CRUISE REPORT: P09 (Updated MAR 2012) A. CRUISE NARRATIVE 1. HIGHLIGHTS CRUISE SUMMARY INFORMATION WOCE Section Designation P09 (RF10-05) Expedition designation (ExpoCodes) 49RY20100706 Chief Scientists Toshiya Nakano Dates Leg 1: 6 July 2010 - 28 July 2010 Leg 2: 1 August 2010 - 22 August 2010 Ship R/V Ryofu Maru Ports of call Leg 1: Tokyo - Palau, Leg 2: Palau - Saipan 34° 14.92' N Geographic Boundaries 136° 47.11' E 142° 0.12' E 2° 19.81' S Stations 124 Floats and drifters deployed One drifting ocean data buoy Moorings deployed or recovered 0 Recent Contact Information: Toshiya Nakano • Marine Environment Monitoring and Analysis Center Marine DivisionGlobal Environment and Marine Department Japan Meteorological Agency 1-3-4, Otemachi, Chiyoda-ku • Tokyo • 100-8122 • Japan Phone: +81+3+3212-8341 x5163 • Fax: +81-3-3211-6908 Email: nakano_t@met.kishou.go.jp Contents A. Cruise narrative 1. Highlights 2. Cruise Summary Information 3. List of Principal Investigators for all Measurements 4. Scientific Program and Methods 5. Major Problems and Goals not Achieved 6. List of Cruise Participants B. Underway measurements 1. Navigation and Bathymetry 2. Maritime Meteorological Observations 3. Thermo-Salinograph (in preparation) 4. pCO2 (in preparation) 5. Chlorophyll-a 6. Acoustic Doppler Current Profiler C. Hydrographic Measurement Techniques and Calibration 1. CTD/O2 Measurements 2. Bottle Salinity 3. Bottle Oxygen 4. Nutrients 5. Total Dissolved Inorganic Carbon (DIC) / Total Alkalinity (TA) (in preparation) 6. pH (in preparation) 7. Chlorofluorocarbon (CFC-11 and CFC-12) (in preparation) 8. Phytopigment (Chlorophyll-a and phaeopigmens) 9. Lowered Acoustic Doppler Current Profiler 2. CRUISE SUMMARY INFORMATION RF10-05 cruise was carried out during the period from July 6 to September 1, 2010. The cruise started from the south of Honshu, Japan, and sailed towards south along approximately 137°E meridian. This line was observed by JMA in 1994 as 'WHP-P9', which is a part of WOCE (World Ocean Circulation Experiment) Hydrographic Programme. A total of 124 stations was occupied using a Sea-Bird Electronics (SBE) 36 position carousel equipped with 10-liter Niskin water sample bottles, a CTD system (SBE911plus) equipped with SBE35 deep ocean standards thermometer, JFE Advantech oxygen sensor (RINKO III), Teledyne Benthos altimeter, and Teledyne RD Instruments Lowered Acoustic Doppler Current Profiler (L-ADCP). To examine consistency of data, we carried out the observation three times at 7°N, 137°E (Stn.67, 68 and 124) and twice at 2°N, 142°E (Stn.83 and 104). Cruise track and station location are shown in Figure 1. At each station, full-depth CTDO2 (temperature, conductivity (salinity) and dissolved oxygen) profile and up to 36 water samples were taken and analyzed. Water samples were obtained from 10 dbar to approximately 10 m above the bottom. In addition, surface water was sampled by a stainless steel bucket at each station. Sampling layer is designed as so-called staggered mesh as shown in Table 1 (Swift, 2010). The bottle depth diagram is shown in Figure 2. Water samples were analyzed for salinity, dissolved oxygen, nutrients, dissolved inorganic carbon (DIC), total alkalinity (TA), pH, CFC-11, CFC-12 and phytopigment (chlorophyll-a and phaeopigmens). Samples for dissolved organic carbon (DOC) and 13C were also collected at the selected stations. Underway measurements of partial pressure of carbon dioxide (pCO2), temperature, salinity, chlorophyll-a, subsurface current, bathymetry and meteorological parameters were conducted along the cruise track. R/V Ryofu Maru departed Tokyo (Japan) on July 6, 2010. Before the observation at the first station, all watch standers were drilled in the method of sample drawing and CTD operations near Izu-Oshima (34°40'N, 139°37'E). In order to estimate the misalignment of the ship-mounted Acoustic Doppler Current Profiler (ADCP), we collected the bottom tracking data for about an hour off Omaezaki (around 34°22'N, 137°55'E). The hydrographic cast of CTDO2 was started at the first station (Stn.1 (34°15'N, 137°E; RF3649)) on July 7. Leg 1 consisted of 67 stations from Stn.1 to Stn.67 (7°N, 137°E; RF3715). She called for Palau (Republic of Palau) on July 28, 2010 (Leg 1). She left Palau on August 1, 2010 for Saipan (Commonwealth of the Northern Mariana Islands) and arrived on August 22, 2010 (Leg 2). Leg 2 consisted of 57 stations from Stn.68 (7°N, 137°E; RF3716) to Stn.124 (7°N, 137°E; RF3772). To wait the issue of a clearance letter for the EEZ of Papua New Guinea, we carried out from Stn.105 (2°03'N, 141°45'E; RF3732) to Stn.107 (2°09'N, 141°15'E; RF3734) after observation at Stn.83 (2°N, 142°E; RF3731) on August 5. After the issue of the clearance letter, we resumed from Stn.84 (1°45'N, 142°E; RF3735) on August 6. To carry out four stations from Stn.100 (2°05'S, 141°45'E; RF3750) to Stn.103 (2°22'S, 141°08'E; RF3747) near the coast of Papua New Guinea during the daytime, we sailed to Stn.103 (2°22'S, 141°08'E; RF3747) after at Stn.95 (1°S, 142°E; RF3746), and resumed on August 9. One drifting ocean data buoy (WMO number： 21595) was deployed at 32°01.988'N, 137°00.620'E on July 8, 2010. Figure 1: Cruise track of RF10-05. Figure 2: The bottle depth diagram for WHP-P9 revisit. Table 1: The scheme of sampling layer in meters. Yap North of 20°N South of 20°N Trench (Stn.1 - Stn.38) (Stn-38 - Stn.124) (Stn.66) Bottle | ------------------------- | ------------------------- | -------- count | scheme1 scheme2 scheme3 | scheme4 scheme5 scheme6 | scheme7 ----- | ------- ------- ------- | ------- ------- ------- | -------- 1 | 10 10 10 | 10 10 10 | 10 2 | 25 25 25 | 25 25 25 | 50 3 | 50 50 50 | 50 50 50 | 75 4 | 75 75 75 | 75 75 75 | 100 5 | 100 100 100 | 100 100 100 | 125 6 | 125 125 125 | 125 125 125 | 150 7 | 150 150 150 | 150 150 150 | 200 8 | 200 200 200 | 200 200 200 | 250 9 | 250 250 250 | 250 250 250 | 300 10 | 300 330 280 | 300 320 280 | 400 11 | 400 430 370 | 350 370 330 | 500 12 | 500 530 470 | 400 420 380 | 600 13 | 600 630 570 | 450 470 430 | 700 14 | 700 730 670 | 500 530 480 | 800 15 | 800 830 770 | 600 630 570 | 900 16 | 900 930 870 | 700 730 670 | 1000 17 | 1000 1070 970 | 800 830 770 | 1250 18 | 1200 1270 1130 | 900 930 870 | 1500 19 | 1400 1470 1330 | 1000 1080 970 | 1750 20 | 1600 1670 1530 | 1250 1330 1170 | 2000 21 | 1800 1870 1730 | 1500 1580 1420 | 2250 22 | 2000 2080 1930 | 1750 1830 1680 | 2500 23 | 2250 2330 2170 | 2000 2080 1920 | 2750 24 | 2500 2580 2420 | 2250 2330 2170 | 3000 25 | 2750 2830 2680 | 2500 2580 2420 | 3250 26 | 3000 3080 2920 | 2750 2830 2680 | 3500 27 | 3250 3330 3180 | 3000 3080 2920 | 3750 28 | 3500 3580 3420 | 3250 3330 3180 | 4000 29 | 3750 3830 3680 | 3500 3580 3420 | 4250 30 | 4000 4080 3920 | 3750 3830 3680 | 4500 31 | 4250 4330 4180 | 4000 4080 3920 | 4750 32 | 4500 4580 4420 | 4250 4330 4180 | 5000 33 | 4750 4830 4680 | 4500 4580 4420 | 5250 34 | 5000 5080 4920 | 4750 4830 4680 | 5500 35 | 5250 5330 5180 | 5000 5080 4920 | 5750 36 | 5500 5580 5420 | 5250 5330 5180 | 6000 Table 2: Station data of RF10-05 cruise. The 'RF' column indicates the JMA station identification number. Station Position | Station Position ---------- ----------------------- | ---------- ----------------------- Leg Stn. RF Latitude Longitude | Leg Stn. RF Latitude Longitude --- ---- ---- ---------- ----------- | --- ---- ---- ---------- ----------- 1 1 3649 34-14.85 N 136-59.47 E | 1 36 3684 20-59.83 N 136-58.21 E 1 2 3650 34-06.71 N 136-59.24 E | 1 37 3685 20-29.06 N 136-59.41 E 1 3 3651 34-00.94 N 136-58.40 E | 1 38 3686 19-58.25 N 137-00.39 E 1 4 3652 33-50.14 N 137-00.82 E | 1 39 3687 19-29.39 N 136-59.28 E 1 5 3653 33-41.22 N 137-00.79 E | 1 40 3688 18-59.74 N 136-59.04 E 1 6 3654 33-30.31 N 137-01.55 E | 1 41 3689 18-30.52 N 136-59.94 E 1 7 3655 33-21.12 N 137-02.20 E | 1 42 3690 18-00.58 N 137-01.81 E 1 8 3656 33-11.27 N 137-02.34 E | 1 43 3691 17-30.53 N 136-57.81 E 1 9 3657 33-01.56 N 137-02.01 E | 1 44 3692 17-00.27 N 136-57.57 E 1 10 3658 32-42.25 N 137-00.65 E | 1 45 3693 16-30.38 N 136-58.83 E 1 11 3659 32-20.90 N 137-01.94 E | 1 46 3694 16-00.61 N 136-58.58 E 1 12 3660 32-00.61 N 137-00.75 E | 1 47 3695 15-29.31 N 136-59.09 E 1 13 3661 31-41.64 N 136-58.71 E | 1 48 3696 14-58.91 N 136-58.90 E 1 14 3662 31-21.19 N 137-00.50 E | 1 49 3697 14-29.66 N 136-58.10 E 1 15 3663 30-59.46 N 137-01.14 E | 1 50 3698 14-00.03 N 136-58.18 E 1 16 3664 30-39.21 N 136-59.69 E | 1 51 3699 13-29.87 N 136-57.56 E 1 17 3665 30-21.57 N 136-59.92 E | 1 52 3700 12-59.96 N 136-58.26 E 1 18 3666 30-00.10 N 137-01.43 E | 1 53 3701 12-30.05 N 136-58.33 E 1 19 3667 29-28.67 N 137-11.93 E | 1 54 3702 12-00.31 N 136-58.25 E 1 20 3668 29-01.75 N 136-59.89 E | 1 55 3703 11-29.76 N 136-58.70 E 1 21 3669 28-31.08 N 137-00.02 E | 1 56 3704 11-00.26 N 136-58.61 E 1 22 3670 27-59.90 N 136-59.33 E | 1 57 3705 10-29.85 N 136-58.61 E 1 23 3671 27-31.45 N 136-58.97 E | 1 58 3706 10-00.08 N 136-58.83 E 1 24 3672 27-00.52 N 136-59.86 E | 1 59 3707 9-30.74 N 136-58.65 E 1 25 3673 26-30.40 N 136-57.70 E | 1 60 3708 9-00.24 N 136-58.45 E 1 26 3674 25-59.83 N 136-59.19 E | 1 61 3709 8-40.27 N 136-59.58 E 1 27 3675 25-29.17 N 136-59.31 E | 1 62 3710 8-20.10 N 136-59.98 E 1 28 3676 25-00.65 N 137-00.21 E | 1 63 3711 7-59.77 N 136-59.20 E 1 29 3677 24-30.44 N 136-58.66 E | 1 64 3712 7-40.05 N 136-49.64 E 1 30 3678 24-00.94 N 136-59.92 E | 1 65 3713 7-30.48 N 136-49.37 E 1 31 3679 23-29.77 N 136-59.67 E | 1 66 3714 7-20.26 N 136-48.74 E 1 32 3680 23-00.92 N 137-18.82 E | 1 67 3715 7-00.04 N 136-58.93 E 1 33 3681 22-29.37 N 137-18.40 E | 2 68 3716 7-00.88 N 136-59.76 E 1 34 3682 21-59.97 N 137-18.57 E | 2 69 3717 6-39.49 N 137-21.88 E 1 35 3683 21-29.80 N 136-58.52 E | 2 70 3718 6-17.74 N 137-43.07 E Table 2. Continue. Station Position | Station Position ----------- ---------------------- | ----------- ---------------------- Leg Stn. RF Latitude Longitude | Leg Stn. RF Latitude Longitude --- ---- ---- ---------- ----------- | --- ---- ---- ---------- ----------- 2 71 3719 5-55.67 N 138-03.99 E | 2 101 3749 2-08.67 S 141-29.57 E 2 72 3720 5-33.31 N 138-25.79 E | 2 102 3748 2-15.11 S 141-13.64 E 2 73 3721 5-11.89 N 138-48.44 E | 2 103 3747 2-19.60 S 141-09.45 E 2 74 3722 4-50.02 N 139-10.52 E | 2 104 3755 1-59.43 N 142-00.12 E 2 75 3723 4-27.07 N 139-31.75 E | 2 105 3732 2-03.14 N 141-44.45 E 2 76 3724 4-06.04 N 139-54.57 E | 2 106 3733 2-06.16 N 141-29.56 E 2 77 3725 3-44.95 N 140-15.73 E | 2 107 3734 2-09.49 N 141-13.84 E 2 78 3726 3-21.94 N 140-37.71 E | 2 108 3756 2-11.70 N 140-59.67 E 2 79 3727 3-00.77 N 140-58.68 E | 2 109 3757 2-17.51 N 140-28.74 E 2 80 3728 2-45.45 N 141-14.11 E | 2 110 3758 2-24.22 N 139-59.72 E 2 81 3729 2-30.34 N 141-28.92 E | 2 111 3759 2-30.02 N 139-30.12 E 2 82 3730 2-14.41 N 141-44.74 E | 2 112 3760 2-35.75 N 138-59.52 E 2 83 3731 1-59.46 N 141-59.05 E | 2 113 3761 2-41.87 N 138-30.87 E 2 84 3735 1-44.79 N 141-58.73 E | 2 114 3762 2-47.99 N 138-00.11 E 2 85 3736 1-29.52 N 141-58.56 E | 2 115 3763 2-54.55 N 137-29.93 E 2 86 3737 1-14.31 N 141-59.87 E | 2 116 3764 2-59.58 N 136-59.63 E 2 87 3738 0-59.52 N 141-59.07 E | 2 117 3765 3-29.59 N 136-59.81 E 2 88 3739 0-44.71 N 141-59.89 E | 2 118 3766 4-01.31 N 136-58.47 E 2 89 3740 0-29.62 N 141-59.51 E | 2 119 3767 4-29.55 N 136-59.55 E 2 90 3741 0-14.50 N 141-59.26 E | 2 120 3768 4-59.94 N 136-59.75 E 2 91 3742 0-00.24 N 141-59.11 E | 2 121 3769 5-30.16 N 137-00.06 E 2 92 3743 0-15.42 S 141-59.21 E | 2 122 3770 5-59.22 N 136-58.21 E 2 93 3744 0-29.95 S 141-59.54 E | 2 123 3771 6-29.06 N 136-59.06 E 2 94 3745 0-44.90 S 141-59.39 E | 2 124 3772 7-00.20 N 136-59.16 E 2 95 3746 1-00.14 S 141-58.81 E | 2 96 3754 1-15.01 S 141-58.48 E | 2 97 3753 1-31.09 S 141-58.78 E | 2 98 3752 1-45.22 S 141-58.92 E | 2 99 3751 2-00.11 S 141-59.09 E | 2 100 3750 2-05.25 S 141-43.59 E | 3. LIST OF PRINCIPAL INVESTIGATORS FOR ALL MEASUREMENTS The principal investigator (PI) and the person in charge responsible for major parameters measured on the cruise are listed in Table 3. Table 3: List of principal investigator and the person in charge on the ship for RF10-05. Principal Person in charge Item Investigator （PI） on the ship ------------------ ----------------- ----------------- Hydrography -------------------------------------------------------- CTDO2 / LADCP Hitomi KAMIYA Tetsuya NAKAMURA Salinity Hitomi KAMIYA Keizo SHUTTA Dissolve oxygen Hitomi KAMIYA Yusuke TAKATANI Nutrients Hitomi KAMIYA Takahiro KITAGAWA Phytopigment Hitomi KAMIYA Yusuke TAKATANI DIC Hitomi KAMIYA Shinji MASUDA Total Alkalinity Hitomi KAMIYA Shinji MASUDA pH Hitomi KAMIYA Shinji MASUDA CFCs Hitomi KAMIYA Kazuki ISHIMARU DOC Masao ISHII Shinji MASUDA 13C Masao ISHII Shinji MASUDA Underway -------------------------------------------------------- Meteorology Hitomi KAMIYA Keizo SHUTTA Thermo-Salinograph Hitomi KAMIYA Shinji MASUDA pCO2 Hitomi KAMIYA Shinji MASUDA Chlorophyll-a Hitomi KAMIYA Yusuke TAKATANI ADCP Hitomi KAMIYA Tetsuya NAKAMURA Bathymetry Hitomi KAMIYA Takahiro SEGAWA Hitomi KAMIYA (hkamiya@met.kishou.go.jp) Marine Division, Global Environment and Marine Department, JMA 1-3-4, Otemachi, Chiyoda-ku, Tokyo 100-8122, JAPAN Phone: +81-3-3212-8341 Ext. 5150 FAX: +81-3-3211-6908 Masao ISHII (mishii@mri-jma.go.jp) Geochemical Research Department, Meteorological Research Institute, JMA 1-1, Nagamine, Tsukuba, Ibaraki 305-0052, JAPAN Phone: +81- 29-853-8727 FAX: +81-29-853-8728 4. SCIENTIFIC PROGRAM AND METHODS In recent years, the global environmental issues such as global warming and climate change have become one of the major socio-economic concerns, and it has become apparent that the ocean plays a key role in the climate system. For the better understanding and assessment of global environmental conditions, continuous monitoring of climate variables, concentrations of greenhouse gases both in the ocean and in the atmosphere. To meet those requirements, JMA has been conducting operational oceanographic observations by research vessels in the western North Pacific on a seasonal basis. RF10-05 cruise is one of these activities. The purposes of this cruise are as follows: (1) To observe profiles of seawater temperature, salinity, dissolved oxygen, nutrients and carbon parameters, as well as upper ocean current; (2) To observe concentrations of greenhouse gases both in the ocean and in the atmosphere; (3) To observe bio-geochemical parameters to study carbon cycle in the ocean. These activities are expected to contribute to international projects related to global environmental issues such as the World Climate Research Programme (WCRP), IOCCP (International Ocean Carbon Coordination Project) and the Global Atmosphere Watch (GAW). 5. MAJOR PROBLEMS AND GOALS NOT ACHIEVED Owing to kink in the wire, we reconnected the CTD cable at Stn.19 (29°30'N, 137E; RF3667). After the observation at Stn.104 (2° N, 142°E; RF3755), owing to damage in the wire, we cut the wire about 700 m in length, and reconnected the CTD cable. 