speed, gyro compass heading and other basic data for navigation, and calculated speed/course over ground on workstation. Radio navigation System also distributed ship’s standard time synchronized to GPS time server via Network Time Protocol. These data were logged on the network server as “SOJ” data every 5 seconds. Sensors for navigation data are listed below; i) GPS system: MultiFix6 (software version 1.01), Differential GPS system. Receiver: Trimble SPS751, with two GPS antennas located on navigation deck, starboard side and port side, manually switched as to GPS receiving state and offset to radar-mast position, datum point. Decoder: Fugro STARFIX 4100LR ii) Doppler log: Furuno DS-30, which use three acoustic beam for current measurement under the hull. iii) Gyrocompass: Tokimec TG-6000, sperry type mechanical gyrocompass. iv) GPS time server: SEIKO TS-2540 Time Server, synchronizing to GPS satellite every 1 second. (3) Data period (Times in UTC) Leg1: 04:50 4th Dec. 2011 to 00:00 20th Dec. 2011 Leg2: 06:00 20th Dec. 2011 to 02:00 12th Jan. 2012 Leg3: 23:00 12th Jan. 2012 to 00:00 9th Feb. 2012 Figure 2.1.1: Cruise Track of MR11-08 Leg 1. Figure 2.1.2: Cruise Track of MR11-08 Leg 2. Figure 2.1.3: Cruise Track of MR11-08 Leg 3. 2.2 Swath Bathymetry February 5, 2014 (1) Personnel Takeshi Matsumoto (U. of the Ryukyu): Principal Investigator (Not on-board) Naoto Hirano (Tohoku U.): Principal Investigator (Not on-board) Kazuho Yoshida (GODI) -leg1, leg2- Ryo Kimura (GODI) -leg1, leg2- Satoshi Okumura (GODI) -leg2- Katsuhisa Maeno (GODI) -leg3- Asuka Doi (GODI) -leg3- Toshimitsu Goto (GODI) -leg3- Ryo Ohyama (MIRAI Crew) -leg1, leg2, leg3- (2) Introduction R/V MIRAI is equipped with a Multi narrow Beam Echo Sounding system (MBES), SEABEAM 2112 (SeaBeam Instruments Inc.). The objective of MBES is collecting continuous bathymetric data along ship’s track to make a contribution to geological and geophysical investigations and global datasets. (3) Data acquisition The “SEABEAM 2112” on R/V MIRAI was used for bathymetry mapping during the MR11-08 cruise from 4th December 2011 to 9th February 2012. 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 (6.2m) sound velocity, and the deeper depth sound velocity profiles were calculated by temperature and salinity profiles from CTD or XCTD or ARGO data by the equation in Del Grosso (1974) during the cruise. Table 2.2.1 shows system configuration and performance of SEABEAM 2112.004 system. Table 2.2.1: System configuration and performance. SEABEAM 2112 (12 kHz system) 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 +/-1m, whichever is greater, over the entire swath. (Nadir beam has greater accuracy; typically within < 0.2%of depth or +/-1m, whichever is greater) (4) Data processing i. Sound velocity correction The continuous bathymetry data were split into small areas around each CTD station. For each small area, the bathymetry data were corrected with a sound velocity profile calculated from the CTD data or XCTD data in the area. The equation of Del Grosso (1974) was used for calculating sound velocity. The data processing is carried out using “mbprocess” command of MBsystem. ii. Editing and Gridding Gridding for the bathymetry data were carried out using the HIPS software version 7.1 (CARIS, Canada). Firstly, the bathymetry data during Ship’s turning was basically removed before “BASE surface” was made. A spike noise of each swath data was also removed using “swath editor” and “subset editor”. Then the bathymetry data was gridded by “Interpolate” function of the software with the parameters shown as Table 2.2.2. Finally, raw data and interpolated data are exported as ASCII data, and converted to 150m grid data using “xyz2grd” utility of GMT (Generic Mapping Tool) software. Table 2.2.2: Parameters for interpolate of bathymetry data. BASE surface resolution: 50m Interpolate matrix size: 5 x 5 Minimum number of neighbors for interpolate: 10 (5) Data archives Bathymetric data obtained during this cruise will be submitted to the Data Management Group (DMG) of JAMSTEC, and will be archived there. (6) Remarks (Times in UTC) 1) The observation was carried out within following periods, Leg1: 10:00 5th Dec. 2011 to 08:30 10th Dec.2011 Leg2: 22:10 21th Dec. 2011 to 00:00 22th Dec. 2011 19:30 23th Dec. 2011 to 04:30 1st Jan. 2012 14:00 3rd Jan 2012 to 14:09 12th Jan. 2012 Leg3: 02:48 13th Jan. 2012 to 05:13 06th Feb 2012. 2) The following period, data acquisition was suspended due to system trouble and network trouble. 15:27 to 18:22 8th Dec. 2011 21:00 to 21:37 20th Dec. 2011 08:10 to 08:34 10th Jan. 2012 21:35 to 22:03 22th Jan. 2012 15:48 to 16:15 31th Jan. 2012 3) The following period, GPS data acquisition was suspended due to GPS trouble. 03:39 to 03:52 3rd Feb. 2012 2.3 Surface Meteorological Observation January 25, 2014 (1) Personnel Kunio Yoneyama (JAMSTEC) Kasuo Yoshida (GODI) (Legs 1, 2) Ryo Kimura (GODI) (Legs 1, 2) Satoshi Okumura (GODI) (Leg 2) Katsuhisa Maeno (GODI) (Leg 3) Asuka Doi (GODI) (Leg 3) Toshimitsu Goto (GODI) (Leg 3) Ryo Ohyama (Mirai Crew) (Legs 1, 2, 3) (2) Objective As basic information about general weather conditions during the cruise, surface meteorological observation had been continuously conducted. (3) Methods There are two different surface meteorological observation systems onboard the R/V MIRAI. One is the MIRAI surface meteorological measurement station (SMET), and the other is the Shipboard Oceanographic and Atmospheric Radiation (SOAR) system. Instruments of SMET whose data are used here are listed in Table 2.3.1. All SMET data were collected 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 low starting threshold wind speed (1 m/sec) comparing to SMET’s (2m/sec), and 3) SMET’s radiometers has 10 W/m2 resolution, while SOAR takes 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. SOAR consists of 1) Portable Radiation Package (PRP) that measures short and long wave downwelling radiation, 2) Zeno meteorological system that measures pressure, air temperature, relative humidity, wind speed/direction, and rainfall, and 3) Scientific Computer System (SCS), that has been developed by the U.S. National Oceanic and Atmospheric Administration (NOAA) for data collection, management, real-time monitoring, etc. Information on sensors used here is listed in Table 2.3.2. Table 2.3.1: 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 SBE, USA/SBE-3S bow thruster room / -5 m Barometer pressure Setra System, USA/ captain deck / 13 m Model-370 *1: Gill aspirated radiation shield 43408 made by R. M. Young, USA is attached. *2: Thermometers are equipped at both starboard and port sides, and upwind-side data are used. Table 2.3.2: Instruments and locations of SOAR. Sensor Parameter Manufacturer/type Location/height from sea level ------------- ----------------- ----------------------- ------------------------------ Anemometer Wind speed/ R.M. Young, USA/05106 Foremast / 25 m direction Rain gauge Rainfall R.M. Young, USA/50202 Foremast / 24 m accumulation Radiometer Short wave Eppley, USA/PSP Foremast / 25 m radiation Long wave Eppley, USA/PIR Foremast / 25 m radiation (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). They are mean of 8 samples (10 samples minus maximum/minimum values) to exclude singular values. Liner interpolation onto missing values was applied only when their interval is less than 4 minutes. Since the thermometers are equipped on both starboard/port sides, we adopted air temperature/ relative humidity data taken at upwind side. Dew point temperature was calculated from relative humidity and air temperature data. No adjustment to sea level values is applied except pressure data. Data are stored as ASCII format and contain the 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), shortwave and longwave radiation (W/m2). Missing values are expressed as “9999”. (5) Data quality To ensure the data quality, each sensor was calibrated as follows. It is remarked, however, since there is a possibility that data may contain noises caused by turbulence, it is recommended to filter out such data by using smoothed data (e.g., 1-hour mean) from this 1-minute mean data sets depending on the scientific purpose. T/RH sensor; Temperature and humidity probes were calibrated before (Aug. 3, 2011) and after (Feb. 28, 2012) the cruise by the manufacturer. Certificated accuracy for 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, HMP45A) before each cruise. The results are listed below. Check date Dec. 01, 2011 Feb. 10, 2012 ------------------------------------------------------------------------- Temperature (˚C) Port side SMET 27.6 –5.7 Portable 27.9 –5.6 Starboard side SMET 27.9 –5.1 Portable 27.9 –5.0 Relative Port side SMET 76.9 62.1 Humidity (%) Portable 74.0 61.7 Starboard side SMET 78.1 66.0 Portable 76.2 62.1 Pressure sensor; Using calibrated portable barometer (Vaisala, Finland / PTB220), pressure sensor was checked before/after the cruise. Accuracy is better than ±0.2 hPa. Check date Oct.26 Dec.01 Feb.10 Mar.30 ----------------------------------------------------------------- SMET 1007.45 1008.06 1013.52 1016.51 Reference 1007.43 1008.00 1013.64 1016.40 Difference +0.02 +0.06 –0.12 0.11 Precipitation; Prior to the cruise, we put the water into the rain gauge to check their linearity between the indicated values and actual water amount input. Expected accuracy is better than ± 1mm which corresponds to sensor’s original specification. Calibration date Dec. 2(1) Dec. 2(2) Dec. 2(3) Feb. 9(1) Feb. 9(2) Feb. 9(3) ---------------------------------------------------------------------------------------- Min input water 0.00 0.00 0.00 0.00 0.00 0.00 volume (cc) Min measured 0.13 0.11 0.12 0.47 0.47 0.53 value (mm) Max input water 505.00 504.50 502.50 504.50 506.50 506.00 volume (cc) Max measured 49.28 49.25 49.28 50.10 50.21 50.29 value (mm) Radiation sensors; Short wave and long wave radiometers were calibrated by Remote Measurement & Research Company with the help of Department of Energy, Atmospheric Radiation Measurement Program prior to the cruise. Sensors used here were calibrated on June 3, 2011. For PSP; y = 3.691x + 4.2 For PIR; y = 1.252x – 23.3, where y = Insolation (W/m2), and x = ADC value (mV). 1/(T+T0) = P1 a3 + P2 a2 + P3 a + P4, where a = ln(ADC mV), and T0 = 273.15 K Case temperature fit; max error = 0.000 ˚C P1 = 3.0273e–6, P2 = –3.6335e–5, P3 = 4.2203e–4, P4 = 1.7194e–3 Dome temperature fit; max error = 0.000 ˚C P1 = 3.0297e–6, P2 = –3.6490e–5, P3 = 4.2347e–4, P4 = 1.7153e–3 (6) Data periods Leg-1: December 05, 2011, 1001Z – December 10, 2011, 0829Z Leg-2: December 20, 2011, 2101Z – December 22, 2011, 0000Z December 23, 2011, 1931Z – January 01, 2012, 0429Z January 03, 2012, 1401Z – January 10, 2012, 1400Z Leg-3: January 13, 2012, 0246Z – February 09, 2012, 0900Z (7) Preliminary results Figures 2.3.1, 2.3.2 and 2.3.3 show the time series of surface meteorological observation for each cruise. One hour mean values (time stamp at the medium of the average) instead of 1 minute mean are used to depict these figures. Figure 2.3.1: Time series of (a) air and sea surface temperature, (b) relative humidity, (c) precipitation, (d) pressure, (e) zonal and meridional wind components, and (e) short and long wave radiation for the Leg-1 cruise. Day-330 corresponds to Nov. 26, 2011. Figure 2.3.2: Same as Fig. 2.3.1, but for the Leg-2 cruise. Day-350 corresponds to Dec. 16, 2011. Figure 2.3.3: Same as Fig. 2.3.1, but for the Leg-3 cruise. Vertical scale for (a) and (d) are also different with Fig. 2.3.1. Day-10 corresponds to Jan. 10, 2012. 2.4 Thermo-Salinograph and Related Measurements February 4, 2014 (1) Personnel Hiroshi Uchida (JAMSTEC) Miyo Ikeda (MWJ) (Leg 2) Kanako Yoshida (MWJ) (Leg 2, 3) Yuki Miyajima (MWJ) (Leg 2) Misato Kuwahara (MWJ) (Leg 3) Shinichiro Yokogawa (MWJ) (Leg 3) (2) Objectives The objective is to collect sea surface salinity, temperature, dissolved oxygen, and fluorescence data continuously along the cruise track. (3) Materials and methods The Continuous Sea Surface Water Monitoring System (Marine Works Japan Co, Ltd.) has six sensors and automatically measures salinity, temperature, dissolved oxygen, and fluorescence in sea surface water every one minute. This system is located in the sea surface monitoring laboratory and connected to shipboard LAN system. Measured data along with time and location of the ship were displayed on a monitor and stored in a desktop computer. The sea surface water was continuously pumped up to the laboratory from about 5 m water depth and flowed into the system through a vinyl-chloride pipe. The flow rate of the surface seawater was controlled to be 5 dm3/min. Manufacturer’s specifications of the each sensor in this system are listed below. i. Software Seamoni-kun Ver.1.20 ii. Sensors Temperature and conductivity sensor Model: SBE-45, SEA-BIRD ELECTRONICS, INC. Serial number: 4563325-0362 (leg 1) 4557820-0319 (legs 2, 3) Measurement range: Temperature –5 to 35ºC Conductivity 0 to 7 S m–1 Initial accuracy: Temperature 0.002ºC Conductivity 0.0003 S m–1 Typical stability (per month): Temperature 0.0002ºC Conductivity 0.0003 S m–1 Resolution: Temperatures 0.0001ºC Conductivity 0.00001 S m–1 Bottom of ship thermometer Model: SBE 38, SEA-BIRD ELECTRONICS, INC. Serial number: 3857820-0540 Measurement range: –5 to +35ºC Initial accuracy: ±0.001ºC Typical stability (per 6 month): 0.001ºC Resolution: 0.00025ºC Dissolved oxygen sensor Model: OPTODE 3835, AANDERAA Instruments. Serial number: 1519 Measuring range: 0 - 500 μmol L–1 Resolution: <1 μmol L–1 Accuracy: <8 μmol L–1 or 5%whichever is greater Settling time (63%): <25 s Fluorometer Model: C3, TURNER DESIGNS Serial number: 2300123 (4) Data Processing and Quality Control Data from the Continuous Sea Surface Water Monitoring System were processed as follows. Data gaps were linearly interpolated when the gap was ≤ 7 minutes. Spikes in the temperature and salinity data were removed using a median filter with a window of 3 scans (3 minutes) when difference between the original data and the median filtered data was larger than 0.1 ºC for temperature and 0.5 for salinity. Fluorometer data were low-pass filtered using a median filter with a window of 3 scans (3 minutes) to remove spikes. Raw data from the OPTODE oxygen sensor and the fluorometer data were low-pass filtered using a Hamming filter with a window of 15 scans (15 minutes). Salinity (S [PSU]), dissolved oxygen (O [μmol/kg]) and fluorescence (Fl [RFU]) data were corrected using the water sampled data. Details of the measurement methods are described in Sections 3.2, 3.4, and 3.8 for salinity, dissolved oxygen and chlorophyll-a, respectively. Corrected salinity (Scor), dissolved oxygen (Ocor), and estimated chlorophyll a (Chl-a) were calculated from following equations Scor [PSU] = c0 + c1 S + c2 t Ocor [μmol/kg] = c0 + c1 O + c2 T + c3 t Chl-a [μg/L] = c0 + c1 Fl where t is days from a reference time, T is temperature in ºC. The best fit sets of calibration coefficients (c0~c3) were determined by a least square technique to minimize the deviation from the water sampled data. The reference times were listed in Table 2.4.1. The calibration coefficients were listed in Table 2.4.2. Comparisons between the Continuous Sea Surface Water Monitoring System data and water sampled data are shown in from Figs. 2.4.1 to 2.4.6. For leg 3, sensitivity of the fluorometer to chlorophyll a was different between subtropical region and subarctic region. Therefore, slope (c1) of the calibration coefficients was changed according to the temperature for each area (Table 2.4.2). Table 2.4.1: Reference time used in the calibration equations for salinity and dissolved oxygen. Leg Date Time (UTC) --- ---------- ----- 2 2011/12/20 21:00 3 2012/01/13 02:47 Table 2.4.2: Calibration coefficients for the salinity, dissolved oxygen, and chlorophyll a. Leg c0 c1 c2 c3 --- ------------- --------- ------------- ------------ Salinity 2 1.012865e-02 0.9995585 7.254156e-04 3 -8.713569e-02 1.002669 5.683519e-04 Dissolved oxygen 2 11.34542 1.102664 -0.6163531 -1.981512e-02 3 36.55213 0.9906656 -0.738031 -0.1868786 Chlorophyll a 2 4.082381e-02 0.1021539 3 3.746690e-02 0.1262224 (for temperature < 17 ºC) 3.746690e-02 8.794529e-02 (for temperature ≥ 17 ºC) Figure 2.4.1: Comparison between TSG salinity (red: before correction, green: after correction) and sampled salinity for leg 2. Figure 2.4.2: Same as Fig. 2.4.1, but for leg 3. Figure 2.4.3: Comparison between TSG oxygen (red: before correction, green: after correction) and sampled oxygen for leg 2. Figure 2.4.4: Same as Fig. 2.4.3, but for leg 3. Figure 2.4.5: Comparison between TSG fluorescence and sampled chlorophyll a for leg 2. For bottom panel, red (temperature ≥ 17ºC) and blue (temperature < 17ºC) dots indicate fluorescence and green dots indicate water sampled chlorophyll a. Line indicates chlorophyll a estimated from fluoremeter. Figure 2.4.6: Same as Fig. 2.4.5, but for leg 3. 2.5 Underway pCO2 24 September, 2013 (1) Personnel Akihiko Murata (RIGC, JAMSTEC) Yoshiko Ishikawa (MWJ) Hatsumi Aoyama (MWJ) Makoto Takada (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 P10 revisit cruise, we were aimed at quantifying how much anthropogenic CO2 is absorbed in the surface ocean in the western 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 nondispersive infrared gas analyzer (Li-COR LI-7000), an air-circulation module and a showerhead-type equilibrator. To measure concentrations (mole fraction) of CO2 in dry air (xCO2a), air sampled from the bow of the ship (approx. 30 m above the sea level) was introduced into the NDIR through a dehydrating route with an electric dehumidifier (kept at ~2 °C), a Perma Pure dryer (GL Sciences Inc.), and a chemical desiccant (Mg(ClO4)2). The flow rate of the air was 500 ml min-1. To measure surface seawater concentrations of CO2 in dry air (xCO2s), the air equilibrated with seawater within the equilibrator was introduced into the NDIR through the same flow route as the dehydrated air used in measuring xCO2a. The flow rate of the equilibrated air was 700 – 800 ml min- 1. The seawater was taken by a pump from the intake placed at the approx. 