Cruise Report for PR1S and PR24 PR1S:A Hydrographic Section along 130-00'E PR24:A Hydrographic Section from Mindanao SE to Indonesia 6N :A Hydrographic Section from Mindanao SE to Palau 28 April 1994 R/V KAIYO 12 Feb. 1994 - 3 March 1994 Contents 1. Highlight 2. Summary of the observations and data files 3. Cruise track, stations and sampling depths 4. Preliminary results 5. Parameters, Contribution Institutions, and Personnel 6. Underway Measurement 7. Sampling/measurements equipments 8. CTD/Rosette hardware 9. Moorings 10. CTD/Rosette operation 11. CTD data processing 12. Sample water salinity measurements 13. Dissolved Oxygen determination 14. Nutrients measurements 15. Plant Pigments measurements 16. Drifters 17. Distribution of atmospheric and oceanic CO2 18. C-14 sample drawing 19. Weather and sea condition 20. Problems 21. Report on CTD system performance Acknowledgements List of Tables Table 2-1 KYZZZZ94.SUM Table 4-1 The average and the standard deviation of the properties below 3000 dbar Table 5-1 List of parameters measured, the sampling group(s) responsible for each, and the principal investigator(s) for each. Table 5-2 Cruise participants Table 6-1 Sampling equipments Table 7-1 The differences between water depth estimated summing of CTD observation plus altimeter reading and uncorrected echosounding depth Table 8-1 Summary of RTM and RPM data. Average (upper raw) and Standard deviation (lower raw) Table 11-1 Definition of noise and the number of noise detected by this definition Table 12-1 Summary of standardization Table 12-2 cell factors Table 13-1 Comparison of standards from JAMSTEC and SIO Table 14-1 The standard deviation of the differences between duplicate samples Table 14-2 The results of the quality control samples at the same depth Table 14-3 The results of the repeat analysis as a range of concentration Table 15-1 The Chl. a and Chl. b concentration. Table 16-1 List of drifters deployed on this cruise Table 19-1 Weather observation record Table 21-1 Comparison between primary and secondary temperature sensors Table 21-2 Salinity comparison between primary and secondary sensors Table 21-3 CTD salinity from primary sensors at nominal depths Table 21-4 Difference between CTD salinity and AUTOSAL salinity at selected depths List of Figures* Figure 2-1 Track chart Figure 4-1a Preliminary section of salinity along 6N taken from the CTD stations Figure 4-1b Preliminary section of temperature along 6N taken from the CTD stations Figure 4-2a Preliminary section of salinity along PR24 taken from the CTD stations Figure 4-2b Preliminary section of temperature along PR24 taken from the CTD stations Figure 4-3a Preliminary section of salinity along PR1S taken from the CTD stations Figure 4-3b Preliminary section of temperature along PR1S taken from the CTD stations Figure 8-1 Results from TCCOMP Figure 9-1 The TMN mooring site Figure 9-2 The TMS mooring site Figure 9-3 The mooring line at TMN Figure 9-4 The mooring line at TMS Figure 9-5 The marker buoy Figure 11-1 Computer systems for CTD data processing Figure 11-2 total salinity spike area variability for time lag between temperature and conductivity at cast 6N021 and K1S181. Figure 11-3 Pressure variability Figure 11-4 Variability of deck pressure Figure 11-5 Data flow of CTD data processing Figure 14-1 Flow diagram for TRAACS800 nitrate method Figure 14-2 Flow diagram for TRAACS800 nitrite method Figure 14-3 Flow diagram for TRAACS800 silicate method Figure 14-4 Flow diagram for TRAACS800 phosphate method Figure 17-1 Distribution of atmospheric and oceanic CO2 Figure 21-1a Figure 21-1b Figure 21-2a Figure 21-2b Figure 21-3 Figure 21-4 Figure 21-5 1. Highlight by K. Muneyama (4 March 1994) Chief Scientist: Kei Muneyama, JAMSTEC,Japan Co-Chief Scientist: Syaefudin, BPPT,Indonesia Co-Chief Scientist: Michio Aoyama, JAMSTEC, Japan Cruise: KAIYO-9307 Dates: 12 February to 3 March 1994 Ship: R/V Kaiyo Ports of call: Marakal, Palau to Marakal, Palau Although our first plan was to observe PR23, 7.30'N section between Mindanao and Palau, shiptime restricted us to carry out to observe this WOCE designated section. We planned instead to observe (7-30'N,134-00'E) to (6-00'N,130-00'E) to (6-00'N,127-30'E). One day before we would leave Koror, Palau for the cruise, a sudden request were made for us to search 5 missing Japanese divers and one Palauan diving instructor at a remote island some 60 n.miles apart. Next day R/V KAIYO left Koror for search of the 6 missing persons. This search was kept for 5 days from February 7 to 11. We started the WOCE cruise at (7-00'N,134-00'E) to (6-00'N, 130-00'E) to (6-00'N,127-30'E) on February 12 1994. As this section is not PR23 ,we designated it simply 6N. This 6N section consists 15 stations(STN 1-15), and required us 5 days for completion. Station spacing was 30 n.miles from the start to the end of this section. PR24 section is extended from K6N STN 15(6-00'N,127-30'E) to PR24 STN 20 (1-33.3'N,129-40.0'E). Station spacing was kept less than 30 n.miles in this section. Stations 5,12,13,18 and 21 were excluded to save shiptime. We added an optional section PR24-2 because current flows in this region are known to be complex by the previous observation executed last year. We have deployed ADCP moorings at 4-01.239'N,127-30.634'E and 3-10.793'N,128-27.367E with double acoustic releasers for each mooring. PR1S section (S means southern part of PR1) occupies between PR1S STN 1( 0- 45'N,130-00'E) and PR1S STN 25(10-00'N,130-00'E). The lack of shiptime has forced us to delete STNs 3, 5, 7, 10, 14, 22, 23, 24 and 25. We carried out observations from 0- 45'N to 8-00'N on the 130E by 30 n.miles of station spacing. We deployed 8 surface drifters between 2-00'N and 8-00'N on 130-00'E. We arrived at Koror on March 3rd. A General Oceanics (GO) 36 position rosette water sampler with 12 liter Niskin bottles has worked well with a Sea Bird Electronics CTD 9-11 plus deck unit. If we did not have a 36 position rosette water sampler, our cruise track had to be forced notably to change due to 5 days reduction for the unfortunate accident. Our preliminary survey of PR24 region executed in 1992 has told us a very steep topographic change. We installed two altimeters to the GO 36 position water sampler, one Benthos'model 2110-1 and another Datasonic PSA-900A. Nevertheless we did not notice at one occasion that the wirecable was bent almost rectangularly at the top of protection frame of the rosette as wirecable was hooked to a Niskin bottle until the CTD/rosette surfaced obliquely. We used 12 position rosette water sampler at PR24-2 section as the topography there is very steep. We had paid attention to the length difference of CTD/ rosette water sampler between the reading of CTD pressure and the wire-out measurement of the winch. The analysis of CTD corrected by the Autosal indicate that they meet WHP quality guideline for precision and accuracy. Salinity measurement due to bottle samplings has shown ca. 0.001 PSS in accuracy and ca. 0.0005 PSS in precision. The precision of dissolved oxygen (DO.) measurement is ca. 0.5% and its accuracy is ca. 0.1% when the interlab comparison of the standard solution at ODF/SIO is adopted. The precision of nitrate analysis is ca. 0.4% , that of silicate analysis is ca. 0.4% and that of phosphate analysis is ca. 1.2% when experiments tried at duplicative water samples below 3000m depth is adopted. 2. Summary of the observations and data files by M. Aoyama ( 10 March 1994) The ship's track is shown in Figure 2-1*. Station positions and all scientific events are in the WOCE format KYZZZZ94.SUM file and shown in Table 2-1. K6NZZZ94.SEA, K24ZZZ94.SEA and K1SZZZ94.SEA are the WOCE format ---.SEA files for section 6N, PR24 and PR1S, respectively. The ---.SEA files for section TM (from Talaud Is. to Morotai Is.) are not reported. The WOCE format ---.CTD files are named as follows; 1st digit: K ( This means KAIYO) 2nd and 3rd digits: line designator 4th and 5th digits: station number 6th digits: cast number 7th and 8th digit: the last two digits of the year For example, the ---.CTD file name of the first cast at the station 15 on section PR1S becomes K1S15194.CTD. In each ---.SUM, ---.SEA and ---.CTD files, we use "KY " as a ship code. Sampling accomplished: 57 CTD/Rosette stations and 3 trial casts were occupied. Number of water samples analyzed: Salinity ca. 1600 Oxygen 1602 Nutrients ca. 1600 Plant Pigment 73 Number of water samples collected for shore-based analysis: AMS radiocarbon ca. 220 (7 stations, all replicate samples) 8 drifters were deployed. 2 ADCP moorings were deployed. Measurements of surface layer pCO2 and atmospheric pCO2 were made along the entire ship track. 3. Cruise Track, Stations and sampling depths by M. Aoyama (5 March 1994) The ship's track is shown in Figure 2-1*. Station positions are in the KYZZZZ94.SUM file. The sampling interval from 7-00N, 134-00E to 6-00N,127-00E was 30 nm. Sampling continued from 6-00N, 127-00E to 2-40N, 129-00E with station interval 20 nm or less across the east mouth of the Celebes Sea along over the 3000 to 6000 meters isobaths just west of the Philippine trench. From 2-40N, 129-00E, we turned toward Talaud Is. and continue to sample at 20 nm interval or less. Stations include over the ridges and trenches between 2-40N, 129-00E and 2-52N, 128-42E. From 2-52N, 128-42E, we turned back to 2-23N, 129-10E and continue to sample at approximately 20 nm interval until we approach 1-33N,129-40E. Then we turned south to 0-45N, 130-00E and turned north to 8-00N, 130-00E. The sampling interval along 130-00E was at 30 nm . The sampling depths shallower than 1000 meters were 10, 20, 30, 50, 75, 100, 125, 150, 200, 250, 300, 400, 500, 600, 700, 800, 900, and 1000 meters. Below 1000 meters, the vertical sampling interval is 250 meters and the deepest sampling depth will be up to within 7-50 meters of the bottom. Although our rosette sampler used in section 6N, PR24 and PR1S is 36 positions, 2 casts was not done at few stations deeper than 5000 meters due to save the ship time. At the stations deeper than 5000 meters, we canceled some of the shallower sampling layers. Since the sea condition became hard at the station PR1S- 19,20,21, we reduced the Niskin bottles to 30 (at PR1S-19,20), 24 (at PR1S-21) to make the CTD/Rosette operation safety. Since we used 12 position Rosette In the section PR24- 2, the sampling depths were largely reduced. 