6. LIST OF CRUISE PARTICIPANTS The cruise participants of the cruise is listed in Table 4. Table 4: List of cruise participants for RF10-05. Name Responsibility Affiliation ----------------- --------------------------------- ----------- Yasuaki BUNGI Salinity GEMD / JMA Kazutaka ENYO Carbon Items GEMD / JMA Hiroyuki FUJIWARA Nutrients GEMD / JMA Sho HIBINO Dissolved Oxygen GEMD / JMA Yoshikazu HIGASHI CTDO / ADCP / LADCP GEMD / JMA Kazuki ISHIMARU CFCs GEMD / JMA Takahiro KITAGAWA Nutrients GEMD / JMA Tomoyuki KITAMURA CTDO / ADCP / LADCP GEMD / JMA Naohiro KOSUGI Carbon Items MRI / JMA Shinji MASUDA Carbon Items / Thermo-Salinograph GEMD / JMA Tetsuya NAKAMURA CTDO / ADCP / LADCP GEMD / JMA Toshiya NAKANO Chief Scientist GEMD / JMA Etsuro ONO CFCs GEMD / JMA Takahiro SEGAWA Salinity / Bathymetry GEMD / JMA Kazuhiro SAITO Nutrients GEMD / JMA Keizo SHUTTA Salinity / Meteorology GEMD / JMA Yusuke TAKATANI Dissolved Oxygen / Phytopigment GEMD / JMA Shinichiro UMEDA Dissolved Oxygen / Phytopigment GEMD / JMA GEMD / JMA: Marine Division, Global Environment and Marine Department, JMA MRI / JMA: Geochemical Research Department, Meteorological Research Institute, JMA Reference Swift, J. H. (2010): Reference-quality water sample data: Notes on acquisition, record keeping, and evaluation. IOCCP Report No.14, ICPO Pub. 134, 2010 ver.1. B. Underway measurements 1. Navigation and Bathymetry (1) Personnel Takahiro SEGAWA (GEMD/JMA) Tetsuya NAKAMURA (GEMD/JMA) Keizo SHUTTA (GEMD/JMA) Yoshikazu HIGASHI (GEMD/JMA) Tomoyuki KITAMURA (GEMD/JMA) Yasuaki BUNGI (GEMD/JMA) (2) Navigation (2.1) Overview of the equipment The ship's position was measured by navigation system made by FURUNO ELECTRIC CO., LTD. JAPAN. The system has two 3-channels GPS receivers (GP-80, GP-150). GPS antennas was installed at Compass deck. We switched the receivers to choose better receiving state if the number of GPS satellites decreased or HDOP increased. GPS data, gyro heading and log speed were integrated and delivered to two workstations. One workstation works as primary NTP (Network Time Protocol) server and the other works secondary server. The navigation data were obtained approximately every one second and one minute data were extract from one second data. These one minute data were recorded as "LOG data". (2.2) Data Period 05:00, 06 Jul. 2010 to 00:00, 1 Sep. 2010(UTC) (3) Bathymetry (3.1) Overview of the equipment R/V Ryofu Maru equipped a single beam echo sounder, Kongsberg EA 600 (SIMRAD Fisheries Research, Norway). The main objective of the survey is collecting continuous bathymetry data along ship's track. At first we set up system choosing 1500 m/s for sound speed. During the cruise, we used averaged sound velocity data obtained from the nearest CTD cast to get accurate depth data. Data interval was about 8 seconds at 6000m. (3.2) System Configuration and Performance System: Kongsberg EA 600 Frequency: 12kHz Transmit power: 2kW Transmit pulse interval: Within 20seconds Depth range: 5 to 15,000m Depth resolution: 1cm Depth accuracy: Within 20cm (3.3) Data Period The collecting bathymetry data was carried out during the cruise except for port of Palau and Saipan. 05:00, 06 Jul. 2010 to 00:00, 1 Sep. 2010(UTC) (3.4) Data Processing The bathymetry data are obtained using a mean sound velocity calculated from the data of nearest CTD cast. The formula of the sound velocity calculated in SEASAVE, CTD data acquisition software, is Chen and Millero (1977). The system combines bathymetry data with navigation data, so the data file consists of date, time, location, depth and flag of bathymetry data. If the erroneous data were obtained, the bathymetry data flag was set to '9' and the data was set to '0' automatically. Reference Chen, C.-T. and F. J. Millero (1977): Speed of sound in seawater at high pressures. J. Acoust. Soc. Am. 62(5), 1129-1135. 2. MARITIME METEOROLOGICAL OBSERVATIONS (1) Personnel Keizo SHUTTA (GEMD/JMA) Tetsuya NAKAMURA (GEMD/JMA) Takahiro SEGAWA (GEMD/JMA) Yoshikazu HIGASHI (GEMD/JMA) Yasuaki BUNGI (GEMD/JMA) Tomoyuki KITAMURA (GEMD/JMA) (2) Data Period 09:00, 6 Jul. 2010 to 23:00, 31 Aug. 2010(UTC) (3) Methods The maritime meteorological observation system on R/V Ryofu Maru is Ryofu Maru maritime meteorological measurement station (RMET). Instruments of RMET are listed in Table B.2.1. All RMET data were collected and processed by KOAC-7800 weather data processor made by Koshin Denki Kogyo CO., Ltd. Japan. Figure B.2.1 and B.2.2 show maritime meteorological observation data. Table B.2.1: Instruments and locations of RMET. Location Manufacture (Height from max- Sensor Parameter (Type) imum load line) ----------- ----------------- -------------------- ----------------- Thermometer Air Temperature Koshin Denki Kogyo Compass deck (Electric type) (13.3m) Hygrometer Relative humidity Koshin Denki Kogyo Compass deck (Electrostatic type) (13.3 m) Thermometer Sea Temperature Koshin Denki Kogyo Engine Room (Electric type) (-4.7 m) Aerovane Wind Speed Koshin Denki Kogyo Mast top Wind Direction (Propellar type) (19.8 m) Wave gauge Wave Height Tsurumi-Seiki Ship front Wave period (Micro wave type) (6.5 m) Barometer Pressure Koshin Denki Kogyo Observation room (Electrostatic type) (2.8 m) Note that there are two set of thermometer and hygrometer at starboard and port sides. Figure B.2.1: Time series of (a) air and sea surface temperature, (b) relative humidity, (c) pressure, (d) wind speed and wave height. The light blue in (d) panel, light blue line shows the non-instrumental observation of wave height. Day 0 correspond to July 6 (JST), 2010. Figure B.2.2: Wind verb along Ryofu Maru at every noon position. Black flag corresponds to 10m/s, long line corresponds to 2m/s and short line corresponds to 1m/s. (4) Data processing and Data format All raw data were recorded every 6-seconds. 1-minute and 10-minute values are averaged from 6-seconds values. 10-minute value of every three hours is available at JMA web site (http://www.data.kishou.go.jp/kaiyou/db/vessel_obs/data-report/html/ship/cruisedata_e.php?id=RF1005). Since the thermometers and hygrometers are equipped on both starboard/port sides on the Compass deck, we used 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 for pressure data. During the cruise, fixed value +0.5hPa is used for sea level correction. Data are stored in ASCII format and representative parameters are as follows. Time in UTC, longitude (E), latitude (N), ship speed (knot), ship direction (degrees), sea surface pressure (hPa), air temperature (degrees Celsius), dew point temperature (degrees Celsius), relative humidity (%), sea surface temperature (degrees Celsius), wind direction (degree) and wind speed (m/sec). Wave height and period are observed twice an hour. The sampling duration is 20 minutes and each sampling starts at 5 minutes and 35 minutes after the hour. In addition to those data, ship's position and observation time are recorded in ASCII format. (5) Data quality To ensure the data quality, each sensor was checked as follows. Temperature/Relative humidity sensor: Temperature and relative humidity (T/RH) sensors were checked by manufacturer and, they were also checked by using calibrated Asman psychrometer before the cruise and arrival at the port. The discrepancy between T/RH sensors and Asman psychrometer were within ±0.4 degrees Celsius and ±4% respectively at both sides. Thermometer (Sea Temperature): Sea temperature sensor was calibrated once per year by the manufacturer. Certificated accuracy of sea temperature sensor is better than ±0.4 degrees Celsius. The values are also compared with bucket samples after the departure. Pressure sensor: Using calibrated portable barometer (Vaisala 765-16B, certificated accuracy is better than ± 0.1 hPa), pressure sensor was checked before the cruise. Mean difference of RMET pressure sensor and portable sensor is less than 0.7 hPa. Aerovane: Aerovane was checked once per year by the manufacturer and, once per five years by the Meteorological Instrument Center, JMA. (6) Ship's weather observation Non-instrumental observations such as weather, cloud, visibility, wave direction and wave height were made by the ship crews every three hours. We sent those data together with RMET data to the Global Collecting Centre for Marine Climatological Data in IMMT (International Maritime Meteorological Tape) -III format. The RMET data is available at JMA web site. (http://www.data.kishou.go.jp/kaiyou/db/vessel_obs/data- report/html/ship/cruisedata_e.php?id=RF1005). 5. CHLOROPHYLl-a (1) Personnel Yusuke TAKATANI (GEMD/JMA) Shinichiro UMEDA (GEMD/JMA) (2) Method The Continuous Sea Surface Water Monitoring System of fluorescence (Nippon Kaiyo Co. Ltd.) automatically had been continuously measured seawater which is pumped from a depth of about 4.5 m below the maximum load line to the laboratory. The flow rate of the surface seawater was controlled by several valves and adjusted to about 0.6 L/min. The sensor in this system is a fluorometer (10-AU, S/N:7063) manufactured by Turner Designs. The system measured every one minute. (3) Measurement Periods of measurement and problems are listed in Table B.5.1. (4) Calibration In order to calibrate the fluorescence sensor, we collected 200 ml of surface seawater from outlet of water line of the system for measuring chlorophyll-a. The seawater samples were collected at nominally 60 N. miles intervals. The seawater sample was gently filtrated by low vacuum pressure through Whatman GF/F filter (diameter 25mm). The filter was immediately transferred into 9 ml of N, N-dimethylformamide (DMF) and then stored at -30ºC to extract chlorophyll-a for more than 24 hours. Concentrations of chlorophyll-a were measured by a fluorometer (10-AU, S/N: 6718, TURNER DESIGNS) that was previously calibrated against a pure chlorophyll-a (Lot.:BCBB4166, Sigma chemical Co.) by the method described in UNESCO (1994). In order to calibrate the fluorometer, fluorometric measurement of chlorophyll-a was performed by the method of Holm-Hansen et al. (1965) and Holm-Hansen and Riemann (1978). The results of the measurements are shown in Table B.5.2. The fluorescence sensor may be contaminated while measuring. Therefore,　we calibrated the fluorescence value of the sensor to 0 (deionized water) and 10 (0.1 ppm Rhodamine solution) at the start of a leg, and measured a solution of the same concentration at the end of a leg. The results are shown in Table B.5.3. The data is calculated by the following procedure; • The fluorescence value of the sensor is calibrated by deionized water and a Rhodamine solution at the starting and the ending. • The ratio between a calibrated fluorescence value and a chlorophyll-a concentration of a seawater sample is interpolated by distance. • The chlorophyll-a concentration is calculated by multiplying a calibrated fluorescence value by an interpolated ratio. (5) Data and Result Quality controlled data, those file name is "20120202_p09_in-vivo.txt", is distributed by JMA format. The record structure of JMA format is shown below. Column1: observed date [UTC] Column2: observed time [UTC] Column3: observed latitude Column4: observed longitude Column5: fluorescence value Column6: fluorescence value calibrated by deionized water and a Rhodamine solution Column7: ratio between a calibrated fluorescence value and a chlorophyll-a Column8: calculated chlorophyll-a concentration (mg/L) Result of chlorophyll-a concentration of underway measurement in shown in Figure B.4.1. Chlorophyll-a data on Figure B.4.1 is averaged over 2-hours. Figure B.4.1: Result of chlorophyll-a concentration of underway measurement. References Holm-Hansen, O., and B. Riemann (1978): chlorophyll a determination: improvements in methodology. Oikos, 30, 438-447. Holm-Hansen, O., C. J. Lorenzen, R. W. Holmes and J. D. H. Strickland (1965): Fluorometric determination of chlorophyll. J. Cons. Perm. Int. Explor. Mer., 30, 3-15. UNESCO (1994), Protocols for the joint global ocean flux study (JGOFS) core measurements: Measurement of chlorophyll a and phaeopigments by fluorometric analysis, IOC manuals and guides 29, Chapter 14. Table B.5.1. Events list of the fluorescence sensor. Date [UTC] Time [UTC] Event ----------- ----------- ---------------------------------------------- 6-Jul-10 08:51 The measurement started. (Leg 1 start) 6-Jul-10 12:19 Error data due to the flow line 6-Jul-10 22:13 Error data due to the flow line 7-Jul-10 00:21 Error data due to the flow line 8-Jul-10 07:26 Error data due to the flow line 8-Jul-10 12:14 Error data due to the flow line 9-Jul-10 12:46 Error data due to the flow line 13-Jul-10 21:54-09:48 Error data due to the flow line. -14-Jul-10 15-Jul-10 01:43-02:56 Failure of data storage due to the PC trouble. 19-Jul-10 21:33 Error data due to the flow line 23-Jul-10 14:29 The measurement stopped. (Leg 1 end) 2-Aug-10 02:38 The measurement started. (Leg 2 start) 2-Aug-10 05:16-05:25 GPS data error. 4-Aug-10 21:03 Error data due to the flow line 4-Aug-10 22:18 Error data due to the flow line 6-Aug-10 09:41-10:26 Failure of data storage due to the PC trouble. 6-Aug-10 21:10 Error data due to the flow line 7-Aug-10 02:56-03:03 Failure of data storage due to the PC trouble. 7-Aug-10 14:38 Error data due to the flow line 8-Aug-10 05:49-08:00 Failure of data storage due to the PC trouble. 9-Aug-10 04:32 Error data due to the flow line 9-Aug-10 18:50 Error data due to the flow line 10-Aug-10 08:57 Error data due to the flow line 10-Aug-10 13:52 Error data due to the flow line 11-Aug-10 12:35-13:16 Failure of data storage due to the PC trouble. 11-Aug-10 22:09-11:09 Error data due to the flow line. -12-Aug-10 16-Aug-10 08:51 The measurement stopped. (Leg 2 end) Table B.5.2: Comparison of sensor fluorescence and bottle chlorophyll-a collected from the pump in each sampling point. Sensor Chloro- Date Time Fluor- phyll-a [UTC] [UTC] Latitude Longitude escence (mg/L) --------- ----- ---------- ----------- ------- ------- 6-Jul-10 08:51 35˚02.06'N 139˚41.04'E 1.242 0.76 7-Jul-10 00:23 34˚14.80'N 136˚59.37'E 0.632 0.48 7-Jul-10 04:48 34˚00.97'N 136˚58.39'E 0.719 0.40 7-Jul-10 15:03 33˚30.36'N 137˚01.73'E 0.507 0.27 8-Jul-10 04:05 33˚03.12'N 137˚03.42'E 0.240 0.21 8-Jul-10 17:38 32˚21.66'N 137˚04.83'E 0.261 0.18 9-Jul-10 05:14 31˚43.51'N 136˚58.28'E 0.453 0.27 9-Jul-10 17:49 30˚58.89'N 137˚02.15'E 0.157 0.09 10-Jul-10 10:38 30˚00.04'N 137˚02.44'E 0.098 0.08 11-Jul-10 03:01 29˚03.78'N 137˚00.31'E 0.056 0.08 11-Jul-10 16:00 27˚59.81'N 136˚58.89'E 0.050 0.04 12-Jul-10 04:43 27˚00.72'N 136˚59.28'E 0.070 0.04 12-Jul-10 19:01 25˚59.15'N 136˚58.26'E 0.049 0.04 13-Jul-10 08:27 25˚01.70'N 137˚00.67'E 0.038 0.04 13-Jul-10 21:52 24˚01.35'N 136˚59.80'E 0.043 0.05 14-Jul-10 12:37 23˚01.36'N 137˚17.09'E 0.009 0.04 15-Jul-10 00:14 21˚59.46'N 137˚16.84'E -0.004 0.05 15-Jul-10 13:39 21˚00.03'N 136˚55.59'E 0.025 0.03 16-Jul-10 01:15 19˚57.38'N 136˚59.99'E 0.029 0.05 16-Jul-10 13:25 18˚59.38'N 136˚58.47'E 0.086 0.07 17-Jul-10 03:10 18˚00.68'N 137˚02.40'E 0.050 0.07 17-Jul-10 17:16 17˚00.64'N 136˚55.61'E 0.127 0.07 18-Jul-10 06:56 16˚00.56'N 136˚57.81'E 0.129 0.08 18-Jul-10 18:48 14˚58.61'N 136˚58.13'E 0.183 0.07 19-Jul-10 08:19 13˚59.99'N 136˚57.16'E 0.145 0.06 19-Jul-10 21:45 12˚59.91'N 136˚57.25'E 0.193 0.06 20-Jul-10 11:13 12˚00.11'N 136˚56.43'E 0.151 0.03 21-Jul-10 01:28 11˚00.56'N 136˚56.68'E 0.212 0.06 21-Jul-10 14:50 10˚00.13'N 136˚58.09'E 0.242 0.04 22-Jul-10 02:57 9˚00.78'N 136˚57.52'E 0.229 0.06 22-Jul-10 17:19 7˚59.83'N 136˚58.61'E 0.339 0.06 23-Jul-10 14:29 7˚00.36'N 136˚58.13'E 0.510 0.05 2-Aug-10 02:38 7˚01.80'N 136˚59.66'E 0.105 0.10 4-Aug-10 11:23 3˚45.89'N 140˚14.74'E -0.111 0.04 5-Aug-10 00:09 3˚00.95'N 140˚57.80'E -0.104 0.06 5-Aug-10 17:49 1˚59.73'N 141˚58.66'E -0.099 0.05 7-Aug-10 03:43 0˚59.99'N 141˚58.33'E -0.024 0.09 7-Aug-10 12:11 0˚29.74'N 141˚57.93'E -0.060 0.06 7-Aug-10 14:37 0˚14.75'N 141˚59.47'E 0.633 0.13 7-Aug-10 21:35 0˚00.34'N 141˚57.14'E 0.288 0.14 8-Aug-10 14:29 0˚59.78'S 141˚57.93'E 0.147 0.13 9-Aug-10 16:39 2˚00.22'S 141˚57.71'E -0.033 0.14 10-Aug-10 22:56 1˚58.91'N 141˚59.16'E -0.124 0.05 11-Aug-10 09:50 2˚11.62'N 140˚57.94'E -0.101 0.05 11-Aug-10 22:08 2˚24.47'N 139˚58.34'E -0.064 0.06 12-Aug-10 11:12 2˚35.48'N 138˚59.16'E -0.071 0.05 13-Aug-10 01:37 2˚47.76'N 137˚59.88'E -0.068 0.05 13-Aug-10 17:37 2˚59.39'N 136˚59.57'E -0.009 0.07 14-Aug-10 09:46 4˚00.91'N 136˚57.92'E -0.050 0.04 15-Aug-10 00:09 4˚59.68'N 136˚59.26'E -0.014 0.06 15-Aug-10 18:15 5˚58.61'N 136˚56.93'E -0.004 0.05 16-Aug-10 08:51 6˚59.93'N 136˚58.48'E -0.009 0.04 Table B.5.3: Results of the fluorescence value of the sensor at the start and end of each leg(0 : deionized water, 10 : 0.1ppm Rhodamine solution). Start End ------------------------- ------------------------- Date [UTC] 0 10 Date [UTC] 0 10 -------------- - ------ --------------- - ----- 1 Leg 6-Jul-10 08:30 0 10.000 27-Jul-10 05:00 0 8.296 2 Leg 1-Aug-10 04:30 0 10.000 20-Aug-10 01:32 0 8.438 6. Acoustic Doppler Current Profiler (1) Personnel Tetsuya NAKAMURA (GEMD/JMA) Yoshikazu HIGASHI (GEMD/JMA) Tomoyuki KITAMURA (GEMD/JMA) Keizo SHUTTA (GEMD/JMA) Takahiro SEGAWA (GEMD/JMA) Yasuaki BUNGI (GEMD/JMA) (2) Instruments and Methods The instrument used was the hull-mounted 38kHz Ocean Surveyor ADCP (Teledyne RD Instruments, Inc., USA; hereafter TRDI). The transducer of the system was installed in a dome at 3 m left of center and 13 m aft of the bow at the water line. The firmware version was 23.17 and the data acquisition software was TRDI/VMDAS Version. 