4.5 m below the sea surface. The flow rate of seawater in the equilibrator was 400 – 500 ml min-1. The CO2 measuring system was set to repeat the measurement cycle such as 4 kinds of CO2 standard gases (Table 2.5.1), xCO2a (twice), xCO2s (7 times). This measuring system was run automatically throughout the cruise by a PC control. (4) Quality control Concentrations of CO2 of the standard gases are listed in Table 2.5.1, which were calibrated after cruise by the JAMSTEC primary standard gases. The CO2 concentrations of the primary standard gases were calibrated by the Scripps Institution of Oceanography, La Jolla, CA, USA. In actual shipboard observations, the signals of NDIR usually reveal a trend. The trends were adjusted linearly using the signals of the standard gases analyzed before and after the sample measurements. Effects of water temperature increased between the inlet of surface seawater and the equilibrator on xCO2s were adjusted based on Takahashi et al. (1993), although the temperature increases were slight, being ~0.3 °C. We checked values of xCO2a and xCO2s by examining signals of the NDIR by plotting the xCO2a and xCO2s as a function of sequential day, longitude, sea surface temperature and sea surface salinity. Reference Takahashi, T., J. Olafsson, J. G. Goddard, D. W. Chipman, and S. C. Southerland (1993): Seasonal variation of CO2 and nutrients in the high- latitude surface oceans: a comparative study, Global Biogeochem. Cycles, 7, 843 – 878. Table 2.5.1: Concentrations of CO2 standard gases used during MR11–08 cruise. Cylinder no. Concentrations (ppmv) ------------ --------------------- CRC00049 270.13 CRC00046 330.29 CRC00047 360.28 CRC00048 420.25 2.6 Shipboard ADCP August 13, 2013 (1) Personnel Shinya Kouketsu (JAMSTEC): Principal Investigator Kazuho Yoshida (Global Ocean Development Inc., GODI) -leg1, leg2- Ryo Kimura (GODI) -leg1, leg2- Satoshi Okumura (GODI) -leg2- Katsuhisa Maeno (GODI) -leg3- Asuka Doi (GODI) -leg3- Toshimitsu Goto (GODI) -leg3- Ryo Ohyama (MIRAI Crew) -leg1, leg2, leg3- (2) Objective To obtain continuous measurement of the current profile along the ship’s track. (3) Methods Upper ocean current measurements were made in MR11-08 cruise, using the hull- mounted Acoustic Doppler Current Profiler (ADCP) system. For most of its operation the instrument was configured for watertracking mode. Bottom- tracking mode, interleaved bottom-ping with water-ping, was made to get the calibration data for evaluating transducer misalignment angle in the shallow water. The system consists of following components; 1) R/V MIRAI has installed vessel-mount ADCP (75 kHz “Ocean Surveyor”, Teledyne RD Instruments). It has a phased-array transducer with single assembly and creates 4 acoustic beams electronically. 2) For heading source, we use ship’s gyro compass (Tokimec, Japan), continuously providing heading to the ADCP system directory. Also we have Inertial Navigation System (PHINS, iXSEA) which provide high- precision heading and attitude information are stored in “.N2R” data files. 3) DGPS system (Trimble SPS751 & StarFixXP) providing position fixes. 4) We used VmDas version 1.4.6 (TRDI) for data acquisition. 5) To synchronize time stamp of pinging with GPS time, the clock of the logging computer is adjusted to GPS time every 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). Data were configured for 8-m intervals starting 19-m below the surface. Every ping was recorded as raw ensemble data (.ENR). Also, 60 seconds and 300 seconds averaged data were recorded as short term average (.STA) and long term average (.LTA) data, respectively. Major parameters for the measurement (Direct Command) are shown in Table 2.6.1. (4) Preliminary results Figs.2.6.1, 2.6.2 and 2.6.3 shows surface current profile along the ship’s track, averaged four depth cells from the top, 23 m to 55 m with 30 minutes average. In the layer upper 300m, the velocity estimation were good during this cruise, because the echo intensities for each beams were over 60 counts at such depths (Fig. 2.6.4). (5) Data The processed data were fixed the ADCP misalignment by comparison between bottom track and ship velocities (based on GPS data) and were averaged over 10 minutes. All the data obtained in this cruise will be submitted to the Data Management Group (DMG) of JAMSTEC, and will be opened to the public via JAMSTEC home page. (6) Remarks (Times in UTC) The observation was carried out within following periods Leg1: 10:00 5th Dec. 2011 to 08:30 10th Dec. 2011 Leg2: 21:00 20th Dec. 2011 to 00:00 22th Dec. 2011 19:30 23th Dec. 2011 to 04:30 1st Jan. 2012 14:00 3rd Jan. 2012 to 14:00 10th Jan. 2012 Leg3: 02:45 13th Jan. 2012 to 00:00 9th Feb. 2012 Table 2.6.1. Major parameters. Environmental Sensor Commands EA = +04500 Heading Alignment (1/100 deg) EB = +00000 Heading Bias (1/100 deg) ED = 00065 Transducer Depth (0 - 65535 dm) EF = +001 Pitch/Roll Divisor/Multiplier (pos/neg) [1/99 - 99] EH = 00000 Heading (1/100 deg) ES = 35 Salinity (0-40 pp thousand) EX = 00000 Coord Transform (Xform:Type; Tilts; 3Bm; Map) EZ = 10200010 Sensor Source (C; D; H; P; R; S; T; U) C (1): Sound velocity calculates using ED, ES, ET (temp.) D (0): Manual ED H (2): External synchro P (0), R (0): Manual EP, ER (0 degree) S (0): Manual ES T (1): Internal transducer sensor U (0): Manual EU Timing Commands TE = 00:00:02.00 Time per Ensemble (hrs:min:sec.sec/100) TP = 00:02.00 Time per Ping (min:sec.sec/100) Water-Track Commands WA = 255 False Target Threshold (Max) (0-255 count) WB = 1 Mode 1 Bandwidth Control (0=Wid, 1=Med, 2=Nar) WC = 120 Low Correlation Threshold (0-255) WD = 111 100 000 Data Out (V; C; A; PG; St; Vsum; Vsum^2;#G;P0) WE = 1000 Error Velocity Threshold (0-5000 mm/s) WF = 0800 Blank After Transmit (cm) WG = 001 Percent Good Minimum (0-100%) WI = 0 Clip Data Past Bottom (0 = OFF, 1 = ON) WJ = 1 Rcvr Gain Select (0 = Low, 1 = High) WM = 1 Profiling Mode (1-8) WN = 100 Number of depth cells (1-128) WP = 00001 Pings per Ensemble (0-16384) WS = 0800 Depth Cell Size (cm) WT = 000 Transmit Length (cm) [0 = Bin Length] WV = 0390 Mode 1 Ambiguity Velocity (cm/s radial) Figure 2.6.1: Current profile along the ship’s track, from 23m to 55m, averaged every 30 minutes (Leg1). Figure 2.6.2: Current profile along the ship’s track, from 23m to 55m, averaged every 30 minutes (Leg2). Figure 2.6.3: Current profile along the ship’s track, from 23m to 55m, averaged every 30 minutes (Leg3). Figure 2.6.4. Echo intensity. 2.7 XCTD February 5, 2014 (1) Personnel Hiroshi Uchida (JAMSTEC) Katsuhisa Maeno (GODI) Ryo Ohyama (GODI) Asuka Doi (GODI) Toshimitsu Goto (GODI) (2) Objectives In this cruise, XCTD (eXpendable Conductivity, Temperature and Depth profiler) measurements were carried out to evaluate the fall rate equation and temperature by comparing with CTD (Conductivity, Temperature and Depth profiler) measurements, and to substitute for CTD measurements. (3) Instrument and Method The XCTDs used were XCTD-2 (Tsurumi-Seiki Co., Ltd., Yokohama, Kanagawa, Japan) with an MK-150N deck unit (Tsurumi-Seiki Co., Ltd.). The manufacturer’s specifications are listed in Table 2.7.1. In this cruise, the XCTD probes were deployed by using 8-loading automatic launcher (stations 64, 67, 89_1, 89_2, 91, 93, 95, 103 and 105) or hand launcher (Tsurumi-Seiki Co., Ltd.). For comparison with CTD, XCTD was deployed at about 10 minutes after the beginning of the down cast of the CTD (stations 64, 67, 110, 112). (4) Data Processing and Quality Control The XCTD data were processed and quality controlled based on a method by Uchida et al. (2011). Depth error of the XCTD data was corrected by using the estimated terminal velocity error (–0.0362 m s–1) (Fig. 2.7.1). Mean thermal bias (+0.014 °C) of the XCTD data was estimated by comparing with the CTD data and corrected (Fig. 2.7.2). 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 2.7.2). For the XCTD data of the station P10N_89_1~4 and P10N_113_1, salinity bias could not be estimated because the maximum depth was too shallow to estimate the salinity bias. The temperature and salinity relationships in the deep ocean obtained from the post-cruise calibrated CTD and XCTD data were shown in Fig. 2.7.3. 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 2.7.1: Manufacturer’s specifications of 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 ~ 1850 m (for XCTD-2) 5 m or 2%, whichever is greater * * Depth error is shown in Kizu et al (2008). Table 2.7.2: Serial number 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. Station Serial number Depth SST SSS Max Salinity Reference salinity [m] [°C] [PSU] pressure offset [PSU] [dbar] [PSU] ------- ------------- ----- ------ ------ -------- -------- ------------------ 64_1 11022006 5714 25.045 35.045 2018 0.025 34.6081 @ 2.1°C 67_3 11022005 5786 23.895 35.178 2018 0.022 34.6017 @ 2.0°C 89_1 11022004 6145 17.866 34.717 889 – NA 89_2 11022001 6078 17.788 34.715 655 – NA 89_3 11021998 6130 17.797 34.717 823 – NA 89_4 11022002 6134 17.857 34.717 846 – NA 91_1 11021999 6067 12.769 34.303 2021 -0.002 34.5834 @ 2.0°C 93_1 11021995 5778 14.356 34.513 2021 0.008 34.5834 @ 2.0°C 95_1 11021996 5711 12.258 34.315 2021 0.008 34.5834 @ 2.0°C 97_1 11021849 5622 15.091 34.592 1999 0.004 34.5834 @ 2.0°C 99_1 11021850 5555 10.229 34.184 2021 -0.009 34.5834 @ 2.0°C 101_1 11021851 5450 10.151 34.189 2011 0.005 34.5834 @ 2.0°C 103_1 11022000 5300 9.662 34.128 2021 0.005 34.5834 @ 2.0°C 105_1 11021846 5276 4.441 33.353 2022 0.025 34.5834 @ 2.0°C 107_1 11021848 5817 4.642 33.409 2022 0.005 34.5834 @ 2.0°C 108_1 11021847 6224 3.454 33.329 2016 0.019 34.5834 @ 2.0°C 109_1 11021844 6321 3.415 33.325 2020 0.015 34.5834 @ 2.0°C 110_2 11021843 4057 4.001 33.409 2022 0.018 34.5834 @ 2.0°C 111_1 11021840 2695 3.810 33.370 2022 0.034 34.5834 @ 2.0°C 112_1 11021841 1481 1.748 33.157 1475 0.010 34.4829 @ 2.4°C 113_1 11021842 1047 0.501 32.511 1051 – NA Figure 2.7.1: Differences between XCTD and CTD depths for stations 64, 67, 110 and 112. Differences were estimated with the same method as Uchida et al. (2011). Standard deviation of the estimates (horizontal bars) and the manufacturer’s specification for XCTD depth error (dotted lines) are shown. The regression for the XCTD-2 data obtained in this cruise (black line) and for the XCTD-2 data obtained in the MR09-01 cruise (red line) are shown. Figure 2.7.2: Comparison between XCTD and CTD temperature profiles. (a) Mean temperature profile of CTD profiles (thick line) with standard deviation (shade). (b) Mean temperature difference (thick line) with standard deviation (shade) between the XCTD and CTD. Figure 2.7.3: Comparison of temperature-salinity profiles of post-cruise calibrated CTD (red lines) and XCTD (black lines). 3 Hydrographic Measurement Techniques and Calibrations 3.1 CTDO2 Measurements February 10, 2014 (1) Personnel Hiroshi Uchida (JAMSTEC) Shinsuke Toyoda (MWJ) (Leg 2) Hirokatsu Uno (MWJ) (Leg 2) Shungo Oshitani (MWJ) (Leg 2) Kenichi Kato (MWJ) (Leg 2) Satoshi Ozawa (MWJ) (Leg 2) Kenichi Katayama (MWJ) (Leg 3) Toru Idai (MWJ) (Leg 3) Naoko Miyamoto (MWJ) (Leg 3) Takami Mori (MWJ) (Leg 3) (2) Winch arrangements The CTD package was deployed by using 4.5 Ton Traction Winch System (Dynacon, Inc., Bryan, Texas, USA), which was installed on the R/V Mirai in April 2001 (Fukasawa et al., 2004). Primary system components include a complete CTD Traction Winch System with up to 8000 m of 9.53 mm armored cable (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), two oxygen optodes (RINKO-III; JFE Alec Co., Ltd, Kobe Hyogo, Japan), a fluorometer (Seapoint sensors, Inc., Kingston, New Hampshire, USA), a transmissometer (C-Star Transmissometer; WET Labs, Inc., Philomath, Oregon, USA), and a Photosynthetically Active Radiation (PAR) sensor (Satlantic, LP, Halifax, Nova Scotia, Canada) were also used with the SBE 9plus underwater unit. To minimize 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). An additional set of SBE 911plus CTD system with 12-position SBE 32 was also used for three deep casts (P10N 90_2, 92_1, and 94_1) in leg 3, because tension of the winch exceeded the load capacity (3 ton) of the winch system at the CTD depths deeper than 5700 dbar, although tension of the winch had not exceeded the load capacity for the maximum depth of the CTD (6500 dbar) before the calibration of the tension meter performed in April 2011. The SBE 9plus was mounted horizontally in a 12-position carousel frame. Summary of the system used in this cruise 36-position CWS system (Set 1) Deck unit: SBE 11plus, S/N 0272 Under water unit: SBE 9plus, S/N 117457 (Pressure sensor: S/N 1027) Temperature sensor: SBE 3plus, S/N 4815 (primary) SBE 3plus, S/N 5329 (secondary, leg 2) SBE 3plus, S/N 4811 (secondary, leg 3) Conductivity sensor: SBE 4, S/N 2854 (primary) SBE 4, S/N 3036 (secondary) Oxygen sensor: SBE 43, S/N 0394 JFE Advantech RINKO-III, S/N 0024 (foil batch no. 144002A) JFE Advantech RINKO-III, S/N 0079 (foil batch no. 160002A) Pump: SBE 5T, S/N 4598 (primary) SBE 5T, S/N 4595 (secondary) Altimeter: PSA-916T, S/N 1100 (leg 2) PSA-916T, S/N 1157 (leg 3) Deep Ocean Standards Thermometer: SBE 35, S/N 0045 Fluorometer: Seapoint Sensors, Inc., S/N 3054 Transmissometer: C-Star, S/N CST-1363DR PAR: Satlantic LP, S/N 0049 Carousel Water Sampler: SBE 32, S/N 0391 (36-position) SBE 32, S/N 0389 (12-position) Water sample bottle: 12-litre Niskin-X model 1010X (no TEFLON coating) 12-position CWS system (Set 2) Deck unit: SBE 11plus, S/N 0272 Under water unit: SBE 9plus, S/N 94766 (Pressure sensor: S/N 0786) Temperature sensor: SBE 3plus, S/N 1359 (primary) SBE 3plus, S/N 1525 (secondary) Conductivity sensor: SBE 4, S/N 1203 (primary) SBE 4, S/N 2435 (secondary) Oxygen sensor: SBE 43, S/N 0205 JFE Advantech RINKO-III, S/N 0037 (foil batch no. 144005A) Pump: SBE 5T, S/N 3118 (primary) SBE 5T, S/N 3293 (secondary) Altimeter: PSA-916T, S/N 1100 Deep Ocean Standards Thermometer: SBE 35, S/N 0022 Carousel Water Sampler: SBE 32, S/N 0389 Water sample bottle: 12-litre Niskin-X model 1010X (no TEFLON coating) (4) Pre-cruise calibration i. Pressure The Paroscientific series 4000 Digiquartz high pressure transducer (Model 415K: Paroscientific, Inc., Redmond, Washington, USA) uses a quartz crystal resonator whose frequency of oscillation varies with pressure induced stress with 0.01 per million of resolution over the absolute pressure range of 0 to 15000 psia (0 to 10332 dbar). Also, a quartz crystal temperature signal is used to compensate for a wide range of temperature changes at the time of an observation. The pressure sensor has a nominal accuracy of 0.015 %FS (1.5 dbar), typical stability of 0.0015 %FS/month (0.15 dbar/month), and resolution of 0.001 %FS (0.1 dbar). Since the pressure sensor measures the absolute value, it inherently includes atmospheric pressure (about 14.7 psi). SEASOFT subtracts 14.7 psi from computed pressure automatically. Pre-cruise sensor calibrations for linearization were performed at SBE, Inc. S/N 1027, 4 February 2011 S/N 0786, 17 November 2009 The time drift of the pressure sensor is adjusted by periodic recertification corrections against a deadweight piston gauge (Model 480DA, S/N 23906; Piston unit, S/N 079K; Weight set, S/N 3070; Bundenberg Gauge Co. Ltd., Irlam, Manchester, UK). The corrections are performed at JAMSTEC, Yokosuka, Kanagawa, Japan by Marine Works Japan Ltd. (MWJ), Yokohama, Kanagawa, Japan, usually once in a year in order to monitor sensor time drift and linearity. S/N 1027, 19 May 2011 slope = 1.00017335 offset = 0.16281 S/N 0786, 27 May 2011 slope = 0.99988759 offset = 0.05087 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, 25 January 2011 S/N 5329, 11 February 2011 S/N 4811, 9 February 2011 S/N 1359, 18 May 2011 S/N 1525, 10 June 2011 Pressure sensitivities of SBE 3s were corrected according to a method by Uchida et al. (2007), for the following sensors. S/N 4815, –3.45974716e–7 [°C/dbar] S/N 4811, –2.7192e–7 [°C/dbar] S/N 1359, –1.8386e–7 [°C/dbar] Pressure sensitivities were not yet determined for S/N 5329 and 1525. iii. Conductivity (SBE 4) The flow-through conductivity sensing element is a glass tube (cell) with three platinum electrodes to provide in-situ measurements at depths up to 10500 (6800) m by titanium (aluminum) housing. The SBE 4 has a nominal accuracy of 0.0003 S/m, typical stability of 0.0003 S/m/month, and resolution of 0.00004 S/ m at 24 samples per second. The conductivity cells have been replaced to newer style cells for deep ocean measurements. Pre-cruise sensor calibrations were performed at SBE, Inc. S/N 2854, 1 June 2011 S/N 3036, 1 June 2011 S/N 1203, 25 May 2011 S/N 2435, 2 March 2011 The value of conductivity at salinity of 35, temperature of 15 °C (IPTS-68) and pressure of 0 dbar is 4.2914 S/m. iv. Oxygen (SBE 43) The SBE 43 oxygen sensor uses a Clark polarographic element to provide in- situ measurements at depths up to 7000 m. The range for dissolved oxygen is 120 %of surface saturation in all natural waters, nominal accuracy is 2 %of saturation, and typical stability is 2 %per 1000 hours. Pre-cruise sensor calibration was performed at SBE, Inc. S/N 0394, 25 October 2011 S/N 0205, 27 May 2011 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 September 2002 S/N 0022, 4 March 2009 Then the SBE 35 is certified by measurements in thermodynamic fixed-point cells of the TPW (0.01 °C) and GaMP (29.7646 °C). The slow time drift of the SBE 35 is adjusted by periodic recertification corrections. Precruise sensor calibration was performed at SBE, Inc. S/N 0045, 10 February 2011 (slope and offset correction) S/N 0022, 23 January 2011 (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. From the end of 2011, the SBE has been applying a NIST correction to the fixed-point cells used for the calibration. The offset values were estimated for the above fixed-point cells as 140 μK (TPW) and 89 μK (GaMP) for the S/N 0045 and 120 μK (TPW) and 89 μK (GaMP) for the S/N 0022, and the following NIST corrected coefficients were used in this cruise. S/N 0045: Slope = 1.000030, Offset = –0.001513 S/N 0022: Slope = 1.000010, Offset = –0.000116 vi. Altimeter Benthos PSA-916T Sonar Altimeter (Teledyne Benthos, Inc.) determines the distance of the target from the unit by generating a narrow beam acoustic pulse and measuring the travel time for the pulse to bounce back from the target surface. It is rated for operation in water depths up to 10000 m. The PSA-916T uses the nominal speed of sound of 1500 m/s. vii. Oxygen optode (RINKO) RINKO (JFE Alec Co., Ltd.) is based on the ability of selected substances to act as dynamic fluorescence quenchers. RINKO model III is designed to use with a CTD system which accept an auxiliary analog sensor, and is designed to operate down to 7000 m. Outputs from RINKO are the raw phase shift data. The RINKO can be calibrated by the Stern-Volmer equation, according to a method by Uchida et al. (2010): O2 (μmol/l) = [(V0 / V) – 1] / Ksv where V is voltage, V0 is voltage in the absence of oxygen and Ksv is Stern- Volmer constant. The V0 and the Ksv are assumed to be functions of temperature as follows. Ksv = C0 + C1 x T + 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 accurate temperature data from the CTD temperature sensor instead of temperature data from the RINKO. The pressure- compensated oxygen concentration O2c can be calculated as follows. 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 salinitycompensated oxygen can be calculated by multiplying the factor of the effect of salt on the oxygen solubility (García and Gordon, 1992). García and Gordon (1992) have recommended the use of the solubility coefficients derived from the data of Benson and Krause. Pre-cruise sensor calibrations were performed at RIGC/JAMSTEC. S/N 0024, 20 June 2011 S/N 0079, 6 December 2011 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. Transmittance (Tr) is related to the beam attenuation coefficient c by the relationship: Tr = e–cx x = 0.25 m (S/N CST-136DR) where x is the pathlength through the water volume. x. PAR Satlantic’s Photosynthetically Active Radiation (PAR) sensors provide highly accurate measurements of PAR (400 – 700 nm) for a wide range of aquatic and terrestrial applications. The ideal spectral response for a PAR sensor is one that gives equal emphasis to all photons between 400 – 700 nm. Satlantic PAR sensors use a high quality filtered silicon photodiode to provide a near equal spectral response across the entire wavelength range of the measurement. Pre-cruise sensor calibration was performed at Satlantic, LP. 22 January 2009 (5) Data collection and processing i. Data collection CTD system was powered on at least 20 minutes in advance of the data acquisition to stabilize the pressure sensor and was powered off at least two minutes after the operation in order to acquire pressure data on the ship’s deck. The pressure windows of the transmissometer were wiped with Kimwipes wetted with ethanol before each CTD cast to clean the windows. 