4. Preliminary results by M. Aoyama (22 April 1994) The temperature and salinity section along 6N, PR24 and PR1S are shown in Fig. 4-1a*, 1b*, Fig. 4-2a*,-2b*, and Fig. 4-3a*,-3b*. The densest water having almost the same properties are found below 4000 db among all stations at the interested area, where the densest water is 27.77 in sigma-theta, 34.679 to 34.680 in salinity, 1.245 to 1.240 in potential temperature. The average and the standard deviation for salinity, temperature, dissolved oxygen, silicate, nitrate and phosphate concentrations are summarized in table 4-1. As shown in Table 4-1, the deep water properties below 5000 dbar at the stations along 6N, PR24 and PR1S are 1.2395 in potential temperature, 34.6794 in salinity, 150.6 umol/kg in dissolved oxygen, 139.7 umol/kg in silicate concentration, 36.08 umol/kg in nitrate concentration and 2.46 umol/kg in phosphate concentration. The salinity decreased to 34.6748 in the depth between 4000 to 3000 dbar and it becomes variable in five times magnitude larger than that below 5000 dbar. The distinctive feature in the salinity section along PR1S is the saline water below 4000 dbar around 4 degree north and 5 degree north (stations PR1S-12,13,15). This saline water is exceeding 34.680 in salinity. Table 4-1 The average and the standrad deviation of the properties below 3000 dbar. Range THETA SALNTY OXYGEN SILICAT NITRAT PHSPHT dbar degree PSS umol/kg umol/kg umol/kg umol/kg 7600 - 4998 1.2395 34.6794 150.6 139.7 36.08 2.46 0.0029 0.0007 0.73 1.06 0.31 0.03 6001 - 4998 1.2403 34.6793 150.6 139.7 36.11 2.47 0.0024 0.0008 0.76 1.14 0.31 0.02 5003 - 3996 1.2447 34.6790 150.4 139.8 36.12 2.47 0.0042 0.0009 0.88 1.22 0.33 0.03 4003 - 2998 1.3060 34.6748 146.79 140.47 36.29 2.48 0.0482 0.0034 3.03 1.26 0.34 0.04 5. Parameters, Contribution Institutions, and Personnel by M. Aoyama (4 March 1994) The details for these factors are given in Tables 5-1 and 5-2. Table 5-1: List of parameters to be measured, the sampling group(s) responsible for each, and the Principal Investigator(s) for each. Parameter / Instr. Sampling Group Principal Investigator(s) CTD/rosette JAMSTEC Yuji Kashino and Kentaro Ando Salinity JAMSTEC Takeshi Kawano O2, NO3, NO2, PO4, SiO2 JAMSTEC Michio Aoyama Mooring JAMSTEC/STM Kentaro Ando, Hidetoshi Watanabe and Atsushi Ito Plant Pigments BPPT Rusana Meisianti Djalimun Surface Drifter JAMSTEC Shoichiro Nakamoto CO2 MRI Hisayuki Y. Inoue Radiocarbon* JAMSTEC Michio Aoyama Cs-137 and Sr-90** JAMSTEC/MRI Michio Aoyama and Katsumi Hirose * Funding still Pending. ** Cancelled Table 5-2: Cruise participants Cruise participants with role and / or affiliation in parentheses. Kei Muneyama JAMSTEC Chief Scientist Syaefudin BPPT Co-Chief Scientist/CTD Michio Aoyama JAMSTEC Co-Chief Scientist/O2, Nutrients,C-14,Cs-137, Sr-90 Takeshi Kawano JAMSTEC Salinity Yuji Kashino JAMSTEC CTD Softwares Kentaro Ando JAMSTEC CTD/rosette hardware/ Mooring Yudi Anantasena BPPT CTD Rusana Meisianti Djalimun BPPT Plant pigments Akira Sonoda NME O2 Hiroshi Yamamoto NME CTD/Mooring Koichi Takao NME Salinity Atsuo Ito NME Salinity Misumi Aoki NME O2 Hidetoshi Watanabe STM CTD/Mooring Ranko Takeo STM O2 Takehiko Shiribiki STM O2 Keiko Komine STM Nutrients Teruhisa Hattori STM CTD/Mooring Hidekazu Ota KEEC Nutrients Kiyotaka Nakao KEEC Nutrients Kazuhiro Murakami KEEC CTD/CO2 Richard J. Bauman SBE CTD hardware/software support note: JAMSTEC Japan Marine Science and Technology Center, Japan BPPT Badan Pengkajian Dan Penerapan Teknologi (Agency for the Assessment and Application of Technology of the Republic of Indonesia), Indonesia STM Sanyo Techno Marine, Inc., Japan NME Nippon Marine Enterprises, Ltd., Japan KEEC Kansai Environmental Engineering Center, Ltd., Japan SBE Sea-Bird Electronics, Inc., United States of America MRI Meteorological Research Institute, Japan 6. sampling/measurements equipments by M. Aoyama (4 March 1994) The details for these factors are given in Tables 6-1. Table 6-1: Sampling Equipments Small-Volume :One 36-place rosette (GO1016) with 12-liter bottles. sampling One 24-place rosette (GO1016) with 30-liter bottles. One 12-place rosette (GO1015) with 5-liter bottles for backup. CTD System: :One SBE-911plus CTD with altimeter and O2 sensor. Another SBE-911plus with altimeter and O2 sensor for backup. Two SBE-11plus deck units of sampling frequency at 24 Hz. Winch and cable: Two Tsurumi Seiki TS-10PVCTD winches having 8000 meters cable of 10.6 mm diameter. The maximum rolling load is 3800 kg x 47 m/minute. Salinometer: :Two Guildline Autosal 8400B with HP 2804A quarts thermometer. One ampoule of IAPSO Standard Seawater per station. Oxygen Analysis:Carpenter method. Automated potentiometric titration. Two ligs of Metrohm 716 DMS Titrino. Nutrient Analysis:Bran Luebbe TRACCS 800 4 channels system. Plant Pigments :Shimazu UV2000 Spectrophotometer 7.Underway Measurement a. Navigation-GPS by M. Aoyama (6 March 1994) Navigation, ship position and velocity over the ground was provided throughout the cruise by a Magnavox MX4400 GPS receiver. Throughout the cruise, the positioning was based on the WGS-84 and in 3-D mode. Since we cloud get 4 satellites throughout the cruise, the HDOP was ranged from 1 to 2. Positions were logged in port Marakal at the start and the end of the cruise and a rms position error are as follows; Pre-Cruise; Mean position at Marakal harbor, Palau: 7-19.831N, 134-27.482E Rms position error: N-S: 19 meters E-W: 29 meters Post-Cruise; Mean position at Marakal harbor, Palau: 7-19.???N, 134-27.???E Rms position error: N-S: ?? meters E-W: ?? meters b. Echosounding by M. Aoyama (22 April 1994) The water depth obtained by the multi-narrow beam echo sounder (General Instrument) and by using the CTD observation and altimeter equipped to CTD are summarized in Table 7-1. The differences are less than +/- 0.5 % at the most stations, while the differences increased up to 4 % at the stations at steep topography. Table 7-1. The differences between water depth estimated summing of CTD observation plus altimeter reading and uncorrected echosounding depth. Station number CTD plus altimeter echosounding Diff. (uncorrected) meter meter meter 6N 1 3188 3180 -8 6N 2 4129 4133 4 6N 3 3751 3798 47 6N 4 4017 4026 9 6N 5 4862 4852 -10 6N 6 5278 5258 -20 6N 7 5561 5539 -22 6N 8 5568 5541 -27 6N 9 5494 5470 -24 6N 10 5580 5567 -13 6N 11 5327 5349 22 6N 12 4642 4654 12 6N 13 5572 5547 -25 6N 15 3787 3782 -5 24 1 5370 5270 -100 24 2 5677 5733 57 24 3 6430 6390 -40 24 4 3987 4031 44 24 6 3172 3178 6 24 7 2479 2475 -4 24 8 2884 3003 119 24 9 2033 2060 27 24 11 3474 3483 9 24 12 3571 3551 -20 24 14 3488 3489 1 24 15 4163 4175 12 24 16 3408 3430 22 24 17 3594 3640 46 24 19 4735 4727 -8 24 20 4266 4270 4 1S 1 1473 1526 53 1S 2 3006 3020 14 1S 4 4114 4124 10 1S 6 4394 4395 1 1S 8 3996 4003 7 1S 9 3128 3120 -8 1S 11 4500 4508 8 1S 12 4712 4707 -5 1S 13 4816 4856 40 1S 15 5035 5031 -4 1S 16 5462 5436 -26 1S 17 5479 5456 -23 1S 18 5546 5516 -30 1S 19 5549 5521 -28 1S 20 5542 5514 -28 1S 21 5672 5636 -36 8. CTD/Rosette hardware by K. Ando and M. Aoyama (6 March 1994) (1) CTD/rosette systems The 12-liters 36-positions intelligent GO rossette ttached on the CTD were two temperature sensors, two conductivity sensors, one DO sensor, one pressure sensor and two altimeter sensors. The CTD and 36 position rosette were mounted within a stainless frame of dimension 1.7 m height x 2.2 meter diameter. The weight of the package in the air is 800 Kg when the 36 bottles of 12 liters are full. Thirteen to seventeen of the rosette bottles were fitted with the set of two SIS digital reversing thermometers and one SIS digital reversing pressure meter. The wire was a single conductor 10.6 mm steel rope manufactures by Rochester cables, and the winch was built by Tsurumi Seiki Japan. Since our winch was not of traction winch design nor jumble sheave design, we reduce the bottles from 36 to 30-24 when the swell became up to 2 to 2.5 meters for the safety operation. After a cast the rosette was pushed forward on a railway about 6 meters in the shelter that is modified standard sea carrier container with air conditioned and all sampling was performed there. Subsequently digital instruments were read and the TC sensors was cleaned by Triton-X detergent, fresh water and pure water at each cast. The 5 liters 12-positions rosette water sampler with SBE9plus CTD for 6,800 meters (secondary CTD system) was used on the line of TM to save the ship-time. The sensors used attached on the primary CTD system and the secondary CTD system are listed in (a) and (b). (a) The sensors of the primary CTD system The sensors used are listed below. Primary temperature sensor: Model SBE3 for 10,500 meters S/N 031462 Primary conductivity sensor: Model SBE4 for 10,500 meters S/N 041045 Pump for primary sensor pair: Model SBE5 for 10,500 meters S/N 050846 Secondary temperature sensor: Model SBE3 for 10,500 meters S/N 031465 Secondary conductivity sensor: Model SBE4 for 10,500 meters S/N 041174 Pump for secondary sensor pair: Model SBE5 for 10,500 meters S/N 050847 Pressure sensor: Digiquarts pressure sensor for 10,500 meters S/N 41223 Primary Altimeter: Benthos model 2110-1 for 12,000 meters S/N 199 Secondary Altimeter: DATASONIC PSA-900A for 6,000 meters S/N 396 Dissolved Oxygen sensor: Model SBE13 for 10,500 meters S/N 130311 The calibrations of temperature, conductivity and pressure sensors were conducted by NRCC in October 1993. The drift of temperature and conductivity sensors are reported in Chapter 11. Sensor performances during this cruise : The differences of two sensors for temperature and conductivity are shown in Figure 8-1*. Though the calculation of these differences are performed by using the raw data under 500 meters, the maximum differences are within 0.001 C in temperature sensors and within 0.0002 S/m in conductivity sensors. (b) The secondary CTD system The sensors used are listed below. Primary temperature sensor : Model SBE3 for 6,800 meters S/N 031207 Primary conductivity sensor : Model SBE4 for 6,800 meters S/N 040960 Pump for primary sensor pair : Model SBE5 S/N 050484 Secondary temperature sensor : Model SBE3 for 6,800 meters S/N 031523 Secondary conductivity sensor : Model SBE4 for 6,800 meters S/N 041148 Pump for secondary sensor pair: Model SBE5 S/N 050863 Pressure sensor: Digiquarts pressure sensor for 6,885 meters S/N 43435 Altimeter: DATASONIC PSA-900A for 6,000 meters S/N 396 Dissolved Oxygen sensor: Model SBE13 for 6,800 meters S/N 130257 During the cast, we used the 32 of reversing thermometers (SIS RTM) and 17 of reversing pressuremeters (SIS RPM). 