WHP Cruise Summary Information WOCE section designation I02EW Expedition designation (EXPOCODE) 316N145/14-15 Chief Scientist(s) and their affiliation Gregory Johnson, NOAA/PMEL Bruce Warren, WHOI Dates 1995.12.02 - 1996.01.22 Ship KNORR Ports of call Singapore to Mombasa, Kenya to Diego Garcia Number of stations 168 Geographic boundaries of the stations 2°30.00''S 39°49.50''E 105°38.18''E 12°21.33''S Floats and drifters deployed 27 Floats and 20 Drifters Moorings deployed or recovered none Contributing Authors none listed Draft Cruise Report World Ocean Circulation Experiment Indian Ocean Hydrographic Program Section I02 R/V KNORR Voyage 145-14 2 December 1995 - 22 January 1996 A. Cruise Narrative A.1. Highlights WOCE Hydrographic Program Section I02 (EXPCODE 316N145/14) was carried out aboard the R/V KNORR on voyage 145-14. This voyage began in Singapore on 2 December 1995 and ended in Mombasa, Kenya on 22 January 1996 with an intermediate port call in Diego Garcia from 28 to 30 December 1995. The chief scientist from Singapore to Diego Garcia was Gregory Johnson: NOAA/Pacific Marine Environmental Laboratory, Ocean Climate Research Division, 7600 Sand Point Way NE Bldg. 3, Seattle WA 98115, USA, gjohnson@pmel.noaa.gov. The chief scientist from Diego Garcia to Mombasa, Kenya was Bruce Warren: Woods Hole Oceanographic Institution, Department of Physical Oceanography, Woods Hole MA 02543, USA, bwarren@whoi.edu. A.2. Cruise Summary The work done during this cruise comprised WOCE Hydrographic Program Section I02, a transindian ocean section along nominal latitude 8°S, and three diversions to nearby gaps in ridges to explore possible avenues for flow of deep and bottom water between various deep basins. During the cruise a total of 168 CTD/O2 stations were occupied within 10 m of the bottom with a 36 position 10-l bottle frame equipped with a lowered ADCP. Discounting one test station, 139 of these stations were occupied along the I02 section. The nominal station spacing along the I02 section is 40 nm in the interior, reduced near boundaries, mid-ocean ridges, and other places where narrow currents might exist. The average station spacing along the section is 32 nm. The positions of the CTD stations are plotted in Fig. 1*, and the distribution of points along the main section at which water samples were drawn is plotted in Fig. 2*. Special attention was given to the bottom topography in laying out the station positions because of the opportunity offered for the exploration of the three major deep flows in the South Indian Ocean. The deep western boundary current of the eastern Indian Ocean, flowing northward along the Ninety east Ridge, had never been observed north of 18°S. The central deep boundary current had been inferred to divide near 15°S, with ill- defined branches flowing northward along the Chagos-Laccadive Ridge, Central Indian Ridge, and Mascarene Plateau. In the west the major deep and mid-depth flows between the Mascarene and Somali Basins could be documented on a complete section from the Mascarene Plateau to Madagascar. Three diversions were made from the main section to investigate flow of bottom water through deep gaps in mid-ocean ridges. The first diversion, 7 stations from 6°50'S to 5°S around a mean longitude of 88°28'E, mapped a westward flow of bottom water from the West Australian Basin to the Central Indian Basin across a deep gap in the Ninety east Ridge at 5°S. The second diversion consisted of 11 stations between 11°S - 10°S and 88°E - 88°25'E to investigate a similar flow across a gap in the ridge at 10°S. The third diversion consisted of 10 stations between 4°00'S - 2°30'S and 71°45'E - 73°20'E, placed within and on the western flank of a deep gap in the Chagos-Laccadive Ridge. This diversion explored, for the first time, suspected flow of bottom water through this gap between the Central Indian Basin and the Arabian Basin. The ship left Singapore at 0900L on 2 December 1995 without the Indonesian observers, who had elected not to participate since clearance to work within the Indonesian Exclusive Economic Zone was not obtained. After a roughly 3 day steam, stations 1077 and 1078 were occupied at the location of station 1075, occupied ten days earlier during I10, at 9°S, 105°38'E; these served as test stations for equipment and personnel. Stations 1079 though 1084 went from 105°10'E to 102°E along 9°7.5'S. By station 1090 the line reached 8°S at 98°E, after skirting the offshore edge of the Indonesian Exclusive Economic Zone (EEZ). The ship crossed the Ninety-east Ridge at station 1105, and the Chagos-Laccadive Ridge at 1154. Stations 1106-1112 and 1116-1126 comprised the first two diversions from the main section along 8°S. The cruise broke off after station 1156 for a 48 hour port call in Diego Garcia, where Gregory Johnson departed to join another cruise and the two Kenyan observers joined the ship. After departing Diego Garcia at 0900L 30 Dec 1995 the ship steamed north for the third diversion, at the Chagos-Laccadive gap, stations 1157-1166. Returning to the 8°S line, it passed the crest of the Central Indian Ridge at station 1172, and that of the Mascarene Plateau at station 1185. At station 1194 at 54°E, the ship's course turned southwestward to cross the Amirante Passage (stations 1199-1201 in the Amirante Trench proper) and reached the northern tip of Madagascar at station 1215. After rounding the tip, the ship resumed stations heading northwestward toward Africa, taking a dog-leg track with turns at stations 1227 and 1232 to avoid the Tanzanian EEZ, and arriving in Mombasa on 22 January 1996 after completing station 1244. Twenty-seven Autonomous Lagrangian Circulation Explorer (ALACE) floats and twenty surface drifters were deployed during the course of the cruise. Serial numbers, launch dates, launch times, positions, and CTD station numbers corresponding to launch sites are listed in Tables 1 and 2, respectively. An underway program of meteorological, sea surface, and hull-mounted ADCP measurements was carried out along the entire cruise track outside the Indonesian EEZ. For a non-WOCE, adjunct project, 25-ml samples for barium analysis ashore were drawn from every Niskin bottle on alternate stations, and stored for shipment to the U.S. Figure 1a*) WOCE I02E Cruise Track (produced by .SUM files by WHPO) Figure 1b*) WOCE I02W Cruise Track (produced by .SUM files by WHPO) Table 1. WOCE-I02 ALACE Float Deployment Log. Date and time shown in GMT. After SELF TEST DEPLOYMENT CTD S/N Date Time Date Time Lat Lon Stn# 1. 560 951206 1158 951206 1407 9°07.70'S 103°20.10'E 1082 2. 561 951208 1107 951208 1124 8°22.42'S 98°20.01'E 1088 3. 573 951212 1008 951212 1326 7°59.91'S 91°20.20'E 1100 4. 574 951214 2004 951214 2155 5°00.22'S 88°28.25'E 1109 5. 568 951216 1206 951216 1510 8°00.14'S 87°59.85'E 1115 6. 567 951218 0001 951218 0154 11°00.06'S 88°01.93'E 1120 7. 563 951221 1600 951221 1900 8°00.06'S 83°19.57'E 1133 8. 549 951223 0419 951223 0618 8°00.31'S 79°59.84'E 1138 9. 562 951225 0007 951225 0207 7°59.92'S 75°59.90'E 1144 10. 495 951226 1423 951226 1618 7°59.88'S 72°49.56'E 1150 11. 535 951227 1335 951227 1532 7°59.71'S 70°39.20'E 1156 12. 538 960104 1935 960104 2048 8°00.06'S 67°19.93'E 1172 13. 570 960106 1517 960106 1742 8°00.28'S 62°39.77'E 1179 14. 569 960107 0450 960107 0628 8°00.45'S 61°27.08'E 1181 15. 550 960107 2327 960108 0035 7°59.96'S 59°19.99'E 1185 16. 557 960109 1501 960109 1752 8°00.10'S 55°19.57'E 1192 17. 555 960111 0705 960111 1008 8°56.92'S 53°02.88'E 1200 18. 558 960112 0914 960112 1227 9°32.84'S 51°54.29'E 1205 19. 556 960113 1125 960113 1436 11°12.53'S 50°47.23'E 1209 20. 553 960114 0707 960114 0946 12°12.24'S 49°47.87'E 1213 21. 571 960114 2209 960115 0158 11°54.06'S 48°44.03'E 1218 22. 554 960116 0149 960116 0412 10°16.80'S 47°30.30'E 1223 23. 572 960117 0010 960117 0137 8°44.88'S 46°20.50'E 1226 24. 552 960117 2028 960117 2103 7°00.47'S 45°57.29'E 1229 25. 564 960119 0046 960119 0355 5°02.51'S 45°16.75'E 1233 26. 565 960120 0605 960120 0852 4°33.47'S 42°41.33'E 1237 27. 551 960121 0036 960121 0206 4°15.63'S 40°58.22'E 1240 Table 2. WOCE I02 Surface Drifter Deployment Log. Date and time shown in GMT. After DEPLOYMENT CTD S/N Date Time Lat Lon Stn # 1. 21904 120595 1508 9°07.98'S 105°09.99'E 1079 2. 21903 120895 0346 8°33.77'S 99°59.65'E 1087 3. 21933 121095 1709 8°00.41'S 95°20.26'E 1094 4. 21932 121395 0254 7°59.96'S 89°59.84'E 1102 5. 21870 121495 0533 6°00.10'S 88°28.56'E 1106 6. 21871 121495 2200 5°00.36'S 88°28.49'E 1109 7. 21905 121695 1511 8°00.20'S 87°59.84'E 1115 8. 21901 121795 0520 10°02.88'S 87°59.98'E 1116 9. 21912 121895 1557 10°59.99'S 88°01.93'E 1120 10. 21913 122095 2148 7°59.97'S 85°19.97'E 1130 11. 21921 122395 0620 8°00.33'S 79°59.81'E 1138 12. 21920 122595 0918 7°59.97'S 75°19.88'E 1145 13. 21926 010196 0029 2°30.30'S 72°32.24'E 1160 14. 21928 010396 1956 7°59.84'S 69°59.86'E 1168 15. 21929 010596 1653 7°59.95'S 65°19.75'E 1175 16. 21927 010796 1724 7°59.90'S 60°09.62'E 1183 17. 21952 010996 1753 8°00.10'S 55°19.33'E 1192 18. 21951 011596 2134 10°46.69'S 47°52.15'E 1222 19. 21923 011796 2205 7°00.40'S 45°57.26'E 1229 20. 21922 012096 1515 4°27.84'S 42°06.66'E 1238 A.3. Principal Investigators 1. Gregory Johnson Salinity Oxygen CTD/O2 NOAA/Pacific Marine Environmental Laboratory, Ocean Climate Research Division, 7600 Sand Point Way NE Bldg. 3, Seattle WA 98115-0070, USA, gjohnson@pmel.noaa.gov 2. Bruce Warren Salinity Oxygen CTD/O2 Woods Hole Oceanographic Institution, Department of Physical Oceanography, Woods Hole MA 02543, USA, bwarren@whoi.edu 3. John Toole Salinity Oxygen CTD/O2 Woods Hole Oceanographic Institution, Department of Physical Oceanography, Woods Hole MA 02543, USA, jtoole@whoi.edu 4. Louis Gordon Nutrients Oregon State University, College of Ocean and Atmospheric Sciences, 104 Ocean Administration Building, Corvallis OR 97331-5503, USA, lgordon@oce.orst.edu 5. John Bullister CFCs (F11, F12) & Air Chemistry NOAA/Pacific Marine Environmental Laboratory, Ocean Climate Research Division, 7600 Sand Point Way NE Bldg. 3, Seattle WA 98115-0070, USA, bullister@pmel.noaa.gov 6. William Jenkins Shallow Helium/tritium Woods Hole Oceanographic Institution, Chemistry Department, Woods Hole MA 02543, USA, wjenkins@whoi.edu 7. Peter Schlosser Deep Helium Lamont Doherty Earth Observatory, Columbia University, Pallisades NY 10964, peters@ldeo.columbia.edu 8. Robert Key AMS C14 & Radium Princeton University, Geology Department, Guyot Hall, Princeton NJ 08544, USA, key@wiggler.princeton.edu 9. Kelly Falkner Barium Oregon State University, College of Ocean and Atmospheric Sciences, 104 Ocean Administration Building, Corvallis OR 97331-5503, USA, kfalkner@oce.orst.edu 10. Chris Winn Total Carbon & Alkalinity Scripps Institution of Oceanography, Marine Physical Laboratory 0902, University of California at San Diego, 9500 Gilman Drive, La Jolla CA 92037, USA, cwinn@chiton.ucsd.edu 11. Douglass Wallace Total Carbon & Alkalinity Brookhaven National Laboratory, Building 318, Upton NY 11973, USA, wallace@bnl.gov 12. Peter Hacker ADCP & LADCP University of Hawaii, Joint Institute for Marine and Atmospheric Research, 1000 Pope Road, Honolulu HI 96882, USA, hacker@soest.hawaii.edu 13. Eric Firing ADCP & LADCP University of Hawaii, Joint Institute for Marine and Atmospheric Research, 1000 Pope Road, Honolulu HI 96882, USA, efiring@soest.hawaii.edu 14. Barrie Walden Meteorology Woods Hole Oceanographic Institution, Woods Hole MA 02543, USA, bwalden@whoi.edu 15. Russ Davis ALACE Floats Scripps Institution of Oceanography, University of California at San Diego, 9500 Gilman Drive 0230, La Jolla CA 92093-0230, USA, davis@nemo.ucsd.edu 16. Mark Bushnell Surface Drifters NOAA/Atlantic Oceanographic Marine Laboratory, 4301 Rickenbacker Causeway, Miami FL 33149, USA, bushnell@aoml.noaa.gov A.4. List of Cruise Participants 1. Gregory Johnson* chief scientist NOAA/Pacific Marine Environmental Laboratory, Ocean Climate Research Division, 7600 Sand Point Way NE Bldg. 3, Seattle WA 98115-0070, USA, gjohnson@pmel.noaa.gov 2. Bruce Warrren** co-chief scientist Woods Hole Oceanographic Institution, Department of Physical Oceanography, Woods Hole MA 02543, USA, bwarren@whoi.edu 3. Sara Zimmermann CTD data processor Woods Hole Oceanographic Institution, Department of Physical Oceanography, Woods Hole MA 02543, USA, szimmermann@whoi.edu 4. George Knapp oxygen analyst Woods Hole Oceanographic Institution, Department of Physical Oceanography, Woods Hole MA 02543, USA, gknapp@whoi.edu 5. Toshiko Turner (WHOI) salinity analyst Woods Hole Oceanographic Institution, Department of Physical Oceanography, Woods Hole MA 02543, USA, tturner@whoi.edu 6. H. Marshall Swartz CTD electronics technician & CTD watch leader Woods Hole Oceanographic Institution, Department of Physical Oceanography, Woods Hole MA 02543, USA, mswartz@whoi.edu 7. Laura Goepfert CTD watch leader Woods Hole Oceanographic Institution, Department of Physical Oceanography, Woods Hole MA 02543, USA, lgoepfert@whoi.edu 8. Paul Bennett CTD watch stander Woods Hole Oceanographic Institution, 110 High Park Place, Pittsburgh PA 15266, USA 9. Steven Jayne CTD watch stander Woods Hole Oceanographic Institution, Department of Physical Oceanography, Woods Hole MA 02543, USA, sjayne@whoi.edu 10. Arthur Voorhis CTD watch stander Woods Hole Oceanographic Institution, 54 Whitman Road, Woods Hole MA 02543, USA 11. Mela Swapp CTD watch stander University of Washington, P.O. Box 8231, Kirkland WA 98034, USA, swapp@pmel.noaa.gov 12. Deborah LeBel CTD watch stander University of Washington, School of Oceanography, Box 357940, Seattle WA 98195-7940, lebel@ocean.washington.edu 13. Stanley Moore Nutrient analyst Oregon State University, College of Ocean and Atmospheric Sciences, 104 Ocean Administration Building, Corvallis OR 97331-5503, USA, moores@ucs.orst.edu 14. Consuelo Carbonell-Moore Nutrient analyst Oregon State University, College of Ocean and Atmospheric Sciences, 104 Ocean Administration Building, Corvallis OR 97331-5503, USA, carbonec@oce.orst.edu 15. Elodie Kestenare ADCP & LADCP watch leader University of Hawaii, Joint Institute for Marine and Atmospheric Research, 1000 Pope Road, Honolulu HI 96882, USA, elodie@soest.hawaii.edu 16. Mark Majodina ADCP & LADCP watch stander University of Cape Town, Oceanography Department, Rondebosch 7700, SOUTH AFRICA, majodina@physci.uct.ac.za, 17. Frederick Menzia CFC analyst NOAA/Pacific Marine Environmental Laboratory, Ocean Climate Research Division, 7600 Sand Point Way NE Bldg. 3, Seattle WA 98115-0070, USA, menzia@pmel.noaa.gov 18. Bing-Sun Lee CFC analyst University of Washington, School of Oceanography, Box 357940, Seattle WA 98195-7940, blee@pmel.noaa.gov 19. Art Dorety C-14 and Radium analyst Princeton University, Geology Department, Guyot Hall, Princeton NJ 08544, USA, key@wiggler.princeton.edu 20. Dan Smith Deep Helium-3 analyst Lamont Doherty Earth Observatory, Columbia University, Palisades NY 10964, dansmith@lamont.ldgo.columbia.edu 21. Scot Birdwhistell Tritium/Helium-3 analyst Woods Hole Oceanographic Institution, Chemistry Department, Woods Hole MA 02543, USA, sbirdwhistell@whoi.edu 22. Rolf Schottle TCO2/Alkalinity analyst Scripps Institution of Oceanography, Marine Physical Laboratory, University of California at San Diego, 9500 Gilman Drive 0902, La Jolla CA 92037, USA, rolfs@chiton.ucsd.edu 23. Jennifer Phillips TCO2/Alkalinity analyst University of Hawaii at Hilo, Department of Marine Science. 