1.46. The instrument was used in water-tracking mode during the operations, and was recording each ping raw data in 20 m × 60 bin from about 36 m to 1200 m in depth. Sampling interval was variable as short as possible and typically 6.4 seconds. GPS navigation data and ship's gyrocompass data were recorded with the ADCP data. In addition to the raw data, 60 seconds and 300 seconds averaged data were stored as short time average (STA) and long time average (LTA) data, respectively. Current field based on the gyrocompass was used to check the operation and the performance on board. (3) Performance and quick view of the ADCP data on board The performance of the ADCP instrument was almost good throughout the cruise, and current profiles were usually reached about 1000m. We monitored the profiles and currents based on LTA data in this cruise on board. The ADCP had been installed on the R/V Ryofu Maru just before the cruise, so the scale factor and misalignment angle (Joyce, 1989) to ADCP firmware for Leg 1 were set 1.0 and 0.0, respectively. The scale factor and misalignment for Leg 2 and Leg 3 were set 1.0012 and -1.0627, respectively, based on the calibration constants evaluated by the Leg 1 data. (4) Data Processing LTA data were processed by using CODAS (Common Oceanographic Data Access System) software, developed at the University of Hawaii (http://currents.soest.hawaii.edu/docs/doc/index.html). We use a standard CODAS processing including a PC time correction, a sound-speed correction based on the thermistor temperature at the transducers, and an amplitude and phase calibration constant applied to the measured velocities. Calibration constants to be applied were evaluated for each leg using the water track data. For Leg 1, the amplitude and phase were 1.0012 and -1.0627, respectively, and for Leg 2 and Leg 3, those were 1.0005 and -0.5528, respectively. Figure B.6.1 shows surface current at the depth of 36 m during the cruise. Figure B.6.1: Surface current at the depth of 36 m. Reference Joyce, T. M. (1988): On in-situ "calibration" of shipboard ADCPs. J. Atmos. Oceanic Technol., 6, 169-172. C. HYDROGRAPHIC MEASUREMENT TECHNIQUES AND CALIBRATION 1. CTD/O2 MEASUREMENTS (1) Personnel Tetsuya NAKAMURA (GEMD/JMA) Yoshikazu HIGASHI (GEMD/JMA) Tomoyuki KITAMURA (GEMD/JMA) Keizo SHUTTA (GEMD/JMA) Takahiro SEGAWA (GEMD/JMA) Yasuaki BUNGI (GEMD/JMA) (2) CTD Traction Winch and Motion Compensated Crane Arrangements The CTD/O2 system was deployed by using a Traction Winch System with ca. 7000 m of 8.03 mm armored cable (Tyco Electronics, USA) and a Motion Compensated Crane (Dynacon, Inc., USA). The system was installed on the R/V Ryofu Maru in March, 2010 (Photo C.1.1). Photo C.1.1: (Left) The Traction Winch and (right) Motion Compensated Crane. (3) Overview of the CTD/O2 system The CTD/O2 system, SBE 911plus system (Sea-Bird Electronics, Inc., USA), was used for entire cruise. The system is consisted of a SBE 9plus underwater unit and a SBE 11plus deck unit. The SBE 11plus deck unit is a rack-mountable interface which supplies DC power to under water unit, decodes serial data stream, formats data under microprocessor control, and passes the data to a computer. The real time serial data from the underwater unit is sent to the deck unit. The deck unit decodes the serial data and sends them to a personal computer to display and a storage in a file using SEASAVE data acquisition software (SEASAVE-Win32, version 7.18) . The SBE 911plus system controls 36-position SBE 32 Carousel Water Sampler (Photo C.1.2). The Carousel with a custom frame accepts 10-liter Niskin bottles (General Oceanics, Inc., USA). The SBE 9plus was mounted horizontally in the 36- position carousel frame. Two set of SBE's temperature (SBE 3plus) and conductivity (SBE 4C) sensor modules were used with the SBE 9plus underwater unit. Two modular units of underwater housing pump (SBE 5T) flush water through sensor tubing at a constant rate independent of the CTD's motion (Photo C.1.3). Two dissolved oxygen sensors (RINKO III: JFE Advantech Co., Ltd., Japan; http://www.jfe-alec.co.jp/html/english_top.htm) were mounted on CTD housing, by the side of primary T/C sensors (Photo C.1.3). Auxiliary sensors, Deep Ocean Standards Thermometer (SBE 35) and an altimeter (PSA-916D: Teledyne Benthos, Inc., USA) were also used with the SBE 9plus underwater unit. The SBE 35 was mounted at the center of CTD between two pumps. The altimeter was mounted at the same height of pressure sensor of SBE 9plus. Photo C.1.2: The CTD/O2 system (left) top view and (right) bottom view. Photo C.1.3: (left) SBE 9plus CTD with SBE35 and (right) RINKO III. Table C.1.1: Specification and serial number of the CTD/O2 measurements system components. Deck unit Serial Number SBE 11plus (SBE) 0648 Under water unit Serial Number Range Accuracy Stability Resolution SBE 9plus (SBE) 35560 0 to 10000 psi 0.015%(FS) 0.002%FS/year 0.001% (FS) (Pressure: 0764) 0 to 6800 dbar 1.0 dbar 0.2 dbar/year 0.1 dbar Temperature Serial Number Range Accuracy Stability Resolution SBE 3plus (SBE) 4923 (primary) -5 to 35°C 0.001°C 0.0002°C/month 0.0002°C 4199 (secondary) Conductivity Serial Number Range Accuracy Stability Resolution SBE 4C (SBE) 3670 (primary) 0 to 7 S/m 0.0003 S/m 0.0003 S/m/month 0.00004 S/m 2842 (secondary) Pump Serial Number SBE 5T (SBE) 3887 (primary) 5501 (secondary) Oxygen Serial Number Range Linearity Response time Resolution RINKO III (JFE) 25 (primary, 0 to 200% ±2% (FS) ≤1 second 0.01 to 0.04% foil number:144) (saturation) 26 (secondary, foil number:144) Water sampler Serial Number SBE 32 (SBE) 0734 Altimeter Serial Number Range Resolution PSA-916D (TB) 1267 0 to 100 m 1 cm Water Sampling Bottle Niskin Bottle •10-Liter •Bottle O-ring: Viton (GO) •No TEFRON coating •Stainless spring SBE: Sea-Bird Electronics Inc., USA → JFE: JFE Advantech Co., Ltd., Japan GO: General Oceanics, Inc., USA → TB: Teledyne Benthos, Inc., USA (4) Pre-cruise calibration (4.1) Pressure Pre-cruise calibration were performed at SBE, Inc., USA. The following coefficients were used in the SEASOFT: S/N 0764, 25 May 2010 c1 = -4.318853e+04 c2 = -4.853949e-01 c3 = 1.294200e-02 d1 = 3.706500e-02 d2 = 0.000000e+00 t1 = 3.005385e+01 t2 = -4.407111e-04 t3 = 4.098190e-06 t4 = 1.662250e-09 t5 = 0.000000e+00 Pressure coefficients are formulated into c = c1 + c2 x U + c3 x U2 d = d1 + d2 x U t0 = t1 + t2 x U + t3 x U2 + t4 x U3 + t5 x U4 where U is temperature in degrees Celsius. The pressure temperature, U, is determined according to U(degrees Celcius) = M x (12bit pressuretemperaturecompensation word)-B The following coefficients were used for S/N 0764 in SEASOFT: M = 1.289080e-02 B = -8.282450e+00 (in the underwater unit system configuration sheet dated on 25 May, 2010) Finally, pressure is computed as ⎛ 2 2⎞ ⎛ 2 2⎞ P(psi) = c x ⎜1 - t / t ⎟ x { 1 - d x ⎜1 - t / t ⎟ } ⎝ 0 ⎠ ⎝ 0 ⎠ where t is pressure period (µsec). 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 above automatically. The pressure sensor drift is known to be primarily an offset drift at all pressures rather than a change of span slope. The following coefficients for the sensor drift correction were also used in SEASOFT: S/N 0764, 25 May 2010 Slope = 0.999930 Offset = -0.56680 The drift-corrected pressure is computed as Drift corrected pressure(dbar) = slope?(cmputed pressure in dbar) + offset (4.2) Temperature (SBE 3plus) Pre-cruise calibrations were performed at SBE, Inc., USA. The following coefficients were used in SEASOFT: S/N 4923(primary), 26 May 2010 g = 4.35306322e-03 h = 6.39215989e-04 i = 2.11728148e-05 j = 1.77647263e-06 f0 = 1000.000 S/N 4199(secondary), 26 May 2010 g = 4.39450115e-03 h = 6.49623486e-04 i = 2.38724882e-05 j = 2.21735485e-06 f0 = 1000.000 Temperature (ITS-90) is computed according to 1 Temperature(ITS-90) = ------------------------------------------------ - 273.15 g + h x 1n(f0/f) + i x 1n2(f0/f) + j x 1n3(f0/f) where f is the instrument frequency (Hz). Time drift of the SBE 3plus temperature sensors based on the laboratory calibrations is shown in Figure C.1.1. Figure C.1.1: Time drift of the SBE 3plus temperature sensors (S/N 4923 and 4199) based on laboratory calibrations performed by SBE, Inc. The secondary sensor (S/N4199) was resecured the temperature probe retaining nut in December 2007, and replaced the main piston O-rings in August 2009 (4.3) Conductivity (SBE 4C) Pre-cruise sensor calibrations were performed at SBE, Inc., USA. The following coefficients were used in SEASOFT: S/N 3670(primary), 26 May 2010 g = -1.02022781e+001 h = 1.57745207e+000 i = -2.48735605e-003 j = 2.86313468e-004 Cpcor = -9.57e-08 Ctcor = 3.25e-06 S/N 2842(secondary), 26 May 2010 g = -1.01321263e+001 h = 1.38952824e+000 i = 2.52094473e-004 j = 4.58018677e-005 Cpcor = -9.57e-08 Ctcor = 3.25e-06 Conductivity of a fluid in the cell is expressed as: C(S/m) = (g + h x f2 + i x f3 + j x f4)/{10 x (1 + CTcor x t + CPcor x p)} where f is the instrument frequency (kHz), t is the water temperature (degrees Celsius) and p is the water pressure (dbar). (4.4) Deep Ocean Standards Thermometer (SBE 35) In the first place, a newly manufactured SBE 35 is first calibrated in a temperature controlled bath against Standard Platinum Resistance Thermometer, and this calibration is referred as the Linearization Calibration. In the next place SBE 35 is calibrated to generate slope and offset coefficients that correct for the time drift from the Linearization Calibration. This calibration is referred as the Fixed Point Calibrations. Pre-cruise sensor calibrations were performed at SBE, Inc., USA. The following coefficients were stored in EEPROM: S/N 0069, 23 October 2006(1st step: Linearization Calibration) a0 = 4.96812728e-003 a1 = -1.39341438e-003 a2 = 2.06596098e-004 a3 = -1.14827915e-005 a4 = 2.44200422e-007 Linearized temperature (ITS-90) is computed according to Linearized temperatures(ITS-90) = 1/{a0 + a1 x 1n(n) + a2 x 1n2(n) + a3 x 1n3(n) + a4 x ln4(n)}273.15 where n is the instrument output. Then the SBE 35 is certified by measurements in thermodynamic fixed-point cells of the Triple Point of Water (TPW: 0.0100 degrees Celsius) and Gallium Melting Point (GaMP: 29.7646 degrees Celsius). The slow time drift of the SBE 35 is adjusted by periodic recertification corrections. S/N 0069, 21 August 2009 (2nd step: Fixed Point Calibration) Slope = 0.999998 Offset = 0.000258 Temperature (ITS-90) is calibrated according to Temperature(ITS-90) = slope?(Linearized temperature) + offset The time required per sample = 1.1 * NCYCLES + 2.7 seconds. The 1.1 seconds is total time per an acquisition cycle. NCYCLES is the number of acquisition cycles per sample. The 2.7 seconds is required for converting the measured values to temperature and storing average in EEPROM. In this cruise NCYCLES was set to 2. (5) Data processing (5.1) Data Collection CTD system was powered on at least five minutes in advance of the operation and was powered off after CTD came up from the surface. The package was lowered into the water from the port side and held about 10 m beneath the surface for about one minute in order to activate the pump. After the pump was activated, the package was lifted to the surface and lowered at a rate of 0.6 m/s approximately to 50 m depth (or more when wave height was high), then the package was stopped to turn on the heave compensator of the crane. The package was lowered again at a rate of 0.9 m/s to the bottom. For the up cast, the package was lifted at a rate of 0.9 m/s except for bottle firing stops. At each bottle firing stops, the bottle was fired after waiting for about 30 seconds and the package was stayed at least 10 seconds for measurement of the SBE 35 after firing. At 50 m depth from the surface, the package was stopped to turn off the heave compensator of the crane. Water samples were collected using a 36-position SBE 32 Carousel Water Sampler with 10-liter Niskin bottles. In addition, surface water was sampled by stainless steel buckets when the CTD package was lifted to about 300 m depth. The SBE11plus deck unit received the data signal from the CTD. Digitized data were forwarded to a personal computer running the SEASAVE data acquisition software (SEASAVE-Win32, version 7.18). Temperature, conductivity, salinity, oxygen and descent/ascent rate profiles were displayed in real-time with the package depth, altimeter reading and sound speed. Differences in temperature, salinity, and oxygen between primary and secondary sensor were also displayed in order to monitor the status of sensors. Note that oxygen data were displayed and monitored in voltage (0 - 5 V). Altimeter (PSA-916D) was mounted at the same height of pressure sensor of SBE 9plus (Photo C.1.4). The altimeter detected the sea floor at 100 of 124 stations. The average distance from the sea floor at the beginning of the detection was 26.4 m, and the average distance from the sea floor at the closest in each station was 13.8m. The summary of sea floor detection of PSA-916D was shown in Figure C.1.2. Photo C.1.4: The location of PSA-916D. Figure C.1.2: The summary of detection of PSA-916D. The left panel shows the stations of detection, the right panel shows the relationship among PSA-916D, bathymetry and CTD depth. (5.2) Data Processing SEASOFT (SEASOFT-Win32, version 7.18) consists of modular menu driven routines for acquisition, display, processing, and archiving of oceanographic data acquired with SBE equipment, and is designed to work with a personal computer. 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. Each SEASOFT module that modifies the converted data file adds proper information to the header of the converted file permitting tracking of how the various oceanographic parameters were obtained. The converted data is stored in rows and columns of ASCII numbers. The last data column is a flag field used to mark scans as good or bad. We developed some original module for the process of RINKO III oxygen sensor and other data treatment. The followings are the SEASOFT data processing module and JMA original module sequence and specifications used in the reduction of CTD data in this cruise. DATCNV converted the raw data to engineering unit data such as scan number, pressure, temperatures, conductivities, RINKO III voltages, time in Julian days, pump status, and flag. DATCNV also extracted bottle information where scans were marked with the bottle confirm bit during acquisition. The duration was set to 2.0 seconds, and the offset was set to 0.0 seconds. DECKP_OFF (original module) cancelled the deck pressure. After this module applied, spikes in temperature and salinity were eliminated manually. RINKO_hystoff (original module) cancelled the pressure hysteresis of RINKO III using the same method of SBE 43 (Sea-Bird Electronics, 2009). SECT_IN (original module) found the first and last scan numbers while pump was activated, and made the surface data while pump was not activated for down cast. SECTION 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 package came up from the surface. 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. ALIGNCTD converted the time-sequence of RINKO III sensor outputs into the pressure sequence to ensure that all calculations were made using measurements from the same parcel of water. RINKO III sensor output delays 1 second compared to pressure, temperature and conductivity. ALIGNROS (original module) replace the RINKO III output of the bottle to that of all scan data applied ALIGNCTD module. BOTTOLESUM created a summary of the bottle data. The bottle position, date, time were output as the first two columns. Salinities, pressure, temperatures, conductivities and oxygen voltage were averaged over 2.0 seconds. 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. LOOPEDIT marked scans where the CTD was moving less than the minimum velocity of 0.0 m/s (traveling backwards due to ship roll). 