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 (or 20 seconds from station P10_78_1 to save time) 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 (or 12-bottles) SBE 32 Carousel Water Sampler with 12-litre Niskin-X bottles. Before a cast taken water for CFCs, the bottle frame and Niskin-X bottles were wiped with acetone. Data acquisition software SEASAVE-Win32, version 7.18c ii. Data collection problems (a) Miss trip and miss fire Niskin bottles did not trip correctly at the following stations. Miss trip Miss fire P10_46_1, #11 P10N_106_2, #31 (b) Detaching the fluorometer, transmissometer and LADCP At station P10_74_2 and P10N_77_2, the fluorometer, transmissometer and LADCP were detached from the CTD system, because the maximum depth of the CTD cast exceeded the pressure capacity of the sensors. (c) Cancellation of CTD casts At station P10_67_1, the CTD cast was cancelled at 236 dbar of down cast, because the ship maneuvering equipment was on the blink. At station P10N_84_1, the CTD cast was cancelled at 5073 dbar of down cast because of rough weather. (d) Bottle firing without stops At following stations, the Niskin bottles were fired without stop of the CTD package because of rough weather. P10N_83_1: bottles #24~36 P10N_87_1: bottles #14~27, #29~36 iii. Data processing SEASOFT consists of modular menu driven routines for acquisition, display, processing, and archiving of oceanographic data acquired with SBE equipment. Raw data are acquired from instruments and are stored as unmodified data. The conversion module DATCNV uses instrument configuration and calibration coefficients to create a converted engineering unit data file that is operated on by all SEASOFT post processing modules. The following are the SEASOFT and original software data processing module sequence and specifications used in the reduction of CTD data in this cruise. Data processing software SBEDataProcessing-Win32, version 7.21d 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. When the bottle was fired without bottle firing stop, the duration was set to 1.0 second and the offset was set to 0.0 second, and a quality flag of 4 (bad) was set to the SBE 35 data. The hysteresis correction for the SBE 43 data (voltage) was applied for both profile and bottle information data. TCORP (original module, version 1.1) corrected the pressure sensitivity of the SBE 3 for both profile and bottle information data. RINKOCOR (original module, version 1.0) corrected the time-dependent, pressure-induced effect (hysteresis) of the RINKO for both profile data. RINKOCORROS (original module, version 1.0) corrected the time-dependent, pressure-induced effect (hysteresis) of the RINKO for bottle information data by using the hysteresis-corrected profile data. BOTTLESUM created a summary of the bottle data. The data were averaged over 4.4 seconds (or 1 second for the bottle fired without stop). ALIGNCTD converted the time-sequence of sensor outputs into the pressure sequence to ensure that all calculations were made using measurements from the same parcel of water. For a SBE 9plus CTD with the ducted temperature and conductivity sensors and a 3000-rpm pump, the typical net advance of the conductivity relative to the temperature is 0.073 seconds. So, the SBE 11plus deck unit was set to advance the primary and the secondary conductivity for 1.73 scans (1.75/24 = 0.073 seconds). Oxygen data are also systematically delayed with respect to depth mainly because of the long time constant of the oxygen sensor and of an additional delay from the transit time of water in the pumped plumbing line. This delay was compensated by 6 seconds advancing the SBE 43 oxygen sensor output (voltage) relative to the temperature data. Delay of the RINKO data was also compensated by 1 second advancing sensor output (voltage) relative to the temperature data. Delay of the transmissometer data was also compensated by 2 seconds advancing sensor output (voltage) relative to the temperature data. WILDEDIT marked extreme outliers in the data files. The first pass of WILDEDIT obtained an accurate estimate of the true standard deviation of the data. The data were read in blocks of 1000 scans. Data greater than 10 standard deviations were flagged. The second pass computed a standard deviation over the same 1000 scans excluding the flagged values. Values greater than 20 standard deviations were marked bad. This process was applied to pressure, temperature, conductivity 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, and RINKO output. DERIVE was used to compute oxygen (SBE 43). BINAVG averaged the data into 1-dbar pressure bins. The center value of the first bin was set equal to the bin size. The bin minimum and maximum values are the center value plus and minus half the bin size. Scans with pressures greater than the minimum and less than or equal to the maximum were averaged. Scans were interpolated so that a data record exist every dbar. DERIVE was re-used to compute salinity, potential temperature, and density (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 to check the pressure sensor time drift. The atmospheric pressure was measured at the captain deck (20 m high from the base line) and subsampled one-minute interval as a meteorological data. Time series of the CTD deck pressure is shown in Fig. 3.1.1. The CTD pressure sensor offset was estimated from the deck pressure. Mean of the pre- and the postcasts data over the whole period gave an estimation of the pressure sensor offset (0.25 dbar for S/N 1027 and –0.47 dbar for S/N 0786) from the pre-cruise calibration. The post-cruise correction of the pressure data is not deemed necessary for the pressure sensor. 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 in August 2013. S/N 0045, 15 April 2012 (2nd step: fixed point calibration) Slope = 1.000029 Offset = –0.001423 S/N 0022, 12 March 2012 (2nd step: fixed point calibration) Slope = 1.000012 Offset = –0.000023 Offset of the SBE 35 data from the pre-calibration was estimated to be smaller than 0.1 mK for temperature smaller than 4.5°C. So the post-cruise correction of the SBE 35 temperature data was not deemed necessary for the SBE 35. The CTD temperature was 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 950 dbar. The primary temperature data were used for the post-cruise calibration. The calibration coefficients are listed in Table 3.1.1. The results of the post- cruise calibration for the CTD temperature are summarized in Table 3.1.2 and shown in Fig. 3.1.2. Fig. 3.1.1: Time series of the CTD deck pressure. Atmospheric pressure deviation (magenta dots) from a standard atmospheric pressure was subtracted from the CTD deck pressure. Blue and green dots indicate pre- and post-cast deck pressures, respectively. Red dots indicate averages of the pre- and the post-cast deck pressures. Table 3.1.1: Calibration coefficients for the CTD temperature sensors. Leg Serial number c0 (°C/dbar) c1 (°C/day) c2 (°C) --- ------------- ------------ ----------- ------- 2 4815 –2.68889e–8 2.87072e–5 –0.0071 3 4815 –4.08124e–8 9.57543e–6 –0.0025 3 1359 1.13346e–7 0.0004 Table 3.1.2: Difference between the CTD temperature and the SBE 35 after the post-cruise calibration. Mean and standard deviation (Sdev) are calculated for the data below and above 950 dbar. Number of data used is also shown. Leg Serial number Pressure ≥ 950 dbar Pressure < 950 dbar ------------------- ------------------- Number Mean Sdev Number Mean Sdev (mK) (mK) (mK) (mK) --- ------------- ------ ---- ---- ------ ---- ---- 2 4815 647 0.0 0.2 1286 –0.6 7.0 3 4815 631 –0.0 0.2 1060 0.1 7.6 3 1359 36 –0.0 0.1 Fig. 3.1.2: Difference between the CTD temperature (primary) 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. 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 23 December 2011 and c0, c1, c2, c3 and c4 are calibration coefficients. The best fit sets of coefficients were determined by a least square technique to minimize the deviation from the conductivity calculated from the bottle salinity data. The primary conductivity data created by the software module ROSSUM were basically used after the postcruise calibration for the temperature data. The secondary conductivity sensor was also calibrated and used instead of the primary conductivity data when the data quality of the primary temperature or conductivity data was bad. The coefficients were determined for each leg. The calibration coefficients are listed in Table 3.1.3. The results of the post- cruise calibration for the CTD salinity are summarized in Table 3.1.4 and shown in Fig. 3.1.3. Table 3.1.3: Calibration coefficients for the CTD conductivity sensors. Leg Serial c0 c1 c2 c3 c4 Number [S/(m dbar)] (1/dbar) [S/(m day)] (S/m) --- ------ -------- ------------ ----------- ----------- ----------- 2 2854 0.999999 1.52141e–7 –5.00025e–8 3.69363e–6 2.68130e–4 3 2854 0.999969 –1.92594e–7 5.97695e–8 –1.20584e–6 4.13868e–4 3 120 1.00070 –1.03014e–6 2.97097e–7 –1.93434e–3 Table 3.1.4: Difference between the CTD salinity and the bottle salinity after the post-cruise calibration. Mean and standard deviation (Sdev) (in 10–3) are calculated for the data below and above 950 dbar. Number of data used is also shown. Leg Serial Pressure ≥ 950 dbar Pressure < 950 dbar number ------------------- ------------------- Number Mean Sdev Number Mean Sdev --- ------ ------ ---- ---- ------ ---- ---- 2 2854 939 –0.0 0.6 748 0.0 4.7 3 2854 845 0.0 0.4 549 –0.0 2.8 3 1203 39 0.0 0.3 Fig. 3.1.3: Difference between the CTD salinity (primary) 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. iv. Oxygen The RINKO oxygen optodes (S/N 0024 and S/N 0037) were calibrated and used as the CTD oxygen data, since the RINKO has a fast time response. The pressure- hysteresis corrected RINKO data was calibrated by the Stern-Volmer equation, basically according to a method by Uchida et al. (2010): [O2] (μmol/l) = [(V0 / V) – 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 working time (in days) of the RINKO sensor integrated from the first CTD cast for each leg. Time drift of the RINKO output was corrected. The pressure-compensated oxygen concentration O2c was calculated as follows. O2c = O2 (1 + Cpp / 1000)1/3 where p is CTD pressure (dbar) and Cp is the compensation coefficient. The calibration coefficients were determined by minimizing the sum of absolute deviation with a weight from the bottle oxygen data. The revised quasi-Newton method (DMINF1) was used to determine the sets. The post-cruise calibrated temperature and salinity data were used for the calibration. The calibration coefficients are listed in Table 3.1.5. The results of the post-cruise calibration for the RINKO oxygen are summarized in Table 3.1.6 and shown in Fig. 3.1.4. Table 3.1.5: Calibration coefficients for the RINKO oxygen sensors. Leg Serial number c0 c1 c2 c3 c4 --- ------------- ---------- ---------- ----------- ----------- --------- 2 0024 3.89290e–3 1.52171e–4 1.93156e–6 –5.08841e–4 –0.117182 3 0024 4.11419e–3 1.64439e–4 2.93308e–6 4.45790e–4 –0.140317 3 0037 3.04531e–3 1.09824e–3 –3.46770e–4 7.63642e–3 –0.146284 Table 3.1.5: Continue. Leg Serial number c5 c6 c7 Cp --- ------------- -------- ----------- ---------- ---- 2 0024 0.336087 5.16436e–5 2.38398e–4 0.05 3 0024 0.342439 –2.97398e–4 1.80689e–4 0.05 3 0037 0.325744 0.05 Table 3.1.6: Difference between the RINKO oxygen and the bottle ooxygen after the post-cruise calibration. Mean and standard deviation (Sdev) are calculated for the data below and above 950 dbar. Number of data used is also shown. Leg Serial number Pressure ≥ 950 dbar Pressure < 950 dbar Number Mean Sdev Number Mean Sdev [μmol/kg] [μmol/kg] --- ------------- ------ ---- ---- ------ ---- ---- 2 0024 890 0.00 0.23 753 0.03 0.47 3 0024 851 0.01 0.28 550 –0.09 0.81 3 0037 39 –0.03 0.27 Fig. 3.1.4: Difference between the calibrated CTD oxygen and the bottle oxygen. Lower two panels show histogram of the difference. v. Fluorometer The CTD fluorometer (Fl in μg/L) was calibrated with the bottle sampled chlorophyll-a (Chla) as Fl = c0 + c1 x Chla where c0 and c1 are calibration coefficients. The CTD fluorometer data is slightly noisy so that the up cast profile data which was averaged over one decibar agree with the bottle sampled data better than the discrete CTD fluorometer data obtained at bottle-firing stop. Therefore, the CTD fluorometer data at water sampling depths extracted from the up cast profile data were compared with the bottle sampled chlorophyll-a data (Fig. 3.1.5) and the calibration coefficients are listed in Table 3.1.7. Fig. 3.1.5: Comparison of the CTD fluorometer and the bottle sampled chlorophyll-a. The solid line is the regression line. Table 3.1.7. Calibration coefficients for the CTD fluorometer. c0 c1 Standard deviation from the regression line ------ ------ --------------------------- –0.039 0.9218 0.05 μg/L vi. Transmissometer The transmissometer is calibrated as Tr = (V–Vd) / (Vr–Vd) where V is the measured signal (voltage), Vd is the dark offset for the instrument, and Vr is the signal for clear water. Vd can be obtained by blocking the light path. Vd was measured on deck before each cast and estimated to be 0.0012 during the cruise. Vr is estimated from the measured signal in the deep ocean, although the transmittance tended to decrease when the water depth was shallow (Fig. 3.1.6). Since the transmissometer drifted in time, Vr is expressed as Vr = 4.84280 – 6.73551e–3xt + 1.78673e–4xt2 where t is working time (in days) of the transmissometer. vii. PAR The PAR sensor was calibrated with an offset correction. The offset was estimated from the data measured in the deep ocean during the cruise. The corrected data (PARc) is calculated from the raw data (PAR) as follows: PARc [μE m–2 s–1] = PAR – 0.046. Fig. 3.1.6: Time series of an output signal (voltage) from transmissometer at on deck before CTD casts (Vair) and deep ocean (Vdeep). The solid line indicates the modeled signal in the deep clear ocean. (7) Combining of CTD profiles Two sets of SBE 911plus CTD system with 36 and 12-position SBE 32 were used at three CTD stations (Table 3.1.8). The 12-position CWS CTD system (set 2) can be accurately calibrated with water sampled data for the depths deeper than about 3000 dbar. Therefore, the CTD profiles obtained at these casts were combined to obtain a calibrated CTD profile from surface to bottom. The data between the shallow and deep profiles were linearly interpolated for 100 dbar from the maximum depth of the shallow profile to the top of the deep profile used to combine (Fig. 3.1.7). Table 3.1.8: List of deep double casts of CTD in leg 3. Set 1 is 36-position CWS system and set 2 is 12-position CWS system. Station no. Cast no. Set of CTD system Water sampling depth ----------- -------- ----------------- -------------------- P10N 90 2 2 3170 dbar – bottom 3 1 Surface – 2930 dbar P10N 92 1 2 3250 dbar – bottom 3 1 Surface – 2999 dbar P10N 94 1 2 3332 dbar – bottom 3 1 Surface – 3082 dbar Fig. 3.1.7: Combined CTD profiles of stations P10N 90_3, 92_3, and 94_3. References Edwards, B., D. Murphy, C. Janzen and N. Larson (2010): Calibration, response, and hysteresis in deep-sea dissolved oxygen measurements, J. Atmos. Oceanic Technol., 27, 920–931. Fukasawa, M., T. Kawano and H. Uchida (2004): Blue Earth Global Expedition collects CTD data aboard Mirai, BEAGLE 2003 conducted using a Dynacon CTD traction winch and motion-compensated crane, Sea Technology, 45, 14–18. García, H. E. and L. I. Gordon (1992): Oxygen solubility in seawater: Better fitting equations. Limnol. Oceanogr., 37 (6), 1307–1312. Uchida, H., G. C. Johnson, and K. E. McTaggart (2010): CTD oxygen sensor calibration procedures, The GOSHIP Repeat Hydrography Manual: A collection of expert reports and guidelines, IOCCP Rep., No. 14, ICPO Pub. Ser. No. 134. Uchida, H., K. Ohyama, S. Ozawa, and M. Fukasawa (2007): In situ calibration of the Sea-Bird 9plus CTD thermometer, J. Atmos. Oceanic Technol., 24, 1961–1967. 3.2 Bottle Salinity May 10, 2012 (1) Personnel Hiroshi Uchida (JAMSTEC) Fujio Kobayashi (MWJ) (Leg 2) Tatsuya Tanaka (MWJ) (Leg 3) Hiroki Ushiromura (MWJ) (Leg 2) Tamami Ueno (MWJ) (Leg 3) (2) Objectives Bottle salinities were measured to calibrate CTD salinity data. (3) Instrument and Method Salinity measurement was conducted basically based on a method by Kawano (2010). i. Salinity Sample Collection Samples for salinity measurement were collected and stored in 250-mL brown borosilicate glass bottles with GL32 screw caps with PTFE liners (without cones). Each bottle and cap was rinsed three times with sample water, and the water was allowed to overflow the bottle. Excess water was poured out until the water was level with the shoulder of the bottle. The bottles were stored at least 12 hours in a laboratory where the salinity was to be measured for temperature equilibration with upside down in a carrying case. ii. Instruments and Method Salinity of water samples was measured with two salinometers (Autosal model 8400B; Guildline Instruments Ltd., Ontario, Canada; serial no. 62556 for leg 2 and serial no. 62827 for leg 3), which was modified by adding an peristaltic-type intake pump (Ocean Scientific International Ltd., Hampshire, UK) and two platinum thermometers (Guildline Instruments Ltd., model 9450). One thermometer monitored an ambient temperature and the other monitored a salinometer’s bath temperature. The resolution of the thermometers was 0.001 °C. The measurement system was almost same as Aoyama et al. (2002). The salinometer was operated in the air-conditioned laboratory of the ship at a bath temperature of 24 °C. The ambient temperature varied from approximately 20 to 24 °C, while the bath temperature was stable and varied within ±0.002 °C. A measure of a double conductivity ratio of a sample was taken as a median of 31 readings. Data collection was started after 10 seconds and it took about 10 seconds to collect 31 readings by a personal computer. Data were sampled for the sixth and seventh filling of the cell. In case where the difference between the double conductivity ratio of this two fillings was smaller than 0.00002, the average value of the two double conductivity ratios was used to calculate the bottle salinity with the algorithm for practical salinity scale, 1978 (UNESCO, 1981). When the difference was grater than or equal to the 0.00003, we measured another additional filling of the cell. In case where the double conductivity ratio of the additional filling did not satisfy the criteria above, we measured other additional fillings of the cell within 10 fillings in total. In case where the number of fillings was 10 and those fillings did not satisfy the criteria above, the median of the double conductivity ratios of five fillings were used to calculate the bottle salinity. The measurement was conducted about from 6 to 23 hours per day and the cell was cleaned with soap after the measurement for each