200 West Kawili St, Hilo HI 96720, jphillip@hawaii.edu 24. Angela Adams TCO2/Alkalinity analyst University of Hawaii, Department of Oceanography, 1000 Pope Road, Honolulu HI 96822, aadams@soest.hawaii.edu 25. Cathy Cipolla TCO2/Alkalinity analyst University of Rhode Island, Graduate School of Oceanography, Equipment Development Laboratory, South Ferry Road - Box 60, Narragnasett RI 02882-1197, USA, seabiz@gsosun1.gso.uri.edu 26. Stanley Rosenblad Resident Technician Woods Hole Oceanographic Institution, Woods Hole MA 02543, USA, srosenblad@whoi.edu 27. Michael Mutua Nguli*** Kenyan scientist Kenya Marine and Fisheries Research Institute, P.O. box 81651, Mobassa, KENYA, modido@main.bib.uia.ac.be 28. Mika Oduor Odido*** Kenyan scientist Kenya Marine and Fisheries Research Institute, P.O. box 81651, Mobassa, KENYA, modido@main.bib.uia.ac.be * Departed Ship in Diego Garcia ** Chief Scientist from Diego Garcia to Mombasa *** Joined ship in Diego Garcia A.5. Special Notes Extraordinary time and effort were expended by the chief scientist and Indonesian scientists from the Bogor Agricultural University in an attempt to gain clearance to occupy hydrographic stations within the Indonesian EEZ as part of WOCE Section I02.Formal clearance was never granted. Late on 30 November 1995 one of the Indonesian scientists involved called the Chief Scientist saying that he had obtained clearance. He requested a three day delay in the start of I02 to accommodate the schedules of the Indonesian military observers. The stations to be allowed started 19 nm from the Indonesian coast at about2000 m depth. After a brief consideration weighing the experience gained in Indonesian clearance procedure from the preceding cruise, WOCE Section I10, a decision was made to start the cruise on time and abandon hope of working within the Indonesian EEZ. This lack of clearance was most unfortunate as measurement of the South Java Current, most likely flowing southeastward along Indonesia, had to be omitted from the program. B. Underway Measurements B.1. Navigation and Bathymetry To obtain bathymetric data, uncorrected sonic depths and times were logged manually from the 12 khz PDR every 5 minutes by the CTD watch. These depths were then merged by time with the navigation data. B.2. Meteorological Observations The IMET system was calibrated prior to the departure of the Knorr and extra sensors were aboard. The data were automatically recorded once per minute on the ship's computer. Variables measured included computer time, ship's heading (Gyro syncro),ship's speed (EDO Speed log), sea surface conductivity (mmho/cm), sea surface temperature (°C), port GPS 200 time & position, stbd GPS 200 time &position, GPS course over ground, GPS speed over ground, GPS time & position, air temperature (°C),barometric pressure (millibars), relative humidity (percent), precipitation(millimeters),short wave radiation (watts/sq m), compass reading (degrees), wind direction (ship relative), and wind speed (m/s, ship relative). The quality of the wind records may have been degraded sometimes when red-footed boobies (Sula sula) sat on the sensors. B.3. Acoustic Doppler Current Profilers Ocean velocity observations were taken using two acoustic Doppler current profiler(ADCP) systems and accurate navigation data. The two systems are the hull-mounted ADCP and a lowered ADCP mounted on the rosette with the CTD. The purpose of the observations was to document the upper ocean horizontal velocity structure along the cruise track, and to measure vertical profiles of the horizontal velocity components at the individual hydrographic stations. The observations provide absolute velocity estimates including the ageostrophic component of the flow. B.3.1. Hull-mounted ADCP The hull-mounted ADCP is part of the ship's equipment aboard the KNORR. The ADCP is a 150 kHz unit manufactured by RD Instruments. The instrument pings about once per second, and for most of the cruise the data were stored as 5-minute averages or ensembles. The user-exit program, ue4, receives and stores the ADCP data along with both the P- code navigation data from the ship's Magnavox receiver and the Ashtech gps receiver positions. The P-code data are used as navigation for the ADCP processing. The ship gyro provides heading information for vector averaging the ADCP data over the 5- minute ensembles. The user-exit program calculates and stores the heading offset based on the difference between the heading determination from the Ashtech receiver and from the ship gyro. The ADCP transducer is mounted at a depth of about 5 meters below the sea surface. The setup parameters were a blanking interval of 4 meters, a vertical pulse length of 16 meters, and a vertical bin size of 8 meters. We used a 5 minute sampling interval for the entire cruise. Bottom tracking was activated during the shallow water transits near Diego Garcia Atoll, and along the coasts of Madagascar and Mombasa. For the processing of the ADCP data aboard ship, we used a rotation amplitude of 1.0085, a rotation angle of -0.06 degrees (added to the gyro minus gps heading), and a time filter width of 0.0104 days (15 minutes). Final editing and calibration of the ADCP data has not yet been done. A couple of days before arriving at Diego Garcia, the performance of beam 4 became poorer than usual. During the second leg (Diego Garcia - Mombasa), the beam 4 failed and the three other beams were going slowly worse and worse. Several tests have been done: the results confirm that the main electronics works well but a problem occurs inside the transducers. We suspect that beam 4 (and maybe the three others) has flooded. A complete set of preliminary plots was generated during the cruise. The plots consist of: vector plots with velocity averaged over several depth intervals, and over a tenth or a twentieth of degrees in spatial grid; and contour plots of u (positive east) and v (positive north) typically averaged over 0.1 degree of longitude or latitude, depending on the track. The velocity was measured from a depth of 21 m to a depth of about 300 to 400 m, typically during the first leg and about 200 to 300 m during the second leg since a beam failed. B.3.2. Lowered ADCP The second ADCP system is the lowered ADCP (LADCP), which was mounted to the rosette system with the CTD. The LADCP yields vertical profiles of horizontal velocity components from near the ocean surface to near the bottom. Two LADCP were available: Teresa Chereskin's (Scripps Institution of Oceanography - SIO) and Eric Firing & Peter Hacker's (University of Hawaii - UH). Both units are a broadband, self-contained 150 kHz system manufactured by RD Instruments. The SIO instrument, used with an asynchronous signal (with alternating sampling intervals of about 1.2 and 1.8 seconds), allows one to decrease the number of samples contaminated by bottom interference. We used single ping ensembles. Vertical shear of horizontal velocity was obtained from each ping. These shear estimates were vertically binned and averaged for each cast. By combining the measured velocity of the ocean with respect to the instrument, the measured vertical shear, and accurate shipboard navigation at the start and end of the station, absolute velocity profiles are obtained (Fisher and Visbeck, 1993). Depth is obtained by integrating the vertical velocity component; a better estimate of the depth coordinate will be available after final processing of the data together with the CTD profile data. The shipboard processing results in vertical profiles of u and v velocity components, from a depth of 60 m to near the ocean bottom in 16-m intervals. These data have been computer contoured to produce preliminary plots for analysis and diagnosis (see enclosed figures). The SIO (newest) LADCP was used between CTD stations 1077 and 1094. The very poor performance of the instrument below 3000 m and then below 2000 m during these first 18 stations is due to a low transmit current inside the instrument (the HP module failed). The UH LADCP was used from station 1095 until the end of the cruise. Five stations (1015, 1118 - 1121) were missed owing to the use of an improper configuration file. One command required for proper LADCP operation with the new resistor (changed July 95) was not included correctly in the initial file. Also, the LADCP was not deployed during station 1215, because of shallow water (around 300 m). The deep casts often have noise problems below 3000 m or so owing to poor instrument range and interference from the return of the previous ping. B.3.3. Navigation The ship used a Trimble precision code (P-code) receiver for navigation, with data coming in once per second. These one-second data were stored for the entire cruise. The Ashtech receiver uses a four antennae array to measure position and attitude. The heading estimate was used with the gyro to provide a heading correction for the ADCP ensembles. The Ashtech data were stored by the ADCP user-exit program along with the ADCP data. B.4. Thermosalinograph Surface temperature and salinity from an FSI thermosalinograph were recorded on the ship's computer. The thermosalinograph was not calibrated prior to the departure of the Knorr from Woods Hole and will require station calibrations with the CTD/rosette system to obtain correct salinity data. B.5. Atmospheric Chemistry The CFC group ran 3/8" O.D. Dekaron air sampling lines (reinforced plastic tubing) from the CFC van to the bow and stern and their personell periodically analysed air for: CFC-11, CFC-12, CFC-113, carbon tetrachloride, and methyl chloroform. B.6. pCO2 Equilibrated seawater and surface air were monitored underway for pCO2 by the TCO2 and Total Alkalinity personell. Two separate systems were continuously monitoring pCO2. One system uses a shower type equilibrator and gas chromatographic detection. The other system uses a rotating disk equilibrator and infra-red detection. Sample analyses were typically completed within 12 hours of sample collection for discrete samples (TCO2 and Total Alkalinity). C. Hydrographic Measurements C.1. Water Sampling (Rosette) Equipment 2 SIO/ODF 36 position/10-liter frame with LADCP mounts. 1 WHOI/Bullister 25 position/4-liter frame. 1 WHOI 24 position/1.2 liter frame. 80 SIO/ODF 10-liter bottles with spares. 32 WHOI/Bullister 4-liter bottles with spares. 28 Bullister 4-liter bottles with spares. 36 WHOI/GO 1.2 liter bottles with spares. 3 GO 36-position pylons model 1016-36. 2 GO 24-position pylons model 1015-24. 2 GO 36-position surface control interfaces. 2 GO 24-position pylon deck units. 1 GO GO-FIRE external tonefire system for 36-position pylons. C.2. CTD Data acquisition and processing C.2.1. CTD Equipment 3 WHOI-modified EG&G Mk-IIIb CTD/O2 system with WHOI titanium pressure transducer and pressure temperature channel. 2 WHOI/FSI ICTD/O2 systems with separate fast temperature channels. 