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 could exist in every dbar. (6) Post-cruise calibration (6.1) Pressure The CTD pressure sensor offset in the period of this cruise is estimated from the pressure readings on the ship deck. In order to get the calibration data for the pre-cast pressure sensor drift, the CTD deck pressure was averaged over five scan pressure data after the CTD system had been stable on the deck. Deck pressure was used to cancel the CTD pressure sensor offset in CTD data processing. Time series of the CTD deck pressure is shown in Figure C.1.3. Tendencies of CTD deck pressure and air pressure were almost similar during the cruise. Figure C.1.3: Time series of the CTD deck pressure. Red line indicates atmospheric pressure anomaly. Blue line and dots indicate pre-cast deck pressure and average. Post-cruise sensor calibrations were performed at SBE, Inc., USA. The pressure sensor drift is known to be primarily an offset drift at all pressures rather than a change of span slope. S/N 0764, 27 September 2010 Slope = 0.999940 Offset = -0.55550 The pressure sensor drift was estimated to be 0.07 dbar at the pressure of 6000 dbar. The pressure sensor drift was small, so post-cruise calibration is not applied. (6.2) Temperature Budeus and Schneider (1998) noted that the CTD temperature sensor (SBE 3plus) showed a pressure sensitivity. The pressure sensitivity for a SBE 3plus sensor is usually less than +2 mK/6000 dbar. It is somewhat difficult to measure this effect in the laboratory and the difficulty is one of the primary reasons to use the SBE 35 at sea for critical work. Also SBE 3plus measurements may be affected by viscous heating (about +0.5 mK) that occurs in a TC duct and does not occur for un-pumped SBE 35 measurements (Larson and Pederson, 1996). Furthermore, the SBE 35 calibrations have some uncertainty (about 0.2 mK) and SBE 3plus calibrations have some uncertainty (about 1 mK). So the practical corrections for CTD temperature data can be made by using a SBE 35, correcting the SBE 3plus to agree with the SBE 35 (Uchida et al., 2007). Post-cruise sensor calibration for the SBE 35 was performed at SBE, Inc., USA. S/N 0069, 03 October 2010 (2nd step: fixed point calibration) Slope = 1.000009 Offset = 0.000313 The discrepancy between the CTD temperature and the SBE 35 temperature is considered to be a function of pressure and time. But the time drift correction is regarded as 0 due to following reasons; 1) The time drift of the SBE 3plus estimated to be as -0.00094 K/year for S/N 4923, -0.00044 K/year for S/N 4199 and that of SBE 35 is estimated to be as +0.01 mK during cruise according to pre-cruise and post-cruise calibrations performed at SBE, 2). Effect of the viscous heating is assumed to be constant. Since the pressure sensitivity is thought to be constant in time at least during observation period, the CTD temperature is calibrated as Callibrated temperature = T - (C0 + c1 x P) where T is the CTD temperature in degrees Celsius, P is pressure in dbar and c0, c1 are calibration coefficients. The calibration is performed for the primary and secondary temperature data. The CTD data created by the software module BOTTLESUM are used. (The deviation of CTD temperature from the SBE35 temperature at depth shallower than 1900 dbar is large for determining the coefficients with sufficient accuracy since the vertical temperature gradient is too large in the regions. So the coefficients are determined by least squares method using the data for the depth deeper than 1900 dbar. The temperature calibration summary is listed in Table C.1.1 for Pressure _ 1900dbar. We adopted secondary conductivity sensor (S/N 2842) as described in subsection (6.3), so secondary temperature sensor (S/N4199) is adopted. Table C.1.1. Temperature Calibration summary (Pressure _ 1900dbar). S/N Num c0 (K) c1 (K/dbar) Average (K) STD (K) Note ---- --- ------------ ------------ ----------- ------- ----- 4923 620 5.2348920e-4 2.3591956e-7 0.0000 0.0002 Leg 1 4923 378 5.8598217e-4 2.3668426e-7 0.0000 0.0002 Leg 2 4199 620 2.0889685e-4 2.4549467e-7 0.0000 0.0002 Leg 1 4199 378 2.3835674e-4 2.3980066e-7 0.0000 0.0002 Leg 2 Figure C.1.4: Difference between the CTD temperature (secondary) and the Deep Ocean Standards thermometer (SBE35) at Leg 1. Blue and red dots indicate before and after the calibration using SBE35 data respectively. Lower two panels show histogram of the difference after calibration. Figure C.1.5: Difference between the CTD temperature (secondary) and the Deep Ocean Standards thermometer (SBE35) at Leg 2. Blue and red dots indicate before and after the calibration using SBE35 data respectively. Lower two panels show histogram of the difference after calibration. (6.3) Salinity The CTD salinity is computed from pressure, conductivity and temperature according to algorithm of the Practical Salinity Scale of 1978 (PSS78). The discrepancy between the CTD conductivity and the bottle conductivity is considered to be a function of pressure and time (McTaggart et al, 2010). Post-cruise sensor calibrations were performed in September 2010 at SBE, Inc., USA._According to the conductivity calibration report, the drifts since pre-cruise calibration was -0.00090 /month in PSS78 at 3.0 S/m for primary sensor (S/N3670), so the effect of SBE 4C drift during the cruise was estimated to be less than 0.002 in PSS78. However the time coefficient was set to zero in this cruise because the calibration with bottle salinity was performed considering the sudden station-dependent shifts of the CTD conductivity and other calibration coefficients included the effect of slow drift by calibration grouping. So the CTD conductivity is calibrated as below. where C is the CTD conductivity and ci and pj are calibration coefficients. Coefficient sets of each (I, J) combination was calculated by least square method between CTD conductivity and the bottle conductivity data except for bad bottle data. In calculated coefficient sets, the best (I, J) combination are determined by referring to AIC (Akaike, 1974). According to McTaggart et al. (2010), maximum of I and J are 2. The discrepancy between the calibrated CTD conductivity and the bottle conductivity was within 0.0001 S/m for each sensor. The results of post-cruise calibration for the CTD salinity (S/N 2849) are summarized in Figure C.1.6. The calibration coefficients and the data (Num) used for the calibration are listed in Table C.1.2, and the calibration summary are listed in Table C.1.3 and C.1.4 for S/N 3670 and S/N 2842, respectively. Secondary sensor (S/N 2842) is adopted because of large time drift of primary sensor (S/N 3670). Table C.1.2: Conductivity Calibration Coefficient Summary. c0(mS/m) c1 c2(mS/m) S/N Num c0(mS/m) p1(mS/dbar) p2(mS/m/dbar2) Stations ---- ---- --------- ----------- -------------- ----------- 3670 1274 1.5107e-3 -7.4144e-5 0.0000e+0 Stn. 1 - 67 6.6856e-7 -8.3866e-11 3670 308 2.2680e-3 -8.0696e-5 0.0000e+0 Stn. 68 - 83, -1.2437e-8 0.5038e-11 Stn. 105 - 107 3670 608 1.0048e-3 -7.6991e-5 0.0000e+0 Stn. 84 - 104, 3.9031e-7 -4.2466e-11 Stn. 108 - 124 2849 2195 2.1693e-3 -5.5359e-5 0.0000e+0 Stn. 1 - 124 8.3709e-7 -7.6495e-11 Table C.1.3: Conductivity Calibration Summary for S/N 3670. Pressure < 1900dbar Pressure ≥ 1900 dbar --------------------- --------------------- Num Average Std Num Average Std Stations (mS/cm) (mS/cm) (mS/cm) (mS/cm) ------------- --- ------- ------- --- ------- ------- Stn. 1 - 67 830 0.0000 0.0022 444 -0.0000 0.0006 Stn. 68 - 83, 211 0.0000 0.0024 94 0.0000 0.0004 105 - 107 Stn. 84 - 104, 411 0.0000 0.0023 197 -0.0000 0.0005 108 - 124 Table C.1.4: Conductivity Calibration Summary for S/N 2842. Pressure < 1900dbar Pressure ≥ 1900 dbar --------------------- --------------------- Num Average Std Num Average Std Stations (mS/cm) (mS/cm) (mS/cm) (mS/cm) ------------- ---- ------- ------- --- ------- ------- Stn. 1 - 124 1455 0.0000 0.0022 740 -0.0000 0.0004 Figure C.1.6: Difference between the CTD conductivity (secondary) and the bottle conductivity. Blue and red dots indicate before and after the calibration using bottle data respectively. Lower two panels show histogram of the difference before and after calibration. (6.4) Oxygen RINKO III (JFE Advantech Co., Ltd., Japan) is based on the ability of selected substance to act as dynamic fluorescence quenchers. RINKO III model is designed to use with a CTD system which accept an auxiliary analog sensor, and is designed to operate down to 7000 m. The CTD oxygen is calculated using RINKO III output (voltage) by the Stern-Volmer equation, according to a method by Uchida et al. (2008). The formulas are as follows: P0 = 1.0 + c4 x t Pc = c5 + c6 x v + c7 x T + c8 x T x v Ksv = c1 + c2 x t + c3 x t2 coef = (1.0 + c9 x P/1000)1/3 [O2] = {(P0/Pc - 1.0)/Ksv x coef} Where P is the pressure in dbar, t is the potential temperature, v is RINKO III output voltage in volt, T is elapsed time of the sensor from the beginning of first station in calculation group in day and [O2] is the dissolved oxygen saturation, dissolved oxygen is calculated from [O2], potential temperature and salinity by Garcìa and Gordon (1992) in µmol/kg. Calibration coefficients (c1-c9) are determined by minimizing difference between CTD oxygen and bottle dissolved oxygen by quasi-newton method (Shanno, 1970). In general, the calibration was performed for each Leg. But in this cruise, both RINKO III had large time drift especially in the early part of Leg 1, we could not solve on c7 and c8. Worse yet, bottle dissolved oxygen data were flagged bad due to the problem of titration (please refer to section C.3. (15)) in the latter part of Leg1 (Stn. 58 - 67). To avoid extrapolation in time during the period when bottle dissolved oxygen data were flagged bad, the calibration was performed across Leg 1 and Leg 2. The calibration was performed only for primary sensor (S/N 25, foil number: 144) because the output of secondary sensor (S/N 26 foil number: 144) was very noisy during the entire cruise. Calibration coefficients are listed in Table C.1.5. The result of the calibration during cruise is shown in Figure C.1.7, the data summary is listed in Table C.1.6. Table C.1.5: Dissolved Oxygen Calibration Coefficients. c1 c2 c3 c4 c5 Stations c6 c7 c8 c9 ------------- ---------- ----------- ---------- ----------- ----------- Stn. 1 - 29 1.89890 1.71137e-2 1.59838e-4 -1.07941e-3 -1.23152e-1 3.06114e-1 -4.58703e-5 9.88747e-4 4.50828e-2 Stn. 30 - 80 1.92314 2.01695e-2 1.61815e-4 -8.26530e-4 -1.29883e-1 3.08780e-1 -5.98333e-4 8.81185e-4 4.21446e-2 Stn. 81 - 124 1.78777 1.54077e-2 1.57742e-5 -1.66459e-3 -1.02899e-1 3.06817e-1 9.27247e-5 4.29204e-4 4.59279e-2 Table C.1.6: Dissolved Oxygen Calibration Summary. Pressure < 950dbar Pressure ≥ 950dbar ------------------------- -------------------------- Average STD Average STD of of of of deviation deviation deviation deviation Stations Num (µmol/kg) (µmol/kg) Num (µmol/kg) (µmol/kg) ------------- --- --------- --------- --- --------- ---------- Stn. 1 - 29 228 -0.26 0.97 218 -0.07 0.34 Stn. 30 - 80 446 -0.02 0.83 422 0.00 0.22 Stn. 81 - 124 435 -0.04 0.77 308 -0.01 0.25 Figure C.1.7: Difference between the CTD oxygen and bottle dissolved oxygen in the early part of Leg 1. Red dots in upper two panels indicate the result of calibration. Lower two panels show histogram of the difference between calibrated oxygen and bottle oxygen. Figure C.1.8: Difference between the CTD oxygen and bottle dissolved oxygen across Leg 1 and Leg 2. Red dots in upper two panels indicate the result of calibration. Lower two panels show histogram of the difference between calibrated oxygen and bottle oxygen. Figure C.1.9: Difference between the CTD oxygen and bottle dissolved oxygen in the latter part of Leg 2. Red dots in upper two panels indicate the result of calibration. Lower two panels show histogram of the difference between calibrated oxygen and bottle oxygen. References McTaggart, K. E., G. C. Johnson, M.C.Johnson, F.M.Delahoyde, and J.H.Swift (2010): The GO-SHIP Repeat Hydrography Manual : A Collection of Expert Reports and guidelines. IOCCP Report No 14, ICPO Publication Series No. 134, version 1, 2010 Budeus. G., and W. Schneider (1998): In-situ temperature calibration: A remark on instruments and methods. International WOCE Newsletter, No.30, WOCE International Project Office, Southampton, United Kingdom, 16-18. Larson, N., and A.M. Pedersen (1996): Temperature measurements in flowing water: Viscous heating of sensor tips. Proc. of the First IGHEM Meeting, Montreal, QC, Canada, International Group for Hydraulic Efficiency Measurement. [Available online at http://www.seabird.com/technical_references/viscous.htm] 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. Akaike, H. (1974): A new look at the statistical model identification. IEEE Transactions on Automatic Control, 19:716 - 722. Uchida, H., T. Kawano, I. Kaneko, and M. Fukasawa (2008): In -situ calibration of optode-based oxygen sensors. J. Atmos. Oceanic Technol., 25, 2271-2281. Garcìa, H. E., and L. I. Gordon (1992): Oxygen solubility in seawater: Better fitting equations. Limnol. Oceanogr., 37, 1307-1312. Shanno, David F. (1970): Conditioning of quasi-Newton methods for function minimization. Math. Comput. 24, 647-656. MR 42 #8905 Sea-Bird Electronics (2009): SBE 43 dissolved oxygen (DO) sensor - hysteresis corrections, Application note no. 64-3, 7 pp. 2. BOTTLE SALINITY (1) Personnel Keizo SHUTTA (GEMD/JMA) Takahiro SEGAWA (GEMD/JMA) Yasuaki BUNGI (GEMD/JMA) Tetsuya NAKAMURA (GEMD/JMA) Yoshikazu HIGASHI (GEMD/JMA) Tomoyuki KITAMURA (GEMD/JMA) (2) Station occupied A total of 68 stations (Leg 1: 40, Leg 2: 28) were occupied for bottle salinity. Station location and sampling layers of bottle salinity are shown in Figure C.2.1. Figure C.2.1: Station location (left panel) and sampling layers of bottle salinity (right panel). (3) INSTRUMENTS AND METHOD (3.1) Salinity sample collection The bottles in which the salinity samples are collected and stored are 250 ml colorless transparent glass bottles with screw caps. Each bottle was rinsed three times with sample water and was filled to the shoulder of the bottle. The screw caps were also thoroughly rinsed. Salinity samples were wiped with dry clothes and stored for more than 24 hours in the same laboratory as the salinity measurement was made. (3.2) Instruments and methods The salinity analysis was carried out on AUTOSAL Laboratory Salinometer model 8400B (S/N69677; Guildline Instruments Ltd., Canada), which was modified by addition of an Ocean Science International peristaltic-type sample intake pump and two Guildline platinum thermometers model 9450. One thermometer monitored an ambient temperature and the other monitored a bath temperature. The resolution of the thermometers was 1 mK. The measurement system was almost same as Aoyama et al (2003). The salinometer was operated in a ship's laboratory air-conditioned at a bath temperature of 24 deg-C. Ambient temperature varied from approximately 21.5 to 23.5 deg-C, while bath temperature is very stable and varied within ± 0.001 deg-C. A measure of a double conductivity ratio of a sample is taken as a median of thirty-one 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 fourth and the fifth filling of the cell. In case the difference in the double conductivity ratio between this two fillings was smaller than 0.00003, the average value of the two double conductivity ratios was used to calculate the bottle salinity with the algorithm for the Practical Salinity Scale, 1978 (hereafter PSS-78; UNESCO, 1981). If the difference was greater than or equal to 0.00003, we measured the sixth filling of the cell. In case the double conductivity ratio of the sixth filling did not satisfy the criteria above, we measured the next filling of the cell and chose proper two fillings which satisfied the criteria. We continued these process at most ninth fillings. (4) Result Standardization control was set to 5.72 and all the measurements were done by this setting. During the whole measurement, readings of STANDBY were almost 6019 ± 0001 and those of ZERO were 0.00001 or 0.00002. We used IAPSO Standard Seawater batch P152 whose conductivity ratio was 0.99981 (double conductivity ratio is 1.99962) as the standard for salinity. We measured 2 or 3 bottles of P152 for each station, total amount was 187. If some readings of SSW bottle were extremely high or low, we measured another bottle of SSW. Figure C.2.2 shows the history of ambient temperature, bath temperature, double conductivity ratio of standard sea water (P152) and time drift of P152 readings but for four bad bottles. In raw P152 readings, it was found offset and long-term variability. To remove long-term variability, raw P152 readings were corrected to label value 1.99962 in the least significant digit of readings. After the correction, SSW drift was steady within 1 digit of readings in each leg. The average of corrected SSW double conductivity ratio was 1.999621 and the standard deviation was 0.000010, which was equivalent to 0.0002 in salinity. The same correction was applied to sample readings. The