day. A total of about 4,000 sea water samples were measured during the cruise. (4) Results i. Standard Seawater Standardization control was set to 796 (leg 2) and 482 (leg 3). The value of STANDBY was 5602 ± 0002 (leg 2) and 5408 ± 0.002 (leg 3), and that of ZERO was 0.00000 ± 0.00001 for both legs. We used IAPSO Standard Seawater (Ocean Scientific International Ltd., Havant, UK) batch P153 whose conductivity ratio was 0.99979 (double conductivity ratio is 1.99958) as the standard for salinity measurement. We measured 90 (leg 2) and 85 (leg 3) bottles of the Standard Seawater during routine measurement. Figs. 3.2.1 and 3.2.2 show the history of the measured double conductivity ratio of the Standard Seawater during legs 2 and 3. For leg 2, the salinometer was not stable. Therefore, an offset of the measurements was estimated by averaging the measured double conductivity ratio of the Standard Seawater for each day. The estimated offset was subtracted from the measured double conductivity ratio of the sample. After the offset correction, the average of the double conductivity ratio of the Standard Seawater became 1.99958 and the standard deviation was 0.00002, which is equivalent to 0.0003 in salinity. For leg 3, the salinometer was slightly drifted in time. Therefore, a linear trend of the measurements was estimated by fitting the measured double conductivity ratio of the Standard Seawater for whole period. The estimated linear trend was subtracted from the measured double conductivity ratio of the sample. After the correction, the average of the double conductivity ratio of the Standard Seawater became 1.99958 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 μm and stored in a 20 liter cubitainer made of polyethylene and stirred for at least 24 hours before measurement. It was measured every 6 water samples in order to check the possible sudden drift of the salinometer. In this cruise, no remarkable sudden drift was detected for the salinometers. iii. Replicate Samples We took 323 (leg 2) and 245 (leg 3) pairs of replicate samples during the cruise. Histograms of the absolute difference between replicate samples are shown in Figs. 3.2.3 and 3.2.4. The root-mean squares of the absolute difference of replicate samples were 0.00035 (leg 2) and 0.00017 (leg 3). Figure 3.2.1: History of measured double conductivity ratio of the Standard Seawater (P153) during leg 2. Horizontal and vertical axes represents date and double conductivity ratio, respectively. Red dots are raw data and blue dots are corrected data. Figure 3.2.2: Same as Fig. 3.2.1, but for leg 3. Figure 3.2.3: Histogram of the absolute difference between replicate samples for leg 2. Horizontal axis is absolute difference in salinity and vertical axis is frequency. Figure 3.2.4: Same as Fig. 3.2.3, but for leg 3. References Aoyama, M., T. Joyce, T. Kawano and Y. Takatsuki (2002): Standard seawater comparison up to P129. Deep-Sea Research, I, 49, 1103–1114. Kawano, T. (2010): Method for salinity (conductivity ratio) measurement. The GO-SHIP Repeat Hydrography Manual: A Collection of Expert Reports and Guidelines, IOCCP Rep. 14, ICPO Publication series 134, Version 1. UNESCO (1981): Tenth report of the Joint Panel on Oceanographic Tables and Standards. UNESCO Tech. Papers in Mar. Sci., 36, 25 pp. 3.3 Density February 13, 2014 (1) Personnel Hiroshi Uchida (JAMSTEC) (2) Objectives The objective of this study is to collect absolute salinity (also called “density salinity”) data, and to evaluate an algorithm to estimate absolute salinity provided along with TEOS-10 (the International Thermodynamic Equation of Seawater 2010) (IOC et al., 2010). (3) Materials and methods Seawater densities were measured during the cruise and a part of the seawater samples were measured in a laboratory in the Japan Agency for Marine-Earth Science and Technology, Yokosuka, Japan, after the cruise with an oscillation-type density meter (DMA 5000M, serial no. 80570578, Anton-Paar GmbH, Graz, Austria) with a sample changer (Xsample 122, serial no. 80548492, Anton-Paar GmbH). The sample changer was used to load samples automatically from up to ninety-six 12-mL glass vials. AC power was supplied to the density meter through a frequency conversion AC power supply unit (AA500F, Takasago, Ltd., Japan). The water samples were collected in 100-mL PFA bottles (Sanplatec Co., Japan), 100-mL or 50-mL I-BOY polypropylene bottles (AS ONE, Co., Japan), and vacuum sealed with an aluminum bag (HRS, MAL or ALH, Meiwa Sanshou Co., Ltd, Japan). Densities of the samples were measured at 20 ºC by the density meter from two to six times for each bottle. The glass vial was sealed with Parafilm M (Pechiney Plastic Packaging, Inc., Menasha, Wisconsin, USA) until the density was measured. Time drift of the density meter was monitored by periodically measuring the density of ultra-pure water (Milli-Q water, Millipore, Billerica, Massachusetts, USA) prepared from Yokosuka (Japan) tap water in July 2010. The true density (ρPW) at 20 ºC of the Milli-Q water was estimated to be 998.2041 kg/m3 from the isotopic composition (δD = –9.08 ‰, δ18O = –58.8 ‰) and International Association for the Properties of Water and Steam (IAPWS)- 95 standard. An offset correction was applied to the measured density by using the Milli-Q water measurements (ρMilli-Q) with a slight modification of the density dependency (Uchida et al., 2011). The offset (ρoffset) of the measured density (ρ) was estimated from the following equation: ρoffset = (ρMilli-Q – ρPW) – (ρ – ρPW) x 0.000241 [kg/m3]. The offset correction was verified by measuring Reference Material for Nutrients in Seawater (RMNS) lot BF (Kanso Technos Co., Ltd., Osaka, Japan) along with the Milli-Q water. Reference Material for Density in Seawater (prototype Dn-RM1) developed with Marine Works Japan, Ltd., Kanagawa, Japan, and produced by Kanso Technos Co., Ltd., Osaka, Japan, was also measured at post-cruise measurements. The Dn-RM1 was similarly produced with the RMNS. Material of the bottle is not polypropylene but PFA, and vacuumed sealed aluminum bag (MAL) is not single but double. Density salinity can be back calculated from measured density and temperature (20 ºC) with TEOS-10. The water samples collected at stations 56, 53, 49, 45, 41, 37, 34, 31, 27, 1, 5, and 10 were vacuum sealed with the HRS aluminum bag and measured within a few days after the collection. The rest of water samples were vacuum sealed with the HRS or ALH aluminum bag and stored in a refrigerator to measure in the laboratory after the cruise since the density meter was broken during the cruise. (4) Results List of the series of density measurement was shown in Table 3.3.1. The water samples for station 68 (#2, 5, 8, 15, 16, 22, 24, 25, and 30), 71 (#6, 10, 16, and 29), 90 (#2, 5-12, 23, 24, 27, 29, 31, 32, and 36), 92 (#8-12), and 110 (#10, 12, 13, 16, 17_2, 19, 23, and 28-32) were not measured because the aluminum bags were torn during their storage. For the series of measurement at April 5, 2012, the density meter was largely drifted in time between the first and the last measurement of Milli-Q water (about 16 hours). In addition, magnitude of the drift was different for the Milli-Q water (+0.008 kg/m3) and the RMNS (+0.018 kg/m3). Therefore, linear time drift and offset for the sea water measurement was estimated from the result of the RMNS measurement. Density of the RMNS was adjusted to 1024.4826 kg/m3 to match with the overall mean density of the RMNS (Table 3.3.1). The measured density of the RMNS was smaller than twice the standard deviation from the mean for the series of measurement at January 5 and April 6, 2012. Therefore, offset for the sea water measurement was estimated from the RMNS measurement. Mean density of the RMNS at the series of measurement was adjusted to 1024.4826 kg/m3 to match with the overall mean density of the RMNS (Table 3.3.1). The estimated offsets were +0.0041 and +0.0043 kg/m3 for the series of measurements at January 5 and April 6, respectively. To check those time drift and offset corrections by using the RMNS measurements, measured densities of the Dn-RM1 were compared (Table 3.3.2). The measured densities agreed well with each other. A total of 26 pairs of replicate samples were measured. The root-mean square of the absolute difference of replicate samples was 0.0011 g/kg. The measured density salinity anomalies (δSA) are shown in Fig. 3.3.1. The measured δSA well agree with calculated δSA from Pawlowicz et al. (2011) which exploits the correlation between δSA and nutrient concentrations and carbonate system parameters based on mathematical investigation using a model relating composition, conductivity and density of arbitrary seawaters. Table 3.3.1: List of the series of density measurement. Date Stations (samples no.) Mean density of RMNS Note Lot BF (kg/m3) 2011/12/25 56 1024.4847 relatively large variation #15: bad (flag 4) 2011/12/26 53 1024.4849 2011/12/27 49 1024.4821 2011/12/29 45 1024.4814 #12: questionable (flag 3) 2011/12/30 41 1024.4841 2011/12/31 (1) 37 1024.4838 2011/12/31 (2) 34 1024.4840 2012/01/01 31 1024.4816 2012/01/02 27 1024.4820 relatively large variation 2012/01/04 1 1024.4799 2012/01/05 5, 10 1024.4831 frequent errors, large variation, bias correction using RMNS 2012/04/04 74, 77 (except for #6,9, 1024.4838 10,16,27,30,36) 2012/04/05 15, 21, 71 (#1,3-5,11, 1024.4827 time drift correction using RMNS 13,20-25,28,31,32,35,36), 77 (#6,9,10,16,27,30,36) 2012/04/06 60 (#1,11,12,16-18,26), 1024.4829 bias correction using RMNS 110, 114 2012/04/09 90 1024.4810 2012/10/15 60 (except for #1,11,12, 1024.4823 16-18,26),64 (except for #30-33,35) 2012/10/18 102, 106 1024.4833 2012/10/25 (1) 64 (#30-33,35), 68 1024.4836 2012/10/25 (2) 71, 79 (#1-16) 1024.4815 2012/10/26 (1) 79 (except for #1-16),83 1024.4825 (except for #23,25) 2012/10/26 (2) 83 (#23,25), 86, 92 1024.4817 2012/10/28 94 1024.4837 2012/10/30 98 1024.4831 Average: 1024.4827 ± 0.0016 Table 3.3.2: Comparison of density measurement for the Reference Material for Density in Seawater (prototype Dn-RM1). Date Serial no. Density [kg/m3] Note ---------- ---------- --------------- ----------------- 2012/04/04 050 1024.2616 2012/04/05 051 1024.2612 drift correction 2012/04/06 052 1024.2624 offset correction 2012/04/09 053 1024.2590 Average: 1024.2611 ± 0.0015 Figure 3.3.1: Vertical distribution of density salinity anomaly measured by the density meter. Absolute Salinity anomaly estimated from nutrients and carbonate parameters (Pawlowicz et al., 2011) are also shown for comparison. Acknowledgment The author thank Tamami Ueno (MWJ) for helping density measurement of station 83 (#23,25) and 86. References IOC, SCOR and IAPSO (2010): The international thermodynamic equation of seawater – 2010: Calculation and use of thermodynamic properties. Intergovernmental Oceanographic Commission, Manuals and Guides No. 56, United Nations Educational, Scientific and Cultural Organization (English), 196 pp. Pawlowicz, R., D. G. Wright and F. J. Millero (2011): The effects of biogeochemical processes on ocean conductivity/salinity/density relationships and the characterization of real seawater. Ocean Science, 7, 363– 387. Uchida, H., T. Kawano, M. Aoyama and A. Murata (2011): Absolute salinity measurements of standard seawaters for conductivity and nutrients. La mer, 49, 237–244. 3.4 Oxygen September 27, 2013 (1) Personnel Yuichiro Kumamoto (Japan Agency for Marine-Earth Science and Technology) Miyo Ikeda (Marine Works Japan Co. Ltd) Misato Kuwahara (Marine Works Japan Co. Ltd) Shin’ichiro Yokogawa (Marine Works Japan Co. Ltd) Kanako Yoshida (Marine Works Japan Co. Ltd) Yuki Miyajima (Marine Works Japan Co. Ltd) (2) Objectives Dissolved oxygen is one of good tracers for the ocean circulation. Recent studies indicated that 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 MR11-08 cruise, we measured dissolved oxygen concentration from surface to bottom layers at all the hydrocast stations along approximately 149ºE in the western Pacific. These stations reoccupied the WOCE Hydrographic Program P10 and P10N stations in 1993 and 2005. Our purpose is to evaluate temporal change in dissolved oxygen concentration in the western Pacific between the 1993/2005 and 2011/12. (3) Reagents Pickling Reagent I: Manganous chloride solution (3M) Pickling Reagent II: Sodium hydroxide (8M) / sodium iodide solution (4M) Sulfuric acid solution (5M) Sodium thiosulfate (0.025M) Potassium iodate (0.001667M): Wako Pure Chemical Industries, Ltd., volumetric standard, reference material for iodometry, Lot No.EPR3227, Purity: 99.96 ± 0.01% CSK standard of potassium iodate: Lot EPJ3885, Wako Pure Chemical Industries Ltd., 0.0100N (4) Instruments Burette for sodium thiosulfate and potassium iodate; APB-620 and APB-510 manufactured by Kyoto Electronic Co. Ltd. / 10 cm3 of titration vessel Detector; Automatic photometric titrator, DOT-01X manufactured by Kimoto Electronic Co. Ltd. (5) Seawater sampling Following procedure is based on a determination method in the WHP Operations Manual (Dickson, 1996). Seawater samples were collected from 12-liters Niskin sampler bottles attached to a CTD-system. Seawater for bottle oxygen measurement was transferred from the Niskin sampler bottle to a volume calibrated glass flask (ca. 100 cm3). Three times volume of the flask of seawater was overflowed. Sample temperature was measured by a thermometer during the overflowing. Then two reagent solutions (Reagent I, II) of 0.5 cm3 each were added immediately into the sample flask and the stopper was inserted carefully into the flask. The sample flask was then shaken vigorously to mix the contents and to disperse the precipitate finely throughout. After the precipitate has settled at least halfway down the flask, the flask was shaken again to disperse the precipitate. The sample flasks containing pickled samples were stored in a laboratory until they were titrated. (6) Sample measurement At least two hours after the re-shaking, the pickled samples were measured on board. A magnetic stirrer bar and 1 cm3 sulfuric acid solution were added into the sample flask and stirring began. Samples were titrated by sodium thiosulfate solution whose molarity was determined by potassium iodate solution. Temperature of sodium thiosulfate during titration was recorded by a thermometer. We measured dissolved oxygen concentration using two sets of the titration apparatus, named DOT-7 and DOT-8. Dissolved oxygen concentration (μmol kg-1) was calculated by the sample temperature during the sampling, a value of bottle salinity, the flask volume, and the titrated volume of the sodium thiosulfate solution. When the bottle salinity datum is flagged to be 3 (questionable), 4 (bad), or 5 (missing), CTD salinity (primary) datum is referred in the calculation alternatively. (7) Standardization Concentration of sodium thiosulfate titrant (ca. 0.025M) was determined by potassium iodate solution. Pure potassium iodate was dried in an oven at 130ºC. 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 the volume-calibrated dispenser. Then 90 cm3 of deionized water, 1 cm3 of sulfuric acid solution, and 0.5 cm3 of pickling reagent solution II and I were added into the flask in order. Amount of titrated volume of sodium thiosulfate (usually 5 times measurements average) gave the molarity of the sodium thiosulfate titrant. Table 3.4.1 shows result of the standardization during this cruise. Error (coefficient of variation) of the standardization was 0.02 %, or c.a. 0.05 μmol kg-1. (8) Determination of the blank The oxygen in the pickling reagents I (0.5 cm3) and II (0.5 cm3) was assumed to be 3.8 x 10-8 mol (Murray et al., 1968). The blank from the presence of redox species apart from oxygen in the reagents (the pickling reagents I, II, and the sulfuric acid solution) was determined as follows. 1 and 2 cm3 of the standard potassium iodate solution were added to the flask each. Then 100 cm3 of deionized water, 1 cm3 of sulfuric acid solution, and 0.5 cm3 of pickling reagent solution II and I each were added into the two flasks in order. The blank was determined by difference between the two times of the first (1 cm3 of KIO3) titrated volume of the sodium thiosulfate and the second (2 cm3 of KIO3) one. The results of 3 times blank determinations were averaged (Table 3.4.1). The averaged blank values for DOT-7 and DOT-8 were –0.001 ± 0.002 (standard deviation, n=21) and 0.001 ± 0.001 (standard deviation, n=21) cm3, respectively. (9) Replicate sample measurement From a single routine CTD cast, a pair of replicate samples was collected at three layers of 10, 1800, and 3750 dbar. In order to estimate uncertainty including instrumental error, one and the other of a replicate pair were measured using DOT-7 and DOT-8, respectively. The total amount of the replicate sample pairs in good measurement (flagged 2) was 331. The standard deviation of the replicate measurement was 0.13 μmol kg-1 that was calculated by a procedure (SOP23) in DOE (1994). A difference between measurements of a replicate pair is slightly large in samples from low-oxygen layers (Fig. 3.4.1), which is probably due to sampling error on the deck. In the hydrographic data sheet, the first of the two results from a replicate pair was presented with the flag 2 (see section 12). (10) Duplicate sample measurement A duplicate sampling, water samplings from two Niskin bottles that collected seawater at a same depth (deeper than 1000 dbar), were conducted at 35 stations during this cruise. Niskin numbers and sampling pressure of the duplicate pairs are shown in Table 3.4.2. One and the other of a duplicate pair were measured using DOT- 7 and DOT-8 respectively in the same way of the replicate sample measurements. The standard deviation of the duplicate measurements was calculated to be 0.14 μmol kg-1 that was equivalent with that of the replicate measurements (0.13 μmol kg-1, see section 9), suggesting that there was no problem in a water sampling system during our CTD casts. (11) CSK standard measurements The CSK standard is a commercial potassium iodate solution (0.0100 N) for analysis of dissolved oxygen. We titrated the CSK standard solutions (Lot EPJ3885) against our KIO3 standards prepared in our laboratory in 2010 and 2011 (Table 3.4.3). A good agreement among them confirms that there was no systematic shift in our oxygen analyses using our KIO3 standards during 2010 and 2011. (12) Quality control flag assignment Quality flag values were assigned to oxygen measurements using the code defined in Table 0.2 of WHP Office Report WHPO 91-1 Rev.2 section 4.5.2 (Joyce et al., 1994). Measurement flags of 2 (good), 3 (questionable), 4 (bad), and 5 (missing) have been assigned (Table 3.4.4). 