5 WHOI/FSI Ocean Temperature Modules (external platinum resistance thermometers) for redundancy on Mk-IIIb. 2 WHOI/FSI Ocean Conductivity Module for redundancy on Mk-IIIb. C.2.2. CTD Equipment Configuration Equipment used aboard Knorr for WOCE section I02 has been provided by both Woods Hole Oceanographic Institution CTD Operations, and the Scripps Institution of Oceanography's Shipboard Technical Services/ Ocean Data Facility (SIO STS/ODF). A total of 168 stations were taken during the cruise, which includes two test stations to check instrument performance. The underwater equipment was attached to an ODF-provided aluminum frame, capable of mounting thirty-six 10-liter bottles and a range of electronics. For this cruise two CTDs were usually used, along with a 36-position pylon, pinger, independent temperature modules and a lowered acoustic doppler current profiler (LADCP). Nearly all CTD data came from CTD-9, a WHOI-modified Neil Brown Mk-3b sampling at 23.8Hz, and incorporating a Sensormedics oxygen sensor assembly and a titanium pressure transducer with temperature sensor. Two early stations were taken with CTD-8, a General Oceanics-upgraded Mk3-c CTD. On most stations, one of two Falmouth Scientific (FSI) ICTDs were used in memory mode to provide an independent CTD trace. Both of the ICTDs provide 26Hz scan rate and Sensormedics oxygen sensors. Either can be configured for use in FSK mode to send data up the cable or in memory mode to internally record data and dump it at the end of a cast. Additionally, an FSI Ocean Temperature Module (OTM) was attached to each of the Mk-3 and ICTDs to give further temperature benchmarks. A General Oceanics (GO) model 1016-36 pylon and thirty-six ODF 10-liter bottles mounted in two concentric circles on the frame were provided by ODF. Also clamped into the frame were an Ocean Instrument Systems pinger for bottom-finding and an RDI LADCP and battery pack (see separate LADCP discussion). The underwater system was lowered from the Knorr's starboard Markey winch spooled with approximately 10,000 meters of Rochester 0.322 inch 3-conductor electromechanical cable. Standard lowering rates were 30 meters per minute to 200 meters wire out, and then 60 meters per minute to the target depth, as well as 60 meters per minute on the upcast. Significant backup equipment was available aboard but not used, including one spare 36-position frame complete with bottles from ODF, a WHOI-owned 25-position 4-liter bottle frame, two GO 1016-36 pylons, three GO 1015-24 pylons and two pingers. C.2.3. CTD Equipment Performance Of the 168 stations, 166 were taken with CTD-9, and two with CTD-8. The two FSI ICTDs took data on 137 stations, configured for internal recording and mounted on the frame at the same height as the Mk-3 to provide an independent CTD data set. ICTD-1338 was used for 67 stations, and ICTD-1344 provided 70 stations. CTD-8 was not used further because of jumps in the multiplexed data channels, which resulted in unfittable data in the oxygen and pressure temperature channels. OTM data were integrated directly into the CTD data streams at the regular scan rate for that CTD. One OTM was replaced when it developed an intermittent output. Preliminary reviews have shown no obvious temperature shifts comparing the OTMs with either of the CTDs' temperature data. ICTD data were downloaded from the ICTD at the end of each station. Early problems maintaining connection to the downloading computer were traced to a faulty cable from the ICTD to the lab, and a replacement provided satisfactory performance. CTDs and OTMs used during the cruise are being returned to WHOI for post-cruise calibrations in WHOI's CTD Calibration Laboratory during early 1996. Power was maintained to the CTDs and pylon at all times to assure warm up conditions. Each of the three conductors of the sea cable were used, one providing power and signal to/from the pylon, one for power and signal to/from the FSK mode CTD, and one providing power to the memory- mode CTD. The memory mode CTD was also provided with a backup battery in a pressure case to minimize the possibility of logging mode shutdown in the event of a power dropout. The starboard winch, wire and boom arrangement worked flawlessly. The sea cable was reterminated approximately every 25 stations to avoid fatigue and corrosion failure, but in every case the wire was observed in apparently good to excellent shape at the termination. Retermination was not needed because of any cable problems. It should be noted that sea conditions were calm to moderate during the cruise. Winch operators were well-trained, attentive and proactive, making the CTD watch significantly smoother. Equipment provided by Scripps STS/ODF was in well maintained condition, and performed reliably during the cruise. There were occasional communications errors with the pylon traced to cross-talk from the CTD and pylon telemetry, but these were minor inconveniences. Special thanks go to the ODF group for their technical and logistics assistance and equipment support to WHOI in conducting this section as well as the I8S/I9S and I1 sections. C.2.4. CTD Data Acquisition and Processing Methods CTD data were acquired using a Neil Brown Instrument Systems Mk-III deck unit/display providing demodulated data to two personal computers running EG&G CTD acquisition software version 5.2 rev 2 (EG&G, Oceansoft acquisition manual, 1990). One computer provided graphical data to screen and plotter, the other provided a listing output. Two more personal computers were used, one for pylon control and one for recovering the data from the internal-recording ICTD. The pylon was driven by an ODF-provided pylon control system. Bottom approach of the CTD package was monitored by following the attached pinger's direct and bottom return signals on the ship-provided PDR trace. Following each station, the CTD data were forwarded to another set of personal computers running both EG&G CTD post-processing 5.2 rev 2 software and custom software from WHOI (Millard and Yang, 1993). The raw data were edited, pressure sorted, scaled and pressure centered into 2 decibar bins for final data quality control and analysis. A first pass fit of CTD salinity and oxygen to water sample salinity and oxygen was performed. C.2.5. CTD Calibration Summary C.2.5.1.Pre-cruise Laboratory Calibration: The pressure, temperature, and conductivity sensors of CTD-9, CTD-8, ICTD-1338 and ICTD-1344 were calibrated at the Woods Hole Oceanographic Institution's CTD Calibration Laboratory in November 1995 directly before the I02 cruise began. OTMs used during the cruise were also calibrated at that time. PRESSURE AND TEMPERATURE CALIBRATIONS: The pressure, temperature, and conductivity sensors of CTD-9, CTD-8, ICTD-1344 and ICTD-1338 were calibrated at the Woods Hole Oceanographic Institution's CTD Calibration Laboratory in November 1995 directly before the I02 cruise began. OTMs used during the cruise were also calibrated at that time. Post cruise calibrations for all instruments were performed in April and May 1996. There was a strong case for applying pre-cruise calibrations to this data as they were considerably closer in time than the post-cruise calibrations to this cruise. Only calibrations of instruments used in the final data set are included here. Calibration runs for all instruments are available from the WHOI CTD group. Laboratory calibrations of the conductivity and oxygen cells are not included in this section as multiple regression fits of the ctd data to the rosette data yeilding more accurate descriptions of the data are discussed later. Special Notes on Primary Instrument CTD 9: Pressure calibrations: Pre-cruise laboratory calibrations were used for the final data load for stations collected with ctd 9. There was a .33 to .5 db shift over the 0- 7000db range between the pre and post calibrations. Different from other cruises, a single pressure bias term was used for the entire cruise for CTD 9. This term was set equal to the mean of a regression fit to all of the on deck pressure bias data and the original pre-cruise laboratory pressure bias term. Pressure Sensor Issues: The pressure reading of CTD 9 before each station varied from 0.5 to 1.5 dbars on deck and 5.0 to 6.5 when back on deck. It was discovered, post cruise, that there was, in fact, a real pressure historesis of the CTD 9 pressure cell induced by a huge temperature gradient characteristic of this part of the ocean. Pressure historesis: This problem took us through many an iteration during the processing of the ctd data. At sea, the pre-to-post cast pressure bias differential was attributed to a malfunction of the pressure sensor specific to the last 100m or so of the upcast during warming. In fact, the CTD was measuring 2db too shallow at depth as well as 4.5 db too deep back at the surface! It was particularly evident when overplotting with ictd 1344 showed the discrepancy. Finally, the solution was to apply a C1(D1) and an S1(S2) term to the pressure temperature sensor calibrations as described by Millard, Bond and Toole 1993. These additional terms, although part of the original equation for scaling pressure temperature, have not previously contributed significant adjustments to pressure data. However, we encountered an especially steep pressure/temperature gradient during this cruise and the application of these terms proved to be the solution. The values of these terms were worked out from a post-cruise laboratory dunk test of the ctd from a warm bath directly to a cold bath and visa versa. The C1(D1) term accommodates the lag associated with the thermal propagations from the end cap into the interior of the pressure temperature transducer. Implementing these terms reduced the down/up historesis of the pressure term to less than 1 db. Temperature Sensor Issues: Stations 1075 from the previous leg and station 1077 from this leg were collected in the same geographic location with two different CTD's. Comparison of these data show that station 1077, the first station on this cruise, was .002 degrees colder in the deep water. The consensus, after many comparisons of ictd, otm, and ctd calibration data was that the .002 difference could be real. Since there is virtually no difference between CTD 9 pre and post temperature calibrations, and since comparisons of all other simultaneously used profiling instruments vary within that .002 spectrum, it was decided to load the data with the original pre-cruise temperature calibrations. Conductivity Sensor Issues: CTD 9 exhibited a subtle, yet distinct, conductivity sensor historesis which is discussed in detail in the conductivity fitting section of the documentation. Even after compensating both for this and the pressure historesis, it was impossible to compensate for a digitizer problem which the conductivity cell also displayed. Final calibrated data still shows a mismatch in the down/up salinity that is at the +/- 1 conductivity digitizer unit level. KB45 - I02 - Instrument calibrations: CTD9 PRESSURE: * pre-cruise 1.8-C -.123343E+02 0.999335E-01 0.262451E-10 stdev=0.520752 (pr09d018.fit ... 12-02-95) meandev=-0.468648E-4 post-cruise 30.3C -.781314E+01 0.999537E-01 0.368139E-10 stdev=0.413239 (pr09d001.fit ... 04-23-96) meandev=-0.530802E-4 * actual bias used: -.118000E+02 PRESSURE TEMPERATURE: S1 T0 BIAS SLOPE * pre-cruise 2.9980E-07 1.8 .374183E02 -.917955E-02 stdev=.103365 (te09d002.fit ... 12-02-95) meandev=.101896E-5 * The D1 and S2 terms were derived from post-cruise laboratory dunk test! S2=0.1067 D1(C1)=-290.15 TEMPERATURE: * pre-cruise -.179140E+01 .496259E-03 .473093E-11 stdev=.319748E-03 (te09d002.fit ... 12-02-95) meandev=.371819E-06 A temperature lag of 0.150 was used for all CTD9 stations. post-cruise -.179157E+01 .496325E-03 .382716E-11 stdev=.277972E-03 (te09d010.fit ... 05-08-96) meandev=.720932E-06 CTD8 PRESSURE: * pre-cruise 1.5-C -55.9266 0.107747 -.230898E-08 stdev=.582264 (pr08d001.fit ... 9-09-95 really post mw95) PRESSURE TEMPERATURE: S1 S2 T0 BIAS SLOPE * pre-cruise 4.0859E-07 -0.35786 1.5 .121813E+03 -.268788E-02 stdev=.175228 (te08d001.fit ... 12-12-95) (note that a portion of station 1078 was loaded with bias of .135813E+03 to compensate for pressure/temp drop at 865 db. This correction altered calculated pressure by 5 db.) TEMPERATURE: * pre-cruise -.571426E-01 .499145E-03 .207133E-11 stdev=.374120E-03 (te08d002.fit ... 12-02-95) meandev=.867638E-06 A temperature lag of 0.240 seconds was used for all CTD 8 stations. post-cruise FAST TEMPERATURE: pre-cruise -.255953 .524715e-03 -.136373e-08 .145946E-13 stdev=.200573E-02 (te08d002.fit ... 12-02-95) meandev=.261125E-06 ICTD 1344 PRESSURE: pre-cruise 1.8-C 1.926020 .100003 -.201953E-08 .199206E-13 stdev=.500850 (pr44d001.fit ... 11-19-95) meandev=-.517319E-04 post-cruise 30.3C 0.170542E+01 0.999827E-01 -.141189E-08 0.148897E-13 stdev=.399364 (pr44d001.fit ... 05-09-96) meandev=.226782E-04 TEMPERATURE: pre-cruise -.863030E-02 .500618E-03 -.224525E-10 .220719E-15 stdev=.364214E-03 (te44d002.fit ... 11-19-95) meandev=.169501E-06 post-cruise -.107943E-01 0.500615E-03 -.235938E-10 0.233805E-15 stdev=.490960E-03 (te44d010.fit ... 05-06-96) meandev=.295274E-06 A temperature lag of 0.50 seconds was used for ICTD 1344. Fast Temp -.169302E-01 .523736E-03 -.113775E-08 .125944E-1 stdev=.167868E-02 (te44d002.fit ... 11-19-95) meandev=.718449E-07 A temperature lag of 0.250 seconds was used for this sensor. 2nd Temp -.715269E-02 .500605E-03 -.246339E-10 .257380E-15 stdev=.397759E-03 (te44d002.fit ... 11-19-95) meandev=.362196E-06 post-cruise -.704266E-02 0.500570E-03 -.244250E-10 0.256205E-15 stdev=.678849E-03 (te44d010.fit ... 