correction of AUTOSAL drift for salinity measurements was from 0 to 2 digits of readings. During measurement of a sample taken at Stn.28 (RF3676), one heater lamp of the salinometer was broken down so the result of measurement was omitted from salinity calibration. Figure C.2.2: The upper panel shows time-series of ambient temperature during cruise. The lower panel, black dots and red dots indicate raw and corrected time-series of the double conductivity ratio of the standard sea water (P152), red line indicate linear regression of corrected standard sea water for each leg, gray line indicate label value double conductivity ratio of P152 and blue line indicates time- series of bath temperature during cruise. (5) Sub-Standard Water We also used sub-standard seawater which was filtered by pore size of 10 micrometer and stored in a 20 liter cubitainer made of polyethylene and stirred for at least 24 hours before measuring. It was measured every six samples in order to check possible sudden drift of the salinometer. During the whole measurements, there was no detectable sudden drift of the salinometer except for measurement of a sample taken at Stn.28 (RF3676). (6) Replicate and Duplicate Samples We took 267 pairs of replicate samples and 210 pairs of duplicate samples during the cruise. Figure C.2.3 and Figure C.2.4 show the absolute difference among replicate and duplicate samples in salinity, respectively. There were 30 bad measurements and 2 questionable measurements in replicate pairs and 23 bad measurements, 4 questionable measurements and 1 failure of sampling in duplicate pairs. Excluding those bad and questionable measurements, the mean absolute difference and standard deviation in 237 pairs of replicate samples was 0.0004±0.0004 in salinity and that in 182 pairs of duplicate samples was 0.0005±0.0006 in salinity. Note that standard deviation was calculated by a procedure (SOP23) in DOE (1994). Table C.2.1: Summary of assigned quality control flags Flag Definition Salinity ---- ---------------------- -------- 2 Good 1716 3 Questionable 34 4 Bad (Faulty) 290 6 Replicate measurements 237 -------------------------------------- Total number of samples 2277 Figure C.2.3: Result of replicate samplings during this cruise against (a) station number, (b) sampling pressure and (c) salinity. Dotted line denotes the average of replicate samplings. Bottom panel (d) shows histogram of the result of replicate samplings. Figure C.2.4: Same as Fig.C.2.3 but for duplicate samplings. References Aoyama, M., T. Joyce, T. Kawano and Y. Takatsuki (2003): Standards seawater comparison up to P129. Deep-sea Research, 1, Vol. 49, 1103-1114. UNESCO (1981): Tenth report of the Joint Panel on Oceanographic Tables and Standards. UNESCO Tech. Papers in Mar. Sci., 36, 25 pp. 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. 3. BOTTLE OXYGEN (1) Personnel Yusuke TAKATANI (GEMD/JMA) Shinichiro UMEDA (GEMD/JMA) Sho HIBINO (GEMD/JMA) (2) Station occupied A total of 71 stations (Leg 1: 42, Leg 2: 29) were occupied for bottle oxygen. Station location and sampling layers of bottle oxygen are shown in Figure C.3.1. Figure C.3.1: Station location (left panel) and sampling layers of bottle oxygen (right panels). (3) Reagents • Manganous chloride solution (3 M) (Pickling Reagent-I) Dissolved 600 g of MnCl2•4H2O in deionized water, then dilute the solution with deionized water to a final volume of 1 L. MnCl2•4H2O (Lot. CDP6460) used to make pickling reagent-I was guaranteed reagent manufactured by Wako Pure Chemical industries, Ltd. • Sodium hydroxide (8 M) / sodium iodide solution (4 M) (Pickling Reagent-II) Dissolved 320 g of NaOH in about 500 ml of deionized water, allow to cool, then add 600 g NaI and dilute with deionized water to a final volume of 1 L. NaOH (Lot. STN1103) and NaI (Lot. STQ5226) used to make pickling reagent-II were guaranteed reagent manufactured by Wako Pure Chemical industries, Ltd. • Sulfuric acid solution (5 M) Slowly add 280 ml concentrated H2SO4 to roughly 500 ml of deionized water. After cooling the final volume should be 1 L. H2SO4 (Lot. KWK1803) used to make sulfuric acid solution was guaranteed reagent manufactured by Wako Pure Chemical industries, Ltd. • Sodium thiosulfate (0.04 M) Dissolved 50 g of Na2S2O3•5H2O and 0.4 g of Na2CO3 in deionized water, then dilute the solution with deionized water to a final volume of 5 L. Na2S2O3•5H2O (Lot. PER3227) and Na2CO3 (Lot.WKF1312) used to make sodium thiosulfate were guaranteed reagent manufactured by Wako Pure Chemical industries, Ltd. • Potassium iodate (0.001667 M) Dry high purity KIO3 for two hours in an oven at 130 deg-C. After weight out accurately KIO3, dissolve it in deionized water in a 5 L flask. Concentration of potassium iodate is determined by a gravimetric method. KIO3 (Lot. 62404E) used to make potassium iodate was manufactured by MERCK & CO., Inc., and a purity of KIO3 that is traceable to NIST (National Institute of Standards and Technology) standard reference material is 99.75±0.05%. (4) Instruments Detector; DOT-01X automatic photometric titrator manufactured by Kimoto Electronic Co. Ltd. Burette for sodium thiosulfate; APB-510 manufactured by Kyoto Electronic Co. Ltd./ 10 ml of titration vessel Burette for potassium iodate; Multipette stream 4986 and Combitip plus manufactured by eppendorf /10 ml of tip vessel Bottle top dispenser for pickling reagent-I and II; CalibrexTM 520 manufactured by SOCOREX ISBA S.A. (5) Seawater sampling Following procedure is based on a determination method in IOCCP Report No.14 (Langdon, 2010). Seawater samples were collected from 10-liters Niskin bottles attached the CTD-system and a stainless steel bucket for the surface. Seawater for bottle oxygen measurement was transferred from the Niskin sample bottle and a stainless steel bucket to a volumetrically calibrated dry glass bottles (ca. 120 ml, standard deviation of calibration = 0.008 ml). At least three times volume of the glass of sample water was overflowed. Two reagent solutions (Reagent-I and II) of 1 ml (standard deviation of calibration = 0.003 ml) each were added immediately, sample temperature was then measured by a thermometer. After the stopper was inserted carefully into the glass, the sample glass was shaken vigorously to mix the content and to disperse the precipitate finely. The precipitate has settled at least halfway down the glass, the glass was then shaken again vigorously to disperse the precipitate. The sample glasses containing pickled samples were stored in a laboratory until they were titrated. To prevent air from entering the flask, deionized water was added to the neck of the flask after sampling. (6) Sample measurement At least 30 minutes after the re-shaking, the pickled samples were measured on board. 1 ml sulfuric acid solution and a magnetic stirrer bar were added into the sample glass 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. The titrations were carried out using the titration apparatus, named DOT-01X. Dissolved oxygen concentration (mmol/kg) was calculated by the sample temperature at the fixation, CTD salinity, glass volume, and titrated volume of the sodium thiosulfate solution. (7) Standardization Concentration of sodium thiosulfate titrant (ca. 0.04 M) was determined by potassium iodate solution. Table C.3.1 shows a list of potassium iodate solution used in this cruise. Using a calibrated volumetric dispenser, 10 ml (standard deviation of calibration = 0.006 ml) of the standard potassium iodate solution was added to a glass with 100 ml of deionized water. Then, 1 ml of sulfuric acid solution, and 1 ml of pickling reagent solution-II and I were added into the glass in order. Amount of titrated volume of sodium thiosulfate (usually 5 times measurements average) gave the molarity of the sodium thiosulfate titrant. Figure C.3.2 and Table C.3.2 show the results of the standardization during this cruise. The sodium thiosulfate titrant of each batch was a mean of titrated volume of sodium thiosulfate on each day and a standard deviation of a concentration at 20 deg-C of sodium thiosulfate on each day was an uncertainty caused by the standardization. A sodium thiosulfate of one batch was assumed to be one sodium thiosulfate titrant. The uncertainty of dissolved oxygen that caused by the standardization was estimated 0.01-0.13%. Table C.3.1: List of the standard potassium iodate solution in this cruise. KIO3 batch Conc. at 20°C (N) ---------- ----------------- KIO3_I 0.009955±0.000003 KIO3_IV 0.009967±0.000003 Figure C.3.2: Results of the standardization. Upper panel shows results of end point, bottom panel shows results of calculated concentration at 20 deg-C of sodium thiosulfate. Crosses show each value for each standardization samples, and closed circles show the mean at each standardizations. Thick lines and dotted lines denote the means and 1 s error for each batch of sodium thiosulfate, respectively. Table C.3.2: Results of the standardization. Date KIO3 Na2S2O3 (ml) Leg (UTC) Batch Bottle Batch End Point Stations --- --------- -------- ------ ----- --------- -------- 2010/7/6 KIO3_ IV 2 #1 2.4359 Stn.1 2010/7/11 KIO3_ IV 3 #1 2.4423 | 2010/7/15 KIO3_ IV 4 #1 2.4372 Stn.43 2010/7/17 KIO3_ IV 5 #1 2.4384 Na2S2O3_#1 2.4385±0.0028 1 2010/7/17 KIO3_ IV 5 #2 2.4392 Stn.44 2010/7/21 KIO3_ IV 6 #2 2.4371 | 2010/7/24 KIO3_ IV 7 #2 2.4390 Stn.67 Na2S2O3_#2_1 2.4384±0.0012 2010/8/1 KIO3_ IV 9 #2 2.4431 Stn.68- 2010/8/5 KIO3_ IV 10 #2 2.4427 Stn.84 Na2S2O3_#2_2 2.4429±0.0003 2 2010/8/5 KIO3_ IV 10 #3 2.4442 Stn.93 2010/8/10 KIO3_ IV 11 #3 2.4415 | 2010/8/16 KIO3_ IV 12 #3 2.4381 Stn.105 Na2S2O3_#4 2.4413±0.0031 (8) Determination of the blank The oxygen in the pickling reagents-I (1 ml) and II (1 ml) was assumed to be 7.6 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. Using a calibrated volumetric dispenser, 1 ml of the standard potassium iodate solution was added to a glass with 100 ml of deionized water. Then, 1 ml of sulfuric acid solution, and 1 ml of pickling reagent solution-II and I were added into the glass in order. First, the sample was titrated to the end-point by sodium thiosulfate solution. Then, the sample was titrated again to the end-point after added a further 1 ml of the standard potassium iodate solution. The blank was determined by difference between the first (1 ml of KIO3) titrated volume of the sodium thiosulfate and the second (2 ml of KIO3) one. Because reagents set were prepared two sets (set A and B), the blank in each sets were determined. Usually, the results of 5 times blank determinations were averaged (Table C.3.3). The standard deviation of the blank determination during this cruise was 0.0010 (set A) and 0.0011 (set B) ml, c.a. 0.02%. Table C.3.3: Result of the blank determinations. Date Na2S2O3 Blank (ml) Samples (UTC) Batch Set A Set B (stations) --------- ------- ------ ------ --------------- 2010/7/6 #1 0.0008 0.0004 Stn.1-Stn.12 2010/7/9 #1 0.0014 0.0029 Stn.13-Stn.18 2010/7/11 #1 0.0024 0.0029 Stn.19-Stn.26 2010/7/13 #1 0.0018 0.0013 Stn.27-Stn.32 2010/7/15 #1 0.0021 0.0023 Stn.33-Stn.42 2010/7/17 #2 0.0015 0.0020 Stn.43-Stn.57 2010/7/21 #2 0.0015 0.0015 Stn.58-Stn.67 2010/8/1 #2 0.0042 0.0042 Stn.68-Stn.83 2010/8/5 #3 0.0028 0.0031 Stn.84-Stn.103 2010/8/10 #3 0.0027 0.0033 Stn.104-Stn.124 (9) Reagent blank The blank determined in section (8), pure water blank (Vblk, dw) can be represented by equation (i), Vblk, dw = Vblk, ep + Vblk, reg (i) where Vblk, ep = blank due to differences between the measured end-point and the equivalence point; Vblk, reg = blank due to oxidants or reductants in the reagent. Here, the reagent blank (Vblk, reg) was determined by following procedure. 1 ml of the standard potassium iodate solution and 100 ml of deionized water were added to two glasses each. 1 ml of sulfuric acid solution, pickling reagent solution-II and I each were added into the first glass in order. Then, two times volume of the reagents (2 ml of sulfuric acid solution, pickling reagent solution-II and I each) was added to the second glass. The reagent blank was determined by difference between the first (3 ml of the total reagent volume added) titrated volume of the sodium thiosulfate and the second (6 ml of the total reagent volume added) one. We also carried out experiments for three and four times volume of the reagents. The results are shown in Figure C.3.3. The relation between difference of the titrant (Na2S2O3) volume and the volume of the reagents added (Vreagent) is expressed by equation (ii), Difference of the titrant volume = -0.0023Vreagent (ii) Vblk, reg was estimated to be about -0.007 ml, suggesting that about 0.04 µmol of reductants was contained in every 3 ml of the reagents added. Figure C.3.3: Blank (ml) due to redox species apart from oxygen in the reagents. (10) Sample blank Blank due to redox species other than oxygen in the sample (Vblk, spl) can be a potential source of measurement error. The total blank during the seawater measurement, the seawater blank (Vblk, sw) can be represented by equation (iii). Vblk, sw = Vblk, spl + Vblk, dw (iii) If the pure water blank (Vblk, dw) that is determined in section (9) is identical both in pure water and in seawater, the difference between the seawater blank and the pure water one gives the sample blank (Vblk, spl). Here, Vblk, spl was determined by following procedure. Seawater sample was collected in the calibrated volumetric glass (c.a. 120 ml) without the pickling. Then 1 ml of the standard potassium iodate solution, sulfuric acid solution, and pickling reagent solution-II and I each were added into the glass in order. Additionally, a glass contained 100 ml of deionized water and 1 ml of the standard potassium iodate solution, sulfuric acid solution, pickling reagent solution-II and I was prepared. The difference of the titrant volumes of the seawater glass and the deionized water one gave the sample blank (Vblk, spl). We measured vertical profiles of the sample blank at 3 stations (Table C.3.4). The sample blank ranged from 0.17 to 1.96 µmol/kg and its vertical and horizontal variations are large. This result does not agree to reported values ranged from 0.4 to 0.8 µmol/kg (Culberson et al., 1991). It does not have been known about the magnitude and variability of the seawater blank, so this result should be discussed carefully. Ignorant of the sample blank will cause systematic errors in the oxygen calculations, but these errors are expected to be the same to all investigators and not to affect the comparison of results from different investigators (Culberson, 1994). Table C.3.4: Results of the sample blank determinations during this cruise. Station: Stn.75 Station: Stn.111 Station: Stn.115 4.45˚N/139.53˚E 2.50˚N/139.50˚E 2.91˚N/137.50˚E ------------------ ------------------ ------------------ Pres. Blank Pres. Blank Pres. Blank (dbar) (µmol/kg) (dbar) (µmol/kg) (dbar) (µmol/kg) ------- --------- ------- --------- ------- --------- 10.3 0.17 10.3 0.35 25.3 0.911 50.6 1.03 103.5 0.73 100.8 0.63 101.7 0.54 201.2 1.04 302.0 0.95 251.5 - 381.9 0.69 503.2 1.09 634.7 0.61 483.8 1.76 1,008.8 0.97 838.0 0.90 675.1 1.96 1,514.0 0.75 1,596.4 0.56 978.3 0.97 2,020.6 1.29 2,611.7 0.82 1,940.0 1.39 3,038.5 1.44 3,631.6 0.71 2,955.6 1.11 4,060.8 1.29 4,142.7 0.84 4,382.1 - 4,574.2 0.90 (11) Replicate sample measurement Replicate samples were carried out at every bottle oxygen observation stations. Total amount of the replicate sample pairs in good measurement (flag=6) was 234, and total amount of the removed pair (flag=3 or 4) was 14. The average and the standard deviation of the replicate measurement during this cruise were 0.17±0.17 µmol/kg. The standard deviation was calculated by a procedure (SOP23) in DOE (1994). The difference between the replicate sample pairs did not depended on sampling pressure, measurement date and concentration of sample (Figure C.3.4). The averages and the standard deviations during Leg 1 and Leg 2 were 0.17±0.17 (n=127) and 0.18±0.16 (n=107) µmol/kg, respectively. Figure C.3.4. Result of replicate samplings during this cruise against (a) station number, (b) sampling pressure and (c) concentration of dissolved oxygen. Dotted line denotes the average of replicate samplings. Bottom panel (d) shows histogram of the result of replicate samplings. (12) Duplicate sample measurement Duplicate samples that were seawater samples