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 (replicate measurements). For the choice between 2, 3, or 4, we basically followed a flagging procedure as listed below: a. Bottle oxygen concentration at the sampling layer was plotted against sampling pressure. Any points not lying on a generally smooth trend were noted. b. A difference between bottle oxygen and CTD oxygen (OPTODE sensor) was then plotted against sampling pressure. If a datum deviated from a group of plots, it was flagged 3. c. Vertical sections against pressure and potential density were drawn. If a datum was anomalous on the section plots, datum flag was degraded from 2 to 3, or from 3 to 4. d. If there was problem in the measurement, the datum was flagged 4. e. If the bottle flag was 4 (did not trip correctly), a datum was flagged 4 (bad). In case of the bottle flag 3 (leaking) or 5 (unknown problem), a datum was flagged according to the steps a, b, c, and d. Table 3.4.1: Results of the standardization and the blank determinations during MR11-08. KIO3 No. DOT-7 DOT-8 ------------------ Na2S2O3 No. ------------- ------------- Stations (UTC) # ID No. E.P. blank E.P. blank ---------- -- -------------- ----------- ----- ------ ----- ------ ------------ P10-059,058, 057,056,055, 2011/12/22 05 20110523-05-02 20110602-01 3.953 -0.002 3.957 -0.001 054,053,052, 051,050,049, 048,047,046, 045 P10-044,043, 2011/12/28 05 20110523-05-01 20110602-01 3.952 -0.001 3.956 0.001 042,041,040, 039 P10-038,037, 036,035,034, 2011/12/29 05 20110523-05-07 20110602-02 3.956 -0.003 3.961 -0.001 033,032,031, 030,029,028, 027 P10-001,002, 003,004,005, 006,007,008, 2012/01/03 05 20110523-05-08 20110602-02 3.963 0.000 3.964 0.003 009,010,011, 012,013,014, 015,016,017, 018,019,020, 021,022 2012/01/07 05 20110523-05-05 20110602-03 3.959 -0.001 3.961 0.001 P10-023,024, 025,026 P10-059,060, 061,062,063, 2012/ 1/14 06 20110524-06-03 20110602-03 3.963 -0.001 3.964 0.001 064,065,066, 067,068,069, 070,071,072, 073 P10-074,P10N- 075,076,077, 078,079,080, 2012/01/19 06 20110524-06-05 20110602-04 4.075 -0.004 4.076 0.000 081,082,083, 084,085,088, 086,087,090, 092,094,096 P10N-098,100, 2012/02/01 06 20110524-06-01 20110602-05 3.957 -0.002 3.959 0.001 102,104,106, 110,112,114, 115 Figure 3.4.1: Oxygen difference between measurements of a replicate pair against oxygen concentration. Table 3.4.2: Results of the duplicate sample measurements during MR11-08. Leg Stations Pres. #1 Niskin #1 Oxygen #2 Niskin #2 Oxygen Difference (db) [μmol/kg] [μmol/kg] [(μmol/kg)2] --- -------- ----- --------- --------- --------- --------- ------------ 1 2 P10-59 5656 1 X12J01 176.21 2 X12J02 176.25 0.002 2 2 P10-58 5500 2 X12J02 174.49 3 X12J03 174.42 0.005 3 2 P10-57 5170 2 X12J02 173.25 4 X12J04 173.33 0.006 4 2 P10-56 5080 2 X12J02 172.65 5 X12J05 172.50 0.023 5 2 P10-55 4750 2 X12J02 164.09 6 X12J06 164.11 0.000 6 2 P10-54 4420 2 X12J02 164.89 7 X12J07 164.94 0.003 7 2 P10-53 4330 2 X12J02 163.54 8 X12J08 163.61 0.005 8 2 P10-52 4000 2 X12J02 155.00 9 X12J09 154.90 0.010 9 2 P10-44 3830 2 X12J02 155.70 10 X12J10 155.56 0.020 10 2 P10-43 3500 2 X12J02 149.74 11 X12J11 149.56 0.032 11 2 P10-42 3170 5 X12102 143.09 12 X12J12 143.07 0.000 12 2 P10-41 3080 2 X12103 139.96 13 X12101 140.13 0.029 13 2 P10-38 2870 4 X12104 138.17 14 X12J14 138.00 0.029 14 2 P10-37 2600 2 X12103 129.87 15 X12J15 129.92 0.002 15 2 P10-36 2330 2 X12103 119.45 16 X12J16 119.35 0.010 16 2 P10-35 2270 2 X12103 117.47 17 X12J17 116.93 0.292 17 2 P10-34 2000 2 X12103 113.64 18 X12J18 113.39 0.063 18 2 P10-33 1730 2 X12103 103.02 19 X12J19 102.90 0.014 19 2 P10-32 1670 2 X12103 101.57 20 X12001 101.45 0.014 20 2 P10-31 1400 2 X12103 96.37 21 X12J21 96.64 0.073 21 2 P10-30 1130 2 X12103 92.36 22 X12J22 92.70 0.116 22 2 P10-4 1400 2 X12103 109.34 21 X12J36 109.40 0.004 23 2 P10-5 1670 2 X12103 110.04 20 X12J35 109.89 0.023 24 2 P10-6 1730 2 X12103 109.66 19 X12J34 109.45 0.044 25 2 P10-12 1930 2 X12103 116.36 18 X12J33 116.08 0.078 26 2 P10-13 2200 2 X12103 125.37 17 X12J32 125.40 0.001 27 2 P10-15 2330 2 X12103 128.02 16 X12046 128.23 0.044 28 2 P10-16 2600 2 X12103 135.43 15 X12J30 135.42 0.000 29 2 P10-17 2870 2 X12103 139.94 14 X12J29 139.56 0.144 30 2 P10-18 2930 2 X12103 140.07 13 X12J28 139.79 0.078 31 2 P10-19 3250 2 X12103 144.23 12 X12J27 143.98 0.063 32 2 P10-21 3920 2 X12103 152.71 9 X12J25 152.57 0.020 33 2 P10-22 4500 2 X12103 156.23 7 X12J23 156.01 0.048 34 2 P10-23 4330 2 X12103 155.42 8 X12J24 155.31 0.012 35 2 P10-24 3670 2 X12103 148.59 10 X12J26 148.72 0.017 Table 3.4.3: Results of the CSK standard (Lot EPJ3885) measurements on board. Date (UTC) KIO3 ID No. DOT-7 DOT-8 Remarks Conc. (N) error (N) Conc. (N) error (N) ---------- -------------- -------- --------- --------- --------- ------------- 2011/12/22 20110523-05-02 0.010008 0.000003 0.010008 0.000007 MR11-08 Leg-2 2012/01/14 20110524-06-07 0.010009 0.000002 0.010005 0.000009 MR11-08 Leg-3 Date (UTC) KIO3 ID No. DOT-7 DOT-8 Remarks Conc. (N) error (N) Conc. (N) error (N) ---------- -------------- -------- --------- --------- --------- ------------- 2011/05/27 20100630-01-11 0.010008 0.000005 − − before cruise 2011/05/30 20110524-07-12 0.010007 0.000004 − − before cruise 2011/05/31 20110523-05-12 0.010006 0.000007 − − before cruise 2011/06/01 20110523-01-12 0.010006 0.000010 before cruise Table 3.4.4: Summary of assigned quality control flags. Flag Definition ---- -------------------- 2 Good 3080 3 Questionable 4 4 Bad 4 5 Not report (missing) 0 Total 3088 (13) Preliminary Results i. Comparison of oxygen measurements at a cross point We compared a vertical profile of oxygen concentration at a cross point (24ºN/149ºE) from this cruise with that from our past cruise (MR05-05). The first and second measurements were conducted on 30-Dec.-2005 (MR05-05_P03- X10, 24.486ºN/149.356ºE) and 17-January-2012 (MR11-08_P10-067, 24.241ºN/149.033ºE), respectively. Below layers below about 2000 dbar, the vertical profiles in 2005 and 2011 agree well within the analytical error (Fig. 3.4.2). ii. Distribution of dissolved oxygen along WHP-P10/P10N in 2011/12 Figure 3.4.3 shows that a tongue-shaped oxygen minima is lying around 500 – 1500 m depth. The highest concentration was measured in surface waters of the northernmost stations off Hokkaido. Another high-oxygen water was found in bottom waters of the north of 10ºN, which corresponds to the Circumpolar Deep Water (CDW). The basin-scale distribution of dissolved oxygen in 2011/12 well agrees with those obtained in 1993 and 2005. iii. Decadal changes in dissolved oxygen along the WHP-P10/P10N line from 2005 and 2011/12 Along the P10/P10N line, difference in dissolved oxygen concentration between 2005 and 2011/12 was large (< about 10 μmol/kg) above 1000 m depth, where the vertical gradient of dissolved oxygen is sharp. In deeper layers dissolved oxygen change less than 10 μmol/kg were also observed in some regions, implying influence of heaving and internal waves. In addition, we found 1~2 μmol/kg of oxygen decrease in near bottom waters between 10ºN and 30ºN. Figure 3.4.2: Vertical profiles of bottle oxygen concentration at a cross point (24ºN/149ºE) from MR05-05 (black circles) and MR11-08 cruises (white circles). Figure 3.4.3: Transect of bottle oxygen concentration (μmol/kg) along the cruse track of MR11-08 in the winter of 2011-2012. References Dickson, A. (1996): Determination of dissolved oxygen in sea water by Winkler titration, in WHPO Pub. 91-1 Rev. 1, November 1994, Woods Hole, Mass., USA. DOE (1994): Handbook of methods for the analysis of the various parameters of the carbon dioxide system in sea water; version 2. A.G. Dickson and C. Goyet (eds), ORNL/CDIAC-74. Joyce, T., and C. Corry, eds., C. Corry, A. Dessier, A. Dickson, T. Joyce, M. Kenny, R. Key, D. Legler, R. Millard, R. Onken, P. Saunders, M. Stalcup (1994): Requirements for WOCE Hydrographic Programme Data Reporting, WHPO Pub. 90-1 Rev. 2, May 1994 Woods Hole, Mass., USA. 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, V. Mohrholz (2008): Expanding Oxygen-Minimum Zones in the Tropical Oceans, Science, 320, 655-668. 3.5 Nutrients June 13, 2012 (ver. 2.0) (1) Personnel Michio AOYAMA (Meteorological Research Institute / Japan Meteorological Agency, Principal Investigator) LEG 2 Minoru KAMATA (Department of Marine Science, Marine Works Japan Ltd.) Kenichiro SATO (Department of Marine Science, Marine Works Japan Ltd.) Masanori ENOKI (Department of Marine Science, Marine Works Japan Ltd.) LEG 3 Minoru KAMATA (Department of Marine Science, Marine Works Japan Ltd.) Kenichiro SATO (Department of Marine Science, Marine Works Japan Ltd.) Yasuhiro ARII (Department of Marine Science, Marine Works Japan Ltd.) (2) Objectives The objectives of nutrients analyses during the R/V Mirai MR11–08 cruise, WOCE P10 revisited cruise in 2011/2012, in the western Pacific Ocean are as follows; - Describe the present status of nutrients concentration with excellent comparability. - The determinants are nitrate, nitrite, silicate and phosphate. - Study the temporal and spatial variation of nutrients concentration based on the previous high quality experiments data of WOCE previous P10 cruises in 1993 and 2005, GOESECS, IGY and so on. - Study of temporal and spatial variation of nitrate: phosphate ratio, so called Redfield ratio. - Obtain more accurate estimation of total amount of nitrate, silicate and phosphate in the interested area. - Provide more accurate nutrients data for physical oceanographers to use as tracers of water mass movement. (3) Summary of nutrients analysis We made 95 QuAAtro 2-HR runs for the samples at 101 stations in MR11–08. The total amount of layers of the seawater sample reached up to 3091 for MR11–08. We made duplicate measurement at all layers. (4) Instrument and Method (4.1) Analytical detail using QuAAtro 2-HR systems (BL-Tech) Nitrate + nitrite and nitrite were analyzed according to the modification method of Grasshoff (1970). The sample nitrate was reduced to nitrite in a cadmium tube inside of which was coated with metallic copper. The sample streamed with its equivalent nitrite was treated with an acidic, sulfanilamide reagent and the nitrite forms nitrous acid which reacted with the sulfanilamide to produce a diazonium ion. N-1-Naphthylethylene-diamine added to the sample stream then coupled with the diazonium ion to produce a red, azo dye. With reduction of the nitrate to nitrite, both nitrate and nitrite reacted and were measured; without reduction, only nitrite reacted. Thus, for the nitrite analysis, no reduction was performed and the alkaline buffer was not necessary. Nitrate was computed by difference. The silicate method was analogous to that described for phosphate. The method used was essentially that of Grasshoff et al. (1983), wherein silicomolybdic acid was first formed from the silicate in the sample and added molybdic acid; then the silicomolybdic acid was reduced to silicomolybdous acid, or “molybdenum blue” using ascorbic acid as the reductant. The analytical methods of the nutrients, nitrate, nitrite, silicate and phosphate, during this cruise were same as the methods used in (Kawano et al. 2009). The phosphate analysis was a modification of the procedure of Murphy and Riley (1962). Molybdic acid was added to the seawater sample to form phosphomolybdic acid which was in turn reduced to phosphomolybdous acid using L-ascorbic acid as the reductant. The details of modification of analytical methods used in this cruise are also compatible with the methods described in nutrients section in GO-SHIP repeat hydrography manual (Hydes et al., 2010). The flow diagrams and reagents for each parameter are shown in Figures 3.5.1 to 3.5.4. (4.2) Nitrate Reagents Imidazole (buffer), 0.06 M (0.4 %w/v) Dissolve 4 g imidazole, C3H4N2, in ca. 1000 ml DIW; add 2 ml concentrated HCl. After mixing, 1 ml Triton(R) X-100 (50 %solution in ethanol) is added. Sulfanilamide, 0.06 M (1 %w/v) in 1.2M 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, C10H7NHCH2CH2NH2·2HCl, in 1000 ml of DIW and add 10 ml concentrated HCl. After mixing, 1 ml Triton(R)X-100 (50 %f solution in ethanol) is added. Stored in a dark bottle. Figure 3.5.1: NO3+NO2 (1ch.) Flow diagram. (4.3) Nitrite Reagents Sulfanilamide, 0.06 M (1 %w/v) in 1.2 M HCl Dissolve 10g sulfanilamide, 4-NH2C6H4SO3H, in 900 ml of DIW, add 100 ml concentrated HCl. After mixing, 2 ml Triton(R)X-100 (50 %solution in ethanol) is added. N-1-Napthylethylene-diamine dihydrochloride, 0.004 M (0.1 %w/v) Dissolve 1 g NEDA, C10H7NHCH2CH2NH2·2HCl, in 1000 ml of DIW and add 10 ml concentrated HCl. After mixing, 1 ml Triton(R)X-100 (50 %f solution in ethanol) is added. This reagent was stored in a dark bottle. Figure 3.5.2: NO2 (2ch.) Flow diagram. (4.4) Silicate Reagents Molybdic acid, 0.06 M (2 %w/v) Dissolve 15 g disodium Molybdate(VI) dihydrate, Na2MoO4·2H2O, in 980 ml DIW, add 8 ml concentrated H2SO4. After mixing, 20 ml sodium dodecyl sulphate (15 %solution in water) is added. Oxalic acid, 0.6 M (5 %w/v) Dissolved 50 g oxalic acid anhydrous, HOOC:COOH, in 950 ml of DIW. Ascorbic acid, 0.01M (3 %w/v) Dissolved 2.5g L (+)-ascorbic acid, C6H8O6, in 100 ml of DIW. This reagent was freshly prepared before every measurement. Figure 3.5.3. SiO2 (3ch.) Flow diagram. (4.5) Phosphate Reagents Stock molybdate solution, 0.03M (0.8 %w/v) Dissolved 8 g disodium molybdate (VI) dihydrate, Na2MoO4·2H2O, and 0.17 g antimony potassium tartrate, C8H4K2O12Sb2·3H2O, in 950 ml of DIW and added 50 ml concentrated H2SO4. Mixed Reagent Dissolved 1.2 g L (+)-ascorbic acid, C6H8O6, in 150 ml of stock molybdate solution. After mixing, 3 ml sodium dodecyl sulphate (15 %solution in water) was added in leg3 of this cruise, 4mL sodium dodecyl sulphate (15 % solution in water) was added in leg2 because to reduce relatively noisy signals. This reagent was freshly prepared before every measurement. Reagent for sample dilution Dissolved sodium chloride, NaCl, 10 g in ca. 950 ml of DIW, added 50 ml acetone and 4 ml concentrated H2SO4. After mixing, 5 ml sodium dodecyl sulphate (15 %solution in water) was added. Figure 3.5.4. PO4 (4ch.) Flow diagram. (4.6) Sampling procedures Sampling of nutrients followed that oxygen, salinity and trace gases. Samples were drawn into two of virgin 10 ml polyacrylates vials without sample drawing tubes. These were rinsed three times before filling and vials were capped immediately after the drawing. The vials were put into water bath adjusted to ambient temperature, 24 ± 2 deg. C, in about 30 minutes before use to stabilize the temperature of samples in MR11–08. No transfer was made and the vials were set an auto sampler tray directly. Samples were analyzed after collection basically within 24 hours in MR11–08. (4.7) Data processing Raw data from QuAAtro 2-HR was treated as follows: - Checked baseline shift. - Checked the shape of each peak and positions of peak values taken, and then changed the positions of peak values taken if necessary. - Carry-over correction and baseline drift correction were applied to peak heights of each samples followed by sensitivity correction. - Baseline correction and sensitivity correction were done basically using liner regression. - Loaded pressure and salinity from CTD data to calculate density of seawater. - Calibration curves to get nutrients concentration were assumed second order equations. (5) Nutrients standards (5.1) Volumetric laboratory ware of in-house standards All volumetric glass ware and polymethylpentene (PMP) ware used were gravimetrically calibrated. Plastic volumetric flasks were gravimetrically calibrated at the temperature of use within 0 to 4 K. Volumetric flasks Volumetric flasks of Class quality (Class A) are used because their nominal tolerances are 0.05 %or less over the size ranges likely to be used in this work. Class A flasks are made of borosilicate glass, and the standard solutions were transferred to plastic bottles as quickly as possible after they are made up to volume and well mixed in order to prevent excessive dissolution of silicate from the glass. High quality plastic (polymethylpentene, PMP, or polypropylene) volumetric flasks were gravimetrically calibrated and used only within 0 to 4 K of the calibration temperature. The computation of volume contained by glass flasks at various temperatures other than the calibration temperatures were done by using the coefficient of linear expansion of borosilicate crown glass. Because of their larger temperature coefficients of cubical expansion and lack of tables constructed for these materials, the plastic volumetric flasks were gravimetrically calibrated over the temperature range of intended use and used at the temperature of calibration within 0 to 4 K. The weights obtained in the calibration weightings were corrected for the density of water and air buoyancy. Pipettes and pipettors All pipettes have nominal calibration tolerances of 0.1 %or better. These were gravimetrically calibrated in order to verify and improve upon this nominal tolerance. (5.2) Reagents, general considerations Specifications For nitrate standard, “potassium nitrate 99.995 suprapur®” provided by Merck, CAS No. : 7757-91-1, was used. For nitrite standard, “sodium nitrate” provided by Wako, CAS No. : 7632-00-0, was used. The assay of nitrite salts was determined according JIS K8019 were 98.31%. We use that value to adjust the weights taken. For the silicate standard, we use “Silicon standard solution SiO2 in NaOH 0.5 mol/l CertiPUR®” provided by Merck, CAS No. : 1310-73-2, of which lot number is HC097572 is used. The silicate concentration is certified by NIST-SRM3150 with the uncertainty of 0.5 %. Factor of HC097572 was signed 1.000, however we reassigned the factor as 0.976 from the result of comparison among RMNS in MR11-E02 cruise. For phosphate standard, “potassium dihydrogen phosphate anhydrous 99.995 suprapur®” provided by Merck, CAS No. : 7778-77-0, was used. Ultra pure water Ultra pure water (MilliQ water) freshly drawn was used for preparation of reagents, standard solutions and for measurement of reagent and system blanks. Low-Nutrient Seawater (LNSW) Surface water having low nutrient concentration was taken and filtered using 0.45 μm pore size membrane filter. This water is stored in 20 liter cubitainer with paper box. The concentrations of nutrient of this water were measured carefully in Jan 2011. Treatment of silicate standard due to high alkalinity Since the silicon standard solution Merck CertiPUR® is in NaOH 0.5 mol/l, we need to dilute and neutralize to avoid make precipitation of MgOH2 etc. When we make B standard, silicon standard solution is diluted by factor 12 with pure water and neutralized by HCl 1.0 mol/l to be about 7. After that B standard solution is used to prepare C standards. (5.3) Concentrations of nutrients for A, B and C standards Concentrations of nutrients for A, B and C standards are set as shown in Table 3.5.1. The C standard is prepared according recipes as shown in Table 3.5.2. 