05-06-96) meandev=.242432E-06 A temperature lag of 0.40 seconds was used for this sensor. C.2.5.2.At-sea Pressure Correction: The pressure reading of the CTD before each station varied from 0.5 to 1.5 dbars on deck. To correct for this bias, the amount was subtracted from the pressure bias term so the calculated pressure read zero at the sea surface at the start of each station. C.2.5.3.At-sea Conductivity Calibration: The CTD conductivity data were fit to the water sample conductivity as described in Millard and Yang, 1993. CTD-9's conductivity sensor appeared quite stable. The sensor drifted 0.003 pss over the first 140 stations. Conductivity Calibration Difficulties: The I02 data was processed many times with various methods in an effort to compensate for three very subtle issues which begged to be addressed: 1) historesis in conductivity sensor (discussed here) 2) historesis in the pressure transducer (discussed earlier) 3) problem with the digitizer of the conductivity cell Well into the processing of this data set it became evident that CTD 9, the primary instrument, had a problem with conductivity historesis. Multiple regression fits of the uptrace ctd data to the rosette salts, when applied to the downtrace ctd data, yielded a subtle, yet consistent, .001 discrepancy between the ctd and the rosette data between theta 1,3 and 3.0. This difference is not evident when applying the results of these fits to the uptrace ctd data. There is a subtle historesis in the conductivity sensor. In an effort to properly calibrate both the uptrace ctd salinity data in the rosette file and the downtrace ctd salinity profiles, different fits were used for each case. The calibrations for ctd salinities in the rosette file were derived from multiple regression fits of the uptrace ctd data to the rosette salts. The calibrations for ctd downtrace salinities were derived from multiple regression fits of downtrace ctd data to the rosette salts. Beyond this problem, was a problem with the digitizer of the ctd 9 conductivities. Final calibrated data still exibits a mismatch in the down/up salinity that is at the +/- 1 conductivity digitizer unit level which could not be compensated for. Brief summary of Conductivity Calibration Iterations: The CTD conductivity data were initially fit to the water sample conductivities as described in Millard and Yang, 1993. Primary CTD 9 stations (166 of 168) were initially treated as a single group. A multiple regression fit of CTD uptrace conductivity data to rosette salt data yielded an initial set of station groupings to use for conductivity calibrations. Fits to initial groupings yielded a data set with a distinct pressure dependence of the delta (ctd-ws) conductivities. Setting the beta term to 0 resolved most of that issue. Next, we discovered the pressure historesis problem and reloaded the data with the new D1 and S2 pressure temperature terms as well as the new mean pressure bias. We refit for conductivities with beta=0 and then discovered the subtle conductivity historesis. These fits to the uptrace data, however, with beta=0 are the conductivity calibrations which were applied to the final hydrographic water sample file. It was necessary, then, to extract down profile ctd conductivities to replace uptrace conductivities in the rosette file for doing new multiple regression fits specific to the downtrace data. When we did this, we discovered that with this new method, there was no pressure dependence of the delta conductivities, and that setting beta equal to zero was like compensating for a problem which did not exist in the downtrace ctd conductivity data. Once again, we refit our station groups with beta back to normal, fitting uptrace rosette data to downtrace ctd data. Results here, except for individual station adjustments, are the final conductivity calibrations applied to the downtrace ctd profiles. Initially, when processing this data, all processing was done in the PC DOS environment with existing programs. As questions arose and more involved details needed addressing, MATLAB procedures proved valuable for looking at the data. In the end, MATLAB was used to determine conductivity calibrations for this data set allowing comparisons of uptrace and downtrace ctd data in a single working environment. Development of these MATLAB procedures, however, required time and testing. In summary, fits to the uptrace conductivities were applied to the final SEA file, and fits of extracted downtrace conductivities to the water sample conductivities were applied to the downtrace ctd profiles. This is non- standard processing, but has provided the best information available for both the ctd profiles and final rosette file. A note about shallow stations 151-158. These stations appear not to match their rosette data as well as surrounding stations. However, the station group used to determine calibrations for these was 134-223 and stations before and after this group match with their rosette data and this data very well. Rather than force the ctd to match the rosette data for these stations, we put faith in the fact that the ctd remained constant and consistent across this shallow group of stations. RESULTS OF CONDUCTIVITY FITS: CTD #8: see special note on ctd 8 stations below: a) 78 -.351557E-01 0.100452E-02 (then add .002 psu) 79 -.351557E-01 0.100452E-02 CTD #9: primary instrument Fits of downtrace ctd data to uptrace rosette data applied to down profiles: Conductivity bias for all ctd 9 stations is -.013 determined from a multiple regression fit to all of the CTD9 data. a) fit stations 80 slope > 2000 st.dev.=.0007487 77 -.130000E-01 0.997904E-03 80 -.130000E-01 0.997904E-03 b) fit stations 81-109 slope > 2000 st.dev.=.0008664 81 -.130000E-01 0.997904E-03 82 -.130000E-01 0.997904E-03 83 -.130000E-01 0.997950E-03 (adj +.0015 add 4.6E-8) 84 -.130000E-01 0.997904E-03 85 -.130000E-01 0.997904E-03 86 -.130000E-01 0.997904E-03 87 -.130000E-01 0.997904E-03 88 -.130000E-01 0.997904E-03 89 -.130000E-01 0.997904E-03 90 -.130000E-01 0.997904E-03 91 -.130000E-01 0.997904E-03 92 -.130000E-01 0.997904E-03 93 -.130000E-01 0.997904E-03 94 -.130000E-01 0.997904E-03 95 -.130000E-01 0.997904E-03 96 -.130000E-01 0.997904E-03 97 -.130000E-01 0.997904E-03 98 -.130000E-01 0.997904E-03 99 -.130000E-01 0.997904E-03 100 -.130000E-01 0.997904E-03 101 -.130000E-01 0.997904E-03 102 -.130000E-01 0.997904E-03 103 -.130000E-01 0.997904E-03 104 -.130000E-01 0.997904E-03 105 -.130000E-01 0.997904E-03 106 -.130000E-01 0.997904E-03 107 -.130000E-01 0.997904E-03 108 -.130000E-01 0.997934E-03 (adj +.001 add 3E-8) 109 -.130000E-01 0.997934E-03 (adj +.001 add 3E-8) c) fit station 110 slope > 2000 st.dev.=.0007355 110 -.130000E-01 0.998058E-03 d) fit stations 111-135 slope > 2000 st.dev.=,000812 111 -.130000E-01 0.997925E-03 (adj +.001 add 3E-8) 112 -.130000E-01 0.997895E-03 113 -.130000E-01 0.997895E-03 114 -.130000E-01 0.997895E-03 115 -.130000E-01 0.997895E-03 116 -.130000E-01 0.997895E-03 117 -.130000E-01 0.997895E-03 118 -.130000E-01 0.997895E-03 119 -.130000E-01 0.997895E-03 120 -.130000E-01 0.997895E-03 121 -.130000E-01 0.997895E-03 122 -.130000E-01 0.997895E-03 123 -.130000E-01 0.997895E-03 124 -.130000E-01 0.997895E-03 125 -.130000E-01 0.997895E-03 126 -.130000E-01 0.997895E-03 127 -.130000E-01 0.997895E-03 128 -.130000E-01 0.997895E-03 129 -.130000E-01 0.997895E-03 130 -.130000E-01 0.997895E-03 131 -.130000E-01 0.997895E-03 132 -.130000E-01 0.997895E-03 133 -.130000E-01 0.997895E-03 134 -.130000E-01 0.997895E-03 135 -.130000E-01 0.997895E-03 e) fit stations 136-223 st.dep. slope > 2000 st.dev.=0009773 136 -.130000E-01 0.997922E-03 137 -.130000E-01 0.997872E-03 138 -.130000E-01 0.997873E-03 139 -.130000E-01 0.997924E-03 140 -.130000E-01 0.997924E-03 141 -.130000E-01 0.997925E-03 142 -.130000E-01 0.997926E-03 143 -.130000E-01 0.997926E-03 144 -.130000E-01 0.997927E-03 145 -.130000E-01 0.997928E-03 146 -.130000E-01 0.997929E-03 147 -.130000E-01 0.997929E-03 148 -.130000E-01 0.997930E-03 149 -.130000E-01 0.997931E-03 150 -.130000E-01 0.997931E-03 151 -.130000E-01 0.997932E-03 152 -.130000E-01 0.997933E-03 153 -.130000E-01 0.997933E-03 154 -.130000E-01 0.997934E-03 155 -.130000E-01 0.997935E-03 156 -.130000E-01 0.997936E-03 157 -.130000E-01 0.997936E-03 158 -.130000E-01 0.997937E-03 159 -.130000E-01 0.997938E-03 160 -.130000E-01 0.997938E-03 161 -.130000E-01 0.997939E-03 162 -.130000E-01 0.997940E-03 163 -.130000E-01 0.997940E-03 164 -.130000E-01 0.997941E-03 165 -.130000E-01 0.997942E-03 166 -.130000E-01 0.997942E-03 167 -.130000E-01 0.997943E-03 168 -.130000E-01 0.997944E-03 169 -.130000E-01 0.997945E-03 170 -.130000E-01 0.997945E-03 171 -.130000E-01 0.997946E-03 172 -.130000E-01 0.997947E-03 173 -.130000E-01 0.997947E-03 174 -.130000E-01 0.997948E-03 175 -.130000E-01 0.997949E-03 176 -.130000E-01 0.997949E-03 177 -.130000E-01 0.997950E-03 178 -.130000E-01 0.997951E-03 179 -.130000E-01 0.997952E-03 180 -.130000E-01 0.997952E-03 181 -.130000E-01 0.997953E-03 182 -.130000E-01 0.997954E-03 183 -.130000E-01 0.997954E-03 184 -.130000E-01 0.997955E-03 185 -.130000E-01 0.997956E-03 186 -.130000E-01 0.997956E-03 187 -.130000E-01 0.997957E-03 188 -.669766E-02 1.000345E-03 ictd 1344 189 -.130000E-01 0.997958E-03 190 -.130000E-01 0.997959E-03 f) re-fit stations 191-198 slope > 2000 st.dev.=.0007966 191 -.130000E-01 0.997938E-03 192 -.130000E-01 0.997938E-03 193 -.130000E-01 0.997938E-03 194 -.130000E-01 0.997938E-03 195 -.130000E-01 0.997938E-03 196 -.130000E-01 0.997938E-03 197 -.130000E-01 0.997938E-03 198 -.130000E-01 0.997938E-03 199 -.130000E-01 0.997965E-03 200 -.130000E-01 0.997966E-03 201 -.130000E-01 0.997967E-03 202 -.130000E-01 0.997967E-03 203 -.130000E-01 0.997968E-03 204 -.130000E-01 0.997969E-03 205 -.130000E-01 0.997970E-03 206 -.130000E-01 0.997970E-03 207 -.130000E-01 0.997971E-03 208 -.130000E-01 0.997972E-03 209 -.130000E-01 0.997972E-03 210 -.130000E-01 0.997973E-03 211 -.130000E-01 0.997974E-03 212 -.130000E-01 0.997974E-03 213 -.130000E-01 0.997975E-03 214 -.130000E-01 0.997976E-03 215 -.130000E-01 0.997977E-03 216 -.130000E-01 0.997977E-03 217 -.130000E-01 0.997978E-03 218 -.130000E-01 0.997979E-03 219 -.130000E-01 0.997979E-03 220 -.130000E-01 0.997980E-03 221 -.130000E-01 0.997981E-03 222 -.130000E-01 0.997981E-03 223 -.130000E-01 0.997982E-03 g) fit stations 224-226 slope > 2000 st.dev.=0008161 224 -.130000E-01 0.997945E-03 225 -.130000E-01 0.997945E-03 226 -.130000E-01 0.997945E-03 h) fit stations 227-244 st.dep. slope > 2000 st.dev.=.000925 227 -.130000E-01 0.998018E-03 228 -.130000E-01 0.998015E-03 229 -.130000E-01 0.998012E-03 230 -.130000E-01 0.998009E-03 231 -.130000E-01 0.998006E-03 232 -.130000E-01 0.998049E-03 (adj +.0015 ad 4.5E-8) 233 -.130000E-01 0.998001E-03 234 -.130000E-01 0.997998E-03 235 -.130000E-01 0.997995E-03 236 -.130000E-01 0.997992E-03 237 -.130000E-01 0.997989E-03 238 -.130000E-01 0.997986E-03 239 -.130000E-01 0.997984E-03 240 -.130000E-01 0.997981E-03 241 -.130000E-01 0.997978E-03 242 -.130000E-01 0.997975E-03 243 -.130000E-01 0.997972E-03 244 -.130000E-01 0.997969E-03 Fits of uptrace ctd data to uptrace rosette data applied to SEA file. CTD #8: 78 -.351557E-01 0.100452E-02 (then add .002 psu) 79 -.351557E-01 0.100452E-02 CTD #9: 8/24/97 fitting of stations 80-111 a) fit stations 80-83 slope & bias all / st.dep. slope > 1500 77 -.97646495E-02 0.99780168E-03 80 -.97646495E-02 0.99780168E-03 st. dev. = .000715 81 -.97646495E-02 0.99782430E-03 82 -.97646495E-02 0.99784693E-03 83 -.97646495E-02 0.99786955E-03 sta 84-92 fit full profile for bias & 99-103 station dep slope > 1500 st. dev. = .000715 b1) fit stations 84-92 99-103 slope & bias all / st.dep. slope > 1500 84 -.72365110E-02 0.99773304E-03 85 -.72365110E-02 0.99773458E-03 86 -.72365110E-02 0.99773613E-03 87 -.72365110E-02 0.99773768E-03 88 -.72365110E-02 0.99773923E-03 89 -.72365110E-02 0.99774078E-03 90 -.72365110E-02 0.99774233E-03 91 -.72365110E-02 0.99774387E-03 92 -.72365110E-02 0.99774542E-03 b2) fit stations 84-92 99-103 slope & bias all / st.dep. slope > 1500 99 -.72365110E-02 0.99775626E-03 100 -.72365110E-02 0.99775781E-03 101 -.72365110E-02 0.99775935E-03 102 -.72365110E-02 0.99776090E-03 103 -.72365110E-02 0.99776245E-03 c) fit stations 93-98 slope and bias all / slope > 1500 93 -.59222312E-02 0.99770399E-03 st. dev. = .000662 94 -.59222312E-02 0.99770399E-03 95 -.59222312E-02 0.99770399E-03 96 -.59222312E-02 0.99770399E-03 97 -.59222312E-02 0.99770399E-03 98 -.59222312E-02 0.99770399E-03 d) fit stations 104-105 slope and bias all / slope > 1500 104 -.60349899E-02 0.99770400E-03 st. dev. = .000584 105 -.60349899E-02 0.99770400E-03 e) fit stations 106-109 slope and bias all / st.dep.slope > 1500 (and apply fit of station 109 to 110 and 111) 106 -.22696049E-02 0.99755894E-03 st. dev. = .000756 107 -.22696049E-02 0.99757846E-03 108 -.22696049E-02 0.99759798E-03 109 -.22696049E-02 0.99761750E-03 110 -.22696049E-02 0.99761750E-03 111 -.22696049E-02 0.99761750E-03 sta 112-127 fit full profile for bias ; fit slope > 1500 112 -.633288E-02 0.997708E-03 st. dev. = .000786 113 -.633288E-02 0.997708E-03 114 -.633288E-02 0.997708E-03 115 -.633288E-02 0.997708E-03 116 -.633288E-02 0.997708E-03 117 -.633288E-02 0.997708E-03 118 -.633288E-02 0.997708E-03 119 -.633288E-02 0.997708E-03 120 -.633288E-02 0.997708E-03 121 -.633288E-02 0.997708E-03 122 -.633288E-02 0.997708E-03 123 -.633288E-02 0.997708E-03 124 -.633288E-02 0.997708E-03 125 -.633288E-02 0.997708E-03 126 -.633288E-02 0.997708E-03 127 -.633288E-02 0.997708E-03 10 July 1997 sta 137-151 fit full profile for bias station dep slope > 1500 stations 128-137 take cals of 137! 128 0.282178E-03 0.997512E-03 st. dev. = .000702 129 0.282178E-03 0.997512E-03 130 0.282178E-03 0.997512E-03 131 0.282178E-03 0.997512E-03 132 0.282178E-03 0.997512E-03 133 0.282178E-03 0.997512E-03 134 0.282178E-03 0.997512E-03 135 0.282178E-03 0.997512E-03 136 0.282178E-03 0.997512E-03 137 0.282178E-03 0.997512E-03 138 0.282178E-03 0.997515E-03 139 0.282178E-03 0.997518E-03 140 0.282178E-03 0.997521E-03 141 0.282178E-03 0.997524E-03 142 0.282178E-03 0.997528E-03 143 0.282178E-03 0.997531E-03 144 0.282178E-03 0.997534E-03 145 0.282178E-03 0.997537E-03 146 0.282178E-03 0.997540E-03 147 0.282178E-03 0.997543E-03 148 0.282178E-03 0.997546E-03 149 0.282178E-03 0.997550E-03 150 0.282178E-03 0.997553E-03 September 1997: sta 151-158 fit full profile for bias station dep slope > 1500 151 -.469850E-02 0.997714E-03 st. dev. = .000683 152 -.469850E-02 0.997708E-03 153 -.469850E-02 0.997702E-03 154 -.469850E-02 0.997697E-03 155 -.469850E-02 0.997691E-03 156 -.469850E-02 0.997685E-03 157 -.469850E-02 0.997680E-03 158 -.469850E-02 0.997674E-03 sta 159-166 fit full profile for bias station dep slope > 1500 159 0.660155E-03 0.997536E-03 st. dev. = .000679 160 0.660155E-03 0.997536E-03 161 0.660155E-03 0.997536E-03 162 0.660155E-03 0.997536E-03 163 0.660155E-03 0.997536E-03 164 0.660155E-03 0.997536E-03 165 0.660155E-03 0.997536E-03 166 0.660155E-03 0.997536E-03 sta 167-171 fit full profile for bias station dep slope > 1500 167 -.774001E-02 0.997788E-03 st. dev. = .000831 168 -.774001E-02 0.997780E-03 169 -.774001E-02 0.997773E-03 170 -.774001E-02 0.997765E-03 171 -.774001E-02 0.997757E-03 sta 171-178 fit full profile for bias station dep slope > 1500 apply to stations 172-177! 172 -.318309E-03 0.997545E-03 st. dev. = .000741 173 -.318309E-03 0.997552E-03 174 -.318309E-03 0.997559E-03 175 -.318309E-03 0.997565E-03 176 -.318309E-03 0.997572E-03 177 -.318309E-03 0.997579E-03 sta 178-186 fit full profile for bias station dep slope > 1500 apply to stations 178-182! 