from two Niskin sample bottles that were collected at same depth were carried out at almost every bottle oxygen observation stations also. Total amount of the duplicate sample pairs in good measurement (flag=2) was 156, and total amount of the removed pair (flag=3 or 4) was 16. The average and the standard deviation of the duplicate measurement during this cruise were 0.22±0.21 µmol/kg. The difference between the duplicate sample pairs did not depended on measurement date and concentration of sample, but the results of the duplicate measurement on surface and subsurface (above 1000 dbar) were large (Figure C.3.5). We thought that this reason was because water mass on a surface and a subsurface was not similar compared with that of an intermediate and a deep layer. The averages and the standard deviations during Leg 1 and Leg 2 were 0.26±0.24 (n=60) and 0.20±0.18 (n=96) µmol/kg, respectively. Figure C.3.5. Result of duplicate samplings during this cruise against (a) station number, (b) sampling pressure and (c) concentration of dissolved oxygen. Dotted line denotes the average of duplicate samplings. Bottom panel (d) shows histogram of the result of duplicate samplings. (13) Mutual comparison between each standard potassium iodate During the cruise, we performed the mutual comparison between two standard potassium iodate of difference Lot. in order to confirm the accuracy of our oxygen measurement and the bias of a standard potassium iodate. We measured concentration of a KIO3 (KIO3_I) against another KIO3 (KIO3_IV), and checked the difference between measurement value and theoretical one (Table C.3.5, Figure C.3.6). Error weighted means of measurement results of KIO3_I were 0.009947±0.000012 N. The averaged value of the KIO3_I was so close to the theoretical value (0.009955±0.000003 N) that was prepared in laboratory. A good agreement among two standard potassium iodate confirmed that there was no systematic shift in our oxygen measurements during this cruise. Table C.3.5. Results of mutual comparison of KIO3_I against KIO3_IV Date (UTC) KIO3 Batch Measurement Value (N) ---------- ---------- --------------------- 2010/7/6 KIO3_I_4 0.009957±0.000013 2010/7/11 KIO3_I_5 0.009940±0.000011 2010/7/15 KIO3_I_6 0.009944±0.000011 2010/7/17 KIO3_I_7 0.009943±0.000012 2010/7/17 KIO3_I_7 0.009938±0.000012 2010/7/21 KIO3_I_8 0.009951±0.000012 2010/7/24 KIO3_I_9 0.009952±0.000013 2010/8/1 KIO3_I_10 0.009956±0.000011 2010/8/5 KIO3_I_11 0.009942±0.000011 2010/8/5 KIO3_I_11 0.009941±0.000013 2010/8/10 KIO3_I_12 0.009958±0.000012 2010/8/16 KIO3_I_13 0.009946±0.000012 --------------------------------------------- Weighted Mean 0.009947±0.000012 Figure C.3.6: Results of mutual comparison of KIO3_I against KIO3_IV. Closed circles show mean of measurement value with 1 σ error at each mutual comparison, and gray opened diamonds and error bar show the theoretical value and the uncertainty of the standard potassium iodate. (14) Quality control flag assignment Quality flag values were assigned to oxygen measurements using the code defined in IOCCP Report No.14 (Swift, 2010). Measurement flags of 2 (good), 3 (questionable), 4 (bad), 5 (not reported), and 6 (replicate measurement) have been assigned (Table C.3.6). The replicate data were averaged and flagged 6 if both of them were flagged 2. If either of them was flagged 3 or 4, a datum with "younger" flag was selected. For the choice between 2, 3, or 4, we basically followed a flagging procedure as listed below: a.→Vertical sections against pressure and potential density were drawn. Any points not lying on a generally smooth curve were noted. b.→Dissolved oxygen was then plotted against potential temperature, salinity and nutrients. If a datum deviated from a group of plots, it was flagged 3. c.→If a datum was deviated from the mean ±3σ on the section, datum flag was degraded from 2 to 3, or from 3 to 4. d.→We Compared bottle oxygen with CTD oxygen at the sampling depth. If a datum deviated from CTD oxygen, datum flag was degraded from 2 to 3, or from 3 to 4. e.→If the bottle flag was 4 (did not trip correctly), a datum was flagged 4 (bad). If the bottle flag was 3 (leaking) or 5 (unknown problem), a datum was flagged based on steps a, b, c, and d. Table C.3.6: Summary of assigned quality control flags. Flag Definition ---- ---------------------------------- 2 Good 2353 3 Questionable 326 4 Bad (Faulty) 52 5 Not reported 1 6 Replicate measurements 234* ---------------------------------------- Total number of samples 2732* *Samples of flag 6 are counted as flag 2 (15) Problems A leak of sodium thiosulfate from a joint of burette was revealed at the standardization after Stn.67. From the comparison between bottle oxygen and the oxygen sensor (RINKO III manufactured by JFE Advantech Co. Ltd.), it was thought that this problem had happened from Stn.58 (Figure C.3.7). The data between Stn.58 and Stn.67 were flagged 3 or 4. Figure C.3.7: Comparison between bottle oxygen and RINKO III. Closed circles show data between Stn.58 and Stn.67. (16) Uncertainty in Oxygen data of this cruise The reproducibility in this cruise determined by replicate samples and duplicate samples in section (11) and (12) was 0.17±0.17 µmol/kg and 0.22±0.21 µmol/kg. Bottle oxygen data in this cruise were calculated based on IOCCP Report No.14 (Langdon, 2010). In these results, various uncertainties were included (ex. standardization, calibration of glass bottles, precision of burette etc.). Considering these uncertainty that can be estimated theoretically, it was estimated that the standard uncertainty of bottle oxygen data in this cruise is about 0.43 µmol/kg. However, it is impossible to estimate an accurate uncertainty because there is no reference material. (17) Results (17.1) Comparison at cross-stations during this cruise Cross-stations during this cruise were two stations. The one was located at 2°N/142°E, the another was located 7°N/137°E. At stations of Stn.83 (RF3731) and Stn.104 (RF3755), hydrocast sampling for dissolved oxygen was conducted two times at interval of about five days. Dissolved oxygen profiles of the two hydrocasts agreed well (Figure C.3.8). We compared interpolated data, because the sampling layers of the two hydrocasts were difference. In the layers deeper than 2000 dbar, difference of interpolated data between the two hydrocasts was calculated to be about 1.25±0.28 µmol/kg. In these layers, difference of the oxygen sensor between the two hydrocasts was also about 0.8±0.6 µmol/kg. At stations of Stn.67 (RF3715), Stn.68 (RF3716), and Stn.124 (RF3772), hydrocast sampling for dissolved oxygen was conducted three times. Interval between the first and the second was about a week, interval between the second and the third was about two weeks. Dissolved oxygen profiles between the second and third hydrocasts agreed well, but the data of the first hydrocast had slightly larger than that of second and third hydrocast because of a leak of sodium thiosulfate from a joint of the burette (Figure C.3.7). In the layers deeper than 2000 dbar, difference between the second and third hydrocast was calculated to be about 0.08±0.64 µmol/kg. Figure C.3.8: Comparison of dissolved oxygen profiles between the first hydrocast (pluses), the second one (gray diamonds) and the third one (circles) at the cross-stations of (a) 2°N/142°E and (b) 7°N/137°E. Lines denote the profiles of the oxygen sensor. (17.2) Comparison at cross-stations of WHP-P2 section in 1994 and 2004 We compared our oxygen data and one of WHP-P2 at a cross point, around 30°N/137°E. WHP-P2 line was observed two times, first in 1994 by R/V Shoyo belonged to Maritime Safety Agency of Japan (MSA) (present Japan Coast Guard (JCG)) and repeated in 2004 by R/V Melville belonged to Scripps Institution of Oceanography (SIO). Dissolved oxygen profiles between one in this cruise and in 2004 agreed well (Figure C.3.9), and the difference blow 2000 dbar is 0.18±0.75 µmol/kg. But it was found that oxygen data in this cruise were significantly lower than those in 1994 in deep layers, the differences below 2000 dbar is -4.14±2.45µmol/kg. This difference should be discussed carefully. (17.3) Comparison at cross-stations of WHP-P3 section in 1985 and 2005/06 We compared our oxygen data and one of WHP-P3 at a cross point, around 24°N/137°E. WHP-P3 line was observed two times, first in 1985 by R/V Thomas G. Thompson belonged to SIO and repeated in 2005/06 by R/V Mirai belong to Japan Agency for Marine-Earth Science and Technology (JAMSTEC). Dissolved oxygen profiles between one in this cruise and in 2005/06 agreed well (Figure C.3.9). The differences between oxygen data below 2000 dbar in this cruise and these in 1985, or in 2005/06 are -1.76±0.53, -0.17±1.01 µmol/kg, respectively. For the comparison with oxygen data in 1985, the offset value is larger than reported adjustments, about minus 0.3 µmol/kg (Johnson et al., 2001; Gouretski and Jancke, 2001). For the comparison with oxygen data in 2005/06, it should also be noted that the relatively large difference in deep layer ranged from about 1000 to 2000 dbar. Though it might be caused by the slight difference of the observation position, it is necessary to discussed it carefully. Figure C.3.9: Comparison of dissolved oxygen profiles at cross-stations of (a) WHP-P2 and (b) WHP-P3. Pluses, gray diamonds and opened circles show the first observation, the second one and this cruise, respectively. Lines denote the profiles of the oxygen sensor. (17.4) Comparison with WHP-P9 oxygen data in 1994 We compared oxygen data in this cruise and one of WHP-P9 in 1994. In deep layers in a wide region, dissolved oxygen have been decreased from 1994 (Figure C.3.10). Below 2000 m, the difference in average is calculated in -1.47±2.48 µmol/kg (Figure C.3.11). This offset value is closed to reported adjustments, about -1 µmol/kg for dissolved oxygen data of WHP-P9 (Johnson et al., 2001; Gouretski and Jancke, 2001). Therefore, it was thought that oxygen measurements in this cruise were conducted correctly. Figure C.3.10: Difference of dissolved oxygen between 2010 and 1994 against water depth. Figure C.3.11: Bottle oxygen data in 1994 (pluses) and 2010 (circles) below 1500 m (left panel) and difference of dissolved oxygen on the standard depth (right panel). Black closed circles denote mean of the differences with 1 σ error. References Cullberson, A.H. (1994), Dissolved oxygen, in WHPO Pub. 91-1 Rev. 1, November 1994, Woods Hole, Mass., USA. Cullberson, A.H., G. Knapp, M.C. Stalcup, R.T. Williams, and F. Zemlyak (1991), A comparison of methods for the determination of dissolved oxygen in seawater, WHPO Pub. 91-2, August 1991, 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. Gouretski, V.V. and K. Jancke (2001), Systematic errors as the causes for an apparent deep water property variability: global analysis of the WOCE and historical hydrographic data, Prog. Oceanogr., 48, 337-402. JAMSTEC, WHP P03 REVISIT DATA BOOK (2001), edited by T. Kawano and H. Uchida, JAMSTEC Johson, G.C., P.E. Robbins, and G.E. Hufford (2001), Systematic adjustments of hydrographic sections for internal consistency, J. Atomos. Oceanic Technol., 18, 1234-1244. Murray, C.N., J.P. Riley and T.R.S. Wilson (1968), The solubility of oxygen in Winkler reagents used for the determination of dissolved oxygen, Deep-Sea Res., 15, 237-238 Langdon, C. (2010), Determination of dissolved oxygen in seawater by Winkler titration using the amperometric technique, IOCCP Report No.14, ICPO Pub. 134, 2010 ver.1 Swift, J. H. (2010): Reference-quality water sample data: Notes on acquisition, record keeping, and evaluation. IOCCP Report No.14, ICPO Pub. 134, 2010 ver.1 4. NUTRIENTS (1) Personnel Kazuhiro SAITO (GEMD/JMA) Hiroyuki FUJIWARA (GEMD/JMA) Takahiro KITAGAWA (GEMD/JMA) (2) Station occupied A total of 104 stations (Leg1: 61, Leg2: 43) were occupied for nutrients. Station location and sampling layers of nutrients are shown in Figure C.4.1. Figure C.4.1: Station location (left) and sampling layers (right) of nutrients. (3) INSTRUMENT AND METHOD (3.1) Analytical detail using Auto Analyzer III systems (BLTEC) The nutrients analyses were carried out on 4-channel Auto Analyzer III (BLTEC). Measured Parameters are nitrate + nitrite, nitrite, phosphate and silicate. Nitrate + nitrite and nitrite are analyzed according to the modification method of Armstrong (1967). The sample nitrate is reduced to nitrite in a cadmium tube inside of which is coated with metallic copper. The sample stream with its equivalent nitrite is treated with an acidic, sulfanilamide reagent and the nitrite forms nitrous acid which reacts with the sulfanilamide to produce a diazonium ion. N-1-Naphthylethylene-diamine added to the sample stream then couples with the diazonium ion to produce a red, azo dye. With reduction of the nitrate to nitrite, both nitrate and nitrite react and are measured; without reduction, only nitrite reacts. Thus, for the nitrite analysis, no reduction is performed and the alkaline buffer is not necessary. The phosphate analysis is a modification of the procedure of Murphy and Riley (1962). Molybdic acid is added to the seawater sample to form phosphomolybdic acid which is in turn reduced to phosphomolybdous acid using L-ascorbic acid as the reductant. The silicate method is analogous to that described for phosphate. The method used is essentially that of Grasshoff et al. (1983), wherein silicomolybdic acid is first formed from the silicate in the sample and added molybdic acid, then the silicomolybdic acid is reduced to silicomolybdous acid, or "molybdenum blue," using L-ascorbic acid as the reductant. The flow diagrams and reagents for each parameter are shown in Figures C.4.2-C.4.5. (3.2) Nitrate Reagents Ammonium chloride (buffer), 0.7 M (0.04% w/v); Dissolve 190 g Ammonium chloride, NH4Cl, in ca. 5000 ml of milli-Q water, add about 5 ml Ammonia (aq.), adjust pH 8.2-8.5. Sulfanilamide, 0.06 M (1% w/v); Dissolve 5 g Sulfanilamide, 4-NH2C6H4SO3H, in 430 ml milli-Q water, add 70 ml concentrated HCl. After mixing, 1 ml Brij-35 (22% w/w) is added. N-1-Naphtylethylene-diamine dihydrochloride (NEDA), 0.004 M (0.1% w/v); Dissolve 0.5 g NEDA, C10H7NH2CH2CH2NH2•2HCl, in 500 ml milli-Q water. Figure C.4.2: 1ch. (Nitrate + Nitrite) Flow diagram. (3.3) Nitrite Reagents Sulfanilamide, 0.06 M (1% w/v); Dissolve 5 g Sulfanilamide, 4-NH2C6H4SO3H, in 430 ml milli-Q water, add 70 ml concentrated HCl. After mixing, 1 ml Brij-35 (22% w/w) is added. N-1-Naphtylethylene-diamine dihydrochloride (NEDA), 0.004 M (0.1% w/v); Dissolve 0.5 g NEDA, C10H7NH2CH2CH2NH2•2HCl, in 500 ml milli-Q water. Figure C.4.3: 2ch. Nitrite Flow diagram. (3.4) Phosphate Reagents Ammonium molybdate, 0.005 M (0.6% w/v); Dissolve 3 g Ammonium molybdate(VI) tetrahydrate, (NH4)6Mo7O24•4H2O, and 0.05 g Potassium antimonyl tartrate, C8H4K2O12Sb2•3H2O, in 400 ml milli-Q water and add 100 ml H2SO4 (12.6N). After mixing, 2 ml Sodium dodecyl sulfate (15% solution in water) is added. L(+)-Ascorbic acid, 0.08 M (1.5% w/v); Dissolve 4.5 g L(+)-Ascorbic acid, C6H8O6, in 300 ml milli-Q water. After mixing, 10 ml Acetone is added. Freshly prepared before every measurement. Figure C.4.4: 3ch. Phosphate Flow diagram. (3.5) Silicate Reagents Ammonium molydate, 0.005 M (0.6% w/v); Dissolve 3 g Ammonium molybdate (VI) tetrahydrate, (NH4)6Mo7O24•4H2O, in 495 ml milli-Q water and added 5 ml H2SO4 (12.6N). After mixing, 2 ml Sodium dodecyl sulfate (15% solution in water) is added. Oxalic acid, 0.4 M (5% w/v); Dissolve 25 g Oxalic acid dihydrate, (COOH)2•2H2O, in 500 ml milli-Q water. L(+)-Ascorbic acid, 0.08 M (1.5% w/v); Dissolve 4.5 g L(+)-Ascorbic acid, C6H8O6, in 300 ml milli-Q water. After mixing, 10 ml Acetone is added. Freshly prepared before every measurement. Figure C.4.5: 4ch. Silicate Flow diagram. (3.6) Sampling procedures Seawater samples were collected from 10-liters Niskin bottle attached CTD-system and a stainless steel bucket for the surface. Sampling of nutrients followed that oxygen and trace gases. Samples were drawn into 10 ml polymethylpenten vials with sample drawing tubes. These were rinsed three times before filling and vials were capped immediately after the drawing. No transfer was made and the vials were set an auto sampler tray directly. Samples were analyzed immediately after collection. (3.7) Data processing Raw data from Auto Analyzer