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-5 and C-6. Table 3.5.1: Nominal concentrations of nutrients for A, B and C standards. A B C-1 C-2 C-3 C-4 C-5 C-6 -------- ----- ---- --- --- --- --- --- ----- NO3(μM) 45000 900 BS BU BT BD BF 55 NO2(μM) 4000 20 BS BU BT BD BF 1.2 SiO2(μM) 36000 2880 BS BU BT BD BF 167 PO4(μM) 3000 60 BS BU BT BD BF 3.6 Table 3.5.2: Working calibration standard recipes. C Std. B-1 Std. B-2 Std. ------ -------- -------- C-6 30 ml 30 ml ---------------------------------------------------- B-1 Std.: Mixture of nitrate, silicate and phosphate B-2 Std.: Nitrite (5.4) Renewal of in-house standard solutions. In-house standard solutions as stated in (iii) were renewed as shown in Table 3.5.3(a) to (c). Table 3.5.3(a): Timing of renewal of in-house standards. NO3, NO2, SiO2, PO4 Renewal -------------------------------------- ---------------------------- A-1 Std. (NO3) maximum 1 month A-2 Std. (NO2) maximum 1 month A-3 Std. (SiO2) commercial prepared solution A-4 Std. (PO4) maximum 1 month B-1 Std. (mixture of NO3, SiO2, PO4) 8 days B-2 Std. (NO2) 8 days Table 3.5.3(b): Timing of renewal of in-house standards. Working standards Renewal -------------------------------------- ---------------------------- C-6 Std. (mixture of B-1 and B-2 Std.) 24 hours Table 3.5.3(c): Timing of renewal of in-house standards for reduction estimation. Reduction estimation Renewal -------------------------------------- ---------------------------- D-1 Std. (3600μM NO3) 8 days 43μM NO3 when C Std. renewed 47μM NO2 when C Std. renewed (6) Reference material of nutrients in seawater To get the more accurate and high quality nutrients data to achieve the objectives stated above, huge numbers of the bottles of the reference material of nutrients in seawater (hereafter RMNS) are prepared (Aoyama et al., 2006, 2007, 2008, 2009). In the previous worldwide expeditions, such as WOCE cruises, the higher reproducibility and precision of nutrients measurements were required (Joyce and Corry, 1994). Since no standards were available for the measurement of nutrients in seawater at that time, the requirements were described in term of reproducibility. The required reproducibility was 1 %, 1 to 2 %, 1 to 3 %for nitrate, phosphate and silicate, respectively. Although nutrient data from the WOCE one-time survey was of unprecedented quality and coverage due to much care in sampling and measurements, the differences of nutrients concentration at crossover points are still found among the expeditions (Aoyama and Joyce, 1996, Mordy et al., 2000, Gouretski and Jancke, 2001). For instance, the mean offset of nitrate concentration at deep waters was 0.5 μmol kg-1 for 345 crossovers at world oceans, though the maximum was 1.7 μmol kg-1 (Gouretski and Jancke, 2001). At the 31 crossover points in the Pacific WHP one-time lines, the WOCE standard of reproducibility for nitrate of 1 %was fulfilled at about half of the crossover points and the maximum difference was 7 %at deeper layers below 1.6 deg. C in potential temperature (Aoyama and Joyce, 1996). During the period from 2003 to 2010, RMNS were used to keep comparability of nutrients measurement among the 8 cruises of CLIVAR project (Sato et al., 2010) , MR10–05 cruise for Arctic research (Aoyama et al., 2010) and MR10–06 cruise for “Change in material cycles and ecosystem by the climate change and its feedback” (Aoyama et al., 2011). (6.1) RMNSs for this cruise RMNS lots BS, BU, BT, BD and BF, which cover full range of nutrients concentrations in the western Pacific Ocean are prepared. 80 sets of BS, BU, BT, BD and BF are prepared. One hundred forty bottles of RMNS lot BE are prepared for MR11–08. Lot BE was used all stations. These RMNS assignment were completely done based on random number. The RMNS bottles were stored at a room in the ship, REAGENT STORE, where the temperature was maintained around 13-24 deg. C. (6.2) Assigned concentration for RMNSs We assigned nutrients concentrations for RMNS lots BS, BU, BT, BD, BE, and BF as shown in Table 3.5.4. Table 3.5.4: Assigned concentration of RMNSs (in μmol kg-1). Nitrate Phosphate Silicate Nitrite ------- --------- -------- ------- BS* 0.07 0.064 1.61 0.02 BU* 3.97 0.379 20.30 0.07 BT* 18.21 1.320 41.00 0.47 BD* 29.86 2.194 64.39 0.05 BE** 36.70 2.662 99.20 0.03 BF*** 41.39 2.809 150.23† 0.02 -------------------------------------------------------------- * The values are assigned for this cruise on 27 July 2011. ** The values are assigned for this cruise on 4 April 2009 (Table 3.4.4 in WHP P21 REVISIT DATA BOOK). *** The values are assigned for this cruise on 10 October 2007 (Table 3.4.4 in WHP P1, P14 REVISIT DATA BOOK). † This value is changed in MR11–03 cruise. (6.3) The homogeneity of RMNSs The homogeneity of lot BE used in MR11–08 cruise and analytical precisions are shown in Table 3.5.5. These are for the assessment of the magnitude of homogeneity of the RMNS bottles those are used during the cruise. As shown in Table 3.5.5 homogeneity of RMNS lot BE for nitrate, phosphate and silicate are the same magnitude of analytical precision derived from fresh raw seawater in January 2009. Table 3.5.5: Homogeneity of lot BE derived from simultaneous 209 samples measurements and analytical precision onboard R/V Mirai in MR11–08. Nitrate Phosphate Silicate ------- --------- -------- CV % CV % CV % BE 0.17 0.28 0.17 Precision 0.12 0.20 0.14 BE: N=209 Figure 3.5.6: Time series of RMNS-BE of silicate for MR11–08. Figure 3.5.7: Time series of RMNS-BE of phosphate for MR11–08. (6.4) Comparability of RMNSs during the periods from 2003 to 2011 Cruise-to-cruise comparability has examined based on the results of the previous results of RMNSs measurements obtained among cruises, and RMNS international comparison experiments in 2003 and 2009. The uncertainties for each value were obtained similar method described in 7.1 in this chapter at the measurement before each cruise and inter-comparison study, shown as precruise and intercomparison, and mean of uncertainties during each cruise, only shown cruise code, respectively. As shown in Table 3.5.6, the nutrients concentrations of RMNSs were in good agreement among the measurements during the period from 2003 to 2011. For the silicate measurements, we show lot numbers and chemical company names of each cruise/ measurement in the footnote. As shown in Table 3.5.6, there shows less comparability among the measurements due to less comparability among the standard solutions provided by chemical companies in the silicate measurements. Table 3.5.6 (a): Comparability for nitrate (in μmol kg-1). RM Lots Cruise / Lab. ----------------------------------------------------------------------------------------------- AH unc. AZ unc. BA unc. AX unc. AV unc. BC unc. BE unc. ------------------------------------------------------------------------------------------------------------------------ Nitrate ----------------------------------------------------------------------------------------------- 2003 2003intercomp_repeorted 35.23 0.06 21.39 MR03-K04 Leg1 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 2010 SGONS stability test_2 42.46 0.05 0.10 0.00 21.51 0.02 33.52 36.76 0.02 SGONS stability test_3 42.48 0.09 21.52 33.63 36.77 2011 SGONS stability test_4 42.56 0.07 0.08 0.01 21.62 0.01 33.65 0.07 36.83 0.03 SGONS stability test_5 42.49 0.05 0.06 0.00 36.87 0.06 MR11-08_2 36.83 0.07 SGONS stability test_6 MR11-08_3 36.83 0.06 Table 3.5.6 (b). Comparability for Phosphate (in μmol kg-1). RM Lots Cruise / Lab. ----------------------------------------------------------------------------------------------- AH unc. AZ unc. BA unc. AX unc. AV unc. BC unc. BE unc. ------------------------------------------------------------------------------------------------------------------------ Phosphate ----------------------------------------------------------------------------------------------- 2003 2003intercomp 2.141 0.001 MR03-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 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 2010 SGONS stability test_2 3.012 0.008 0.059 0.001 1.618 0.004 2.520 0.008 2.663 0.006 SGONS stability test_3 3.024 0.055 1.617 2.528 2.666 2011 SGONS stability test_4 3.017 0.006 0.066 0.004 1.624 0.005 2.533 0.030 2.668 0.006 SGONS stability test_5 3.011 0.004 0.003 2.665 0.002 MR11-08_2 2.676 0.008 SGONS stability test_6 MR11-08_3 2.676 0.007 Table 3.5.6 (C). Comparability for Silicate (in μmol kg-1). RM Lots Cruise / Lab. ----------------------------------------------------------------------------------------------- AH unc. AZ unc. BA unc. AX unc. AV unc. BC unc. BE unc. ------------------------------------------------------------------------------------------------------------------------ Silcate ----------------------------------------------------------------------------------------------- 2003 2003intercomp * 130.51 0.20 MR03-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 MR07-04 $$ 1.62 0.07 58.11 0.11 154.45 0.21 156.62 0.48 MR07-06_1 precruise $$ 133.02 0.09 1.64 0.00 58.50 0.04 155.06 0.11 156.33 0.11 MR07-06_2 precruise $$ 132.70 0.07 1.56 0.00 58.25 0.03 154.39 0.08 156.57 0.08 MR07-06_1 $$ 1.61 0.04 58.13 0.08 154.48 0.13 156.64 0.08 MR07-06_2 $$ 1.58 0.07 58.04 0.10 154.38 0.16 156.61 0.13 2008 2008intercomp ¥ 1.64 0.00 58.17 0.05 2006intercomp_re ¥ 134.11 0.11 1.65 0.00 58.26 0.05 154.36 0.12 2003intercomp_re ¥ 132.11 0.11 2009 MR09-01_0 precruise ¥ 133.93 0.04 1.57 0.00 58.06 0.02 154.23 0.05 156.16 0.05 99.20 0.03 MR09-01_1 ¥ 133.97 0.11 1.34 0.11 58.15 0.08 154.48 0.09 155.89 0.13 99.24 0.08 MR09-01_2 ¥ 133.96 0.11 58.19 0.08 154.42 0.12 99.23 0.08 INSS stability 132.40 0.35 1.69 0.02 58.18 0.02 154.43 0.09 test_1 ¥¥ 2010 SGONS stability 133.89 0.12 1.58 0.02 58.15 0.04 154.43 0.21 99.20 0.07 test_2 ¥¥ SGONS stability 134.20 1.58 58.10 154.90 99.18 test_3 ¥¥ 2011 SGONS stability test_4+ 134.16 0.09 1.68 0.04 58.26 0.05 154.56 0.05 99.30 0.07 SGONS stability test_5+ 133.27 0.21 1.49 0.02 98.82 0.18 MR11-08_2++ 99.21 0.17 SGONSstability test_6++ MR11-08_3++ 99.25 0.18 ------------------------------------------------------------------------------------------------------------------------ List of lot numbers: *: Kanto 306F9235; **: Kanto 402F9041; #: Kanto 507F9205; ##: Kanto 609F9157; $: Merck OC551722; $$: Merck HC623465; ¥: Merck HC751838; ¥¥: HC814662; +: HC074650; ++: HC097572 (7) Quality control (7.1) Precision of nutrients analyses during the cruise Precision of nutrients analyses during the cruise was evaluated based on the 9 to 11 measurements, which are measured every 10 to 13 samples, during a run at the concentration of C-6 std. Summary of precisions are shown as shown in Table 3.5.7 and Figures 3.5.8 to 3.5.10, 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 3.5.6. 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 0.12 %for nitrate, 0.20 %for phosphate and 0.14 %for silicate in terms of median of precision, respectively. Then we can conclude that the analytical precisions for nitrate, phosphate and silicate throughout this cruise became relatively bad. The reasons of the phenomenon is discussed in chapter (8). Table 3.5.7: Summary of precision based on the replicate analyses. Nitrate Phosphate Silicate CV % CV % CV % ------- --------- -------- Median 0.12 0.20 0.14 Mean 0.13 0.21 0.13 Maximum 0.4 0.4 0.25 Minimum 0.04 0.05 0.05 N 102 102 102 Figure 3.5.8: Time series of precision of nitrate for MR11–08. Figure 3.5.9. Time series of precision of phosphate for MR11–08. Figure 3.5.10. Time series of precision of silicate for MR11–08. (7.2) Carry over We also summarize the magnitudes of carry over throughout the cruise. These are small enough within acceptable levels as shown in Table 3.5.8 and Figures 3.5.11 – 3.5.13. Table 3.5.8: Summary of carry over through out MR11–08 cruise. Nitrate Phosphate Silicate CV % CV % CV % ------- --------- -------- Median 0.11 0.19 0.10 Mean 0.12 0.21 0.10 Maximum 0.33 0.8 0.28 Minimum 0.00 0.00 0.00 N 102 102 102 Figure 3.5.11: Time series of carryover of nitrate for MR11–08. Figure 3.5.12: Time series of carryover of silicate for MR11–08. Figure 3.5.13. Time series of carryover of phosphate for MR11–08. (7.3) Estimation of uncertainty of phosphate, nitrate and silicate concentrations Empirical equations, eq. (1), (2) and (3) to estimate uncertainty of measurement of phosphate, nitrate and silicate are used based on measurements of 140 sets of RMNSs during the this cruise. These empirical equations are as follows, respectively. Phosphate Concentration Cp in μmol kg-1: Uncertainty of measurement of phosphate (%) = 0.14871+ 0.61128 x (1/Cp) + 0.02228 x (1/Cp) x (1/Cp) --- (1) where Cp is phosphate concentration of sample. Nitrate Concentration Cn in μmol kg-1: Uncertainty of measurement of nitrate (%) = 0.14629 + 2.5141 x (1/Cn) + 0.056725 x (1/Cn) x (1/Cn) --- (2) where Cn is nitrate concentration of sample. Silicate Concentration Cs in μmol kg-1: Uncertainty of measurement of silicate (%) = 0.12394+ 9.9377 x (1/Cs) + 7.6725 x (1/Cs) x (1/Cs) --- (3) where Cs is silicate concentration of sample. (8) Problems/improvements occurred and solutions During this cruse, we observed noisy signals in output of QuAAtro 2-HR systems. After this cruise we investigated on this and confirmed that noisy signals were originated from Kr-lamps of the colorimeters. We did fix this problem by using LED lamps instead of Kr-lamps. References Aminot, A. and Kerouel, R. 1991. Autoclaved seawater as a reference material for the determination of nitrate and phosphate in seawater. Anal. Chim. Acta, 248: 277-283. Aminot, A. and Kirkwood, D.S. 1995. Report on the results of the fifth ICES intercomparison exercise for nutrients in sea water, ICES coop. Res. Rep. Ser., 213. Aminot, A. and Kerouel, R. 1995. Reference material for nutrients in seawater: stability of nitrate, nitrite, ammonia and phosphate in autoclaved samples. Mar. Chem., 49: 221-232. Aoyama M., and Joyce T.M. 1996, WHP property comparisons from crossing lines in North Pacific. In Abstracts, 1996 WOCE Pacific Workshop, Newport Beach, California. Aoyama, M., 2006: 2003 Intercomparison Exercise for Reference Material for Nutrients in Seawater in a Seawater Matrix, Technical Reports of the Meteorological Research Institute No.50, 91pp, Tsukuba, Japan. Aoyama, M., Susan B., Minhan, D., Hideshi, D., Louis, I. G., Kasai, H., Roger, K., Nurit, K., Doug, M., Murata, A., Nagai, N., Ogawa, H., Ota, H., Saito, H., Saito, K., Shimizu, T., Takano, H., Tsuda, A., Yokouchi, K., and Agnes, Y. 2007. Recent Comparability of Oceanographic Nutrients Data: Results of a 2003 Intercomparison Exercise Using Reference Materials. Analytical Sciences, 23: 1151-1154. Aoyama M., J. Barwell-Clarke, S. Becker, M. Blum, Braga E. S., S. C. Coverly,E. Czobik, I. Dahllof, M. H. Dai, G. O. Donnell, C. Engelke, G. C. Gong, Gi-Hoon Hong, D. J. Hydes, M. M. Jin, H. Kasai, R. Kerouel, Y. Kiyomono, M. Knockaert, N. Kress, K. A. Krogslund, M. Kumagai, S. Leterme, Yarong Li, S. Masuda, T. Miyao, T. Moutin, A. Murata, N. Nagai, G.Nausch, M. K. Ngirchechol, A. Nybakk, H. Ogawa, J. van Ooijen, H. Ota, J. M. Pan, C. Payne, O. Pierre-Duplessix, M. Pujo-Pay, T. Raabe, K. Saito, K. Sato, C. Schmidt, M. Schuett, T. M. Shammon, J. Sun, T. Tanhua, L. White, E.M.S. Woodward, P. Worsfold, P. Yeats, T. Yoshimura, A. Youenou, J. Z. Zhang, 2008: 2006 Intercomparison Exercise for Reference Material for Nutrients in Seawater in a Seawater Matrix, Technical Reports of the Meteorological Research Institute No. 58, 104pp. Aoyama, M., Nishino, S., Nishijima, K., Matsushita, J., Takano, A., Sato, K., 2010a. Nutrients, In: R/V Mirai Cruise Report MR10-05. JAMSTEC, Yokosuka, pp. 103-122. Aoyama, M., Matsushita, J., Takano, A., 2010b. Nutrients, In: MR10-06 preliminary cruise report. JAMSTEC, Yokosuka, pp. 69-83 Gouretski, V.V. and Jancke, K. 2001. Systematic errors as the cause for an apparent deep water property variability: global analysis of the WOCE and historical hydrographic data, REVIEW ARTICLE, Progress in Oceanography, 48: Issue 4, 337-402. Grasshoff, K., Ehrhardt, M., Kremling K. et al. 1983. Methods of seawater anylysis. 2nd rev. Weinheim: Verlag Chemie, Germany, West. Hydes, D.J., Aoyama, M., Aminot, A., Bakker, K., Becker, S., Coverly, S., Daniel, A., Dickson, A.G., Grosso, O., Kerouel, R., Ooijen, J. van, Sato, K., Tanhua, T., Woodward, E.M.S., Zhang, J.Z., 2010. Determination of Dissolved Nutrients (N, P, Si) in Seawater with High Precision and Inter- Comparability Using Gas- Segmented Continuous Flow Analysers, In: GO-SHIP Repeat Hydrography Manual: A Collection of Expert Reports and Guidelines. IOCCP Report No. 14, ICPO Publication Series No 134. Joyce, T. and Corry, C. 1994. Requirements for WOCE hydrographic programmed data reporting. WHPO Publication, 90-1, Revision 2, WOCE Report No. 67/91. Kawano, T., Uchida, H. and Doi, T. WHP P01, P14 REVISIT DATA BOOK, (Ryoin Co., Ltd., Yokohama, 2009). Kirkwood, D.S. 1992. Stability of solutions of nutrient salts during storage. Mar. Chem., 38 : 151-164. Kirkwood, D.S. Aminot, A. and Perttila, M. 1991. Report on the results of the ICES fourth intercomparison exercise for nutrients in sea water. ICES coop. Res. Rep. Ser., 174. Mordy, C.W., Aoyama, M., Gordon, L.I., Johnson, G.C., Key, R.M., Ross, A.A., Jennings, J.C. and Wilson. J. 2000. Deep water comparison studies of the Pacific WOCE nutrient data set. Eos Trans-American Geophysical Union. 80 (supplement), OS43. Murphy, J., and Riley, J.P. 1962. Analytica chim. Acta 27, 31-36. Sato, K., Aoyama, M., Becker, S., 2010. RMNS as Calibration Standard Solution to Keep Comparability for Several Cruises in the World Ocean in 2000s. In: Aoyama, M., Dickson, A.G., Hydes, D.J., Murata, A., Oh, J.R., Roose, P., Woodward, E.M.S., (Eds.), Comparability of nutrients in the world’s ocean. Tsukuba, JAPAN: MOTHER TANK, pp 43-56. Uchida, H. & Fukasawa, M. WHP P6, A10, I3/I4 REVISIT DATA BOOK Blue Earth Global Expedition 2003 1, 2, (Aiwa Printing Co., Ltd., Tokyo, 2005). 