5 of 32 RTM were broken during the cruise. Since 8 of RTM were varied much and 2 of RTM began to drift, we basically adapted the data of stable 17 RTM data. Since one RPM (RPM 10055) showed larger difference of 20 dbar, we do not refer to the data of RPM 10055. A comparison result of CTD and RTM temperature and RPM pressure below 4000 dbar is given in Table 8-1. Table 8-1 Summary of RTM and RPM data. Average (upper raw) and Standard deviation (lower raw). Range CTD-RTM CTD-RPM dbar 7600 - 4998 0.003 -1.1 0.001 2.5 6001 - 4998 0.003 -1.1 0.001 2.6 5003 - 3996 0.004 -0.4 0.002 1.8 9. Moorings by Kentaro Ando (JAMSTEC) for ADCP and CTD Hidetoshi Watanabe (STM) for current meters Atsuo Ito (NME) for mooring system (3 March 1994) Here we describe the deployment of two moorings and the recovery of two moorings between Talaud-Morotai Islands. The deployments of two moorings have successfully finished, but the recovery of two moorings have failed. (a) DEPLOYMENT OF MOORING BETWEEN TALAUD AND MOROTAI ISLAND The purpose of these moorings is to estimate the seasonal change of the volume transport between Talaud and Morotai islands with comparisons with the results of numerical simulation. The Indonesian through flow is an inter-ocean current between Pacific Ocean and Indian Ocean, which is continued to the Atlantic Ocean (Gordon(1983)). The estimation of the net volume flux between Pacific Ocean and Indian Ocean have been performed for many years, using the historical data analysis and numerical simulations. Recently, Masumoto and Yamagata (1993) shows the seasonal variability of baroclinic ocean circulation around the Indonesian islands from the results of their numerical-simulated ocean. They shows the large amplitude seasonal transport around the Indonesian islands. For the measurement of seasonal current variation between Talaud and Morotai island, two moorings were deployed at 04-01.239N, 127-30.634E on February 21, and 03- 10.793N, 128-27.367E on February 22 in the strait between Talaud and Morotai Island (see Figure 9-1* and 9-2*). These moorings are named Talaud-Morotai North (TMN) and Talaud-Morotai South (TMS). Each mooring has one upward self-contained broad-band ADCP (150KHz) at 250 meters depth, one CTD (SBE16) at 260 meters depth and three Aanderaa current meters at 350 meters, 550 meters and 1,050 meters depth. The mooring lines are shown in Figure 9-3* and 9-4*. The parameters set in each instrunment are listed below. ADCP : R&D instrument 150 KHz Self-contained Broad-band ADCP Serial number : 1153 for TMN 1152 for TMS Beam angle: 30 degree Beam direction: Upward Sampling layer: 0 - 248 meters in every 8 meters Sampling interval: 1 hour Ping per ensemble: 16 pings Intervals in each pings : 2 seconds CTD : SBE 16 with depth sensor Serial number: 1282 for TMN 1283 for TMS Sampling interval: 30 minutes Current meters :Aanderaa current meter model RCM-4 & RCM-5 Serial Number: 8306 for TMN 350 meters depth 4267 for TMN 550 meters depth 4557 for TMN 1,050 meters depth 8277 for TMS 350 meters depth 8637 for TMS 550 meters depth 4272 for TMS 1,050 meters depth Interval: 60 minutes Record device: IC memory Releaser :Benthos Model 865A-DB Serial Number: 633 for TMN 666 for TMS :Nichiyu Serial Number: 4232 for TMN 4237 for TMS In these mooring lines, we use two releasers for each line. We hope the mooring lines would be released and recovered successfully after one year mooring. (B) EFFORTS OF RECOVERY AND DEPLOYMENT OF MARK BUOY The two moorings deployed between Talaud and Morotai Islands in October 1992 cruise (Chief Scientist : Kei Muneyama, PI: Takiwaki and Watanabe) were scheduled to be recovered during this cruise. Unfortunately, these two moorings could not be recovered during this cruise. On February 21, we tried to recover the mooring at 03-27.44N, 127-52.96E. The releaser responced and returned the release signals to us. But the buoys did not appeare on the sea surface. The depth of the releaser did not change at all. Having no equipment to recover the mooring line from sea bottom, we deployed the marker buoy for the recovery of a next chance near the mooring line. February 22, the other mooring at 03-12.22N 128-26.89E was not released, neither. The situation of this mooring is the same as that on February 21. We also deployed the marker buoy. Figure 7-5* shows the mark buoys deployed near these two un-recovered moorings. 10. CTD/ Rossete operation by SYAEFUDIN WOCE '94 Cruise using two kinds of CTD/Rosettes, the big rosette and the small rosette. The big rosette is General Oceanic 1016 equipped with a 36 position Niskin bottles (12 l volume) and CTD Sea-Bird Electronics Inc. model SBE 9/11 plus CTD system, 15,000 Psi Pressure and 10,500 depth used in track lines 6N, PR 24 and PR1S. The small rosette is General Oceanic 1015 equipped with a 12 position Niskin bottles (5 l volume) and CTD Sea-Bird Electronics Inc. model SBE 9/11 plus CTD system , 10,000 Psi Pressure and 6,800 depth, only used in the track line PR24-2. Some Niskin bottles of both rosettes are equipped with RPM and RTM to measure pressure and temperature in the depth which we want. Drive rosette out from container and check some bolts on the frame and Niskin bottles and than send HOME command from CR (Control Room) to the Rosette Setting Man (RSM) on deck. HOME command is mean the position of firing bottles equipment is located between bottle number one and the last bottle (No. 12 for small rosette and no. 36 for big rosette). How to make HOME command in CR ??? are as follows : C> SS4200> SEASAVE and return/enter (SEASAVE in dir. SS4200) Display on sreen ........ SEASAVE Main Menu - Display Archived Data - Display Real-Time Data - Serial Out put Setup before running the PC please choose Serial Output Setup and press return/enter if you want to modify (in this cast output ASCII data = No) Press Esc to exit editing and go to Main Menu...and choose Display archived Data and press Enter/Return to Select the Option which you want.....press Esc to Quit and go to Main Menu. Choose Display Real-Time Data Set Up and press Enter/return to Modify. In this Cast : Store Data on Disk = Yes Data File Path = C: WOCE94 Data File Name = Line.No. Cast.DAT. Config File Path = C: SS4031 Config File [.CON]=10000AL2.CON Display File [.DSP]=WOCE depth.DSP Legend: depth : depend on station depth File name : Down Cast and Up Cast and than press F10 to Acquire Real-Time Data and send "HOME" Command to RSM on deck. After that We setup Niskin Bottles from no.1 to 36 (or 12 for small), check kocks of Niskin bottles must be closed and than setup RPM/RTM (Check battery) and write S/N , offset of RPM on the log book. Make disconnected the tube from the bottom of T-Sensor. Tell to CR Rosette ready to deployment !!!!!!!!!!!! Control tension meter, winch speed, wire out length and CTD pressure during operation. On the 10 m depth from sea level , winch stop for a moment and Winch Man (WM) report wire out length, tension to CR operator. CR operator write those data on the CTD Operation Log Book (COLB) and watch the graphic display ot temperature , Dissolved oxygen (D0) on screen (P.C) are those O.K. and than replay to WM with CTD pressure . Winch continued to go out with speed 0.5 m/s and WM tell wire out length, tension and winch speed to CR operator each 100 m depth reached 500 m. In the heavy condition (if sea water not quit) WM tell CR operator range of the tension meter. after reached 200 m increase winch speed to 0.75 m/s or 1.0 m/s if rang of CTD pressure and wire out length not large (approximately 30 - 50). After reached 500 m depth increase winch speed to 1.5 m/s (CR operator must watches the CTD descent rate on screen). WM tell CR operator each 500 m depth and CR operator replay. At the 300 m above sea bottom (estimated from sounding data and CTD pressure ) the altimeter was read (Userpoly 1) in the status line exchanged CTD Deck Control Unit became channel 6 and tell WM to decrease winch speed to 0.5 m/s (better step by step command to winch speed be came 0.5 m/s). At the 50 m to the sea bottom Winch stopped for a moment to check altimeter reading. Winch continued to within 10 m - 20 m (if flat sea bottom topography) and 50 m- 100 m (in heavy condition and sea bottom not flat) and CR operator told CTD in that condition (xx meters to the sea bottom, CTD pressure) to WM and Bridge. Checked Down Cast file exist or not, Press F1 (exit), Esc answer YES and Press enter/return to make Up Cast File and than press F10 to Acquire Real-Time Data. Firing bottom sampling bottle number 1 and 2 , and winch continued go up to next sampling layer wich you want. At the 10 meters before sampling layer CR operator told WM to decrease Winch ters to the sea bottom, CTD pressure) to WM and Bridge. Checked Down Cast file exist or not, Press F1 (exit), Esc answer YES and Press enter/return to make Up Cast File and than press F10 to Acquire Real-Time Data. Firing bottom sampling bottle number 1 and 2 , and winch continued go up to next sampling layer wich you want. At the 10 meters before sampling layer CR operator told WM to decrease Winch speed to 0.5 m/s and on firing bottle equipped with RPM/RTM please wait 1 minutes. After finished all of bottles and CTD on deck press Control F1 to exit Acquire Real-Time Data and turn off CTD Deck Unit. 11. CTD data processing by Y. Kashino (22 April 1994) Introduction The CTD data was acquired by SBE 911 plus system whose frequency was 24 Hz. This data was calibrated as much as possible on board and converted to WOCE-format CTD file. SEASOFT provided by Sea-Bird Electronics Inc. and some programs developed in JAMSTEC were used on this procedure. The programs developed in JAMSTEC were coded in FORTRAN. (Microsoft FORTRAN compiler was used). We used SEASOFT ver. 4.200 except for SEASAVE. SEASAVE Ver. 4.031 was used because SEASAVE ver. 4.200 had a bug. Although we have twin T and C sensors for CTD system, we report only the result of primary sensor. We used the result of secondary sensor to check up one of primary sensor. Although we have DO-sensor, we don't report the result because we haven't established calibration method of DO-sensor. We don't also report the data when CTD was near surface (upper than 15 db) because the pump of CTD was not active then. Pre-cruise and post-cruise calibration for temperature and conductivity sensors were carried out at NRCC (Northwest Regional Calibration Center) in U.S.A. on 28 September 1993 and 26 March 1994. Post-cruise calibration for pressure sensor by dead weight tester was carried out at JAMSTEC on 21 April 1994. We check up and calibrated CTD data considering these result except for one of post-cruise calibration for conductivity sensor. The reason why we didn't consider the result of conductivity sensor calibration was that it showed that its drift was too large and the value in Philippine basin calibrated by this result didn't agree with the values by Autosal on this cruise and value of historical data. a. Seagoing computer We used 3 computer systems for data processing as follows (Fig.11-1*): (1) System 1 (for data acquisition) CPU: DECpc 466D2LP (IBM compatible computer) with 8MB memory, 240MB hard disk and 3.5-inch floppy disk drive. Optical disk: 3.5-inch and 5-inch optical disk drives. We used 3.5-inch optical disk during data processing and 5-inch optical disk for backup of raw data from deck unit. Other: This system