III were recorded at 1-second interval and were treated as follows; - Calculate 11-second moving average. - Check the shape of each peak and position of peak values taken, and then change the positions of peak values taken if necessary. - Baseline correction was done basically using liner regression. - Reagent blank correction was done basically using liner regression. - Carry-over correction was applied to peak heights of each sample. - Sensitivity correction was applied to peak heights of each sample. - Refraction error correction was applied to peak heights of each seawater sample. - Calibration curves to get nutrients concentration were assumed quadratic expression. - Load pressure and salinity from CTD data to calculate density of seawater. - Convert data from µmol/l to µmol/kg. (4) Nutrients standards (4.1) Volumetric Laboratory Ware of in-house standards All volumetric ware used were gravimetrically calibrated. Polymethylpenten volumetric flasks were gravimetrically calibrated at the temperature of use within 3 - 4 K. Volumetric flasks 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. (4.2) Reagents, general considerations Specifications For nitrate standard, "potassium nitrate 99.995 suprapur" provided by Merck, CAS No. : 7757-79-1, was used. For phosphate standard, "potassium dihydrogen phosphate anhydrous 99.995 suprapur" provided by Merck, CAS No. : 7778-77-0, was used. For nitrite standard, "sodium nitrite GR for analysis ACS,Reag. Ph Eur" provided by Merck, CAS No. : 7632-00-0, was used. For the silicate standard, we use "Silicon standard solution traceable to SRM from NIST SiO2 in NaOH 0.5 mol/l 1000 mg/l Si CertiPUR" provided by Merck, which lot number is HC814662 is used. The silicate concentration is certified by NIST-SRM3150 with the uncertainty of 0.5%. Ultra pure water Ultra pure water (Milli-Q water) freshly drawn was used for preparation of reagents, higher concentration standards and for measurement of reagent and system blanks. Low Nutrient Seawater (LNSW) Surface water having low nutrient concentration was taken and filtered using 10 _m pore size membrane filter. This water is stored in 20 liter flexible container with paper box. (4.3) Concentrations of nutrients for A, B and C standards Concentrations of nutrients for A, B and C standards are set as shown in Table C.4.1. The C standard is prepared according recipes as shown in Table C.4.2. All volumetric laboratory tools were calibrated prior the cruise as stated in subsection (4.1). 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 4 levels, C-1, C-2, C-3 and C-4. Table C.4.1: Nominal concentrations of nutrients for A, B and C standards. Unit: µmol/l A B C-1 C-2 C-3 C-4 (Full scale) ----- ------ ----- -------------- -------------- ---------------- NO3 26200 520 LNSW* 1/3 Full scale 2/3 Full scale 43.4 NO2 12500 250 LNSW* 1/3 Full scale 2/3 Full scale 2.0 PO4 2040 40.5 LNSW* 1/3 Full scale 2/3 Full scale 3.2 Si 35600 1950 LNSW* 1/3 Full scale 2/3 Full scale 155 Table C.4.2: Working calibration standard recipes. C Std. B-1 Std. B-2 Std. ---------------- -------- ---------------- C-4 (Full scale) 20 ml 2 ml --------------------------------------------- LNSW* C-4 (Full scale) --------------------------------------------- C-1 30 ml 0 ml C-2 20 ml 10 ml C-3 10 ml 20 ml --------------------------------------------- B-1 Std.: Mixture of nitrate, phosphate and silicate. B-2 Std.: Nitrite. LNSW*: 22 ml milli-Q water in 250 ml volu- metric flask, and LNSW add to marked line. (4.4) Renewal of in-house standard solutions In-house standard solutions as stated in (4.3) were renewed as shown in Table C.4.3. Table C.4.3: Timing of renewal of in-house standards. NO3, NO2, PO4, Si Renewal --------------------------- ---------------------------- A-1 Std. (NO3) no renewal A-2 Std. (NO2) no renewal A-3 Std. (PO4) no renewal A-4 Std. (Si) commercial prepared solution B Std. B-1 Std. maximum 9 days B-2 Std. maximum 14 days C Std. Renewal --------------------------------------------------------- mixture of B-1 and B-2 Std. Every measurement --------------------------------------------------------- B-1 Std.: Mixture of nitrate, phosphate and silicate. B-2 Std.: nitrite. (5) Use of RMNS The reference material of nutrients in seawater (hereafter RMNS), which was prepared by the General Environmental Technos Co. Ltd. (Kanso Technos), was used every analysis at each hydrographic station. According to Aoyama et al. (2010), the RMNS homogeneity is 0.1% - 0.2% in high concentration range, and stability is 48 - 71 months. By the use of RMNSs for the analysis of seawater, it is expected to secure stable comparability and uncertainty of data. If RMNS will be certified in the future, the traceability of our analysis value will be secured. Aoyama et al. (2010) assigned nutrients concentrations for RMNS lot BA, AX, BE and AZ as shown in Table C.4.4. Table C.4.4: INSS assigned concentration of RMNSs. Unit: µmol/kg --------------------------------------------- Nitrate Phosphate Silicate ---------- ----------- ----------- RMNS-BA 0.07±0.01 0.061±0.007 1.61±0.07 RMNS-AX 21.44±0.05 1.614±0.006 58.05±0.12 RMNS-BE 36.70±0.04 2.662±0.005 99.20±0.08 RMNS-AZ 42.36±0.06 3.017±0.005 133.93±0.11 (5.1) RMNSs for this cruise One hundred and five set of RMNS lots BA and BE were prepared to use every analysis at each hydrographic station. BA and BE were renewed every run. To check the inter-bottle consistency of RMNS, we re-measured the RMNS in the next analysis run. Sixteen of RMNS lots AX and AZ were prepared to use every 2 to 4 analysis and renewed every 2 or 3 runs in principle. The RMNS bottles were stored at a wet laboratory in the ship, where the temperature was maintained around 26 deg-C. (5.2) Assigned concentration of RMNSs We assigned nutrients concentrations for RMNS lots BA, AX, BE and AZ as shown in Table C.4.5 based on the analysis during the cruise. The measured concentration of RMNS lot BE during the cruise are shown in Figure C.4.6 - C.4.8 as quality control charts. The concentration variations in these figures represent largely differences of the in-house standard. At Stn.25, one bottle of RMNS_lot BE, No. 0138, showed obviously low concentrations. The measured values of all parameters were ca. 2% lower than expected. The concentrations of another bottle of RMNS_lot BE, which was also analyzed in previous run, showed a good agreement with expected value. So, we neglected the result of No. 0138 of RMNS_lot BE. At Stn.58, nitrate + nitrite concentration of BA No. 0756 had also shown unexpected low value, so it was neglected too. The concentrations of RMNSs were in close agreement with expected values within the range of uncertainty except for the phosphate. Table C.4.5: Assigned concentration of RMNSs. Unit: µmol/kg -------------------------------------------------- Nitrate + Nitrite Phosphate Silicate ----------------- --------- ----------- RMNS-BA 0.07±0.03 0.02±0.00 1.60±0.10 RMNS-AX 21.89±0.08 1.59±0.01 58.14±0.18 RMNS-BE 36.77±0.11 2.64±0.01 99.27±0.19 RMNS-AZ 42.42±0.13 2.98±0.01 133.84±0.23 -------------------------------------------------- Note: N(BA: Nitrate + Nitrite, Silicate)=104, N(BA: Phosphate)=105, N(BE: Nitrate + Nitrite, Phosphate)=104, N(BE: Silicate)=103, N(AX,AZ)=45. Figure C.4.6: Result of RMNS lot BE concentrations of nitrate + nitrite during the cruise. Figure C.4.7: Result of RMNS lot BE concentrations of phosphate during the cruise. Figure C.4.8: Result of RMNS lot BE concentrations of silicate during the cruise. (5.3) Relative standard deviation of RMNSs measurement The relative standard deviation of lot BA, AX, BE and AZ throughout the cruise are shown in Table C.4.6. Table C.4.6: Relative standard deviation of RMNSs lot BA, AX, BE and AZ measurements in each run throughout cruise. Nitrate + Nitrite Phosphate Silicate CV % CV % CV % ----------------- --------- -------- RMNS-BA 41.03 16.02 6.47 RMNS-AX 0.35 0.43 0.31 RMNS-BE 0.30 0.30 0.19 RMNS-AZ 0.31 0.31 0.17 ------------------------------------------------ Note: N(BA: Nitrate + Nitrite, Silicate)=104, N(BA: Phosphate)=105, N(BE: Nitrate + Nitrite, Phosphate)=104, N(BE: Silicate)=103, N(AX,AZ)=45. (6) Quality control (6.1) Precision of nutrients analyses during the cruise Precision of nutrients analyses during the cruise was evaluated based on 5 or 6 measurements of the C-4 (full scale) standard in each run. Summary of precisions are shown in Table C.4.7. During this cruise, analytical precisions were 0.11% for nitrate, 0.16% for phosphate and 0.09% for silicate in terms of mean of precision, respectively. The time series of precision are shown in Figure C.4.9 - C.4.11. Table C.4.7: Summary of precisions during the cruise. Nitrate + Nitrite Phosphate Silicate CV % CV % CV % ----------------- --------- -------- Median 0.11 0.14 0.08 Mean 0.11 0.16 0.09 Maximum 0.32 0.38 0.31 Minimum 0.03 0.03 0.01 Number 105 105 104 Figure C.4.9: Time series of precision of nitrate + nitrite. Figure C.4.10: Time series of precision of phosphate. Figure C.4.11: Time series of precision of silicate. (6.2) Replicate sample measurement Replicate samples were analyzed at every hydrographic station. Total amount of the replicate sample pairs was 405. Summary of replicate sample measurements are shown in Table C.4.8, and Figure C.4.12 - C.4.14. During this cruise, the average difference and standard deviation of replicate measurement were 0.038±0.036 µmol/kg for nitrate + nitrite, 0.004±0.004 µmol/kg for phosphate and 0.140±0.139 µmol/kg for silicate, respectively. Table C.4.8: Average difference of replicate samples in each run throughout cruise. Unit: µmol/kg ------------------------------------------- Nitrate + Nitrite Phosphate Silicate ----------------- ----------- ----------- 0.038±0.036 0.004±0.004 0.140±0.139 ------------------------------------------- Note: N=403(nitrate, phosphate), N=399(silicate) at flag 2. Figure C.4.12: Result of nitrate + nitrite replicate samplings (N=403) during RF10-05 against (a) station number, (b) sampling pressure, (c) concentration and (d) histogram of the result of replicate samplings. Figure C.4.13: Result of phosphate replicate samplings (N=403) during RF10-05 against (a) station number, (b) sampling pressure, (c) concentration and (d) histogram of the result of replicate samplings. Figure C.4.14. Result of silicate replicate samplings (N=399) during RF10-05 against (a) station number, (b) sampling pressure, (c) concentration and (d) histogram of the result of replicate samplings. (6.3) Duplicate sample measurement Duplicate samples were analyzed at every hydrographic station. Total amount of the duplicate sample pairs was 295. Summary of duplicate sample measurements are shown in Table C.4.9, and Figure C.4.15 - C.4.17. During this cruise, the average difference and standard deviation of replicate measurement were 0.040±0.039 µmol/kg for nitrate + nitrite, 0.005±0.004 µmol/kg for phosphate and 0.167±0.163 µmol/kg for silicate, respectively. Table C.4.9: Average difference of duplicate samples in each run throughout cruise. Unit: µmol/kg ------------------------------------------- Nitrate + Nitrite Phosphate Silicate ----------------- ----------- ----------- 0.040±0.039 0.005±0.004 0.167±0.163 ------------------------------------------- Note: N=293(nitrate + nitrite), N=290(phosphate), N=289(silicate) at flag 2. Figure C.4.15: Result of nitrate + nitrite duplicate samplings (N=293) during RF10-05 against (a) station number, (b) sampling pressure, (c) concentration and (d) histogram of the result of duplicate samplings. Figure C.4.16: Result of phosphate duplicate samplings (N=290) during RF10-05 against (a) station number, (b) sampling pressure, (c) concentration and (d) histogram of the result of duplicate samplings. Figure C.4.17: Result of silicate duplicate samplings (N=289) during RF10-05 against (a) station number, (b) sampling pressure, (c) concentration and (d) histogram of the result of duplicate samplings. (7) Uncertainty* (7.1) Uncertainty of concentration level The 44 sets of RMNS were analyzed during the cruise to get empirical equations to estimate uncertainty of concentrations of seawater samples throughout cruise. The average value and CV for each RMNS level were calculated, graphed, and a curve fit determined. The empirical equation (7.1) is an example of the curve fit between nutrients concentration Cx and the uncertainty at each concentration level. Uncertainty for parameter X(%) = a + b(1/Cx) + c(1/Cx)2 → --(7.1) Where Cx is concentration of sample for parameter X. Empirical equations, eqs. (7.2), (7.3) and (7.4) were used to estimate uncertainty of measurement of nitrate + nitrite, phosphate and silicate during this cruise. The equations are based on analysis of 44 sets of RMNS lots BA, AX, BE and AZ. Figure C.4.18 - C.4.20 show graphic presentations of eqs. (7.2) - (7.4). Nitrate + Nitrite Concentration Cn in µmol/kg: Uncertainty of measurement of nitrate (%)= 0.274 + 1.779 x (1/Cn) + 0.0497 x (1/Cn)2 → -- (7.2) Where Cn is nitrate concentration of sample. Phosphate Concentration Cp in µmol/kg: Uncertainty of measurement of phosphate (%)= 0.166 + 0.416 x (1/Cp) - 0.00146 x (1/Cp)2 → -- (7.3) Where Cp is phosphate concentration of sample. Silicate Concentration Cs in µmol/kg: Uncertainty of measurement of silicate (%)= 0.0638 + 14.192 x (1/Cs) - 5.753 x (1/Cs)2 → -- (7.4) Where Cs is silicate concentration of sample. Figure C.4.18: Uncertainty of nitrate + nitrite concentration level. Figure C.4.19: Uncertainty of phosphate concentration level. Figure C.4.20: Uncertainty of silicate concentration level. (7.2) Uncertainty of analysis Uncertainty of analysis is estimated relative standard deviation of precision throughout cruise as shown in subsection (6.1). (7.3) Uncertainty of in-house standard Uncertainty of in-house standard is estimated relative standard deviation of RMNS throughout cruise as shown in subsection (5.3). (7.4) Combined relative standard uncertainty Combined relative standard uncertainty is calculated equation (7.5). ______________________ Combined relative standard uncertainty = √ Uc2 + Ua2 + Us2 + Ur2 → -- (7.5) Where Uc is uncertainty of concentration level, Ua is uncertainty of analysis, Us is uncertainty of in-house standard, Ur is uncertainty of RMNS. The result of giving the uncertainty by using eq. (7.5) for the decided RMNS concentration were shown Table C.4.11. Table C.4.11: Result of analysis value and expanded uncertainty obtained from measurements. Unit: µmol/kg ------------------------------------------- Nitrate + Nitrite Phosphate Silicate ----------------- ----------- ----------- RMNS-BA 0.07±0.07 0.02±0.01 1.60±0.31 RMNS-AX 21.89±0.24 1.59±0.02 58.14±0.54 RMNS-BE 36.77±0.33 2.64±0.02 99.27±0.57 RMNS-AZ 42.42±0.38 2.98±0.03 133.84±0.69 ---------------------------------------------------- Note: coverage factor k=2 *The description of this section is based on that of Aoyama et al. (2009, unpublished manuscript). (8) Problems/improvements occurred and solutions During the cruise, low-frequency noise (ca. 6 seconds per cycle) in the all channel output of AA III. So moving average was applied to all the raw data. At Stn.16 (Lat. 30°39.21'N / Long. 136°59.69'E, RF3664), the silicate output of quality control samples and sensitivity compensation sample had exceeded the maximum value of the instrument setting. It was impossible to process silicate data for the station properly, so we neglect it. Pump tubes were replaced after the analysis. Due to a problem on Phosphate data at Stn.36 (Lat. 20°59.83'N / Long. 136°58.21'E, RF3684), we had done another analytical run for the station. To reduce the analysis time, we omitted the C-2 and C-3 standard on these run, and processed the data as described below. 1. For each phosphate standard measurement in every run except for Stn.36, calculate the difference dCx between the concentration (Cx2) based on quadratic calibration equation and the concentration (Cx1) based on linear calibration equation. 2. Calculate mean and standard deviation of dCx at each level (C-1, C-2, C-3 and C-4) and reject the data for individual run if any of dCx at each level exceeds the range of mean±standard deviation. 3. The correction equation (8.1) is calculated by the regression analysis using all QCed pair of dCx and Cx1. 