178 -.415914E-02 0.997709E-03 st. dev. = .000777 179 -.415914E-02 0.997701E-03 180 -.415914E-02 0.997694E-03 181 -.415914E-02 0.997686E-03 182 -.415914E-02 0.997678E-03 sta 186-206 fit full profile for bias station dep slope > 1500 station 183-185 extend station dependence backward from 186! 183 -.615559E-02 0.997685E-03 st. dev. = .000727 184 -.615559E-02 0.997690E-03 185 -.615559E-02 0.997695E-03 186 -.615559E-02 0.997700E-03 187 -.615559E-02 0.997705E-03 188 -.669766E-02 1.000345E-03 ictd 1344 189 -.615559E-02 0.997715E-03 190 -.615559E-02 0.997720E-03 191 -.615559E-02 0.997725E-03 192 -.615559E-02 0.997730E-03 193 -.615559E-02 0.997735E-03 194 -.615559E-02 0.997740E-03 195 -.615559E-02 0.997745E-03 196 -.615559E-02 0.997751E-03 197 -.615559E-02 0.997756E-03 198 -.615559E-02 0.997761E-03 199 -.615559E-02 0.997766E-03 200 -.615559E-02 0.997771E-03 201 -.615559E-02 0.997776E-03 202 -.615559E-02 0.997781E-03 203 -.615559E-02 0.997786E-03 204 -.615559E-02 0.997791E-03 205 -.615559E-02 0.997796E-03 206 -.615559E-02 0.997801E-03 207 -.615559E-02 0.997801E-03 sta 208-215 fit full profile for bias fit slope > 1500 208 -.655756E-02 0.997758E-03 st. dev. = .000787 209 -.655756E-02 0.997758E-03 210 -.655756E-02 0.997758E-03 211 -.655756E-02 0.997758E-03 212 -.655756E-02 0.997758E-03 213 -.655756E-02 0.997758E-03 214 -.655756E-02 0.997758E-03 215 -.655756E-02 0.997758E-03 sta 115-232 fit full profile for bias station dep slope > 1500 apply to 216-230 (except 224 & 225) 216 -.669768E-02 0.997767E-03 st. dev. = .000684 217 -.669768E-02 0.997772E-03 218 -.669768E-02 0.997777E-03 219 -.669768E-02 0.997781E-03 220 -.669768E-02 0.997786E-03 221 -.669768E-02 0.997791E-03 222 -.669768E-02 0.997795E-03 223 -.669768E-02 0.997800E-03 226 -.669768E-02 0.997814E-03 227 -.669768E-02 0.997819E-03 228 -.669768E-02 0.997824E-03 229 -.669768E-02 0.997828E-03 230 -.669768E-02 0.997833E-03 sta 224-225 fit full profile for bias fit slope > 1500 224 -.889504E-02 0.997814E-03 st. dev. = .000501 225 -.889504E-02 0.997814E-03 sta 231-240 fit full profile for bias station dep slope > 1500 station 241-244 set to same as 240 231 -.629043E-02 0.997846E-03 st. dev. = .001842 232 -.629043E-02 0.997835E-03 233 -.629043E-02 0.997823E-03 234 -.629043E-02 0.997812E-03 235 -.629043E-02 0.997800E-03 236 -.629043E-02 0.997789E-03 237 -.629043E-02 0.997778E-03 238 -.629043E-02 0.997766E-03 239 -.629043E-02 0.997755E-03 240 -.629043E-02 0.997743E-03 241 -.629043E-02 0.997743E-03 242 -.629043E-02 0.997743E-03 243 -.629043E-02 0.997743E-03 244 -.629043E-02 0.997743E-03 Special Cases for stations 78, 79 and 188: CTD #8: Theta/S plots of CTD 8 stations 78 and 79 are comparable to surrounding CTD 9 stations. These CTD #8 stations were processed at sea. These stations are as they were at cruise end. 78 -.351557E-01 0.100452E-02 (then add .002 psu) 79 -.351557E-01 0.100452E-02 STA 1078 has two pres/temp bias cals applied and salt manually adjusted. The alternate pres/temp bias is to compensate for a 14 degpres/temp drop at 865 db.. It also, however, alters the calculated pressure by 5 db. .121813E+03 (c01 bias) .135813E+03 (c02 bias) The down profile was scaled with each cal file (C01 and C02). It was then cut and pasted to make one whole file. Up cast is scaled with the second cal (C02); no cut and paste needed. However, resulting salt was too low. We manually add +.002 psu to .ctp .prs and .scl files which became standard input for the final data set. ICTD 1344: Station 188 Station 188 was processed from the ICTD 1344 data since the sensor caps were left on during CTD 9 sta 188. Scans in the rosette file for sta 188 were also extracted from the ictd. Conductivity calibrations were derived from a fit to the station 188 rosette data. WATER SAMPLE SALINITY AND OXYGEN DATA: A complete description of the water sample dissolved oxygen and salinity measurement techniques used during this cruise is presented by Knapp et al. (1990). As described in this report, samples were collected for the analysis of dissolved oxygen and salinity from each of the 24 ten-liter bottles tripped on the upcast of each CTD station, in accordance with the recommendations of the WOCE Hydrographic Office. The vertical distribution of these samples was a compromise between the need to obtain deep samples for the calibration of the CTD conductivity and oxygen sensors and the requirement to define the characteristics of the water masses by the distributions of the various measured parameters. C.2.5.4. At-sea Oxygen Calibrations: The CTD oxygen data were fit to the water sample oxygens to determine the six parameters of the oxygen algorithm (Millard and Yang, 1993). As with conductivity, the stations were fit when excessive drift in the sensor was noted. CTD-9's oxygen data, using the same six parameters to calculate oxygen show a drift of only 0.1 ml/l over the first 140 stations. C.2.6. Quality Control Notes For 2 Decibar CTD Data and .SEA Files Pressure difference: On deck difference in CTD-9's pressure between the start and end of cast was consistently close to 4.5 dbars. Comparing the pressure data with the ICTD logging in memory mode, it appears the 4.5 dbar change is occurring as the CTD is warming on the uptrace in the last few hundred meters. CTD-9 temperature and OTM-1326 difference: Difference in temperature at depth appears to have remained constant between these two instruments indicating there has been no temperature shift greater than 0.002šC since the OTM began collecting data on station 1090. Station 1078, CTD-8: The oxygen sensor assembly failed during downtrace at 875 dbar. Water had leaked into the assembly molding. Pressure temperature dropped 14°C, also at 875 dbars. While the oxygen data were not recoverable, the pressure temperature data were corrected by increasing the temperature after the drop by 14°C. The resulting corrected pressure temperature changed the calculated pressure by 5 dbars. Station 1079, CTD-8: The oxygen assembly from ICTD-1344 was put on to CTD-8, however oxygen current and oxygen temperature still did not look good. The oxygen data were unusable. Pressure temperature dropped again just at completion of the station. CTD-8 was removed from the package and replaced with CTD-9. Station 1090, CTD-9: OTM-1326 was connected to CTD-9 and successfully collected data through the end of the cruise. Stations 1100, 1101, 1102, CTD-9: Conductivity jumped low by 0.008 mmho during downtrace, most noticeably below 2.5°C potential temperature. Uptrace appeared fine. Station 1110, CTD-9: Conductivity drifted low by 0.005 mmho during downtrace, most noticeably below 2.5°C potential temperature. Station 1111 to 1174, ICTD-1338: ICTD-1338 was attached to package and successfully recorded and downloaded data from its internal memory. Station 1175 to end of cruise, ICTD-1344: ICTD-1338 was taken off package and replaced with ICTD-1344 and OTM-1372 before station 1175 and used for the remainder of the cruise. C.3. Bottle Salinity Analysis A complete description of the salinity measurement techniques used during this cruise is presented in Knapp et al (1990). All measurements were made in a temperature controlled (23°C) van. The water sample salinities were collected by one of the CTD watch standers in 200 ml bottles with removable polyethylene inserts and caps. Bottles were rinsed three times, filled to the shoulder and securely capped. Samples were then allowed to reach laboratory temperature, and then measured with a Guildline Autosal Model 8400B salinometer (WHOI no. 11) that was standardized daily with IAPSO Standard Sea Water Batch P- 128, dated 18 July 1995. Daily fluctuations of the Autosal standardization were usually less than 0.0002. Long-term drift of the instrument, from the beginning to the end of the cruise was approximately 0.001. The salinity measurements have an accuracy of 0.002. -------------------------------------------------------------------------------- Jan 7 '96 s77t156.sea salts, oxygen, (sta 1077 to 1156) nutrients (sta 1077 to 1156) cfc (sta 1078 to 1156) (duplicates have mistakenly been labeled bad) co2 without quality word (sta 1078 to 1156) (sta 1126 corrected) File does not include final CTD salt and oxygen Sta 1077 has been reordered from shallowest to deepest. Sta 1077 does not have the cfcs or co2 merged in. Sta 1078 CTD pressure has been corrected. The merging program insists the files being used be ordered from deep to shallow. When reordering is necessary, the whole line of bottle and ctd data is swapped, not just part of it thereby keeping the bottle, and ctd data in tact. Sta 1104 put bottles 3 and 4 in reverse order so that pressure is decreasing. Sta 1107 put bottles 5 and 6 in reverse order so that pressure is decreasing. Sta 1127 had pylon problems. Bottle 22 was tripped at 900db and bottles 23 to 31 are believed to have tripped at 900 as well. It is not clear where the remaining bottles tripped and two of them were leakers. Bottles 32 to 36 were removed from data set. Tags were added to the file for the extra 8 bottles at 900db. The tags are copies of the bottle #22's tag with a .1db change in pressure for each tag to keep each tag distinct. Jan 19 '96 s157t199.sea salts, oxygen, (sta 1157 to 1199) nutrients (sta 1157 to 1199) cfc (sta 1157 to 1199) co2 without quality word (sta 1157 to 1199) File does not include final CTD salt and oxygen Jan 22 '96 s200t244.sea salts, oxygen, (sta 1200 to 1244) nutrients (sta 1200 to 1244) cfc (sta 1200 to 1244) co2 without quality word (sta 1200 to 1244) File does not include final CTD salt and oxygen Jan 22 '96 I2.sea all the above sea files appended into one file AND the station numbers have been changed to their true numbers (from 77 through 244 to 1077 through 1244) C.4. Dissolved Oxygen Analysis A complete description of the dissolved oxygen measurement techniques used during this cruise is presented in Knapp et al (1990). All measurements were made in a temperature controlled (23°C) van. Dissolved oxygen samples were also collected by a designated CTD watch stander from each watch. Aliquots of these samples were titrated within fourteen hours of collection. All oxygen reagents were prepared at WHOI in August, 1994, and loaded on the ship when she sailed from Woods Hole. A single batch of sodium bi-iodate standard was also prepared and loaded on the ship at that time. Post-cruise comparison of this standard will be made with a freshly prepared standard when the equipment returns to Woods Hole in March 1996, but based on comparisons made with oxygens measured on earlier legs of the expedition, it does not appear that this standard (17 months old at the end of the cruise) has deteriorated. Accuracy of these dissolved oxygen measurements is 0.5%. RESULTS OF OXYGEN FITS: Oxygens were fit in station groupings according to similar characteristics. Groupings were derived from a plot of delta oxygen (ctd-ws) vs. station number where all stations were scaled to a single set of calibrations. The standard deviation of this plot for data below 1000db was 0.0556.Regression fits were typically done to 2.8 standard deviations unless a tighter criteria was required to obtain acceptable results. After arriving at valid oxygen calibration terms, the lag term for all stations was increased to 10 seconds in an attempt to accommodate an incredibly steep temperature gradient in the shallow water. High quality oxygen profiles were collected for all but 3 stations on this cruise. CTD 8 stations 77 and 78 have no oxygen data. The oxygen sensor assembly failed on station 77 during downtrace at 875 dbar. Water had leaked into the assembly molding. Pressure temperature dropped 14 deg. C, also at 875 dbars. While the oxygen data were not recoverable, the pressure temperature data were corrected by increasing the temperature after the drop by 14 degrees. The resulting corrected pressure temperature changed the calculated pressure by 5 dbars. On station 79, the oxygen assembly from ICTD-1344 was put on to CTD-8. However oxygen current and oxygen temperature still looked ominous and the oxygen data were unusable. Pressure temperature dropped again just at completion of station 79. CTD-8 was no longer used. Station 188 (whose profile was processed from ICTD 1344 instead of CTD 9) has no oxygen data. The standard deviation of calibrated CTD oxygens minus water sample oxygens below 1000 db for the entire cruise was 0.0365 (ml/l). There is no overall pressure dependent shape to the delta oxygen (ctd-ws) plot. Station groupings and fitting results are as follows: a) fit stations 80-106 to 2.8 st. deviations using 833/949 pts std=.029205 apply to 77,80-106 sta bias slope pcor tcor wt lag 77 -.900000E-02 0.139400E-02 0.146500E-03 -.294000E-01 0.620000E+00 0.100000E+02 80 -.900000E-02 0.139400E-02 0.146500E-03 -.294000E-01 0.620000E+00 0.100000E+02 81 -.900000E-02 0.139400E-02 0.146500E-03 -.294000E-01 0.620000E+00 0.100000E+02 82 -.900000E-02 0.139400E-02 0.146500E-03 -.294000E-01 0.620000E+00 0.100000E+02 83 -.900000E-02 0.139400E-02 0.146500E-03 -.294000E-01 0.620000E+00 0.100000E+02 84 -.900000E-02 0.139400E-02 0.146500E-03 -.294000E-01 0.620000E+00 0.100000E+02 85 -.900000E-02 0.139400E-02 0.146500E-03 -.294000E-01 0.620000E+00 0.100000E+02 86 -.900000E-02 0.139400E-02 0.146500E-03 -.294000E-01 0.620000E+00 0.100000E+02 87 -.900000E-02 0.139400E-02 0.146500E-03 -.294000E-01 0.620000E+00 0.100000E+02 88 -.900000E-02 0.139400E-02 0.146500E-03 -.294000E-01 0.620000E+00 0.100000E+02 89 -.900000E-02 0.139400E-02 0.146500E-03 -.294000E-01 0.620000E+00 0.100000E+02 90 -.900000E-02 0.139400E-02 0.146500E-03 -.294000E-01 0.620000E+00 0.100000E+02 91 -.900000E-02 0.139400E-02 0.146500E-03 -.294000E-01 0.620000E+00 0.100000E+02 92 -.900000E-02 0.139400E-02 0.146500E-03 -.294000E-01 0.620000E+00 0.100000E+02 93 -.900000E-02 0.139400E-02 