is connected with deck unit. (2) System 2 (for data processing) CPU: DECpc 466D2LP with 8MB memory, 240Mb hard disk, 3.5-inch floppy disk drive and 5-inch floppy disk drive. Optical disk: 3.5-inch optical disk drive. Plotter: Hewlett Packard 7475A Plotter (Paper size is A4) Other: This system was connected with VAX station 4000 by LAN. (3) System 3 (for data editing) CPU: Hewlett Packard Vectra 386/20N (IBM compatible computer) with 4MB memory, 52MB hard disk and 3.5-inch floppy disk drive. Optical disk: 3.5-inch optical disk drive. b. Data processing (1) General In order to remove noise in raw temperature, conductivity and pressure data, we developed software that replaced noise data by running mean. We defined the noise as shown in table 11-1. The result (also in table 11-1) is shown that there were few noises over criteria shown in table 11-1. (Temperature and conductivity data had no noise!!) When CTD decent rate becomes slow or reversal because of the pitch of the ship, water around rosette will go down faster than CTD and will be mixed with water being measured by CTD. This is called "shed wake" and will make error (See the part III of Chap. 18). We have developed program that finds shed wakes when CTD decent rate is less than 0.25 m/s and linearly interpolates pressure, temperature and conductivity values in the shed wake using its upper and lower values. If the number of the interpolated values is more than half of the number of observations in some 2db pressure bin, its quality flags of pressure, temperature and salinity should be 6 in CTD file. After all on-board calibration, uniform pressure CTD profile data was created by same method as one of Millard and Yang (1992). (2) Temperature The results of laboratory calibrations for temperature sensors show that CTD temperature sensor tend to drift constantly with time (See Chap. 18). The difference between twin temperature sensors was almost constant (See Chap. 5). According to result of post-cruise calibration carried out on 26 March, drift of the temperature sensor was +0.0025 (deg C). Considering these result, we could estimate that offset correction added to the value of primary temperature sensor was +0.0020 (deg C) during this cruise. Laboratory calibration executed on IPTS-68 unit, we converted raw temperature value on IPTS-68 to ITS-90 unit using formula (3) of Millard and Yang (1992) after the offset correction. (3) Conductivity(salinity) Conductivity value was corrected as follows: Step 1. Sensor response correction. Millard and Yang (1992) says that the sensor response correction between temperature and conductivity data should be done for Mark IIIb CTD and the lag is from 0.10 to 0.45 seconds. We checked how long time lag between T and C sensors is for SBE 911 plus system. We determined time lag at the time when total salinity spike area was minimum. Total salinity spike area S is N S = sigma-(P(Li) - P(Ui))H(i). i=1 N is the number of spike, P is pressure, H is height of spike and suffix U and L mean upper and lower boundary of spike. Fig. 11-2* is result at casts 6N-02, and PR1S-18. The results show that time lag should be 0.8 steps, that is, 0.033 seconds. We used ALIGNCTD of SEASOFT for correction throughout this cruise. Step 2. Cell thermal mass correction. Sea-Bird Electronics Inc. recommend that conductivity cell thermal mass effect should be removed. We used CELLTM of SEASOFT to remove this effect. This utility uses recursive filter determined in Lueck (1990). Step 3. Cell factor correction. We used Autosal to calibrate CTD conductivity sensor. We determined cell factor by linear regression between CTD conductivity when bottle was fired and conductivity of sampled water measured by Autosal for every casts. CTD conductivity was corrected using the equation as follows: C(calibrated) = A x C(raw) + B. A and B are slope and offset respectively. Step 4. For salinity spike Even if sensor response correction is done, the salinity spikes still remain. When we find a salinity spike lager than 0.01 PSU in some 2db pressure bin, quality flag of salinity should be 3 in CTD file. (4) Pressure Raw data from pressure sensor has short period oscilation (Fig.11-3*). We used FILTER of SEASOFT and filtered this oscilation by low pass filter that time constant was 0.15 seconds. The correction of pressure value for deck pressure was not carried out because deck pressure of our CTD was less than +/-0.4db during observation. (Fig. 11-4*) The result of post-cruise calibration by dead weight tester are shown in Fig. 11-5*. This shows that the residual between CTD pressure and pressure by dead weight tester is less than 0.7 db and hysterisis is 0.2 db. We don't correct this small residual. c. Data flow (See Fig. 11-6*) (1) SEASAVE (SEASOFT) Acquires, displays and saves raw data from deck unit to disk. On this cruise data was stored in hard disk. We will use RAM disk for device saved raw data on next WOCE cruise. (2) DATCNV (SEASOFT) Converts raw, binary data output by SEASAVE to ASCII format data written on physical unit. When water is sampled, this program can output data to .ROS file from that time to some time. (On this cruise, this interval was 10 seconds.) (3) ROSSUM (SEASOFT) Edits .ROS file output by DATCNV and writes out a summary file to .BTL file. (4) TCCOMP (Made in JAMSTEC) Compares values of primary and secondary sensors and plots histograms for check of sensor performance. (5) SPLIT (SEASOFT) Divides data into upcast data and downcast data. We used this utility to acquire only downcast data for save of disk space. (6) NOISE (Made in JAMSTEC) Finds noise data and replace it by running mean. This program can remove unnecessary surface data. (7) ALIGNCTD (SEASOFT) Corrects time lag between temperature sensor and conductivity sensor for minimizing salinity spiking error. (8) FILTER (SEASOFT) Uses low pass filter to remove short period oscillation in pressure data. (9) CELLTM (SEASOFT) Correct conductivity cell thermal effect using a recursive filter. (10) FDSHDWK (Made in JAMSTEC) Finds shed wake and interpolates data using the values of its upper and lower boundary. (11) FSPIKE (Made in JAMSTEC) Finds salinity spike. (12) CALBC (Made in JAMSTEC) Calibrates conductivity data by cell factor correction. (13) AVGDAT (Made in JAMSTEC) Calculates 2db pressure averaged data. (14) MKCTD (Made in JAMSTEC) Creates WOCE-CTD file. d. Conclusion We could acquire high quality CTD data satisfying WOCE requirement except for the bin where salinity spikes and shed wakes were. The accuracies of pressure, temperature and salinity were as follows: Pressure: 1db Temperature: 0.001 deg C Salinity: 0.002 PSU (from 500m to 2000m depth) 0.001 PSU (deeper than 2000m depth) Problems remain as follows: (1) According to Millard and Yang (1992), time lag between temperature and conductivity sensors depends on CTD velocity. We haven't tested this point and used some constant value for time lag. (2) Accuracy of parameters was not good when shed wakes appeared. We should think how to operate the CTD/Rosette not to make shed wakes. References Millard,R. and K.Yang, 1992, CTD calibration and processing methods used by Woods Hole Oceanographic Institution, Draft (April 20, 1992) Lueck,R.G., 1990, Thermal inertia of conductivity cells: Theory., American Meteorological Society, 741-755, Table 11.1. Definition of noise and the number of noise detected by this definition. Pressure Temperature Conductivity (db) (deg C) (S/m) Noise definition 1. Range 0.5 0 2 2. Difference from previous step value 1.0 0.5 0.05 3. Difference from running mean (a) 0 - 400m 0.5 1.0 0.1 (b) 400 - 1000m 0.5 0.2 0.02 (c) 1000 - 2000m 0.5 0.1 0.01 (d) 2000m - 0.5 0.05 0.005 The number of noise 97 0 0 12. Sample water salinity measurements by T. Kawano, K. Takao, A. Ito (22 April 1994) a. Salinity Sample Bottles The bottles in which the salinity samples are collected and stored are 250 ml Phoenix brown glass bottles with screw caps. We checked the integrity of same type bottles (125 ml) by following method. 1) fill bottles with pure water and screwed caps 2) keep bottles approx. 1 deg C for 12 hours 3) then keep bottles approx. 35 deg C for 12 hours The volume change of pure water was less than 0.01 ml. This result suggests that the salinity change by evaporation should be less than 0.001 practical salinity unit (PSU) in case of 250 ml bottles. b. Salinity Sample Collection and Temperature Equilibration Each bottle was rinsed three times with sample water and was filled to the shoulder of the bottle. The caps was also thoroughly rinsed. Salinity samples were stored for about 24 hours in the same laboratory as the salinity measurement was made. c. Instrument and Method The salinity analysis was carried out by two Guildline Autosal salinometer model 8400B, which were modified by addition of an Ocean Science International peristaltic-type sample intake pump and a Hewlett Packard quartz thermometer model 2804A with two 18111A quartz probes. One probes measured an ambient temperature and another probe measured a bath temperature. The resolution of the quartz thermometer was set to 0.001 deg C. Data of both the salinometer and the thermometer was collected simultaneously by a personal computer. A double conductivity ratio was defined as a median of 31 readings of the salinometer. Data collection was started after 5 seconds and it took about 10 seconds to collect 31 readings by a personal computer. Two salinometers were operated in the air-conditioned ship's laboratory at a bath temperature of 24 deg C. An ambient temperature varied from approximately 22 deg C to 25 deg C, while a variation of a bath temperature was almost within +/- 0.001 deg C. d. Standardization Standardization was effected by use of 92 ampoules of IAPSO Standard Seawater batch P123 whose conductivity ratio was 0.99994. Standardization was made five times during the cruise. Summary is listed on Table 12-1. Four of 92 ampoules were evidently of too high salinity and four of these were dubious. These eight were not used as standards. A standard deviation of these 84 ampoules was about 0.0003 PSU. e. Sub-Standard Seawater We also used sub-standard seawater which was deep-sea water filtered by pore size of 0.45 micrometer and stored in a 20 liter cubitainer made of polyethylene and stirred for at least 24 hours before measuring. It was measured every six samples in order to check and correct the trend. We measured 403 sub-standards and nine of which were dubious. A standard deviation of the remaining 394 sub-standards was approximately 0.0004 PSU. f. Replicate and Duplicate Samples There were 47 pairs of replicate and duplicate samples drawn. We used two types of rosette bottles and they were tripped at the bottom of every station. One is a Niskin bottle equipped with an ordinary rubber tube and