3.6 Chlorofluorocarbons and Sulfur Hexafluoride September 5, 2013 (1) Personnel Ken’ichi Sasaki (MIO, JAMSTEC) Katsunori Sagishima (MWJ) Shoko Tatamisashi (MWJ) Hironori Satoh (MWJ) Masahiro Ohrui (MWJ) (2) Objectives Chlorofluorocarbons (CFCs) and sulfur hexafluoride (SF6) are man – made stable gases. These gases can slightly dissolve in sea surface water by air- sea gas exchange and then are spread into the ocean interior. These dissolved gases could be used as transient chemical tracers for the ocean circulation. We measured concentrations of three chemical species of CFCs, CFC-11 (CCl3F), CFC-12 (CCl2F2) and CFC-113 (C2Cl3F3), and SF6 in seawater on board. (3) Apparatuses Measurement of CFCs and SF6 were made with three gas chromatographs attached with purging and trapping systems (modified from the original design of Bullister and Weiss (1988)). One was SF6/CFCs simultaneous analyzing system (System A). Other two were CFCs analyzing systems (System D and E). These purging and trapping systems were developed in JAMSTEC. (3.1) SF6/CFCs simultaneous analyzing system (System A) Cold trap columns are 30 cm length stainless steel tubing packed the section of 5cm with 100/120 mesh Porapak T and followed by the section of 5cm of 100/120 mesh Carboxen 1000. Outer diameters of the main and focus trap columns are 1/8” and 1/16”, respectively. A gas chromatograph (GC-14B: Shimadzu LTD) has two electron capture detectors, ECD1 and ECD2 (ECD- 14: Shimadzu LTD). A pre-column is Silica Plot capillary column [i.d.: 0.32 mm, length: 10 m, film thickness: 4 μm]. There are two main analytical columns in GC. Main column 1 (MC1) connected up to ECD1 is MS 5A packed column [1/16” OD, 10 cm length stainless steel tubing packed the section of 7 cm with 80/100 mesh Molecular Sieve 5A] followed by Gas Pro capillary column [i.d.: 0.32 mm, length: 35 m] for SF6 and CFC-12 analyses. Main column 2 (MC2) connected up to ECD2 is Silica Plot capillary column [i.d.: 0.32mm, length: 30 m, film thickness: 4 μm] for CFC-11 and CFC- 113 analyses. (3.2) CFCs Systems (System D and E) Cold trap column of the system is 1/16” stainless steel tubing packed with 5cm of 100/120 mesh Porapak T. The GCs (GC-14B) in these systems had single ECD (ECD-14), respectively. A pre column was Silica Plot capillary column [i.d.: 0.53mm, length: 8 m, film thickness: 6μm]. A main column was Pola Bond-Q capillary column [i.d.: 0.53mm, length: 9 m, film thickness: 10μm] followed by Silica Plot capillary column [i. d.: 0.53mm, length: 14 m, film thickness: 6μm] (4) Shipboard measurements (4.1) Sampling The marine water sampler was cleaned by diluted acetone before every CTD cast in order to remove any oils which could cause contaminations of CFCs. Seawater sub-samples were collected from 12 litter Niskin bottles to 250 ml and 400 ml of glass bottles for CFC and SF6 measurements, respectively. CFCs sampling was made in every station and SF6 sampling was done in every other station. The sub-sampling bottles were filled by nitrogen gas before sub- sampling. Two times of the bottle volumes of seawater sample were overflowed. The bottles filled by seawater samples were kept in thermostatic water bath (7ºC). The CFC and SF6 concentrations were determined within 24 hours. In order to confirm stabilities of standard gases and to check saturation levels of CFCs and SF6 in sea surface water, mixing ratios of CFCs and SF6 in background air were periodically analyzed. Air samples were continuously led into the Environmental Research Laboratory of R/V MIRAI by 10 mm OD Dekaron tubing. The end of the tubing was put on a head of the Compass Deck and another end was connected onto an air pump in the laboratory. The tubing was relayed by a T-type union which had a small stop cock. Air sample was collected from the flowing air into a 200 ml glass cylinder attached on the cock. Average mixing ratios of the atmospheric CFC- 11, CFC-12, CFC-113, and SF6 were 237.7 ± 8.4 ppt, 522.8 ± 7.4 ppt, 71.4 ± 4.4 (n = 100) and 7.36 ± 0.25 ppt, respectively. (4.2) Analyses (4.2.1) SF6/CFCs simultaneous analyses (System A) Constant volume of sample water (200 ml) was taken into a sample loop. The sample was send into stripping chamber and dissolved gases were extracted by pure nitrogen gas purging for 9 minutes. The gas sample was dried by magnesium perchlorate desiccant and concentrated on a main trap column cooled to –80 ºC. Stripping efficiencies were frequently confirmed by re-stripping of surface layer samples and more than 99 %of dissolved SF6 and CFCs were extracted on the first purge. Following purging & trapping, the main trap column was isolated and heated to 170 ºC for 1 minute. The desorbed gases were sent onto focusing trap cooled to –80 ºC. Gaseous sample on the focusing trap were desorbed by heating to 170 ºC for 1 minute and led into the pre- column. Sample gases were roughly separated in the pre-column. SF6 and CFC-12 were sent onto MC1 and CFC-11 and CFC-113 still remain on the pre-column. Main column connected up to pre-column was switched to MC2 and another carrier gas line was connected up to MC1. SF6 and CFC-12 were further separated and detected by the ECD1. CFC-11 and CFC-113 led onto MC 2 were detected by ECD2. When CFC-113 eluted from pre-column onto MC 2, the pre- column was switched onto another line and remaining compounds on the pre- column were backflushed. Temperature of the analytical column and ECD was 95 and 300 °C. Mass flow rates of nitrogen gas were 5, 32, 6 and 220 ml/min for carrier gases, detector make up gases, back flush gas and sample purging gas, respectively. Gas loops whose volumes were 0.05, 0.15, 0.3, 1, 3 and 10 ml were used for introducing standard gases into the analytical system. Calibration curves were made every several days and standard gas analyses using largest loop (10 ml) were performed more frequently to monitor change in the detector sensitivity. (4.2.2) CFCs analyses (System D and E) These systems were somewhat simple compared with the system A. Volume of water sample loop was 50 ml. Gas extraction time was for 8 minutes. Cooling and heating temperatures of trap column were –50 and 140 ºC, respectively. There were not focusing trap in the systems. Stripping efficiencies were more than 99.5 % of dissolved CFCs on the first purge. Temperatures of the analytical column and ECD were 95 and 240 °C. Mass flow rates of nitrogen gas were 10, 27, 20 and 120 ml/min for carrier, detector make up, back flush and sample purging gases, respectively. There were three gas loops whose volumes were 1, 3 and 10 ml, respectively. (4.2.3) Standard gases The standard gasses had been made by Japan Fine Products co. ltd. Standard gas cylinder numbers used in this cruise were listed in Table 3.6.1. Cylinder of CPB15651 was used as reference gas. Precise mixing ratios of CFCs/SF6 in the standard gases were calculated by gravimetric data. The standard gases have not been calibrated to SIO scale standard gases yet because SIO scale standard gasses were hard to obtain due to legal difficulties for CFCs import into Japan. The data would be corrected as soon as possible when we obtained the SIO scale standard gases. (5) Quality control (5.1) Interference peak for CFC-113 Analyzing surface layer samples (several hundred meters depth) of tropical and sub-tropical region, a large and broad peak was interfered determining CFC-113 peak area in chromatograms obtained from system D and E. Retention time of the interfering peak was slightly different from that of CFC-113. In this case, quality flag “5” was given (no data). The system A completely separated the unknown compound from CFC-113 peak. At the SF6 stations, measurements of CFC-113 by the system A were adopted. (5.2) Blanks Deep water in the North Pacific which would be one of the oldest water masses in the world ocean. CFC concentrations in these water masses could be considered as overall blanks (from Niskin bottles, sub-sampling, and analytical systems). Average concentrations of CFC-11 and CFC-12 in the deep water masses (sigma theta > 27.7) were 0.011 ± 0.003, 0.005 ± 0.002 pmol kg–1 (n = ~700), respectively. These values were assumed as blanks and were subtracted from all data. Significant blanks were not found in CFC-113 and SF6 measurements. (5.3) Precisions The analytical precisions were estimated from replicate sample analyses (N = 201 pairs for CFC-12 and CFC-11, 166 pairs for CFC-113, and 103 pairs for SF6 measurements). The replicate samples were collected from two or three sampling depths which were around 100, 400 and 600 m depths in every station. Precisions were estimated as less than ± 0.007 pmol kg–1 or 0.6 %for CFC-11, ± 0.004 pmol kg–1 or 0.5 %for CFC-12, ± 0.003 pmol kg–1 or 2 %for CFC-113 (whichever is greater), and ± 0.05 fmol kg–1 for SF6, respectively. Although measurements of CFC-11 and CFC-12 were also obtained from the system A, the precisions were somewhat poor ± 0.016 pmol kg–1 for CFC-11 and ± 0.006 pmol kg–1 for CFC-12) compared with those of measurement by system D and E. Measurements of CFC-11 and CFC-12 from system A were rejected except the stations of P10- 004 and P10-006 (because there was not measurements from the system D or E). Reference Bullister, J.L and Weiss, R.F. Determination of CCl3F and CCl2F2 in seawater and air. Deep Sea Research, 35, 839-853 (1988). Table 3.6.1. Standard gas cylinder list (Japan Fine Products co. ltd.). CFC-11 CFC-12 CFC113 SF6 N2O Cylinder No. Base gas [ppt] [ppt] [ppt] [ppt] [ppb] ------------ -------- ------ ------ ------ ----- ----- CPB23379 Air 501 251 40.3 5.02 198 CPB17172 Air 998 519 90.0 10.0 300 CPB17174 Air 1499 750 130 10.0 502 CPB26826 N2 299 160 30.1 0.0 0 CPB15674 N2 299 160 30.0 0.0 0 CPB15651 N2 299 159 30.2 0.0 0 3.7 Dissolved Inorganic Carbon (CT) October 4, 2013 (1) Personnel Akihiko Murata (RIGC/JAMSTEC) Yoshiko Ishikawa (MWJ) Hatsumi Aoyama (MWJ) Makoto Takada (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 (MR11-08, revisit of WOCE P10 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-C and -D; 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 3000, Nippon ANS, Inc.). The seawater dispensing system has an auto-sampler (6 ports), which takes seawater from a 250 ml borosilicate glass bottle (DURAN®) and dispenses the seawater to a pipette of nominal 20 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 frit 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 C and D) to the coulometer through a dehydrating module. Both the systems have a module with two electric dehumidifiers (kept at 1−2 °C) and a chemical desiccant (Mg(ClO4)2). (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 tightly by a polyethylene inner cap. At a chemical laboratory on the ship, a headspace of approx. 3 ml was made by removing seawater with a plastic pipette. A saturated mercuric chloride of 100 μl was added to poison seawater samples. The glass bottles were sealed with a greased (Apiezon M, M&I Materials Ltd) ground glass stopper and the clips were secured. The seawater samples were kept at 5 °C in a refrigerator until analysis. A few hours just before analysis, the seawater samples were kept at 20 °C in a water bath. (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/L). As it was empirically known that coulometers do not show a stable signal (low repeatability) with fresh (low absorption of carbon) coulometer solutions. Therefore we measured 2%CO2 gas repeatedly until the measurements became stable. Then we started the calibration. The measurement sequence such as system blank (phosphoric acid blank), 1.865%CO2 gas in a nitrogen base, seawater samples (6) was programmed to repeat. The measurement of 1.865%CO2 gas was made to monitor response of coulometer solutions (from UIC, Inc.). For every renewal of coulometer solutions, certified reference materials (CRMs, batch 112) provided by Prof. A. G. Dickson of Scripps Institution of Oceanography were analyzed. In addition, in-house reference materials (RM) (batch Q24 and Q25 for systems C and D, 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 (batch 112), 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 batch 112. Temporal variations of RM measurements for one coulometer solution are shown in Fig. 3.7.1. From this figure, it is evident that RM measurements had a linear trend of ~6 μmol kg-1, implying that measurements of seawater samples also have the trend. The trend was also found in temporal changes of 1.865%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 112. The average and standard deviation of absolute values of differences of CT analyzed consecutively were 0.7 and 0.5 μmol kg-1 (n=96), and 0.7 and 0.6 μmol kg-1 (n=85) for legs 1 and 2, respectively. The values for the entire cruises were 0.7 and 0.6 μmol kg-1 (n=181). Figure 3.7.1: Distributions of RM measurements as a function of sequential day for Stns. 21 and 25 during MR11–08. 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. 3.8 Total Alkalinity (AT) October 4, 2013 (1) Personnel Akihiko Murata (RIGC/JAMSTEC) Tomonori Watai (MWJ) Ayaka Hatsuyama (MWJ) Yasumi Yamada (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 (MR11-08, revisit of WOCE P10 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 Scan, 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 (brosilicate glass bottle; 130 ml) into the water-jacketed (25 ºC) pipette by pressurizing the sample bottle (nitrogen gas), and is introduced into the water-jacketed (25 ºC) titration cell. The seawater is circulated between the titration and the quartz cells by a peristaric pump to rinse the route. Then, Milli-Q water is introduced into the titration cell, and is circulated in the 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 wavelenghts (750, 616 and 444 nm). After the measurement, an acid titrant, which is a mixture of approx. 0.05 M HCl in 0.65 M NaCl and bromocresol green (BCG) is added (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 = (-[H ] V + M V ) / V T T SA A A S, where MA is the molarity of the acid titrant added to the seawater sample, [H+]T is the total excess hydrogen ion concentration in the seawater, and VS, VA and VSA are the initial seawater volume, the added acid titrant volume, and the combined seawater plus acid titrant volume, respectively. [H+]T is calculated from the measured absorbances based on the following equation (Yao and Byrne, 1998): + pH = -log[H ] = 4.2699 + 0.002578(35-S) log((R-0.00131)/(2.3148 0.1299R)) T T -log(1-0.001005S), where S is the sample salinity, and R is the absorbance ratio calculated as: R=(A - A ) / (A - A ) 616 750 444 750 where Ai is the absorbance at wavelength i nm. The HCl in the acid titrant was standardized (0.050002M, 0.50002 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 112, certified value = 2223.26 μmol kg-1, respectively) were also analyzed periodically to monitor systematic differences of measured AT. The reported values of AT were set to be traceable to the certified value of the batch 112. 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: (5) Quality control During the cruise, temporal changes of AT, which originate from analytical problems, were monitored by measuring AT of CRM. We found no abnormal measurements during the cruises. On land, after making the measured values of AT comparable to CRM, we examined vertical profiles of AT. In doing so, we found systematic differences in AT between 2005 and 2011. To quantify the systematic differences, we conducted following analyses; first, we took AT observed below 2000 dbar from both 2005 and 2011 datasets. The AT data for 2005 were obtained by our cruise by the R/V Mirai (MR11-08). Then we selected AT data collected in same or close stations for the two cruises, and found 40 pairs in total. For the selected data of each cruise, after normalizing to a salinity of 35 (nAT), we applied a Piecewise Hermite Interpolating scheme to fixed depths to bottom with an interval of 250 dbar : 2250, 2500, 2750 … . Next, we compared nAT differences of each depth in respective pairs (Fig. 3.8.1). The average of the differences was 6.0 ± 2.6 μmol kg-1. Therefore we applied a value of 6.0 μmol kg-1 to each AT in 2011. The average and standard deviation of absolute values of differences of AT analyzed consecutively were 0.5 and 0.4 μmol kg-1 (n = 96), and 0.5 and 0.4 μmol kg-1 (n = 88) for legs 2 and 3, respectively. The combined values were calculated to be 0.5 and 0.4 μmol kg-1 (n = 184). Fig. 3.8.1: Differences of nAT between 1994 (red) and 2009 (blue) at selected stations. Reference Yao, W. and R. H. Byrne (1998): Simplified seawater alkalinity analysis: Use of linear array spectrometers. Deep-Sea Research I 45, 1383-1392. 3.9 pH October 12, 2013 (1) Personnel Akihiko Murata (RIGC, JAMSTEC) Tomonori Watai (MWJ) Ayaka Hatsuyama (MWJ) Yasumi Yamada (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 cruise (MR11-08, revisit of WOCE P10 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 respective wavelengths. The pH is calculated based on the following equation (Clayton and Byrne, 1993): A1 / A2 - 0.00691 pH = pK + log(------------------------) (1), 2 2.2220 - 0.1331(A1 / A2) where A1 and A2 indicate absorbances at 578 and 434 nm, respectively, and pK2 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. 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 3.9.1 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 0.0006 and 0.0006 pH unit (n = 116), and 0.0008 and 0.0010 pH unit (n = 109) for legs 1 and 2, respectively. The combined values were 0.0007 and 0.0008 pH unit (n = 225). We compared observed pH and pH calculated from CT and AT. The average and standard deviation was 0.0102 and 0.0072 pH unit, respectively. Thus the accuracy of pH was estimated to be 0.01 pH unit at best. 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 F. J. Millero (1987): A Comparison of the equilibrium constants for the dissociation of carbonic acid in seawater media. Deep- Sea Research 34, 1733-1743. 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. 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 3.9.1. Perturbation of absorbance ratios by adding indicator solutions. The line was determined by the method of least squares. 3.10 Chlorophyll a February 6, 2014 (1) Personnel Osamu Yoshida1 (Rakuno Gakuen University) (Principal Investigator) Hiroshi Uchida (JAMSTEC) (co-Principal Investigator) Yuki Okazaki (Rakuno Gakuen University) Shinichi Oikawa (Rakuno Gakuen University) Hikari Shimizu (Rakuno Gakuen University) Chisato Yoshikawa (Tokyo Institute of Technology / Japan Society for the Promotion of Science) (Not on board) Shoko Tatamisashi (MWJ) Masahiro Orui (MWJ) Naohiro Yoshida (Tokyo Institute of Technology) (Not on board) (2) Sampling elements The Rakuno Gakuen University (RGU) group collected chlorophyll a samples at CTD/CWS stations 1, 29, 45, 58, 71, 88, and 114 for bucket and Niskin bottles of 36, 35, 34, 33 and 32. The JAMSTEC collected chlorophyll a samples at CTD/CWS stations 2, 9, 15, 19, 24, 59, 62, 65, 68, 77, 79, 82, 84, 90, 94, 100, 106, and 112 for a Niskin bottle closed near chlorophyll a maximum to calibrate CTD fluorometer data. The JAMSTEC also collected chlorophyll a samples from the sea surface water monitoring system once in a day at night to calibrate the fluorometer of the sea surface water monitoring system. (3) Objective Chlorophyll a is one of the most convenient indicators of phytoplankton stock, and has been used extensively for the estimation of phytoplankton abundance in various aquatic environments. The object of this 83 study is to investigate the vertical distribution of phytoplankton in various light intensity depth and the horizontal distribution of phytoplankton at sea surface along the cruise track. (4) Materials and methods Seawater samples were collected 250 mL at 6 depths from surface to about 200 m with Niskin bottles, except for the Surface water, which was taken by the bucket. For JAMSTEC stations, water samples were collected 500 mL bottle. The samples were gently filtrated by low vacuum pressure (<0.02 MPa) through Whatman GF/F filter (diameter 25 mm) in the dark room. Phytoplankton pigments were immediately extracted in 7 mL of N,Ndimethylformamide (DMF) after filtration and then, the samples were stored at –20°C under the dark condition to extract chlorophyll a for 24 hours or more. The extracted samples are measured the fluorescence by Turner fluorometer (10-AU-005, TURNER DESIGNS) which was previously calibrated against a pure chlorophyll a (Sigma-Aldrich Co.). We applied the fluorometric “Non-acidification method” (Welschmeyer, 1994). (5) Results The results of chlorophyll a at RGU sampling stations and relationship between chlorophyll a concentrations and chlorophyll a estimated from CTD fluorometer were shown in Figures 3.10.1 and 3.10.2, respectively. Reference Welschmeyer, N. A. (1994): Fluorometric analysis of chlrophyll a in the presence of chlorophyll b and pheopigments. Limnol. Oceanogr., 39, 1985- 1992. Figure 3.10.1: Vertical distributions of chlorophyll a at RGU stations. Figure 3.10.2: Relationship between fluorescent values of seawater and chlorophyll a concentrations at RGU (solid circles) and JAMSTEC (open circles) stations. 