0.146500E-03 -.294000E-01 0.620000E+00 0.100000E+02 94 -.900000E-02 0.139400E-02 0.146500E-03 -.294000E-01 0.620000E+00 0.100000E+02 95 -.900000E-02 0.139400E-02 0.146500E-03 -.294000E-01 0.620000E+00 0.100000E+02 96 -.900000E-02 0.139400E-02 0.146500E-03 -.294000E-01 0.620000E+00 0.100000E+02 97 -.900000E-02 0.139400E-02 0.146500E-03 -.294000E-01 0.620000E+00 0.100000E+02 98 -.900000E-02 0.139400E-02 0.146500E-03 -.294000E-01 0.620000E+00 0.100000E+02 99 -.900000E-02 0.139400E-02 0.146500E-03 -.294000E-01 0.620000E+00 0.100000E+02 100 -.900000E-02 0.139400E-02 0.146500E-03 -.294000E-01 0.620000E+00 0.100000E+02 101 -.900000E-02 0.139400E-02 0.146500E-03 -.294000E-01 0.620000E+00 0.100000E+02 102 -.900000E-02 0.139400E-02 0.146500E-03 -.294000E-01 0.620000E+00 0.100000E+02 103 -.900000E-02 0.139400E-02 0.146500E-03 -.294000E-01 0.620000E+00 0.100000E+02 104 -.900000E-02 0.139400E-02 0.146500E-03 -.294000E-01 0.620000E+00 0.100000E+02 105 -.900000E-02 0.139400E-02 0.146500E-03 -.294000E-01 0.620000E+00 0.100000E+02 106 -.900000E-02 0.139400E-02 0.146500E-03 -.294000E-01 0.620000E+00 0.100000E+02 b) fit stations 107-110 to 2.8 st. deviations using 127/139 pts std=.02262 sta bias slope pcor tcor wt lag 107 -.600000E-02 0.137900E-02 0.146100E-03 -.303000E-01 0.530000E+00 0.100000E+02 108 -.600000E-02 0.137900E-02 0.146100E-03 -.303000E-01 0.530000E+00 0.100000E+02 109 -.600000E-02 0.137900E-02 0.146100E-03 -.303000E-01 0.530000E+00 0.100000E+02 110 -.600000E-02 0.137900E-02 0.146100E-03 -.303000E-01 0.530000E+00 0.100000E+02 c) fit stations 111-114 to 2.5 st. deviations using 128/140 pts std=.02342 sta bias slope pcor tcor wt lag 111 -.900000E-02 0.141000E-02 0.144100E-03 -.296000E-01 0.670000E+00 0.100000E+02 112 -.900000E-02 0.141000E-02 0.144100E-03 -.296000E-01 0.670000E+00 0.100000E+02 113 -.900000E-02 0.141000E-02 0.144100E-03 -.296000E-01 0.670000E+00 0.100000E+02 114 -.900000E-02 0.141000E-02 0.144100E-03 -.296000E-01 0.670000E+00 0.100000E+02 115 -.900000E-02 0.141000E-02 0.144100E-03 -.296000E-01 0.670000E+00 0.100000E+02 d) fit stations 116-121 to 2.8 st. deviations using 177/202 pts std=.01996 fitting for station dependent bias term. sta bias slope pcor tcor wt lag 116 -.250000E-02 0.139500E-02 0.143400E-03 -.291000E-01 0.680000E+00 0.100000E+02 117 -.220000E-02 0.139500E-02 0.143400E-03 -.291000E-01 0.680000E+00 0.100000E+02 118 -.200000E-02 0.139500E-02 0.143400E-03 -.291000E-01 0.680000E+00 0.100000E+02 119 -.170000E-02 0.139500E-02 0.143400E-03 -.291000E-01 0.680000E+00 0.100000E+02 120 -.150000E-02 0.139500E-02 0.143400E-03 -.291000E-01 0.680000E+00 0.100000E+02 121 -.120000E-02 0.139500E-02 0.143400E-03 -.291000E-01 0.680000E+00 0.100000E+02 e) fit stations 122-126 to 2.0 st. deviations using 135/169 pts std=.01400 sta bias slope pcor tcor wt lag 122 -.400000E-02 0.140100E-02 0.144500E-03 -.292000E-01 0.700000E+00 0.100000E+02 123 -.400000E-02 0.140100E-02 0.144500E-03 -.292000E-01 0.700000E+00 0.100000E+02 124 -.400000E-02 0.140100E-02 0.144500E-03 -.292000E-01 0.700000E+00 0.100000E+02 125 -.400000E-02 0.140100E-02 0.144500E-03 -.292000E-01 0.700000E+00 0.100000E+02 126 -.400000E-02 0.140100E-02 0.144500E-03 -.292000E-01 0.700000E+00 0.100000E+02 f) fit stations 127-138 to 2.5 st. deviations using 355/414 pts std=.01936 sta bias slope pcor tcor wt lag 127 -.300000E-02 0.138600E-02 0.144200E-03 -.287000E-01 0.690000E+00 0.100000E+02 128 -.300000E-02 0.138600E-02 0.144200E-03 -.287000E-01 0.690000E+00 0.100000E+02 129 -.300000E-02 0.138600E-02 0.144200E-03 -.287000E-01 0.690000E+00 0.100000E+02 130 -.300000E-02 0.138600E-02 0.144200E-03 -.287000E-01 0.690000E+00 0.100000E+02 131 -.300000E-02 0.138600E-02 0.144200E-03 -.287000E-01 0.690000E+00 0.100000E+02 132 -.300000E-02 0.138600E-02 0.144200E-03 -.287000E-01 0.690000E+00 0.100000E+02 133 -.300000E-02 0.138600E-02 0.144200E-03 -.287000E-01 0.690000E+00 0.100000E+02 134 -.300000E-02 0.138600E-02 0.144200E-03 -.287000E-01 0.690000E+00 0.100000E+02 135 -.300000E-02 0.138600E-02 0.144200E-03 -.287000E-01 0.690000E+00 0.100000E+02 136 -.300000E-02 0.138600E-02 0.144200E-03 -.287000E-01 0.690000E+00 0.100000E+02 137 -.300000E-02 0.138600E-02 0.144200E-03 -.287000E-01 0.690000E+00 0.100000E+02 138 -.300000E-02 0.138600E-02 0.144200E-03 -.287000E-01 0.690000E+00 0.100000E+02 g) fit stations 139-144 to 2.5 st. deviations using 178/208 pts std=.02282 sta bias slope pcor tcor wt lag 139 -.500000E-02 0.141200E-02 0.144100E-03 -.286000E-01 0.720000E+00 0.100000E+02 140 -.500000E-02 0.141200E-02 0.144100E-03 -.286000E-01 0.720000E+00 0.100000E+02 141 -.500000E-02 0.141200E-02 0.144100E-03 -.286000E-01 0.720000E+00 0.100000E+02 142 -.500000E-02 0.141200E-02 0.144100E-03 -.286000E-01 0.720000E+00 0.100000E+02 143 -.500000E-02 0.141200E-02 0.144100E-03 -.286000E-01 0.720000E+00 0.100000E+02 144 -.500000E-02 0.141200E-02 0.144100E-03 -.286000E-01 0.720000E+00 0.100000E+02 h) fit stations 145-155 to 2.5 st. deviations using 255/324 pts std=.02000 sta bias slope pcor tcor wt lag 145 -.700000E-02 0.144100E-02 0.142900E-03 -.295000E-01 0.670000E+00 0.100000E+02 146 -.700000E-02 0.144100E-02 0.142900E-03 -.295000E-01 0.670000E+00 0.100000E+02 147 -.700000E-02 0.144100E-02 0.142900E-03 -.295000E-01 0.670000E+00 0.100000E+02 148 -.700000E-02 0.144100E-02 0.142900E-03 -.295000E-01 0.670000E+00 0.100000E+02 149 -.700000E-02 0.144100E-02 0.142900E-03 -.295000E-01 0.670000E+00 0.100000E+02 150 -.700000E-02 0.144100E-02 0.142900E-03 -.295000E-01 0.670000E+00 0.100000E+02 151 -.700000E-02 0.144100E-02 0.142900E-03 -.295000E-01 0.670000E+00 0.100000E+02 152 -.700000E-02 0.144100E-02 0.142900E-03 -.295000E-01 0.670000E+00 0.100000E+02 153 -.700000E-02 0.144100E-02 0.142900E-03 -.295000E-01 0.670000E+00 0.100000E+02 154 -.700000E-02 0.144100E-02 0.142900E-03 -.295000E-01 0.670000E+00 0.100000E+02 155 -.700000E-02 0.144100E-02 0.142900E-03 -.295000E-01 0.670000E+00 0.100000E+02 i) fit stations 156-191 to 2.5 st. deviations using 897/1085 pts std=.02957 sta bias slope pcor tcor wt lag 156 -.800000E-02 0.143700E-02 0.142600E-03 -.294000E-01 0.730000E+00 0.100000E+02 157 -.800000E-02 0.143700E-02 0.142600E-03 -.294000E-01 0.730000E+00 0.100000E+02 158 -.800000E-02 0.143700E-02 0.142600E-03 -.294000E-01 0.730000E+00 0.100000E+02 159 -.800000E-02 0.143700E-02 0.142600E-03 -.294000E-01 0.730000E+00 0.100000E+02 160 -.800000E-02 0.143700E-02 0.142600E-03 -.294000E-01 0.730000E+00 0.100000E+02 161 -.800000E-02 0.143700E-02 0.142600E-03 -.294000E-01 0.730000E+00 0.100000E+02 162 -.800000E-02 0.143700E-02 0.142600E-03 -.294000E-01 0.730000E+00 0.100000E+02 163 -.800000E-02 0.143700E-02 0.142600E-03 -.294000E-01 0.730000E+00 0.100000E+02 164 -.800000E-02 0.143700E-02 0.142600E-03 -.294000E-01 0.730000E+00 0.100000E+02 165 -.800000E-02 0.143700E-02 0.142600E-03 -.294000E-01 0.730000E+00 0.100000E+02 166 -.800000E-02 0.143700E-02 0.142600E-03 -.294000E-01 0.730000E+00 0.100000E+02 167 -.800000E-02 0.143700E-02 0.142600E-03 -.294000E-01 0.730000E+00 0.100000E+02 168 -.800000E-02 0.143700E-02 0.142600E-03 -.294000E-01 0.730000E+00 0.100000E+02 169 -.800000E-02 0.143700E-02 0.142600E-03 -.294000E-01 0.730000E+00 0.100000E+02 170 -.800000E-02 0.143700E-02 0.142600E-03 -.294000E-01 0.730000E+00 0.100000E+02 171 -.800000E-02 0.143700E-02 0.142600E-03 -.294000E-01 0.730000E+00 0.100000E+02 172 -.800000E-02 0.143700E-02 0.142600E-03 -.294000E-01 0.730000E+00 0.100000E+02 173 -.800000E-02 0.143700E-02 0.142600E-03 -.294000E-01 0.730000E+00 0.100000E+02 174 -.800000E-02 0.143700E-02 0.142600E-03 -.294000E-01 0.730000E+00 0.100000E+02 175 -.800000E-02 0.143700E-02 0.142600E-03 -.294000E-01 0.730000E+00 0.100000E+02 176 -.800000E-02 0.143700E-02 0.142600E-03 -.294000E-01 0.730000E+00 0.100000E+02 177 -.800000E-02 0.143700E-02 0.142600E-03 -.294000E-01 0.730000E+00 0.100000E+02 178 -.800000E-02 0.143700E-02 0.142600E-03 -.294000E-01 0.730000E+00 0.100000E+02 179 -.800000E-02 0.143700E-02 0.142600E-03 -.294000E-01 0.730000E+00 0.100000E+02 180 -.800000E-02 0.143700E-02 0.142600E-03 -.294000E-01 0.730000E+00 0.100000E+02 181 -.800000E-02 0.143700E-02 0.142600E-03 -.294000E-01 0.730000E+00 0.100000E+02 182 -.800000E-02 0.143700E-02 0.142600E-03 -.294000E-01 0.730000E+00 0.100000E+02 183 -.800000E-02 0.143700E-02 0.142600E-03 -.294000E-01 0.730000E+00 0.100000E+02 184 -.800000E-02 0.143700E-02 0.142600E-03 -.294000E-01 0.730000E+00 0.100000E+02 185 -.800000E-02 0.143700E-02 0.142600E-03 -.294000E-01 0.730000E+00 0.100000E+02 186 -.800000E-02 0.143700E-02 0.142600E-03 -.294000E-01 0.730000E+00 0.100000E+02 187 -.800000E-02 0.143700E-02 0.142600E-03 -.294000E-01 0.730000E+00 0.100000E+02 189 -.800000E-02 0.143700E-02 0.142600E-03 -.294000E-01 0.730000E+00 0.100000E+02 190 -.800000E-02 0.143700E-02 0.142600E-03 -.294000E-01 0.730000E+00 0.100000E+02 191 -.800000E-02 0.143700E-02 0.142600E-03 -.294000E-01 0.730000E+00 0.100000E+02 j) fit stations 192-197 to 2.0 st. deviations using 116/181 pts std=.02331 sta bias slope pcor tcor wt lag 192 -.140000E-01 0.142800E-02 0.148100E-03 -.288000E-01 0.760000E+00 0.100000E+02 193 -.140000E-01 0.142800E-02 0.148100E-03 -.288000E-01 0.760000E+00 0.100000E+02 194 -.140000E-01 0.142800E-02 0.148100E-03 -.288000E-01 0.760000E+00 0.100000E+02 195 -.140000E-01 0.142800E-02 0.148100E-03 -.288000E-01 0.760000E+00 0.100000E+02 196 -.140000E-01 0.142800E-02 0.148100E-03 -.288000E-01 0.760000E+00 0.100000E+02 197 -.140000E-01 0.142800E-02 0.148100E-03 -.288000E-01 0.760000E+00 0.100000E+02 k) fit stations 198-214 to 2.5 st. deviations using 413/547 pts std=.03565 sta bias slope pcor tcor wt lag 198 -.600000E-02 0.139500E-02 0.146800E-03 -.289000E-01 0.670000E+00 0.100000E+02 199 -.600000E-02 0.139500E-02 0.146800E-03 -.289000E-01 0.670000E+00 0.100000E+02 200 -.600000E-02 0.139500E-02 0.146800E-03 -.289000E-01 0.670000E+00 0.100000E+02 201 -.600000E-02 0.139500E-02 0.146800E-03 -.289000E-01 0.670000E+00 0.100000E+02 202 -.600000E-02 0.139500E-02 0.146800E-03 -.289000E-01 0.670000E+00 0.100000E+02 203 -.600000E-02 0.139500E-02 0.146800E-03 -.289000E-01 0.670000E+00 0.100000E+02 204 -.600000E-02 0.139500E-02 0.146800E-03 -.289000E-01 0.670000E+00 0.100000E+02 205 -.600000E-02 0.139500E-02 0.146800E-03 -.289000E-01 0.670000E+00 0.100000E+02 206 -.600000E-02 0.139500E-02 0.146800E-03 -.289000E-01 0.670000E+00 0.100000E+02 207 -.600000E-02 0.139500E-02 0.146800E-03 -.289000E-01 0.670000E+00 0.100000E+02 208 -.600000E-02 0.139500E-02 0.146800E-03 -.289000E-01 0.670000E+00 0.100000E+02 209 -.600000E-02 0.139500E-02 0.146800E-03 -.289000E-01 0.670000E+00 0.100000E+02 210 -.600000E-02 0.139500E-02 0.146800E-03 -.289000E-01 0.670000E+00 0.100000E+02 211 -.600000E-02 0.139500E-02 0.146800E-03 -.289000E-01 0.670000E+00 0.100000E+02 212 -.600000E-02 0.139500E-02 0.146800E-03 -.289000E-01 0.670000E+00 0.100000E+02 213 -.600000E-02 0.139500E-02 0.146800E-03 -.289000E-01 0.670000E+00 0.100000E+02 214 -.600000E-02 0.139500E-02 0.146800E-03 -.289000E-01 0.670000E+00 0.100000E+02 l) fit stations 215-223 to 2.5 st. deviations using 175/226 pts std=.04467 sta bias slope pcor tcor wt lag 215 0.200000E-02 0.136800E-02 0.145200E-03 -.287000E-01 0.680000E+00 0.100000E+02 216 0.200000E-02 0.136800E-02 0.145200E-03 -.287000E-01 0.680000E+00 0.100000E+02 217 0.200000E-02 0.136800E-02 0.145200E-03 -.287000E-01 0.680000E+00 0.100000E+02 218 0.200000E-02 0.136800E-02 0.145200E-03 -.287000E-01 0.680000E+00 0.100000E+02 219 0.200000E-02 0.136800E-02 0.145200E-03 -.287000E-01 0.680000E+00 0.100000E+02 220 0.200000E-02 0.136800E-02 0.145200E-03 -.287000E-01 0.680000E+00 0.100000E+02 221 0.200000E-02 0.136800E-02 0.145200E-03 -.287000E-01 0.680000E+00 0.100000E+02 222 0.200000E-02 0.136800E-02 0.145200E-03 -.287000E-01 0.680000E+00 0.100000E+02 223 0.200000E-02 0.136800E-02 0.145200E-03 -.287000E-01 0.680000E+00 0.100000E+02 m) fit stations 224-231 to 2.5 st. deviations using 228/275 pts std=.04144 sta bias slope pcor tcor wt lag 224 -.140000E-01 0.146300E-02 0.143500E-03 -.292000E-01 0.770000E+00 0.100000E+02 225 -.140000E-01 0.146300E-02 0.143500E-03 -.292000E-01 0.770000E+00 0.100000E+02 226 -.140000E-01 0.146300E-02 0.143500E-03 -.292000E-01 0.770000E+00 0.100000E+02 227 -.140000E-01 0.146300E-02 0.143500E-03 -.292000E-01 0.770000E+00 0.100000E+02 228 -.140000E-01 0.146300E-02 0.143500E-03 -.292000E-01 0.770000E+00 0.100000E+02 229 -.140000E-01 0.146300E-02 0.143500E-03 -.292000E-01 0.770000E+00 0.100000E+02 230 -.140000E-01 0.146300E-02 0.143500E-03 -.292000E-01 0.770000E+00 0.100000E+02 231 -.140000E-01 0.146300E-02 0.143500E-03 -.292000E-01 0.770000E+00 0.100000E+02 232 -.140000E-01 0.146300E-02 0.143500E-03 -.292000E-01 0.770000E+00 0.100000E+02 233 -.140000E-01 0.146300E-02 0.143500E-03 -.292000E-01 0.770000E+00 0.100000E+02 234 -.140000E-01 0.146300E-02 0.143500E-03 -.292000E-01 0.770000E+00 0.100000E+02 235 -.140000E-01 0.146300E-02 0.143500E-03 -.292000E-01 0.770000E+00 0.100000E+02 236 -.140000E-01 0.146300E-02 0.143500E-03 -.292000E-01 0.770000E+00 0.100000E+02 237 -.140000E-01 0.146300E-02 0.143500E-03 -.292000E-01 0.770000E+00 0.100000E+02 238 -.140000E-01 0.146300E-02 0.143500E-03 -.292000E-01 0.770000E+00 0.100000E+02 239 -.140000E-01 0.146300E-02 0.143500E-03 -.292000E-01 0.770000E+00 0.100000E+02 240 -.140000E-01 0.146300E-02 0.143500E-03 -.292000E-01 0.770000E+00 0.100000E+02 241 -.140000E-01 0.146300E-02 0.143500E-03 -.292000E-01 0.770000E+00 0.100000E+02 242 -.140000E-01 0.146300E-02 0.143500E-03 -.292000E-01 0.770000E+00 0.100000E+02 243 -.140000E-01 0.146300E-02 0.143500E-03 -.292000E-01 0.770000E+00 0.100000E+02 244 -.140000E-01 0.146300E-02 0.143500E-03 -.292000E-01 0.770000E+00 0.100000E+02 C.6. Nutrient Analyses C.6.1. Equipment and Techniques The analyses were performed using a Technicon AutoAnalyzer II (AAII) which is the property of Scripps Institution of Oceanography's Oceanographic Data Facility (ODF). This AutoAnalyzer has been used throughout the