another is that equipped with Teflon coated stainless spring. We drawn two samples from the bottle with the rubber tube as a replicate sample and one sample from the bottle with the spring as a duplicate sample. All pairs of both replicate and duplicate samples were from bellow 1450 m depth. There were two bad measurements of replicate samples and there were also two bad measurements of duplicate samples. Excluding these bad measurements, the standard deviation of 45 pairs of replicate samples was 0.0005 PSU and that of 45 pairs of duplicate samples was 0.0006 PSU. This results shows, as well as our precision of measurements, that concerning about salinity there was no difference between the bottle equipped with the rubber tube and that equipped with Teflon coated stainless spring. g. Cell-Factors Cell-factors were calculated at each station by a linear regression analysis using conductivity data below 700 m depth. Slopes and offsets are listed on Table 12-2. Table 12-1 Summary of Standardization Autosal No. Standardize control No. of Ampoule Mean of 2Rt Station 1 718 13 1.99981 6N01 - 6N06 2 431 6 1.99990 6N07 2 419 12 1.99983 6N08 - 6N14 2 425 33 1.99987 6N15 - PR24-15 1 728 28 1.99989 PR24-16 - PR1S-21 Mean of 2Rt --- Mean of double conductivity ratio Table 12-2 Cell-factors Station Slope Offset 6N-1 1.00041509 -0.00134506 6N-2 1.00048037 -0.00157996 6N-3 1.00053153 -0.00175232 6N-4 1.00045526 -0.00151759 6N-5 1.00023839 -0.00087788 6N-6 1.00040020 -0.00141283 6N-7 1.00015178 -0.00047281 6N-8 0.99990921 +0.00030041 6N-9 1.00058658 -0.00189294 6N-10 1.00067006 -0.00221524 6N-11 1.00023847 -0.00078544 6N-12 1.00014831 -0.00049095 6N-13 1.00046808 -0.00150333 6N-14 1.00046262 -0.00146277 6N-15 1.00045962 -0.00145261 PR24-1 1.00055720 -0.00177583 PR24-2 1.00023161 -0.00074566 PR24-3 1.00047907 -0.00154018 PR24-4 1.00024580 -0.00070473 PR24-6 1.00100610 -0.00314476 PR24-7 1.00002916 -0.00003811 PR24-8 1.00054847 -0.00164449 PR24-9 1.00044089 -0.00127227 PR24-11 1.00055051 -0.00170839 PR24-12 1.00017876 -0.00054066 PR24-14 1.00044016 -0.00140412 PR24-15 1.00016521 -0.00051373 PR24-16 1.00010761 -0.00036839 PR24-17 1.00055353 -0.00180407 PR24-19 1.00078538 -0.00249294 PR24-20 1.00053539 -0.00168593 PR1S-1* 1.00007889 -0.00015122 PR1S-2 1.00037540 -0.00117401 PR1S-4 1.00025666 -0.00075317 PR1S-6 1.00067952 -0.00213944 PR1S-8 1.00054777 -0.00173303 PR1S-9 1.00081087 -0.00251449 PR1S-11 1.00062591 -0.00196514 PR1S-12 1.00049917 -0.00145260 PR1S-13 1.00004944 -0.00004653 PR1S-15 1.00058576 -0.00173603 PR1S-16 1.00043451 -0.00129345 PR1S-17 1.00064930 -0.00198615 PR1S-18 1.00056519 -0.00173534 PR1S-19 1.00033201 -0.00096688 PR1S-20 1.00055058 -0.00168770 PR1S-21 1.00051912 -0.00155780 * Using conductivity data below 300m depth 13. Dissolved Oxygen determination by A. SONODA, M. Aoki, R. Takeo and T. Shiribiki (22 April 1994) Methods: Oxygen samples were collected from Niskin bottles to calibrated dry glass bottles, and overflow it with 3 bottle volumes of sample water. The sub-sampling bottle consists of the ordinary BOD flask(ca. 200 ml) and glass stopper with long nipples that modified Green and Carritt(1966). Sample were fixed dissolved oxygen immediately following the water temperature at the time of collection was measured for correction of the sample density. The samples were analyzed ca. 2 hours later. The samples was determined by Metrohm piston buret of 10 ml with Pt electrode using whole bottle titration in the laboratory controlled temperature (ca. 20 deg. C). The standardization did everyday and whenever change to new reagents. An analytical method was fundamentally done according to the WHP Operations and Methods (Culberson,1991). End point was evaluated by the second-derivative curve method with computerization. Instrument: Titrator ; Metrohm Model 716 DMS Titrino/10 ml of titration vessel Pt Electrode/6.0401.100 Software ; Data acquisition / Metrohm,METRODATA/6.6013.000 Endpoint evaluation / it was written in N88BASIC/MS-DOS(NEC/PC9801nc) Reproducibility: 14 % of total samples was analyzed as replicates taken from same bottle. And, in the bottom layer at many stations, duplicates was analyzed. In addition, at PR24-16 and 1S- 01, different bottles fired at same depth, and duplicates was analyzed. Replicates from 227 pairs of samples were obtained a standard deviation(2 sigma) of 0.96 umol/Kg(0.46% of D.O. maximum in this cruise). Duplicates from 43 pairs of the bottom layer samples taken from different bottles (# 1 and 2) fired at the same depth had a mean difference of 0.41 umol/Kg, and standard deviation(2 sigma) of 1.2 umol/Kg(0.55% of D.O. maximum in this cruise). And 8 samples of station PR24-16 from 3249 m was obtained average of 147.9 umol/Kg, and standard deviation(2 sigma) of 0.98 umol/Kg( 0.66%),while 16 samples of station 1S-01 from 301 m was obtained average of 141.4 umol/Kg, and standard deviation(2 sigma) of 0.34 umol/Kg(0.24%). The results from duplicates of Niskin bottle #1 and #2 were indicated that the values of #2 is smaller in comparison with the values of # 1. However, to the end of this cruise, these differences became it gradually small. Blank Determination: The pure water blanks were determined in distilled water (Milli-RX12, Millipore). The result of the pure water blanks were obtained average of -0.0020 ml, and standard deviation of 0.0010 ml. The amount of dissolved oxygen in the reagents was reported 0.0017 ml at 25.5 deg. C (Murray et al.,1968). In our laboratory onboard ship, however room temperature was controlled at 18 - 21 deg.C. Therefore it was determined for this cruise. Consequently, it was obtained the amount of 0.0027 ml at 21 deg. C. We could obtained 142 samples for seawater blank in this cruise. Seawater blank were measured at surface, the oxygen minimum and bottom layer of many station. On the other hand, seawater blank were analyzed from all Niskin bottles at the station TM- 10 and 1S-21. Vertical profiles of seawater blank were not significantly varied with depth. But it was suggested that were not conservative. In this cruise, seawater blank was obtained average of 0.94 umol/Kg, and standard deviation (2 sigma ) of 0.72 umol/Kg. The precision was only obtained 0.75.28 umol/Kg (n=5 ) at one time. It was suggested that seawater blank varied with each sample. But we could not determined at each depth that oxygen samples are taken in this cruise. Therefore we used average value (=0.94) for calculation of dissolved oxygen concentrations. Thiosulfate Standardization: Measurement of standardization were used thiosulfate of 1 batch,4 bottles and standards of 2 batch,18 bottles(#1 of 15 bottles,#2 of 3 bottles) in this cruise(about one month). The results of standardization was obtained average of 0.7230 ml, and standard deviation of 0.0027 ml (0.37%). It was suggested that reagents probably were influenced by laboratory temperature. Comparison of standards from different institution: Except the KIO3 standard solution, we used the titration system and reagents of Scripps Institution of Oceanography, Oceanographic Data Facility (SIO/ODF). We show the result to the following table. Table 13-1. Comparison of standards from JAMSTEC and SIO. Institution Nominal Avg STD Rasio to normality titer SIO/ODF SIO/ODF .0100102 0.49527 .00004 ------- JAMSTEC1 0.0100200 0.49581 0.00011 1.00011 JAMSTEC2 0.0100200 0.49544 0.00012 0.99936 CSK 0.0100 0.49458 0.00010 0.99963 Blank 0.0100200 -0.00039 0.00020 References: Culberson, C. H.(1991) Dissolved Oxygen,in WHP Operations and Methods, Woods Hole., pp.1-15. Culberson, C. H., G. Knapp, R. T. Williams and F. Zemlyak (1991) A comparison of methods for the determination of dissolved oxygen in seawater(WHPO 91-2), Woods Hole. Horibe,Y., Y. Kodama and K. Shigehara (1972) Errors in sampling pocedure for the of dissolved oxygen by Winkler method,J.Oceanogr.Soc.Jpn., 28, 203-206. Green, E. J. and D. E. Carritt (1966) An Improved Iodine Determination Flask for Whole-bottle Titrations, Analyst, 91, 207-208. Murray, 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. 14. Nutrients measurements by K. Komine, H. Ota, K. Nakao and M. Aoyama (22 April 1994) a. Equipment and techniques The nutrients analyses were performed on Bran+Luebbe continuous flow analytical system Model TRAACS 800 (4 channels). The manifolds for the analysis are shown in Fig. 14-1*, 14-2*, 14-3* and 14-4* for the Nitrate + nitrite, nitrite, silicate and phosphate, respectively.TRAACS 800 was located in the container laboratory on deck the R/V Kaiyo. The laboratory temperature was maintained between 22-24 deg C. The methods used were as follows: 1st channel Nitrate + Nitrite: Nitrate in seawater is reduced to nitrite when a sample is run through a cadmium tube (1 mm diameter, 10 cm length) inside of which is coated with metallic copper. The nitrite produced is determined by diazitizing with sulfanilamide and coupling with N-1-naphthyl- ethylenediamine (NED) to form a colored azo dye which is measured spectrophotometrically at 550 nm using 3 cm length cell. Nitrite initially present in the sample is corrected. 2nd channel Nitrite: The nitrite is determined by diazitizing with sulfanilamide and coupling with N-1- naphthyl- ethylenediamine (NED) to form a colored azo dye which is measured spectrophotometrically at 550 nm using 5 cm length cell. 3rd channel Silicate: The standard AAII molybdate-ascorbic acid method with the addition of a 38-40 C heating bath to reduce the reproducibility problems encountered when analyzing samples at different temperatures. The silicomolybdate produced is measured spectrophotometrically at 630 nm using 3 cm length cell. 4th channel Phosphate: The method of Murphy and Riley (1962) was used, but separate additions of ascorbic acid and mixed molybdate-sulfuric acid-tartrate and addition of a 38-40 deg C heating bath. The phosphomolybdate produced is measured spectrophotometrically at 880 nm using 5 cm length cell. b. Sampling Procedures Sampling for nutrients followed that for oxygen and C-14. Samples were drawn into polypropylene 100 ml small mouth bottles. These were rinced two to three times before filling. Most of the samples were then analyzed 3 to 5 hours after collection. Samples were stored in a refrigerator at 8 degree C when the TRAACS 800 was not available for rapid analysis after collection. Polystilen 4 ml sample cups and glass 3 ml sample cups were used. For the polystilen cups, we used the new polystilen cups soaked by deionized water before use. After the glass cups were washed in the hot detergents, they were rinced by deionized water, and kept in deionized water. These were rinced two times before filling with analyte. Duplicate analysis were carried out by using the both polystilen cup and glass cup for all samples. c. Calibration The calibration of all the volumetric flasks