3.11 LADCP August 13, 2013 (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 WHM300 (Teledyne RD Instruments, San Diego, California, USA), which has 4 downward facing transducers with 20-degree beam angles, rated to 6000 m. The LADCP makes direct current measurements at the depth of the CTD, thus providing a full profile of velocity. The LADCP was powered during the CTD casts by a 50.4 volts expendable Alkali battery pack. The LADCP unit was set for recording internally prior to each cast. After each cast the internally stored observed data was uploaded to the computer on-board. By combining the measured velocity of the sea water and bottom with respect to the instrument, and shipboard navigation data during the CTD cast, the absolute velocity profile can be obtained (e.g., Visbeck, 2002). The instrument used in this cruise were Teledyne RD Instruments, WHM300(S/N 183240). (3) Data collection In this cruise, data were collected with the following configuration. Bin size: 4 m Number of bins: 25 Pings per ensemble: 1 Ping interval: 1 sec (4) Data collection problems Echo intensities are sufficiently high along the section (Fig. 3.11.1), except at the stations of 9. Since the weak echo were observed for all the beams, the weakness was not due to the instrument problem. Figure 3.11.1: Cast-averaged echo intensities at the first bin. Red, blue, green and orange denote beam 1, 2, 3, and 4 respectively. (5) 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 minute are also included in the calculation. The CTD data are used for the sound speed and depth calculation. The directions of velocity are corrected using the magnetic deviation estimated with International Geomagnetic reference field data. 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. Station Summary (see PDF version or data files) Water sample parameters: -------------------------------------------------------- Number Parameter Mnemonic Mnemonic for 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-11 8 Freon-12 CFC-12 9 Tritium TRITUM 12 14Carbon DELC14 C14ERR 13 13Carbon DELC13 C13ERR 22 137Cs CS-137 23 Total carbon TCARBN 24 Total alkalinity ALKALI 26 pH PH 27 Freon-113 CFC113 31 Methane CH4 33 Nitrous oxide N2O 34 Chlorophyll a CHLORA 82 15N-Nitrate 15NO3 89 134Cs CS-134 90 Perfluorinated acids 91 129I I-129 92 Density salinity DNSSAL 93 Sulfur hexafluoride SF6 -------------------------------------------------------- Figure captions Figure 1: Station locations for WHP P10 revisit in 2011 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 6-hour. Figure 4: (a) Sea surface temperature (°C), (b) sea surface salinity (psu), (c) sea surface oxygen (μmol/kg), and (d) sea surface chlorophyll a (mg/m3) measured by the Continuous Sea Surface Water Monitoring System. Figure 5: Difference in the partial pressure of CO2 between the ocean and the atmosphere, ΔpCO2. Figure 6: Surface current at 100 m depth measured by ship board acoustic Doppler current profiler (ADCP). Figure 7: Potential temperature (°C) cross 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 8: CTD salinity (psu) cross section calibrated by bottle salinity measurements. Vertical exaggeration is same as Figure 7. Figure 9: Absolute salinity (g/kg) cross section calculated by using CTD salinity data. Vertical exaggeration is same as Figure 7. Figure 10: Density (σ0) (kg/m3) cross section calculated by using CTD temperature and salinity data. Vertical exaggeration is same as Figure 7. (a) EOS-80 and (b) TEOS-10 definition. Figure 11: Same as Figure 10 but for σ4 (kg/m3). (a) EOS-80 and (b) TEOS-10 definition. Figure 12: Neutral density (γn) (kg/m3) cross section calculated by using CTD temperature and salinity data. Vertical exaggeration is same as Figure 7. Figure 13: Cross section of CTD oxygen (μmol/kg). Vertical exaggeration is same as Figure 7. Figure 14: Cross section of CTD chlorophyll a (mg/m3). Vertical exaggeration of the upper 1000 m section is same as Figure 7. 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 7. Figure 16: Silicate (μmol/kg) cross section. Data with quality flags of 2 were plotted. Vertical exaggeration is same as Figure 7. Figure 17: Nitrate (μmol/kg) cross section. Data with quality flags of 2 were plotted. Vertical exaggeration is same as Figure 7. 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 7. Figure 19: Phosphate (μmol/kg) cross section. Data with quality flags of 2 were plotted. Vertical exaggeration is same as Figure 7. Figure 20: Dissolved inorganic carbon (μmol/kg) cross section. Data with quality flags of 2 were plotted. Vertical exaggeration is same as Figure 7. Figure 21: Total alkalinity (μmol/kg) cross section. Data with quality flags of 2 were plotted. Vertical exaggeration is same as Figure 7. Figure 22: pH cross section. Data with quality flags of 2 were plotted. Vertical exaggeration is same as Figure 7. Figure 23: CFC-11 (pmol/kg) cross section. Data with quality flags of 2 were plotted. Vertical exaggeration is same as Figure 7. Figure 24: CFC-12 (pmol/kg) cross section. Data with quality flags of 2 were plotted. Vertical exaggeration is same as Figure 7. Figure 25: CFC-113 (pmol/kg) cross section. Data with quality flags of 2 were plotted. Vertical exaggeration is same as Figure 7. Figure 26: Cross section of current velocity (cm/s) normal to the cruise track measured by LADCP (eastward is positive). Vertical exaggeration is same as Figure 7. Figure 27: Difference in potential temperature (°C) between results from the previous cruise and the revisit in 2011 (December 2011 – February 2012). The previous cruise is (a) WOCE (October – November 1993) and (b) the first revisit (May – June 2005). 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 7. Figure 28: Same as Fig. 27, but for salinity (psu). On white areas differences in salinity do not exceed the detection limit of 0.002 psu. Figure 29: Same as Fig. 27, but for dissolved oxygen (μmol/kg). CTD oxygen data were used. On white areas differences in dissolved oxygen do not exceed the detection limit of 2 μmol/kg. Note 1. As for the traceability of SSW to Kawano’s value (Kawano et al., 2006), the offset for the batches P114 (WOCE P10 stations from 1 to 12), P120 (WOCE P10 stations from 13 to 74), and P145 (the revisit in 2005) and P153 (the revisit in 2011) are 0.0020, –0.0009, –0.0009 and 0.0004, respectively. The offset values for the recent batches are listed in Table A1 (Uchida et al., in preparation). For P120 of WOCE P10 cruise, salinity was corrected with an offset of –0.0015 (cruise report of WOCE P10). Therefore, the salinity data are corrected with an offset of 0.0006 for the stations from 13 to 74 of WOCE P10. Table A1. SSW batch to batch differences from P145 to P155 (Uchida et al., in preparation). The difference of P145 is reevaluated. Batch no. Production K15 Sp Batch to batch difference (x10–3) date Mantyla’s standard Kawano’s standard --------- ---------- ------- ------- ------------------ ----------------- P145 2004/07/15 0.99981 34.9925 –2.2 –0.9 P146 2005/05/12 0.99979 34.9917 –2.7 –1.4 P147 2006/06/06 0.99982 34.9929 –1.8 –0.5 P148 2006/10/01 0.99982 34.9929 –1.2 0.1 P149 2007/10/05 0.99984 34.9937 –0.6 0.7 P150 2008/05/22 0.99978 34.9913 –0.5 0.8 P151 2009/05/20 0.99997 34.9984 –1.3 0.0 P152 2010/05/05 0.99981 34.9926 –1.3 0.0 P153 2011/03/08 0.99979 34.9918 –0.9 0.4 P154 2011/10/20 0.99990 34.9961 –0.7 0.6 P155 2012/09/19 0.99981 34.9925 –1.1 0.2 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 Leg 2 (49NZ20111220) Date Person Data Type Action Summary ---------- --------------- ---------- -------------- ----------------------------------- 2012-07-25 Uchida, Hiroshi CTD/SUM Submitted to go online Documentation and bottle files will be submitted within a year. 2012-11-21 Staff, CCHDO CTD/SUM Website Update Available under 'Files as received' The following files are now available online under 'Files as received', unprocessed by the CCHDO. 49NZ20120113_ct1.zip 49NZ20111220_sum.txt 49NZ20120113_xct.zip 49NZ20111220_ct1.zip 49NZ20120113_sum.txt 2014-05-14 E, S SUM,CTD Website Update Exchange, netCDF, and WOCE files online. CTDPRS,CTDTMP,CTDSAL,CTDOXY,FLUOR,XMISS, XMISSCP,PAR ============================================================================= P10 2011 49NZ20111220 processing - CTD/SUM - CTDPRS,CTDTMP,CTDSAL,CTDOXY,FLUOR,XMISS,XMISSCP,PAR ============================================================================= 2014.05.14 SE .. contents:: :depth: 2 Submission ========== =============================== =============== ========== ========== ==== filename submitted by date data type id =============================== =============== ========== ========== ==== 49NZ20111220_sum.txt Hiroshi Uchida 2012-07-25 SUM 851 49NZ20111220_ct1.zip Hiroshi Uchida 2012-07-25 CTD 851 =============================== =============== ========== ========== ==== Parameters ---------- 49NZ20111220_sum.txt ~~~~~~~~~~~~~~~~~~~~ 49NZ20111220_ct1.zip ~~~~~~~~~~~~~~~~~~~~ - CTDPRS [1]_ - CTDTMP [1]_ - CTDSAL [1]_ - CTDOXY [1]_ - FLUOR [1]_ - XMISS [1]_ - XMISSCP - PAR [1]_ .. [1] parameter has quality flag column Process ======= Changes ------- 49NZ20111220_sum.txt ~~~~~~~~~~~~~~~~~~~~ - Kept both "Uncorrected Depth" and "Corrected Depth", although one is probably incorrect - Changed order of first header line, added timestamp 49NZ20111220_ct1.zip ~~~~~~~~~~~~~~~~~~~~ - removed last "," from every units line. - changed FLUOR units from MG/CUM to MG/M^3 in every units line. - Updated header. Conversion ---------- ======================= ==================== ======================== file converted from software ======================= ==================== ======================== 49NZ20111220_nc_ctd.zip 49NZ20111220_ct1.zip hydro 0.8.0-117-g2f13399 ======================= ==================== ======================== - Exchange and NetCDF files opened in JOA with no apparent problems. - Exchange file opened in ODV with no apparent problems. Conversion ---------- ======================= ==================== ======================== file converted from software ======================= ==================== ======================== 49NZ20111220_nc_ctd.zip 49NZ20111220_ct1.csv hydro 0.8.0-117-g2f13399 ======================= ==================== ======================== All converted files opened in JOA with no apparent problems. Directories =========== :working directory: /data/co2clivar/pacific/p10/p10_49NZ20111220/original/2014.05.14_SUM,CTD_SE :cruise directory: /data/co2clivar/pacific/p10/p10_49NZ20111220 Updated Files Manifest ====================== ======================= ================ file stamp ======================= ================ 49NZ20111220_ct1.zip 20140514CCHSIOSE 49NZ20111220_sum.txt 49NZ20111220_nc_ctd.zip 20140514CCHSIOSE ======================= ================ 2014-08-18 Key, Bob BTL Submitted to go online 8/15/14 Downloaded file 49NZ20120113_hy1.csv from http://www.jamstec.go.jp/iorgc/ocorp/data/p10rev_2011/index.html 8/18/14 With eXcel Remove leading “X” from bottle numbers Replace “J” in bottle numbers with “0” Surface samples have bottle “-999” replace with 99 Delete CTDPRS_FLAG_W Delete CTDTMP_FLAG_W Delete c13,c14,h3,cs134,cs137 and errors Delete DNSSAL and flag, XMISSCP Delete SILUNC, NRAUNC,PHPUNC Save as P10N.2012.csv Fix line endings with vi and delete extra “,” copy to SUN —————————— From original file header BOTTLE,20140213JAMSTECRIGC #Software_Version: whp_btl_exchange.rb_v3.0 (occrp) #ORIGINAL_SUM_FILE: 49NZ20120113_sum.txt Tue Jan 14 11:26:58 +0900 2014 #ORIGINAL_HYD_FILE: sea201402120503.csv Thu Feb 13 13:01:28 +0900 2014 #DEPTH_TYPE: COR #EVENT_CODE: BO 2014-08-19 Staff, CCHDO BTL/CrsRpt Website Update Available under 'Files as received' The following files are now available online under 'Files as received', unprocessed by the CCHDO. README.Mac.txt 49NZ20111220.exc.csv p10rev_2011_databook.pdf 2014-09-17 Lee, Rox BTL Website Update Exchange and netCDF files online ============================= 49NZ20111220 processing - BTL ============================= 2014-09-17 R Lee .. contents:: :depth: 2 Submission ========== ==================== ============= ========== ========== ==== filename submitted by date data type id ==================== ============= ========== ========== ==== 49NZ20111220.exc.csv Robert M. Key 2014-08-18 BTL/CrsRpt 1202 ==================== ============= ========== ========== ==== Parameters ---------- - CTDPRS - CTDTMP - CTDSAL [1]_ - SALNTY [1]_ - CTDOXY [1]_ - OXYGEN [1]_ - SILCAT [1]_ - NITRAT [1]_ - NITRIT [1]_ - PHSPHT [1]_ - CFC-11 [1]_ - CFC-12 [1]_ - CFC113 [1]_ - SF6 [1]_ - TCARBN [1]_ - ALKALI [1]_ - PH_TOT [1]_ - PH_TMP - XMISS [1]_ [3]_ - CHLORA [1]_ - FLUOR [1]_ [3]_ - PAR [1]_ [3]_ - THETA [3]_ - SBE35 [1]_ [3]_ 49NZ20111220.exc.csv ~~~~~~~~~~~~~~~~~~~~ .. [1] parameter has quality flag column .. [3] not in WOCE bottle file Process ======= Changes ------- - Changed SEB35 to SBE35 49NZ20111220.exc.csv ~~~~~~~~~~~~~~~~~~~~ Conversion ---------- ======================= ==================== ======================= file converted from software ======================= ==================== ======================= 49NZ20111220_nc_hyd.zip 49NZ20111220_hy1.csv hydro 0.8.2-40-g569f4c2 ======================= ==================== ======================= All converted files opened in JOA with no apparent problems. Directories =========== :working directory: /data/co2clivar/pacific/p10/p10_49NZ20111220/original/2014.09.17_BTL_RJL :cruise directory: /data/co2clivar/pacific/p10/p10_49NZ20111220 Updated Files Manifest ====================== ======================= ================= file stamp ======================= ================= 49NZ20111220_nc_hyd.zip 20140917SIOCCHRJL 49NZ20111220_hy1.csv 20140917SIOCCHRJL ======================= ================= 2014-11-04 Kappa, Jerry CrsRpt PDF version online I've placed a new PDF version of the cruise report: 49NZ20111220_do.pdf into the directory: http://cchdo.ucsd.edu/data/co2clivar/pacific/p10/p10_49NZ20111220/ It includes all the reports provided by the cruise PIs, summary pages and CCHDO data processing notes, as well as a linked Table of Contents and links to figures, tables and appendices. 2015-03-02 Kappa, Jerry CrsRpt TXT version online I've placed a new TEXT version of the cruise report: 49NZ20111220_do.txt onto the CCHDO website It includes all the reports provided by the cruise PIs, summary pages and CCHDO data processing notes. Leg 3 (49NZ20120113) Date Person Data Type Action Summary ---------- --------------- ---------- -------------- ----------------------------------- 2012-07-25 Uchida, Hiroshi CTD/SUM Submitted to go online Documentation and bottle files will be submit within a year. 2012-11-21 Staff, CCHDO CTD/SUM Website Update Available under 'Files as received' The following files are now available online under 'Files as received', unprocessed by the CCHDO. 49NZ20120113_ct1.zip 49NZ20111220_sum.txt 49NZ20120113_xct.zip 49NZ20111220_ct1.zip 49NZ20120113_sum.txt 2014-02-12 Berys, Carolina SUM-CTD Website Update SUM and CTD files online ================================= 49NZ20120113 processing - SUM/CTD ================================= 2014-02-12 C Berys .. contents:: :depth: 2 Submission ========== ==================== ============== ========== ========= === filename submitted by date data type id ==================== ============== ========== ========= === 49NZ20120113_ct1.zip Hiroshi Uchida 2012-07-25 CTD/SUM 851 49NZ20120113_sum.txt Hiroshi Uchida 2012-07-25 CTD/SUM 851 ==================== ============== ========== ========= === Parameters ---------- 49NZ20120113_ct1.zip ~~~~~~~~~~~~~~~~~~~~ - CTDPRS [1]_ - CTDTMP [1]_ - CTDSAL [1]_ - CTDOXY [1]_ - XMISS [1]_ - FLUORM [1]_ - XMISSCP - PAR [1]_ .. [1] parameter has quality flag column .. [2] parameter only has fill values/no reported measured data .. [3] not in WOCE bottle file .. [4] merged Process ======= Changes ------- 49NZ20120113_ct1.zip ~~~~~~~~~~~~~~~~~~~~ - SECT changed to SECT_ID - comma removed form units line - FLUOR changed to FLUORM, units changed form MG/CUM to MG/M^3 - NOTE: files with CTDPRS below 6,000 DBAR did not open in joa 49NZ20120113_sum.txt ~~~~~~~~~~~~~~~~~~~~ - renamed to 49NZ20120113su.txt Conversion ---------- ======================= ==================== ======================= file converted from software ======================= ==================== ======================= 49NZ20120113_nc_ctd.zip 49NZ20120113_ct1.zip hydro 0.8.0-96-g8497d06 ======================= ==================== ======================= All converted files opened in JOA with no apparent problems. Directories =========== :working directory: /data/co2clivar/pacific/p10/p10_49NZ20120113/original/2014.02.12_SUM-CTD_CBG :cruise directory: /data/co2clivar/pacific/p10/p10_49NZ20120113 Updated Files Manifest ====================== ======================= =================== file stamp ======================= =================== 49NZ20120113_nc_ctd.zip 49NZ20120113_ct1.zip 20120525JAMSTECRIGC 49NZ20120113su.txt ======================= =================== 2014-08-18 Key, Bob BTL Submitted to go online 8/15/14 Downloaded file 49NZ20120113_hy1.csv from http://www.jamstec.go.jp/iorgc/ocorp/data/p10rev_2011/index.html 8/18/14 With eXcel Remove leading "X" from bottle numbers Replace "J" in bottle numbers with "0" Surface samples have bottle "-999" replace with 99 Delete CTDPRS_FLAG_W Delete CTDTMP_FLAG_W Delete c13,c14,h3,cs134,cs137 and errors Delete DNSSAL and flag, XMISSCP Delete SILUNC, NRAUNC,PHPUNC Save as P10N.2012.csv Fix line endings with vi and delete extra "," copy to SUN __________ From original file header BOTTLE,20140213JAMSTECRIGC #Software_Version: whp_btl_exchange.rb_v3.0 (occrp) #ORIGINAL_SUM_FILE: 49NZ20120113_sum.txt Tue Jan 14 11:26:58 +0900 2014 #ORIGINAL_HYD_FILE: sea201402120503.csv Thu Feb 13 13:01:28 +0900 2014 #DEPTH_TYPE: COR #EVENT_CODE: BO 2014-08-19 Staff, CCHDO BTL Website Update Available under 'Files as received' The following files are now available online under 'Files as received', unprocessed by the CCHDO. 49NZ20120113.exc.csv README.Mac.txt 2014-11-04 Kappa, Jerry CrsRpt PDF version online I've placed a new PDF version of the cruise report: 49NZ20120113_do.pdf into the directory: http://cchdo.ucsd.edu/data/co2clivar/pacific/p10/p10_49NZ20120113/ It includes all the reports provided by the cruise PIs, summary pages and CCHDO data processing notes, as well as a linked Table of Contents and links to figures, tables and appendices. 2014-09-17 R Lee BTL Website Update Exchange and netCDF files online Rox Lee 49NZ20111220 processing - BTL 2014-09-17 Contents * Submission o Parameters * Process o Changes o Conversion * Directories * Updated Files Manifest Submission filename submitted by date data type id -------------------- ------------- ---------- ---------- ---- 49NZ20111220.exc.csv Robert M. Key 2014-08-18 BTL/CrsRpt 1202 Parameters * CTDPRS * CTDTMP * CTDSAL [1] * SALNTY [1] * CTDOXY [1] * OXYGEN [1] * SILCAT [1] * NITRAT [1] * NITRIT [1] * PHSPHT [1] * CFC-11 [1] * CFC-12 [1] * CFC113 [1] * SF6 [1] * TCARBN [1] * ALKALI [1] * PH_TOT [1] * PH_TMP * XMISS [1] [3] * CHLORA [1] * FLUOR [1] [3] * PAR [1] [3] * THETA [3] * SBE35 [1] [3] 49NZ20111220.exc.csv [1] (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20) parameter has quality flag column [3] (1, 2, 3, 4, 5) not in WOCE bottle file Process Changes * Changed SEB35 to SBE35 49NZ20111220.exc.csv Conversion file converted from software ----------------------- -------------------- ----------------------- 49NZ20111220_nc_hyd.zip 49NZ20111220_hy1.csv hydro 0.8.2-40-g569f4c2 All converted files opened in JOA with no apparent problems. Directories working directory: /data/co2clivar/pacific/p10/p10_49NZ20111220/original/2014.09.17_BTL_RJL cruise directory: /data/co2clivar/pacific/p10/p10_49NZ20111220 Updated Files Manifest file stamp ----------------------- ----------------- 49NZ20111220_nc_hyd.zip 20140917SIOCCHRJL 49NZ20111220_hy1.csv 20140917SIOCCHRJL