2 dCx(Cx1) = bCx1 + cCx1 → -- (8.1) 4. For phosphate of Stn.36, calculate tentative sample concentrations Ct1 based on linear calibration equation in each run. 5. The sample concentration C is obtained from equation (8.2) using Ct1 and eq. (8.1). C + Ct1 + dCx(Ct1) → -- (8.2) The correction term represents non-linearity of standard calibration. The correction for phosphate at Stn.36 was smaller than 0.003 µmol/kg. (9) Results (9.1) Comparison at cross-stations during this cruise Cross-stations during this cruise were two stations. The one was located at 2°N/142°E, another was located 7°N/137°E. At stations of Stn.83 (RF3731) and Stn.104 (RF3755), hydrocast sampling for nutrients (nitrate, nitrite, phosphate, silicate) were conducted two times at interval of about five days. Each nutrients parameter profiles of the two hydrocasts agreed well within the range of uncertainty when correcting it by using RMNS. At stations of Stn.67 (RF3715), Stn.68 (RF3716) and Stn.124 (RF3772), hydrocast sampling for nutrients were conducted three times. Interval between the first and the second was about a week, interval between the second and the third was about two weeks. Each nutrients parameter profiles of the three hydrocasts agreed well within the range of uncertainty when correcting it by using RMNS. These profiles are shown in Figure C.4.21 - C.4.23. Figure C.4.21: Comparison of nitrate +nitrite profiles between the first hydrocast (circle) and the second one (triangle) at the cross-stations of 2°N/142°E (left), and the first hydrocast (circle), the second one (triangle) and the third one (square) at the cross-stations of 7˚N/137˚E (right). Figure C.4.22: Comparison of phosphate profiles between the first hydrocast (circle) and the second one (triangle) at the cross-stations of 2°N/142°E (left), and the first hydrocast (circle), the second one (triangle) and the third one (square) at the cross-stations of 7°N/137°E (right). Figure C.4.23: Comparison of silicate profiles between the first hydrocast (circle)and the second one (triangle) at the cross-stations of 2°N/142°E (left), and the first hydrocast (circle), the second one (triangle) and the third one (square) at the cross-stations of 7°N/137°E (right). (9.2) Comparison at cross-stations of WHP-P2 section in 2004 and WHP-P9 in 1994 We compared our nutrients data with gridded data of WHP-P2 at a cross point around 30°N/137°E. WHP-P2 line was observed two times, the repeat cruise was observed in 2004 by R/V Melville belonged to Scripps Institution of Oceanography (SIO). WHP-P9 line was observed in 1994 by JMA. These data may have inter-cruise differences because they did not measure the RMNS in their cruise. Summary of compared these data profiles shown in Figure C.4.24 - C.4.26. Figure C.4.24: Comparison of nitrate + nitrite profiles at cross-station of WHP-P2. Circle, plus, square show the WHP-P9 in 1994 by JMA, WHP-P2 in 2004 by SIO and WHP-P9 revisit in 2010 by JMA, respectively. Figure C.4.25: Comparison of phosphate profiles at cross-station of WHP-P2. Circle, plus, square show the WHP-P9 in 1994 by JMA, WHP-P2 in 2004 by SIO and WHP-P9 revisit in 2010 by JMA, respectively. Figure C.4.26: Comparison of silicate profiles at cross-station of WHP-P2. Circle, plus, square show the WHP-P9 in 1994 by JMA, WHP-P2 in 2004 by SIO and WHP-P9 revisit in 2010 by JMA, respectively. (9.3) Comparison at cross-stations of WHP-P3 section in 1985, 2005/06 and WHP-P9 in 1994 We compared our nutrients data with gridded data of WHP-P3 at a cross point around 24°N/137°E. WHP-P3 line was observed two times, the first was observed in 1985 by R/V Thomas G. Thompson belonged to SIO and the repeat cruise was observed in 2005/06 by R/V Mirai belonged to Japan Agency for Marine-Earth Science and Technology (JAMSTEC, 2007). WHP-P9 line was observed in 1994 by JMA. Our nutrients data at P9 revisit and JAMSTEC data in 2005/06 are comparable directly through the RMNS. However, SIO data in 1985 and JMA data in 1994 may have inter-cruise differences because they did not measure the RMNS in their cruise. Summary of compared these data profiles shown in Figure C.4.27 - C.4.29. Note: Silicate data of WHP-P3 revisit (JAMSTEC, 2007) is corrected by a scale factor provided by M. Aoyama, PI of nutrients of the cruise (personal communication). Figure C.4.27: Comparison of nitrate + nitrite profiles at cross-station of WHP-P3. Plus, square, triangle, circle show the WHP-P3 in 1985 by SIO, WHP-P9 in 1994 by JMA, WHP-P3 in 2005/06 by JAMSTEC and WHP-P9 revisit in 2010 by JMA, respectively. Figure C.4.28: Comparison of phosphate profiles at cross-station of WHP-P3. Plus, square, triangle, circle show the WHP-P3 in 1985 by SIO, WHP-P9 in 1994 by JMA, WHP-P3 in 2005/06 by JAMSTEC and WHP-P9 revisit in 2010 by JMA, respectively. Figure C.4.29: Comparison of silicate profiles at cross-station of WHP-P3. Plus, square, triangle, circle show the WHP-P3 in 1985 by SIO, WHP-P9 in 1994 by JMA, WHP-P3 in 2005/06 by JAMSTEC and WHP-P9 revisit in 2010 by JMA, respectively. Data of WHP-P3 revisit (JAMSTEC, 2007) is corrected by a scale factor provided by M. Aoyama, PI of nutrients of the cruise (personal communication). (9.4) Comparison at cross-stations of WHP-P4 section in 1989, and WHP-P9 in 1994 We compared our nutrients data with gridded data of WHP-P4 at cross point around 9°N/137°E. WHP-P4 line was observed in 1989 by R/V Moan Wave belonged to University of Hawaii (UH). WHP-P9 line was observed 1994 by JMA. These data may have inter-cruise differences because they did not measure the RMNS in their cruise. Summary of compared these data profiles shown in Figure C.4.30 - C.4.32. Figure C.4.30: Comparison of nitrate + nitrite profiles at cross-station of WHP-P4. Circle, plus, square show the WHP-P4 in 1989 by UH, WHP-P9 in 1994 by JMA and WHP-P9 revisit in 2010 by JMA, respectively. Figure C.4.31: Comparison of phosphate profiles at cross-station of WHP-P4. Circle, plus, square show the WHP-P4 in 1989 by UH, WHP-P9 in 1994 by JMA and WHP-P9 revisit in 2010 by JMA, respectively. Figure C.4.32: Comparison of silicate profiles at cross-station of WHP-P4. Circle, plus, square show the WHP-P4 in 1989 by UH, WHP-P9 in 1994 by JMA and WHP-P9 revisit in 2010 by JMA, respectively. References Grasshoff, K., Ehrhardt, M., Kremling K. et al. (1983), Methods of seawater analysis. 2nd rev, Weinheim: Verlag Chemie, Germany, West. Murphy, J., and Riley, J.P. (1962), Analytica chimica Acta 27, 31-36. Armstrong, F. A. J., C. R. Stearns and J. D. H. Strickland (1967), The measurement of upwelling and subsequent biological processes by means of the Technicon TM Autoanalyzer TM and associated equipment, Deep-Sea Res., 14(3), 381-389. JAMSTEC (2007), WHP P3 REVISIT DATA BOOK, WHP P03 REVISIT in 2005. Aoyama, M., A. G. Dickson, D. J. Hydes, A. Murata, J. R. Oh, P. Roose and E. Malcom. S. Woodward (2010), Comparability of nutrients in the world's ocean, INSS international workshop 10-12 Feb. 2009, Paris Aoyama, M., S. Becker, K. Sato and D. Schuller (2009), Plan of use of RMNS during the CLIVAR P6 revisited cruise by R/V Melville. (unpublished manuscript). 8. PHYTOPIGMENT (CHLOROPHYLL-a AND PHAEOPIGMENS) (1) Personnel Yusuke Takatani (GEMD/JMA) Shinichiro Umeda (GEMD/JMA) (2) Station occupied A total of 50 stations (Leg 1: 29, Leg 2: 21) were occupied for phytopigment. Station location and sampling layers of phytopigment are shown in Figure C.9.1. Figure C.9.1: Sation location (left panel) and sampling layers of phytopigment (right panels). (3) Reagents N,N-dimethylformamide (DMF) 0.5 N hydrochloric acid (0.5N HCl) Chlorophyll-a standard from Anacystis nidulans algae (Lot. BCBB4166) manufactured by Sigma Chemical Co. Rhodamine WT manufactured by Turner Designs. (4) Instruments Fluorometer; 10-AU (S/N:6718) manufactured by Turner Designs Spectrophotometer; UV-1800 (S/N:A114547) manufactured by Shimadzu Co. Ltd. Glass Fiber Filiter; Whatman GF/F filter (25 mm) (5) Standardization A chlorophyll-a standard calibration for fluorometric determination was performed by the method described by UNESCO (1994). Before standardization, fluorometer was calibrated by using 100% DMF and a Rhodamine solution diluted to 1ppm with deionized water. Chlorophyll-a standard was dissolved in DMF. The concentration of chlorophyll-a solution was determined spectrophotometrically as follows; Chl-a concentration (µg/ml) = Achl/specific absorption coefficient where Achl is the difference between absorbance at 663.8 nm and 750 nm. The specific absorption coefficient is 88.74 L/g·cm (Porra et al., 1989). Using this precise chlorophyll-a concentration, the linear calibration factor (fph) and the acidification coefficient (R) were calculated. fph was calibrated for each cuvette as the slope of the unacidified fluorometric reading vs. chlorophyll-a concentration calculated spectrophotometrically. R was calculated by averaging the ratio of the unacidified and acidified readings of pure chlorophyll-a. Table C.9.1 shows fph and R in this cruise. Table C.9.1: fph and R determined by the standardization. Linear calibration factor (fph) 5.13 Acidification coefficient (R) 1.848 (6) Seawater sampling and measurement Seawater samples were collected from 10-liters Niskin bottle attached the CTD-system and a stainless steel bucket for the surface in 200 ml. The seawater samples were immediately filtered through 25 mm GF/F filter by low vacuum pressure, and the particulate matter was made to adsorb to the filter. The filter was put into the vial containing 9 ml of DMF, then stored to extract phytogigment in the refrigerator for more than 24 hours at -30 deg-C until analysis. After the extracts were put on the room temperature for at least one hour in the dark, only the extracts except the filter were decanted from the vial to the cuvette. Fluorometer readings for each cuvettes were taken before and after acidification with 1-2 drops 0.5 N HCl. Chlorophyll-a (Chl) and phaeopigment (Phaeo) concentration in the sample are calculated using the following equations; Fo - Fa v Chl(µg/l) = ----------- · - fph · (R-1) V R · Fo - Fa v Phaeo(µg/l) = ----------- · - fph · (R-1) V Fo → = reading before acidification Fa → = reading after acidification R → = acidification coefficient (F0/Fa) for pure chlorophyll-a fph → = linear calibration factor v → = extraction volume V → = sample volume (7) Quality control flag assignment Quality flag values were assigned to phytopigment measurements using the code defined in IOCCP Report No.14 (Swift, 2010). Measurement flags of 2 (good), 3 (questionable), and 4 (bad) have been assigned (Table C.9.2). Table C.9.2: Summary of assigned quality control flags. Flag Definition Chl Phaeo ---- ------------ --- ----- 2 Good 437 437 3 Questionable 0 0 4 Bad (Faulty) 12 12 ------------------------------ Total number 449 449 References Porra, R. J., W. A. Thompson and P. E. Kriedemann (1989): Determination of accurate coefficients and simultaneous equations for assaying chlorophylls a and b extracted with four different solvents: verification of the concentration of chlorophyll standards by atomic absotption spectroscopy. Biochem. Biophy. Acta, 975, 384-394 Swift, J. H. (2010): Reference-quality water sample data: Notes on acquisition, record keeping, and evaluation. IOCCP Report No.14, ICPO Pub. 134, 2010 ver.1 UNESCO (1994), Protocols for the joint global ocean flux study (JGOFS) core measurements: Measurement of chlorophyll a and phaeopigments by fluorometric analysis, IOC manuals and guides 29, Chapter 14. 9. LOWERED ACOUSTIC DOPPLER CURRENT PROFILER (1) Personnel Tetsuya NAKAMURA (GEMD/JMA) Yoshikazu HIGASHI (GEMD/JMA) Tomoyuki KITAMURA (GEMD/JMA) Takahiro SEGAWA (GEMD/JMA) Keizo SHUTTA (GEMD/JMA) Yasuaki BUNGI (GEMD/JMA) (2) Instrument and measurement Direct flow measurement from sea surface to the bottom was carried out using a Lowered Acoustic Doppler Current Profiler (LADCP). The instrument used was the RDI Workhorse Monitor 307.2 kHz unit (S/N 13666; Teledyne RD Instruments, USA). The instrument was attached on the CTD frame, orientating downward. The CPU firmware version was 50.36. One ping raw data were recorded. Settings for the collecting data were as listed in Table C.9.1. A total of 124 operations were made with the CTD observations. The performance of the LADCP was good between Stn.1 (RF3649) and Stn.42 (RF3690). From Stn.43 (RF3691) the echo intensity of beam 4 got weak, and from Stn.50 (RF3698) it might be broken down. From Stn.109 (RF3757), the beam 1 might be also broken down. And besides, data transfer errors often occurred during download process from the LADCP to the PC. So the data processing was performed for 101 stations. Table C9.1: Setting for the correcting data. Bin length 8m Bin number 25 Error Threshold 2000mm/s Ping interval 1.0sec (3) Data process and result Vertical profiles of velocity are obtained by the inversion method (Visbeck, 2002). Both the up and down casts are used for the inversion. Since the first bin from LADCP is influenced by the turbulence generated by CTD frame, the weight for the inversion is set to small value of 0.1. The GPS navigation data are used in the calculation of the reference velocities and the bottom-track data are used for the correction of the reference velocities. Shipboard ADCP (SADCP) data averaged for 5 minutes are also included in the calculation. The CTD data are used for the sound speed and depth calculation. IGRF (International Geomagnetic Reference Field) 11th generation data are used for calculating magnetic deviation to correct the direction of velocity. In the processing, we use Matlab routines (version 8b: 5 April 2004) provided by M. Visbeck and G. Krahmann. We set the weight for SADCP data in the calculation to 3.0, so vertical profiles of velocity obtained by the inversion method is similar to SADCP upper 1000 dbar. The uncertainty of velocity observed by SADCP is about 10 cm/s. So we regard the error velocity from LADCP upper 1000 dbar as about 10 cm/s. Figure C.9.1 and C.9.2 show the results of the zonal velocity (eastward is positive) and the meridional velocity (northward is positive), respectively. The major currents in the western Pacific such as the Kuroshio (34°N to 32°N), the Equatorial Under Current (EQ to 3°N), and New Guinea Coastal Under Current (around 2°S) appeared in the figures. Figure C.9.3 shows error velocity estimated by the inversion method. The error velocities are very small (less than 5 cm/s) upper 1000 dbar and adjacent to the bottom from Stn.1 to Stn.42. After Stn.43, the error velocity below 1000 dbar become larger and exceed 50 cm/s at maximum. This is because the echo intensity of beam 4 got weak down after Stn.43. Figure C.9.1: The cross-section of zonal velocity (m/s, eastward is positive). Black line shows the Stn.43. The data south of the Stn.43 is doubtful due to malfunction of the instrument. Figure C.9.2: The cross-section of meridional velocity (m/s, northward is positive). Black line shows the Stn.43. Note that southern of Stn.43 is doubtful. Figure C.9.3: Cross-section of error velocity (m/s) estimated by the inversion method. Black line shows the Stn.43. Note that southern of Stn.43 is doubtful. 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. CCHDO DATA PROCESSING NOTES Date Contact Data Type Event Summary ---------- --------------- ------------ -------------------------------------- 2010-12-27 Nakano, Toshiya CTDO2 Submitted Preliminary I send the preliminary CTDO2 dataset and document of RF10-05 cruise (WHP-P9 revisit). 2011-02-02 Berys, Carolina CTD02/Report Website Update Available under 'Updates' File 20101228_WHP-P9_revisit_ct1_doc.zip containing CTD data and Cruise Report submitted by Toshiya Nakano on 2010-12-27, available under 'Files as received', unprocessed by CCHDO. 2011-03-14 Diggs, Steve CTD/CTDO2 Update needed CTD/Format CTD files as received need only a few modifications: - TIM -> TIME - 49RY20100706 -> EXPOCODE = 49RY20100706 - END_DATA at the end of each file Matt Shen and I will make the corrections and place the data (and documentation) online 2011-08-17 Shen, Matthew CTD Website Update Corrected Exchange and new NetCDF files online I made the following updates to the CTD files for http://cchdo.ucsd.edu/cruise/49RY20100706: Exchange CTD * Corrected file format _* TIM -> TIME _* 49RY20100706 -> EXPOCODE = 49RY20100706 _* added END_DATA NetCDF CTD * Generated from Exchange CTD 2012-02-21 Nakano, Toshiya CTD/BTL/SUM Submitted to go online