used on the cruise were checked before packing. Calibration of the 6 Eppendorf micropippettes used during the cruise were checked before packing. d. Nutrient standard We prepared nutrient standards by following "an suggested protocol for continuous flow automated analysis of seawater nutrients" by L. I. Gordon etc. (1992). Nutrient primary standards were prepared from salts dried in oven/microwave oven and cooled over silica gel in a desiccator before weighing. The dry powder for the primary standard was packed in the nitrogen gas atmosphere. The precision of the weighing was ca. 0.1 %. The concentration of A standard are 2500 uM for phosphate, 37500 uM for nitrate and 2000 uM for nitrite, and that of B standard is 3500 uM for silicate. A uniform set of seven mixed working standards were prepared in LNSW. Concentrations (umol/l) were: nitrate 52.5,45.0,37.5,30.0,15.0,7.5 and 0; nitrite 1.2,0,0.8,0,0.4,0 and 0; silicate 240,210,175,140,70,35 and 0; phosphate 3.5,3.0,2.5,2.0,1.0,0.5 and 0 thereafter. Since we neglect the highest concentration of working standard in the cruise, the set of six mixed standards were used from the station PR24-3. e. Duplicate samples and the estimation of the precision of the analysis There were 43 pairs of duplicate samples drawn. The standard deviation of the differences between duplicate samples (43 paris) for nitrate, silicate and phosphate is shown in Table 14-1. Quality control samples at the same depth were also drawn at 7 stations. At each station, samples were drawn form the 4 to 14 of Niskin bottles closed at the same depth and analyzed. The results of the quality control samples are summarized as a range of concentaration in Table 14-2. We also made the 3 to 5 times of repeat analysis of one of the samples at 21 statinons. The results of the repeat analysis are summarized as a range of concentration in Table 14-3. Table 14-1. The standard deviation of the differences between duplicate samples (43 paris). standard deviation mean concentration umol/kg umol/kg Nitrate 0.22 37 Silicate 0.6 142 Phosphate 0.03 2.54 Table 14-2. The results of the quality control samples at the same depth. Station n Nitrate Silicate Nitrite Phosphate umol/l umol/l umol/l umol/l 24-04 6 38.81-39.35 139.7-141.0 2.70-2.76 24-08 6 38.60-39.13 139.8-141.7 0.02-0.05 2.69-2.75 24-09 14 39.14-39.60 131.7-133.4 -0.03-0.00 2.72-2.78 24-16 8 36.93-37.60 142.8-144.2 0.00-0.04 2.55-2.59 24-17 7 36.80-37.12 143.6-144.0 0.02-0.05 2.53-2.57 24-20 4 36.93-37.24 144.7-145.2 2.46-2.56 1S-08 5 37.55-37.76 145.1- 147.7 2.48-2.52 Table 14-3. The results of the repeat analysis as a range of concentration . Station n Nitrate Silicate Nitrite Phosphate umol/l umol/l umol/l umol/l 6N-02 5 39.72-40.35 110.3-110.8 -0.01-0.00 2.71-2.78 6N-06 4 36.60-36.96 143.6-143.8 0.00-0.01 2.49-2.53 6N-10 3 37.03-37.04 2.50-2.53 6N-11 3 36.91-37.15 142.1-143.3 2.51-2.52 6N-13 3 142.8-143.6 2.49-2.54 24-01 3 36.24-36.54 2.47-2.53 24-11 3 36.81-36.93 143.5-143.7 0.00-0.01 2.52-2.53 24-12 4 36.85-37.01 143.7-144.2 0.03-0.04 2.57-2.58 24-14 3 37.00-37.31 144.2-144.4 0.02-0.05 2.37-2.43 24-19 3 36.98-37.10 143.4-144.3 2.44-2.54 1S-01 4 39.28-39.55 113.3-114.4 0.00-0.05 2.78-2.80 1S-04 3 36.82-36.98 143.2-143.8 2.51-2.52 1S-09 3 36.91-36.96 146.2-146.9 2.53-2.55 1S-11 3 36.28-36.66 142.6-143.6 2.50-2.55 1S-13 3 36.58-36.73 140.5-141.0 2.52-2.52 1S-15 3 36.95-37.11 142.4-142.9 2.53-2.56 1S-16 3 36.84-37.26 141.9-142.5 2.53-2.54 1S-17 4 37.49-37.74 2.40-2.53 1S-18 3 10.84-11.29 9.4-9.5 0.79-0.84 1S-18 3 36.65-37.31 143.0-144.8 0.17-0.17 2.52-2.55 1S-19 3 37.47-37.91 143.7-144.8 -0.02- -0.01 2.54-2.55 1S-21 3 36.84-36.94 141.7-142.2 2.55-2.57 15. Plant Pigments Analysis by Rusana M. Djalimun (4 March 1994) Objectives: To obtain a pigments data set of the upper layers of the sea by using a spectrophotometric determination method ( - a continuation of LIDAR '94 Cruise/Ocean color data set -). Method: a. Seawater sampling Samples were taken in the morning cast of the WOCE '94 cruise sampling stations ( 1 sta./day) from 0 m (surface), 10 m, 30 m, 50 m, 75 m and 100 m (also 125 m and 150 m at some stations) of depths. A bucket was used to take the surface seawater samples, and a rosette containing 36 Niskin bottles (12 liter volume each) for the other layers. b. Filtration and extraction. About 3 - 10 liters of seawater from each depth was filtered with Nuclepore filter (47mm diameter, 0.4 µm pore size from COSTAR Corp., Cambridge, Massachusetts, USA) to trap the phytoplanktons. The filter(s) then soaked in the 6 ml of solvent N,N- dimethylformamide (DMF, from WAKO PURE CHEMICAL INDUSTRIES, Ltd., Japan) solution for 24 hours to extract the pigments. c. Absorbance measurement and determination of pigments concentration. By using a Shimazu UV-2200 spectrophotometer, the absorbance (OD units) of extracted solution of samples were measured at 603 nm, 625 nm, 647 nm, 664 nm, and 703 nm- wavelength. The concentration of pigments (chlorophyll a and chlorophyll b) were then determined with formulae built by Moran (1981). Results and discussion: The concentration of each sample are shown n Table 15-1. a. In some stations, where the sea states were heavy, sometimes there was no rosette seawater sampling for upper sea level. In stations of section PR24-2, where a smaller rosette (12 Niskin bottles of 5 liter volume) was used, sample was taken only from the surface (0 m) seawater. b. samples from deeper layers were filtered faster than the upper ones. This must be due to the different concentrations of phytoplanktons at those layers. c. The concentration of chlorophyll a and chlorophyll b were shown in the table. Chlorophyll a was concentrated mostly at 50 - 100 meters depth, and the concentration became higher around the sea at the triangle formed by stations 6N-9, 6N-15 and PR1S. At most stations, no chlorophyll b was found at 0-30 meters of sea level except for station PR1S-13, and the concentration distribution pattern of chlorophyll b was similar to one of chlorophyll a. Table 15-1. The Chlorophyll a and chlorophyll b concentration along the section 6N, PR24 and PR1S in 1994 KAIYO WOCE cruise. Depth Niskin Bottle # Sample Volume Chl. a Chl. b meter liter mg/m3 mg/m3 Station 6N-1 surface Bucket 10.0 0.051 -0.004 10 30 9.0 0.043 -0.000 30 28 9.0 0.067 0.001 50 27 9.0 0.132 0.010 100 25 9.0 0.165 0.048 Station 6N-4 surface Bucket 10.0 0.065 -0.003 10 36 9.0 0.061 -0.001 30 34 10.0 0.060 0.001 50 33 9.5 0.093 0.005 100 27 10.0 0.213 0.065 Station 6N-8 surface Bucket 10.0 0.117 -0.006 30 35 9.5 0.105 -0.001 50 34 10.0 0.096 0.001 100 32 9.5 0.232 0.045 Station 6N-11 surface Bucket 10.0 0.059 -0.004 30 35 10.0 0.061 0.004 50 34 9.0 0.183 0.026 75 33 9.0 0.342 0.076 100 32 9.5 0.263 0.058 125 31 10.0 0.169 0.061 150 30 9.0 0.054 0.007 Station 6N-14 surface Bucket 10.0 0.051 0.001 100 36 8.5 0.238 0.070 Station PR24-3 surface Bucket 10.0 0.040 -0.001 30 36 9.0 0.044 0.001 50 35 9.0 0.097 0.029 75 34 9.0 0.215 0.064 100 33 6.5 0.126 0.047 Station PR24-9 surface Bucket 10.0 0.213 -0.000 10 36 8.0 0.198 0.002 30 34 9.5 0.247 0.002 50 33 9.0 0.299 0.006 75 32 9.0 0.134 0.029 100 31 9.5 0.054 0.007 Station PR24-15 surface Bucket 10.0 0.171 0.002 10 36 8.0 0.162 0.002 30 34 9.5 0.199 -0.003 50 33 9.0 0.401 0.026 75 31 9.5 0.237 0.088 100 30 9.0 0.107 0.033 Station PR24-2-4 surface Bucket 10.0 0.172 -0.008 Station PR24-16 surface Bucket 10.0 0.116 -0.001 10 36 7.7 0.125 0.003 30 34 8.3 0.156 0.001 50 33 8.0 0.673 0.117 75 32 8.0 0.242 0.071 100 31 9.0 0.126 0.036 Station PR1S-1 surface Bucket 10.0 0.144 -0.004 10 36 8.0 0.127 -0.002 30 34 8.0 0.197 0.006 50 33 6.0 0.355 0.042 75 32 9.0 0.271 0.049 100 31 8.0 0.050 0.004 Station PR1S-8 surface Bucket 10.0 0.126 -0.004 10 36 7.5 0.122 0.003 30 34 5.5 0.345 -0.006 50 33 3.5 0.436 0.059 75 32 7.4 0.262 0.066 100 31 7.5 0.061 0.014 Station PR1S-13 surface Bucket 10.0 0.243 0.012 10 36 8.5 0.232 0.009 30 34 9.7 0.538 0.147 50 33 7.9 0.254 0.085 75 32 9.5 0.053 0.013 100 31 8.7 0.031 0.007 Station PR1S-18 surface Bucket 10.0 0.033 -0.001 100 36 10.0 0.230 0.068 125 32 8.0 0.124 0.039 150 31 8.0 0.057 0.011 Station PR1S-20 surface Bucket 10.0 0.081 -0.009 50 35 9.0 0.290 0.044 100 33 8.0 0.232 0.060 16.Drifters by Y.Kashino (9 March 1994) 8 holey sock drifters developed by Scripps Institution of Oceanography were deployed as shown in table 16-1. Table 16-1. List of drifters deployed on this cruise. ID Time of deployment Location CTD (GMT) station 20056 25 Feb. 1703 2-00.433N 130-00.058E PR1S-6 20050 26 Feb. 0455 2-59.935N 129-59.897E PR1S-9 20052 26 Feb. 1718 4-00.559N 130-00.334E PR1S-12 20068 27 Feb. 0609 4-59.606N 130-01.085E PR1S-15 20073 27 Feb. 1940 5-59.657N 129-59.473E PR1S-17 20046 28 Feb. 0912 7-00.704N 130-01.390E PR1S-19 20960 1 Mar. 0112 7-30.545N 130-00.000E PR1S-20 20065 1 Mar. 0805 7-59.592N 130-00.946E PR1S-21 17. Distribution of atmospheric and oceanic CO2 by H.Yoshikawa (9 March 1994) Objectives Atmospheric CO2, known as a greenhouse gas, has been increasing due to the emission of anthropogenic CO2. It has increased approximately 25% in comparison with the pre- industrial era(280ppm). In order to predict the level of atmospheric CO2 in the future, it is necessary to understand the present inventory among global carbon reservoirs : atmosphere, biosphere and ocean. CO2 exchange between the atmosphere and ocean plays an important role in determining the level of atmospheric CO2. The difference in partial pressure of CO2 between the ocean and the atmosphere (delta-pCO2 ) is the driving force for air/sea CO2 exchange. During the WOCE cruise, measurements of pCO2 were (will be) made to study the interannual change CO2 outflux. Method Measurements of the CO2 concentration in the background air and the air equilibrated with seawater were made using the MRI CO2 measuring system. Air sample was taken from the top of the bridge at a flow rate of 15 l/min. Sea water was taken from the bottom of ship continuously, and introduced into the equilibrator. Equipment We use the non-disersive infrared gas analyzer (BINOS 4, Germany) to determine the CO2 concentration. CO2 concentration will be reported based on the WMO X85 mole fraction scale. Result Figure 17-1* is distribution of atmospheric and oceanic CO2 (preliminary data). The CO2 trend upward along PR24. This could be caused by the strong upwelling in the eastern equatorial Pacific, and two competitive processes: biological activity and temperature effect. 18. C-14 sample drawing by M. Aoyama (6 March 1994) All samples were drawn from 12 liter Niskin bottles followed that for oxygen. Samples were drawn into glass vials of ca. 200 ml. These were rinsed before filling and overflowed by two to three time of the vial volume. Then 0.2 ml of saturated HgCl2 solution was added and subsequently rubber cap and aluminum cap were clamped to vials. Replicate samples were drawn from the same rosette bottle at all sampling depths. The sampling depths of radiocarbon samples shallower than 1000 meters were 30, 50, 100, 150, 200, 300, 400, 600, 800, 1000. Below 1000 meters the sampling interval was 500 meters. 