Indian Ocean WOCE Programme. A Keithley model 575 data acquisition system was used in parallel with analog stripchart recorders to acquire the absorbance data. The software used to process the nutrient data was developed at OSU. All of the reagent and standard materials were provided by OSU. The analytical methods are described in Gordon et al (1994). C.6.2. Sampling Procedures: Nutrient samples were drawn from all CTD/rosette casts at stations 1077 to 1244. High density polyethylene (HDPE) centrifuge tubes of approximately 50 mL volume were used as sample containers, and these same tubes were positioned directly in the autosampler tray. These sample tubes were routinely rinsed at least 3 times with one half to full volume of sample before filling. Sample tubes were rinsed twice with deionized water after sample runs, and were soaked in 10% HCl every other day. The nutrient samples were drawn following those for CFCs, helium, tritium, dissolved oxygen, carbon dioxide, alkalinity and salinity. At most stations, the AAII sample run was started before sampling was completed to reduce delay and minimize possible changes in nutrient concentration due to biological processes. C.6.3. Calibration and Standardization: Calibration standards for the nutrient analyses were prepared from high purity preweighed crystalline standard materials. The materials used were: Phosphate standard: J.T. Baker potassium di-hydrogen phosphate lot 3246. Nitrate standard: Alfa potassium nitrate lot 121881. Silicic acid standard: J. T. Baker sodium silicofluoride lot 21078 10A. Nitrite standard: MCB sodium nitrite lot 4205. The volumetric flasks and pipettors used to prepare standards were gravimetrically calibrated prior to the cruise. The Eppendorf Maxipettor adjustable pipettors used to prepare mixed standards typically have a standard deviation of less than 0.002 mL on repeated deliveries of 10 mL volumes. High concentration mixed standards containing nitrate, phosphate, and silicic acid were prepared at intervals of 7 to 10 days and kept refrigerated in HDPE bottles. For almost every station, a fresh "working standard" was prepared by adding aliquots of the high concentration mixed standard to low nutrient seawater. This working standard has nutrient concentrations similar to those found in Deep and Bottom waters. A separate nitrite standard solution was also added to these working standards. Corrections for the actual volumes of the flasks and pipettors were included in the preliminary data. The WOCE Operations Manual calls for nutrient concentrations to be reported in units of micromole/Kg. Because the salinity information required to compute density is not usually available at the time of initial computation of the nutrient concentrations, our concentrations are always originally computed as micromole/L. This unit conversion will be made using the corrected salinity data when it is available. Due to some problems with the nitrite analysis (see below), the nitrate values from station 1168 on reported in the .nut files include also nitrite. These values will be replaced later on after the appropriate correction is applied. C.6.4. Measurement of Precision and Bias: C.6.4.1.Short Term Precision and Bias: Throughout the cruise, replicate samples drawn in different sample tubes from the same Niskin bottle were analyzed to assess the precision of the AAII analyses. These replicate samples were analyzed both as adjacent samples (one after the other) and also at the beginning and end of sample runs to monitor deterioration in the samples or uncompensated instrumental drift. When the post cruise QC work is completed, these replicate analyses will be used to estimate short term precision and instrumental drift. C.6.4.2. Longer Term Precision: On most of the sample runs during I02, an "old" working standard from the previous station was run with the "new" working standard which had been freshly prepared. The "old" standards were kept refrigerated in plastic bottles. The average age of the "old" standards when reanalyzed was four to eight hours. The differences between these standards will be analyzed to assess the precision of standard preparation and handling and inter-station precision. C.6.5. Comparison with other data, long term precision and bias:. There were several crossings of other Indian Ocean WOCE lines along the I02 cruise track. Detailed comparisons with the nutrient data from these sections will be made after the post cruise QC work is complete. C.6.6. Nutrient Quality Control Notes: During the I02 cruise, no flagging of the nutrient data was performed, except for those bottles that were obvious leakers and for bottles whose values are average of two replicates. It is expected that during the post cruise QC work, questionable data can be corrected. In some stations the silicate analysis showed abnormally high values. These were due to an aberrant increase in the difference of the absorbance between the matrix (we use low nutrient seawater and distilled water, 25:1) and the distilled water reagent blank. The cause of this increase appears related to the presence of the surfactant used to decrease the noise in the absorbances and the sampler valving system. This actual process of this phenomenon is not clearly understood. However, it is possible to quantify the increase in values so a correction may be applied. There is an "ideal" LNSW-DDW value of ca. 12 absorbance units rather than the aberrant 20-40 we infrequently encountered. The nitrite analysis also showed problems. Beginning with station 1168, no nitrite values were reported. Artificially high values through the entire water column were obtained. Because those values do not really exist except for a couple near the surface, the subtraction of these values from the nitrite+nitrate analysis in order to get nitrate values would result in lower nitrate than the actual values. The nitrite correction will be reviewed at OSU and will be applied accordingly. This file contains documentation for the CFC measurements on WOCE Section I2, along with tables of replicate water sample analyses and air measurements. A listing of the dissolved CFC measurements from I2, with WOCE data quality flags, is in a separate file. ******************************************************************* (Following discussion and files provided by John Bullister, 16 December 1999) John Bullister NOAA-PMEL Building #3 7600 Sand Point Way, NE Seattle, WA 98115 USA Telephone: 206-526-6741 FAX : 206-526-6744 Internet : bullister@pmel.noaa.gov CFC-11 and CFC-12 Measurements on WOCE I2 Specially designed 10 liter water sample bottles were used on the cruise to reduce CFC contamination. These bottles have the same outer dimensions as standard 10 liter Niskin bottles, but use a modified end-cap design to minimize the contact of the water sample with the end-cap O-rings after closing. The O-rings used in these water sample bottles were vacuum-baked prior to the first station on the Indian Ocean Expedition. Stainless steel springs covered with a nylon powder coat were substituted for the internal elastic tubing standardly used to close Niskin bottles. CFC samples were drawn from approximately 50% of 5600 water samples collected during the expedition. Water samples for CFC analysis were usually the first samples drawn from the 10 liter bottles. Care was taken to co-ordinate the sampling of CFCs with other samples to minimize the time between the initial opening of each bottle and the completion of sample drawing. In most cases, dissolved oxygen, total CO2, alkalinity and pH samples were collected within several minutes of the initial opening of each bottle. To minimize contact with air, the CFC samples were drawn directly through the stopcocks of the 10 liter bottles into 100 ml precision glass syringes equipped with 2-way metal stopcocks. The syringes were immersed in a holding tank of clean surface seawater until analysed. To reduce the possibility of contamination from high levels of CFCs frequently present in the air inside research vessels, the CFC extraction/analysis system and syringe holding tank were housed in a modified 20' laboratory van on the aft deck of the ship. For air sampling, a ~100 meter length of 3/8" OD Dekaron tubing was run from the CFC lab van to the bow of the ship. Air was pulled through this line into the CFC van using an Air Cadet pump. The air was compressed in the pump, with the downstream pressure held at about 1.5 atm using a back-pressure regulator. A tee allowed a flow (~100 cc/min) of the compressed air to be directed to the gas sample valves, while the bulk flow of the air (>7 liters per minute) was vented through the back pressure regulator. Concentrations of CFC-11 and CFC-12 in air samples, seawater and gas standards on the cruise were measured by shipboard electron capture gas chromatography, using techniques similiar to those described by Bullister and Weiss (1988). The CFC system used on I2 was built at the Scripps Institution of Oceanography and had been used on several Pacific WOCE legs as well as several Indian Ocean WOCE legs. The SIO system was modified from the Bullister and Weiss (1988) design to use a fixed volume, variable pressure gas loop injection system. The sample loops were either pressurized or evacuated to known pressures in order to vary the amount of gas sample introduced. The sample loop(s) were periodically filled with CFC-free gas to one atmosphere and analyzed to check for analytical blanks. The typical analysis time for a seawater, air, standard or blank sample was about 12 minutes. The CFC analytical system functioned well during this expedition. Concentrations of CFC-11 and CFC-12 in air, seawater samples and gas standards are reported relative to the SIO93 calibration scale (Cunnold, et. al., 1994). CFC concentrations in air and standard gas are reported in units of mole fraction CFC in dry gas, and are typically in the parts-per-trillion (ppt) range. Dissolved CFC concentrations are given in units of picomoles of CFC per kg seawater (pmol/kg). CFC concentrations in air and seawater samples were determined by fitting their chromatographic peak areas to multi-point calibration curves, generated by pressurizing sample loops and injecting known volumes of gas from a CFC working standard (PMEL cylinder 33780) into the analytical instrument. The concentrations of CFC-11 and CFC-12 in this working standard were calibrated versus a secondary CFC standard (32386) before and after the cruise. Full range calibration curves were run several times (approx. every 5 days during the cruise. Single injections of a fixed volume of standard gas at one atmosphere were run much more frequently (at intervals of 1 to 2 hours) to monitor short term changes in detector sensitivity. CFC results from WOCE sections intersecting I2 and from other recent surveys in this region show near-zero CFC concentrations in deep water (>2000 m) in areas removed from deep western boundary flows. Most of the deep samples along the WOCE I2 section had extremely low (but non-zero) measured CFC-11 concentrations. The CFC-12 chromatographic peaks in many of these deep samples were too small to integrate, yielding zero CFC-12 concentrations for these samples. We attribute most of the very low (but non-zero) CFC-11 signal present in many deep samples along the section to the slow release of CFC from the walls and O-rings of the 10 liter bottles into the seawater sample during storage, and to contamination during the transfer and storage of the seawater samples in glass syringes prior to analysis. Based on the median concentrations observed in deep water samples, a CFC-11 blank correction of 0.002 pmol/kg has been applied to the CFC-11 data. As a result of the CFC-11 blank corrections, some concentrations reported for deep samples are negative. No CFC-12 sampling blank correction was applied. On this expedition, we estimate precisions (1 standard deviation) of about 1% or 0.005 pmol/kg (whichever is greater) for dissolved CFC-11 and 1% or 0.005 pmol/kg (whichever is greater) for dissolved CFC-12 measurements (see listing of replicate samples given at the end of this report). A few samples (~34 of a total of ~2800) had clearly anomalous CFC-11 and/or CFC-12 concentrations relative to adjacent samples. These appeared to occur more or less randomly, and were not clearly associated with other features in the water column (eg. elevated oxygen concentrations, salinity or temperature features, etc). This suggests that the high values were due to isolated low- level CFC contamination events. These samples are included in this report and are flagged as either 3 (questionable) or 4 (bad) measurements. A total of 8 analyses of CFC-11 were assigned a flag of 3 and 8 analyses of CFC-12 were assigned a flag of 3. A total of 11 analyses of CFC-11 were assigned a flag of 4 and 17 CFC-12 samples assigned a flag of 4. In addition to the file of mean CFC concentrations, ID), tables of the following are included in this report: Table 1a. I2 Replicate dissolved CFC-11 analyses Table 1b. I2 Replicate dissolved CFC-12 analyses Table 2. I2 CFC air measurements Table 3. I2 CFC air measurments interpolated to station locations A value of -9.0 is used for missing values in the listings. References: Bullister, J.L. Anthropogenic Chlorofluoromethanes as Tracers of Ocean Circulation and Mixing Processes: Measurement and Calibration Techniques and Studies in the Greenland and Norwegian Seas, Ph.D. dissertation, Univ. Calif. San Diego, 172 pp. Bullister, J.L. and R.F. Weiss, Determination of CCl3F and CCl2F2 in seawater and air. Deep-Sea Research, 35 (5), 839-853, 1988. Cunnold, D.M., P.J. Fraser, R.F. Weiss, R.G. Prinn, P.G. Simmonds, B.R. Miller,F.N. Alyea, and A.J.Crawford. Global trends and annual releases of CCl3F and CCl2F2 estimated from ALE/GAGE and other measurements from July 1978 to June 