19. Weather and sea condition by E. Ukekura ( Chief officer, R/V kaiyo) and M. Aoyama The 3 hourly weather records are tabulated in Table 19-1. The Northeasterly trade wind was dominant and the weather was almost fine except sporadic heavy shower in the interested area during the cruise. It was usual weather in the western tropical Pacific and was almost easy. The air temperature showed the diurnal variation, namely high in afternoon up to 28 to 30 degree Celsius low in evening to morning at 27 to 28 degree Celsius in fine day. When the heavy shower was observed, the air temperature decreased to 24 to 25 degree Celsius. The atmospheric pressure showed the semi-diurnal variation. The higher pressure was observed at 0000-0100 UTC and 1300-1500 UTC every day and the lower pressure was observed at 0600-0700 UTC and 1800-2000 UTC every day. The amplitude of the semi- diurnal variation was 2 to 3 hPa. During the observation along section 6N, the wind speed was around 10 m/s and the wave height was around 2 meters. As the ship heads for south, the wind speed decreased to 5 - 8 m/s, the wind direction become NNE to NNW and the wave height decreased to around 1 meters. The Northeasterly trade wind becomes strong up to 10 to 15 m/s on 28 February and 1 March at the stations from PR1S-17 and PR1S-21, producing the large wave height of 2.5 meters. At the same time, the satellite IR image by GMS Himawari observed the week low moving westerly at 5 degree North, 165 degree East. Since the westerly moving low was predicted to come near our interested area and the sea condition had become hard to operate the CTD/Rosette , R/V Kaiyo headed for Palau Is. in the evening on 1 March. 20. Problems by K Muneyama and M. Aoyama We had 4 times of a disconnection of seacable. We spent 2 to 3 hours for fixing the disconnections. The most serious problem we encountered in this cruise was a total loss of a cast data at one occasion. We monitored the profiles of temperature,salinity and dissolved oxgen, and also watched reading of CTD pressure. After CTD/rosette was retrieved on the deck, an operator has intended to copy the file. Then he noticed that a size of datafile was zero byte, however the header file had been stored. The cause of this accident might be a computer virus, or a software bug,or an accidental mechanical failure. But we still could not elucidate the cause. We could not retrieve the 2 Aanderaa currentmetre moorings deployed in October 1992 placed between Talaud and Morotai islands,eventhough each acoustic releaser had worked normally. This R/V Kaiyo is designed to have a wide open deck for setting up many ship boarding containers, and consequently rather small fixed laboratory space. We provided a ship boarding container for a water sampling room with two air conditioners. The CTD/rosette water sampler itself is narrowly kept in the space, however operations for water sampling might be affected to be less convenient and less efficient. Dissolve Oxygen measurement of bottle samples has required us the precisely controled room temperature, however, the room temperature of the laboratory varied at 18 to 21 deg C in this occation. We need to have a better control of the room temperature for more difficult analysis. We have detected "the shed wake". This error could not be corrected. 21. REPORT ON CTD SYSTEM PERFORMANCE RV KAIYO, WOCE 94 CRUISE, SBE 911plus Serial Number 09P8010-0319 By Richard Baumann, Technical Operations Manager, SEA-BIRD Electronics, Inc., Bellevue, WA USA (3 March 1994) This report is a analysis of the performance of a SBE 911plus CTD system during a WOCE hydrography cruise on the Research Vessel KAIYO. The CTD system and vessel belong to the Japan Marine Science and Engineering Center (JAMSTEC). At their request, Mr. R. Baumann from Sea-Bird Electronics, Inc. (SBE) participated in the cruise to help with any problems that occurred with the CTD and to give his observations on the operation and performance of the CTD system. This report was written during the cruise and is divided into four parts. The first part is a brief description of the CTD system followed by a discussion of the steps that SBE recommends be followed in the operation of the CTD and the subsequent analysis and calibration of the CTD data to achieve WOCE accuracy specifications. The second part of the report is an analysis of the accuracy of the data obtained during the cruise. The third section is a discussion of the general operation of the CTD during the cruise with some examples of the data taken. The fourth part is a brief conclusion. PART I THE SBE 9plus CTD The primary CTD underwater unit used for this cruise was a SBE 9plus, S/N 09P8010- 0319. This CTD has dual temperature and conductivity sensors and a 15,000 psia Digiquartz pressure sensor. The main CTD and sensor housings are titanium giving the CTD system a depth capability of 10,500 meters. The CTD was delivered to JAMSTEC in October of 1993. The serial numbers and the factory calibration dates for the sensors mounted on this CTD as used on the cruise are: Primary temperature sensor S/N 1462 calibrated 28 September 1993 Primary conductivity sensor S/N 1045 calibrated 09 September 1993 Secondary temperature sensor S/N 1465 calibrated 28 September 1993 Secondary conductivity sensor S/N 1174 calibrated 22 September 1993 Paroscientific Inc. 15,000 psia pressure sensor calibration dated 24 September 1993 Experience has shown that the calibration of the pressure sensor will change as a slow drift of offset with time (approximately 1 to 2 dbar per year). Before a cast the pressure reading on deck should be observed and this value used as an offset to zero the pressure reading in air. The temperature sensors will tend to drift via a slowly increasing offset with time. This offset (which will be nominally the same at all temperatures) may be of either sign and will tend to be at a constant rate (from 0 to +/- 0.010 deg C per year) over periods of years. The temperature sensors on this CTD were calibrated monthly for a period of 9 months before they were supplied with the CTD system. This is sufficient time to determine their initial drift histories and allows their drift to be predicted with reasonable accuracy for periods of months before they need to be calibrated to verify the actual drift since their last calibration. The drift histories of the temperature sensors on this CTD are included as Figures 21-1* and -2* in this report. Based on an examination of these histories it is felt that as of 15 February 1994 both of these sensors will be reading 0.0028 deg C low (as referenced to the 28 September 1993 calibration coefficients used at sea) and that an offset correction of +0.0028 deg C should be added to the factory calibrations for each of these sensors. This prediction of temperature sensor drift is supported by an analysis in part two of this report where it is shown that the two temperature sensors agree with each to within about 0.0006 deg C throughout the cruise. Conductivity sensors tend to drift with use in two ways. One is a small background drift that can be considered uniform with time. This is thought to be a measure of the gradual fouling and aging of the platinum electrodes. Superimposed on this may be larger fouling events that are related to contact with biological material in the water as it passes through the cell. This type of fouling is seen as a larger shift in the conductivity measurement (towards lower conductivity) on top of the slower background drift. Rinsing the conductivity cell with a 2 to 5% solution of Triton detergent after each cast will help minimize the drift experienced during use. The error in the conductivity sensor is a function of the conductivity value and the correction is a slope adjustment to conductivity. After corrections have been made for the temperature and pressure sensors the calculation of the error in the conductivity measurement can be determined in two ways. One is based upon an analysis of the independent measurement of salinity from insitu water samples collected during the cruise. The other method is to have the conductivity sensor calibrated after the cruise and to base a correction on the observed drift. The first method has the advantage that it will tend to catch the aperiodic fouling events where the second method will average them over the duration of the cruise. An analysis of the CTD and Autosal salinity data from this cruise is given in the second part of this report. To insure that the WOCE accuracy specifications are met it is necessary to regularly calibrate the temperature and conductivity sensors on the SBE 9plus CTD. SBE would recommend that this be at least once a year and for the highest accuracy, calibrations before and after each cruise would be appropriate. Regular calibrations will also establish histories of the performance of the temperature and conductivity sensors. These histories allow the drift of the temperature sensor to be predicted and verify the operational characteristics of the conductivity sensor. The discussion above on calibrations is concerned with the static accuracy of the CTD system. This is the accuracy that the CTD and its sensors can obtain in a uniform, homogenous environment such as a calibration bath. The ocean, however, is not a uniform environment and the dynamic accuracy (the ability of the CTD to measure a parameter as it changes) of the CTD system must be considered. A full discussion of this subject is beyond the scope of this report but it is important to recognize that during data processing the appropriate corrections should be made for those errors that can be corrected (cell thermal mass, misalignment of temperature and conductivity data) and that the data containing errors that can not be corrected (shed wakes) be eliminated from further data processing. In part two of this report the analysis of data will be done in deeper water where gradients (and the resulting dynamic errors) are small. The SBE 9plus as used in the cruise was removed from its factory supplied cage and mounted vertically in the middle of a General Oceanics Model 1016 36 position, 12 liter, rosette water sampler. As mounted the CTD sensors had a good view of unobstructed water during down cast operation. SBE recommends that the CTD be lowered at a drop speed of between 1.0 and 1.5 meter per second. The CTD was deployed from an A-frame at the stern of the KAIYO and because of operational constraints was lowered at a descent rate of 0.5 meter per second (m/s) until a depth of 200 meters at which time the rate was increased to 1.5 m/s until within 200 meters of the bottom when the rate was slowed to 0.5 m/s. During CTD operations the bow of the ship is normally turned into the wind to help maintain a stationary position during the cast. In this orientation the predominant ship motion is pitch which modulates the descent rate when the CTD is deployed over the stern. The coupling of the pitch of the ship with the descent rate can cause the CTD to slow down, stop or even reverse directions and move up towards the surface. When this happens the water that has been entrained by the rosette will continue to move at the original descent rate and will cause a mixing of the water being measured by the CTD sensors. This will contaminate the data to an extent where this data must be removed from future analysis. This problem is most severe in the upper ocean where vertical gradients are the largest but can also affect data in the deep ocean. Examples of this type of data are given in part three of this report. PART II ACCURACY ANALYSIS OF THE SBE 9plus CTD The CTD used for this cruise was equipped with dual temperature and conductivity sensors. This feature allows for the comparison of data from each sensor pair as a check of data quality. This check is best performed below the thermocline where errors associated with the strong gradients of temperature and salinity are at a minimum. COMPARISON OF TEMPERATURE SENSORS. Table 21-1. contains a comparison of the temperatures reported by the primary (T0) and secondary (T1) sensors at two depths for selected casts throughout the cruise. These data points represent 10 second averages obtained when the CTD was stopped to collect insitu water samples. The temperatures in this table are as calculated using the 28 September 1993 calibration coefficients. The data show that the primary sensor is reading approximately 0.0006 deg C higher than the secondary sensor. This agreement supports the idea that both sensors have continued to drift at the rates predicted in the first part of this report. A post calibration of the sensors would determine the actual adjustments needed to bring these measured temperatures to the true temperature. The data at 2000 dbar show a higher variance then the data at 3000 dbar; which can be related to the steeper temperature gradient at that depth and the subsequent mixing of the water as the CTD/water sampler is stopped to collect a water sample (where the motion is that imparted to the instrument package by ship motion). With the good agreement shown between sensors either sensor could be used for subsequent data analysis. COMPARISON OF SALINITY CALCULATED WITH PRIMARY AND SECONDARY SENSOR PAIRS. Table 21-2. contains a comparison of the salinity calculated using the primary (S0) and secondary (S1) sensor pairs at two depths for selected casts throughout the cruise. These data points represent 10 second averages obtained when the CTD was stopped to collect insitu water samples. Salinity was calculated using the data as recorded by the SEASAVE program; no further data processing was performed and no corrections have been made to the calibration coefficients. The data show good agreement with the primary sensor pair giving a salinity which is slightly larger (<0.001) than the secondary salinity during the first part of the cruise but which varies as the cruise progresses. Unlike temperature whose calibration should not significantly change during a 1 month cruise, conductivity sensor calibrations will change as the cell is used. A more complete description of drift of a conductivity sensor is contained in the first part of this report. With the agreement between salinity either pair could be used for subsequent data analysis. COMPARISON OF THE DEEP SALINITY DATA BETWEEN CASTS In the deep water (4000 dbar and below) of the area of the Pacific Ocean where this survey is located it is not expected that the salinity will vary significantly either with location or depth. If this assumption is true than the salinity values observed at these depths can be used to monitor the calibration drift of the conductivity sensors. Table 21- 3 is a compilation of 10 second average CTD (primary sensor pair) salinity values for all water sample locations between 4000 and 5000 dbars. The salinity values in this table have been adjusted by -0.0029 psu from the values obtained with the factory calibration coefficients to reflected the predicted drift correction of +0.0028 deg C applied to the temperature sensor. The table shows agreement to within 0.0005 psu for depths between 4250 and 5000 for casts K6N021 through K6N121. After this cast there appears to be a trend towards lower salinity values with casts K6N131 being somewhat between and casts K6N141 thru K1S122 being about 0.001 PSU lower than the initial values. This is followed by casts K1S132 thru K1S182 being about 0.0015 lower than the initial values. The behavior is consistent with a conductivity cell which is gradually shifting calibration as it is used. Stations K6N091 and K1S172 were at the same location and the approximate 0.0015 difference in salinity between the two stations supports the analysis given here. At the time of this report was written the Autosal salinity values were only available through station K24202. When this information and the post calibrations are available there should be sufficient information to determine the actual calibration of the conductivity sensor at the various stations. Table 21- 3. clearly illustrates the ability of the SBE 911plus CTD system to resolve salinity to better than 0.0003 psu in the deep water where gradients (and the resulting dynamic errors) are low. Figure 21- 3. (which is discussed below) graphically presents this level of CTD precision for data points at or below 4000 dbar for stations up to K24031. Figure 21- 4 in the third section of this report shows the noise level of the unaveraged 24 hz salinity data in deep water to be about 0.001 psu. COMPARISON OF CTD SALINITY WITH AUTOSAL SALINITY Table 21- 4 lists the difference between CTD salinity (S0) and salinity calculated from insitu water samples between 4000 and 5000 meters for those casts for which Autosal salinity was available when this report was written. Figure 21- 3 shows this data along with the data from Table 21- 3 in a graphical format. It is easily seen that the variance of the averaged CTD salinity is much less than the salinity measured from the insitu water samples. Where Table 21- 3 suggests a slow change in the calibration of the conductivity sensor this trend is not obvious in the water bottle data available at the time this report was written. PART III GENERAL PERFORMANCE AND EXAMPLES OF SBE 9plus CTD DATA In part two of this report data were presented that represented 10 second averages obtained when the CTD was held at a depth to obtain a insitu water sample. Figure 21- 4 is a sample of the full rate 24 hz data from which these averages were calculated. This data is as recorded by the SEASAVE program without subsequent post processing. The noise level for temperature ia less than 0.001 deg C and for salinity is approximately 0.001 psu respectively. This data also shows the 0.1 dbar jitter in the pressure measurement which is removed by lowpass filtering pressure with a 0.15 second time constant. The increased variance of the signal during periods of low or negative descent rate is cause by mixing induced by the CTD/water sampler along the small local temperature gradient. The secondary sensor pair gives comparable data. Figure 21- 5* is an example of shed wakes in the data that occur when the motion of the CTD/water sampler through the water column slows and allows the entrained water to overtake the sensor package and be measured as if it were new, undisturbed water. The data during these periods can not be easily corrected and should be removed from subsequent data analysis. PART IV CONCLUSIONS Based on the evidence presented here this it appears that after the zero offset of the pressure sensor is adjusted for and a offset correction is added for the predicted drift of the temperature sensors, the CTD initially was giving a salinity which was about 0.002 psu low of the average insitu samples. As the cruise progressed this difference increased to about 0.0035 psu. In summary, the SBE 911plus CTD system used on this cruise showed the same high quality data which are typical of results obtained elsewhere. Temperature, salinity, and pressure that are within the WOCE requirements can be obtained from this data set when careful attention is paid to the calibration of the sensors. It is highly recommended that the temperature and conductivity sensors used be calibrated after the cruise to confirm the corrections made at sea. Acknowledgements by M. Aoyama (10 March 1994) The cruise participants thanks "very very much" to the captain H. Tanaka of R/V Kaiyo and the 26 crew for their powerfull and heartfull supports during the cruise. The deck crew for the CTD/Rosette operation could handle the big Rosette ( of 2.2 meters diameter, 1.8 meters height and almost 1000 Kg weights ) safely whenever the weather/sea condition becomes hard. The engineers/oilers also could operate the CTD winch well. The engineers and the oilers made many parts/materials to refine/ repair the instruments/machines for the observations. The boatswain and abledemans made the fine shellter for the meteorological observations for WOCE cruise. During the mooring, many of the crew supported the deck work and they often gave us the good comments/suggestions for the preparation of mooring. The radio operators and the cooks supported our living in the ship heartfully. During the pre-cruise stage, three analyst groups of salinity, dissolved oxygen and nutrients were largely supported by Mr. M . Mitsuya and Ms. H. Hamabe, the two staffs of the ocean-chemistry laborotory at Ocean Reseach Department, JAMSTEC. The director T. Nakanishi at the Ocean Research Department , JAMSTEC and the members at the Planning Department did the good arrangements to execute this cruise in the view point of the fund and on-shore laboratory space. Mr. I. Asanuma, the chief scientist at LIDAR cruise carried out just before this cruise, helped us much for the good on deck arrangments of the container laboratories, wiches and railway of the Rosette operation. This cruise have executed on the basis of the collaborative ocean research framework between Japan Marine Science and Technology Center (JAMSTEC) and Badan Pengajian Dan Penerapan Teknologi (BPPT) since 1992. This cruise is funded by the Japan-WOCE program with the Science and Technology Agency of Japan under the special coordinated funds and largery by some of the projects of JAMSTEC. * All figures shown in PDF file.