1991. J. Geophys. Res., 99, 1107-1126, 1994. Table 1a. Replicate F-11 Samples Station Sample F-11 1078 17 0.005 1078 17 0.001 1079 30 0.619 1079 30 0.614 1080 16 0.001 1080 16 0.000 1081 30 0.618 1081 30 0.619 1082 32 1.155 1082 32 1.153 1082 33 1.513 1082 33 1.481 1083 27 0.248 1083 27 0.243 1083 32 1.069 1083 32 1.070 1083 35 1.585 1083 35 1.585 1084 32 1.124 1084 32 1.127 1084 33 1.408 1084 33 1.402 1084 35 1.578 1084 35 1.574 1085 26 0.087 1085 26 0.084 1085 29 0.397 1085 29 0.394 1086 30 0.577 1086 30 0.573 1087 25 0.039 1087 25 0.042 1088 18 0.005 1088 18 0.007 1088 21 0.015 1088 21 0.012 1088 32 0.866 1088 32 0.885 1089 32 0.808 1089 32 0.822 1090 25 0.038 1090 25 0.038 1091 29 0.282 1091 29 0.284 1092 24 0.017 1092 24 0.017 1093 29 0.307 1093 29 0.299 1094 30 0.374 1094 30 0.365 1095 34 1.410 1095 34 1.420 1096 25 0.039 1096 25 0.041 1097 30 0.315 1097 30 0.308 1098 29 0.250 1098 29 0.250 1099 24 0.012 1099 24 0.012 1100 32 0.875 1100 32 0.879 1101 29 0.327 1101 29 0.324 1102 24 0.011 1102 24 0.014 1106 31 0.339 1106 31 0.337 1106 34 1.157 1106 34 1.160 1108 32 0.668 1108 32 0.661 1110 30 0.157 1110 30 0.156 1111 27 0.013 1111 27 0.012 1112 30 0.162 1112 30 0.162 1113 28 0.370 1113 28 0.379 1116 36 1.680 1116 36 1.666 1118 30 0.466 1118 30 0.469 1120 28 0.079 1120 28 0.077 1121 30 0.499 1121 30 0.500 1128 26 0.076 1128 26 0.075 1129 24 0.015 1129 24 0.013 1130 31 0.562 1130 31 0.560 1131 30 0.448 1131 30 0.450 1132 26 0.134 1132 26 0.134 1133 25 0.034 1133 25 0.033 1134 1 0.001 1134 1 0.001 1134 22 0.005 1134 22 0.006 1135 30 0.450 1135 30 0.455 1136 32 1.061 1136 32 1.060 1137 26 0.153 1137 26 0.148 1138 24 0.084 1138 24 0.085 1139 24 0.021 1139 24 0.015 1140 26 0.198 1140 26 0.199 1141 34 1.485 1141 34 1.489 1142 26 0.154 1142 26 0.154 1143 30 0.731 1143 30 0.734 1144 22 0.007 1144 22 0.006 1145 30 0.561 1145 30 0.554 1146 28 0.423 1146 28 0.422 1148 25 0.095 1148 25 0.100 1150 22 0.367 1150 22 0.362 1152 14 0.522 1152 14 0.524 1154 14 1.060 1154 14 1.059 1156 22 0.874 1156 22 0.871 1157 27 0.212 1157 27 0.209 1158 27 0.538 1158 27 0.536 1159 33 1.582 1159 33 1.574 1160 28 0.650 1160 28 0.652 1161 26 0.696 1161 26 0.694 1162 24 0.054 1162 24 0.052 1164 26 0.307 1164 26 0.305 1165 26 0.210 1165 26 0.196 1166 30 1.011 1166 30 1.017 1167 22 0.698 1167 22 0.699 1169 22 0.402 1169 22 0.402 1171 16 0.129 1171 16 0.128 1173 21 0.036 1173 21 0.035 1174 27 0.905 1174 27 0.905 1175 21 0.029 1175 21 0.028 1177 23 0.123 1177 23 0.125 1178 27 0.887 1178 27 0.898 1179 14 0.003 1179 14 0.004 1181 23 0.764 1181 23 0.765 1183 15 0.175 1183 15 0.176 1187 20 1.087 1187 20 1.101 1189 16 0.067 1189 16 0.067 1191 22 0.703 1191 22 0.691 1193 24 1.063 1193 24 1.066 1195 32 1.670 1195 32 1.676 1198 32 1.558 1198 32 1.553 1202 29 1.437 1202 29 1.449 1204 23 0.272 1204 23 0.266 1206 20 0.051 1206 20 0.053 1208 24 0.461 1208 24 0.469 1210 30 1.848 1210 30 1.857 1217 13 1.875 1217 13 1.874 1219 18 1.649 1219 18 1.651 1221 27 1.764 1221 27 1.763 1222 22 0.190 1222 22 0.191 1223 26 1.792 1223 26 1.794 1224 20 0.039 1224 20 0.041 1225 30 1.589 1225 30 1.597 1226 18 0.013 1226 18 0.015 1227 26 1.090 1227 26 1.087 1227 36 1.547 1227 36 1.532 1228 30 1.535 1228 30 1.535 1229 21 0.024 1229 21 0.028 1230 17 0.006 1230 17 0.005 1231 33 1.637 1231 33 1.640 1232 21 0.018 1232 21 0.022 1233 28 0.769 1233 28 0.765 1234 11 -0.001 1234 11 0.000 1235 25 0.543 1235 25 0.542 1236 32 1.590 1236 32 1.589 1238 20 0.375 1238 20 0.374 1239 13 0.026 1239 13 0.025 1240 16 1.669 1240 16 1.659 1244 2 1.280 1244 2 1.277 Table 1b. Replicate F-12 Samples Station Sample F-12 1078 17 -0.002 1078 17 -0.004 1080 16 -0.003 1080 16 -0.002 1081 30 0.340 1081 30 0.326 1082 32 0.623 1082 32 0.614 1083 27 0.133 1083 27 0.128 1084 32 0.611 1084 32 0.603 1085 29 0.209 1085 29 0.214 1086 30 0.305 1086 30 0.294 1087 25 0.032 1087 25 0.033 1088 18 0.005 1088 18 0.003 1088 21 0.005 1088 21 0.002 1088 32 0.463 1088 32 0.479 1089 32 0.441 1089 32 0.456 1090 25 0.023 1090 25 0.026 1091 29 0.158 1091 29 0.159 1092 24 0.006 1092 24 0.009 1093 29 0.155 1093 29 0.153 1094 30 0.186 1094 30 0.192 1095 34 0.788 1095 34 0.790 1096 25 0.025 1096 25 0.021 1097 30 0.160 1097 30 0.154 1098 29 0.128 1098 29 0.129 1099 24 0.005 1099 24 0.003 1100 32 0.457 1100 32 0.453 1101 29 0.162 1101 29 0.160 1102 24 0.007 1102 24 0.005 1106 31 0.181 1106 31 0.172 1106 34 0.625 1106 34 0.629 1108 32 0.349 1108 32 0.337 1110 30 0.091 1110 30 0.083 1111 27 0.004 1111 27 0.009 1112 30 0.092 1112 30 0.091 1113 28 0.193 1113 28 0.187 1115 29 0.217 1115 29 0.213 1116 36 0.929 1116 36 0.951 1118 30 0.228 1118 30 0.228 1119 25 0.035 1119 25 0.033 1120 28 0.041 1120 28 0.039 1121 30 0.244 1121 30 0.246 1128 26 0.047 1128 26 0.041 1129 24 0.006 1129 24 0.008 1130 31 0.283 1130 31 0.263 1131 30 0.229 1131 30 0.229 1132 26 0.069 1132 26 0.074 1133 25 0.016 1133 25 0.017 1134 22 0.002 1134 22 0.003 1135 1 0.002 1135 1 0.001 1135 30 0.237 1135 30 0.236 1136 32 0.552 1136 32 0.550 1137 25 0.024 1137 25 0.022 1137 26 0.088 1137 26 0.088 1138 24 0.043 1138 24 0.043 1139 24 0.015 1139 24 0.007 1140 26 0.105 1140 26 0.104 1141 34 0.822 1141 34 0.809 1142 26 0.082 1142 26 0.085 1143 30 0.371 1143 30 0.377 1144 22 0.006 1144 22 0.004 1145 30 0.290 1145 30 0.294 1146 28 0.219 1146 28 0.217 1148 25 0.050 1148 25 0.055 1150 22 0.190 1150 22 0.186 1152 14 0.263 1152 14 0.264 1154 14 0.536 1154 14 0.536 1156 22 0.444 1156 22 0.446 1157 27 0.108 1157 27 0.106 1158 27 0.273 1158 27 0.264 1159 33 0.880 1159 33 0.872 1160 28 0.323 1160 28 0.322 1161 26 0.349 1161 26 0.341 1161 33 0.814 1161 33 0.824 1162 24 0.029 1162 24 0.028 1164 26 0.158 1164 26 0.159 1165 26 0.099 1165 26 0.105 1166 30 0.517 1166 30 0.522 1167 22 0.347 1167 22 0.351 1169 22 0.204 1169 22 0.201 1171 16 0.068 1171 16 0.067 1173 21 0.020 1173 21 0.017 1174 27 0.444 1174 27 0.452 1175 21 0.016 1175 21 0.015 1177 23 0.067 1177 23 0.064 1178 27 0.444 1178 27 0.448 1179 14 0.000 1179 14 0.001 1181 23 0.380 1181 23 0.378 1183 15 0.085 1183 15 0.089 1187 20 0.545 1187 20 0.558 1189 16 0.033 1189 16 0.033 1191 22 0.350 1191 22 0.347 1193 24 0.531 1193 24 0.526 1195 32 0.913 1195 32 0.914 1198 32 0.933 1198 32 0.918 1202 29 0.738 1202 29 0.738 1204 23 0.138 1204 23 0.135 1206 20 0.022 1206 20 0.024 1206 27 0.698 1206 27 0.717 1208 24 0.229 1208 24 0.229 1210 30 1.024 1210 30 1.033 1217 13 0.962 1217 13 0.969 1219 18 0.833 1219 18 0.839 1221 27 0.935 1221 27 0.932 1222 22 0.096 1222 22 0.094 1223 26 0.897 1223 26 0.898 1224 20 0.019 1224 20 0.017 1225 30 0.847 1225 30 0.854 1226 18 0.005 1226 18 0.006 1227 26 0.545 1227 26 0.535 1228 30 0.797 1228 30 0.792 1229 21 0.012 1229 21 0.014 1230 17 0.000 1230 17 0.002 1231 33 0.911 1231 33 0.919 1232 21 0.008 1232 21 0.012 1233 28 0.385 1233 28 0.383 1234 11 0.000 1234 11 0.000 1235 25 0.270 1235 25 0.270 1235 34 0.976 1235 34 0.977 1236 32 0.850 1236 32 0.841 1238 20 0.197 1238 20 0.197 1239 13 0.015 1239 13 0.016 1240 16 0.859 1240 16 0.852 1244 2 0.648 1244 2 0.646 Table 2. wocei2 CFC Air Measurements: Leg 1 Time F11 F12 Date (hhmm) Latitude Longitude PPT PPT 4 Dec 95 2118 09 00.0 S 105 38.0 E 261.5 518.9 4 Dec 95 2128 09 00.0 S 105 38.0 E 261.2 519.5 4 Dec 95 2137 09 00.0 S 105 38.0 E 261.3 519.1 4 Dec 95 2147 09 00.0 S 105 38.0 E 260.7 520.5 9 Dec 95 1647 08 00.0 S 097 20.0 E 260.8 522.6 9 Dec 95 1659 08 00.0 S 097 20.0 E 261.9 520.6 9 Dec 95 1709 08 00.0 S 097 20.0 E 262.5 521.4 9 Dec 95 1718 08 00.0 S 097 20.0 E 261.2 519.9 13 Dec 95 1859 07 25.9 S 088 51.1 E 257.4 515.3 13 Dec 95 1909 07 25.9 S 088 51.1 E 259.5 515.8 13 Dec 95 1919 07 25.9 S 088 51.1 E 258.3 515.0 13 Dec 95 1929 07 25.9 S 088 51.1 E 257.6 513.5 15 Dec 95 0906 06 20.0 S 088 25.0 E 260.2 520.3 15 Dec 95 0916 06 20.0 S 088 25.0 E 261.7 520.3 15 Dec 95 0925 06 20.0 S 088 25.0 E 267.7 523.5 15 Dec 95 0935 06 20.0 S 088 25.0 E 259.6 518.4 18 Dec 95 2219 10 33.7 S 088 06.9 E 259.8 518.5 18 Dec 95 2229 10 33.7 S 088 06.9 E 259.8 517.0 18 Dec 95 2244 10 33.7 S 088 06.9 E 260.4 518.3 18 Dec 95 2254 10 33.7 S 088 06.9 E 260.0 520.7 21 Dec 95 1811 08 00.0 S 083 20.0 E 263.5 521.2 21 Dec 95 1822 08 00.0 S 083 20.0 E 261.0 520.8 21 Dec 95 2053 08 00.0 S 082 59.0 E 261.3 522.9 21 Dec 95 2103 08 00.0 S 082 59.0 E 260.3 523.1 21 Dec 95 2112 08 00.0 S 082 59.0 E 260.4 524.7 25 Dec 95 0338 07 59.8 S 075 41.7 E 259.6 518.7 25 Dec 95 0348 07 59.8 S 075 41.7 E 258.6 518.3 25 Dec 95 0358 07 59.8 S 075 41.7 E 259.1 518.1 Leg 2 Time F11 F12 Date (hhmm) Latitude Longitude PPT PPT 31 Dec 95 0031 04 00.0 S 071 45.0 E 261.2 522.7 31 Dec 95 0040 04 00.0 S 071 45.0 E 260.7 521.9 31 Dec 95 0052 04 00.0 S 071 45.0 E 260.5 522.0 31 Dec 95 0102 04 00.0 S 071 45.0 E 260.1 523.8 10 Jan 96 0134 08 00.0 S 054 04.0 E 258.6 529.0 10 Jan 96 0144 08 00.0 S 054 04.0 E 259.2 523.2 10 Jan 96 0153 08 00.0 S 054 04.0 E 258.4 522.2 10 Jan 96 0203 08 00.0 S 054 04.0 E 258.2 522.2 18 Jan 96 0817 05 53.0 S 045 58.0 E 258.9 520.4 18 Jan 96 0827 05 53.0 S 045 58.0 E 258.1 521.9 18 Jan 96 0836 05 53.0 S 045 58.0 E 257.9 521.1 19 Jan 96 0530 05 00.0 S 044 57.4 E 263.1 527.8 19 Jan 96 0540 05 00.0 S 044 57.4 E 261.4 525.0 19 Jan 96 0549 05 00.0 S 044 57.4 E 262.2 524.8 21 Jan 96 2128 04 09.8 S 039 49.7 E 261.4 526.3 21 Jan 96 2138 04 09.8 S 039 49.7 E 262.2 524.2 21 Jan 96 2158 04 09.8 S 039 49.7 E 261.2 525.6 Table 3. woce i2 CFC Air values (interpolated to station locations) STATION F11 F12 NUMBER Latitude Longitude Date PPT PPT 1077 09 00.1 S 105 38.1 E 4 Dec 95 261.4 520.3 1078 09 00.0 S 105 38.0 E 5 Dec 95 261.4 520.3 1079 09 07.6 S 105 09.9 E 5 Dec 95 261.4 520.3 1080 09 07.4 S 104 40.0 E 5 Dec 95 261.4 520.3 1081 09 07.5 S 104 00.0 E 6 Dec 95 261.4 520.3 1082 09 07.5 S 103 20.3 E 6 Dec 95 261.4 520.3 1083 09 07.5 S 102 40.0 E 6 Dec 95 261.4 520.3 1084 09 07.5 S 102 00.0 E 7 Dec 95 261.4 520.3 1085 08 56.2 S 101 20.2 E 7 Dec 95 261.4 520.3 1086 08 45.0 S 100 40.8 E 7 Dec 95 261.4 520.3 1087 08 33.7 S 099 60.0 E 7 Dec 95 261.4 520.3 1088 08 22.5 S 099 19.9 E 8 Dec 95 261.4 520.3 1089 08 11.3 S 098 40.0 E 8 Dec 95 261.4 520.3 1090 08 00.0 S 098 00.0 E 8 Dec 95 261.4 520.3 1091 08 00.0 S 097 20.0 E 9 Dec 95 260.3 518.5 1092 07 59.9 S 096 40.0 E 9 Dec 95 259.9 518.0 1093 08 00.0 S 096 00.2 E 10 Dec 95 260.7 518.9 1094 07 59.8 S 095 19.9 E 10 Dec 95 259.9 518.0 1095 08 00.0 S 094 39.9 E 10 Dec 95 259.9 518.0 1096 08 00.2 S 094 00.0 E 11 Dec 95 260.7 518.9 1097 08 00.0 S 093 20.2 E 11 Dec 95 259.9 518.0 1098 07 59.9 S 092 40.2 E 11 Dec 95 260.7 518.9 1099 08 00.0 S 092 00.0 E 12 Dec 95 260.2 517.8 1100 08 00.0 S 091 20.0 E 12 Dec 95 260.2 517.8 1101 07 59.8 S 090 40.0 E 12 Dec 95 260.2 517.8 1102 08 00.0 S 089 60.0 E 12 Dec 95 260.2 517.8 1103 08 00.0 S 089 39.8 E 13 Dec 95 260.2 518.0 1104 08 00.0 S 089 22.5 E 13 Dec 95 260.2 517.8 1105 08 00.0 S 089 00.0 E 13 Dec 95 260.2 517.8 1106 06 00.0 S 088 28.2 E 14 Dec 95 260.2 517.8 1107 05 41.8 S 088 30.0 E 14 Dec 95 260.2 517.8 1108 05 20.0 S 088 30.0 E 14 Dec 95 260.2 517.8 1109 05 00.0 S 088 27.8 E 14 Dec 95 260.2 517.8 1110 05 31.0 S 088 30.0 E 15 Dec 95 260.2 517.8 1111 06 20.0 S 088 25.0 E 15 Dec 95 260.2 517.8 1112 06 50.1 S 088 22.3 E 15 Dec 95 260.2 517.8 1113 07 59.8 S 088 39.9 E 16 Dec 95 260.2 517.8 1114 08 00.0 S 088 20.0 E 16 Dec 95 260.2 517.8 1115 08 00.0 S 088 00.0 E 16 Dec 95 260.2 517.8 1116 10 02.8 S 087 59.8 E 17 Dec 95 259.1 516.8 1117 10 15.2 S 088 08.5 E 17 Dec 95 259.1 516.8 1118 10 30.0 S 088 06.2 E 17 Dec 95 259.1 516.8 1119 10 44.5 S 088 03.9 E 17 Dec 95 259.1 516.8 1120 11 00.0 S 088 02.0 E 17 Dec 95 259.1 516.8 1121 10 37.0 S 088 06.3 E 18 Dec 95 259.1 516.8 1122 10 26.2 S 088 07.0 E 18 Dec 95 259.1 516.8 1123 10 20.4 S 088 07.9 E 18 Dec 95 259.1 516.8 1124 10 33.7 S 088 06.9 E 18 Dec 95 259.1 516.8 1125 10 19.7 S 088 18.5 E 19 Dec 95 259.1 516.8 1126 10 22.7 S 088 24.7 E 19 Dec 95 259.1 516.8 1127 08 00.0 S 087 20.0 E 19 Dec 95 260.2 517.8 1128 08 00.0 S 086 40.0 E 20 Dec 95 260.2 518.0 1129 08 00.0 S 086 00.0 E 20 Dec 95 260.6 519.6 1130 08 00.0 S 085 20.0 E 20 Dec 95 260.5 519.4 1131 08 00.7 S 084 41.3 E 21 Dec 95 261.2 520.8 1132 08 00.0 S 084 00.0 E 21 Dec 95 261.2 520.8 1133 08 00.2 S 083 19.9 E 21 Dec 95 261.2 520.8 1134 08 00.0 S 082 40.0 E 21 Dec 95 261.2 520.8 1135 08 00.0 S 081 59.8 E 22 Dec 95 260.8 520.3 1136 08 00.0 S 081 20.0 E 22 Dec 95 260.5 521.0 1137 08 00.0 S 080 39.9 E 22 Dec 95 260.5 521.0 1138 08 00.0 S 080 00.0 E 23 Dec 95 260.5 521.0 1139 08 00.0 S 079 20.0 E 23 Dec 95 260.5 521.0 1140 08 00.0 S 078 40.0 E 23 Dec 95 260.5 521.0 1141 08 00.0 S 078 00.0 E 24 Dec 95 259.9 521.0 1142 08 00.0 S 077 20.0 E 24 Dec 95 260.5 521.0 1143 08 00.0 S 076 40.0 E 24 Dec 95 260.5 521.0 1144 08 00.0 S 076 00.0 E 24 Dec 95 259.9 521.0 1145 08 00.0 S 075 20.0 E 25 Dec 95 260.5 521.0 1146 08 00.0 S 074 40.0 E 25 Dec 95 260.5 521.0 1147 07 60.0 S 073 60.0 E 25 Dec 95 259.9 521.0 1148 08 00.0 S 073 20.0 E 26 Dec 95 260.5 521.0 1149 08 00.0 S 073 07.0 E 26 Dec 95 259.9 521.0 1150 08 00.3 S 072 49.0 E 26 Dec 95 260.5 521.0 1151 07 60.0 S 072 31.1 E 26 Dec 95 260.5 521.0 1152 08 00.1 S 072 18.0 E 26 Dec 95 260.5 521.0 1153 08 00.0 S 071 52.1 E 27 Dec 95 260.5 521.0 1154 08 00.2 S 071 24.8 E 27 Dec 95 260.5 521.0 1155 08 00.0 S 071 01.5 E 27 Dec 95 259.9 521.0 1156 08 00.0 S 070 39.8 E 27 Dec 95 260.5 521.0 1157 04 00.0 S 071 45.0 E 30 Dec 95 259.0 523.4 1158 03 16.3 S 071 59.0 E 31 Dec 95 259.0 523.4 1159 03 01.8 S 072 35.5 E 31 Dec 95 259.0 523.4 1160 02 30.0 S 072 32.2 E 31 Dec 95 259.0 523.4 1161 02 45.0 S 072 31.6 E 1 Jan 96 259.0 523.4 1162 03 15.0 S 073 10.0 E 1 Jan 96 259.0 523.4 1163 03 14.7 S 073 20.2 E 1 Jan 96 259.0 523.4 1164 03 27.4 S 072 49.2 E 1 Jan 96 259.0 523.4 1165 03 21.3 S 072 37.7 E 2 Jan 96 259.0 523.4 1166 03 40.0 S 072 00.2 E 2 Jan 96 259.0 523.4 1167 07 59.8 S 070 15.7 E 3 Jan 96 259.0 523.4 1168 08 00.0 S 070 00.0 E 3 Jan 96 259.0 523.4 1169 07 59.9 S 069 20.0 E 3 Jan 96 259.0 523.4 1170 08 00.0 S 068 31.7 E 4 Jan 96 259.6 523.4 1171 08 00.0 S 067 59.3 E 4 Jan 96 259.6 523.4 1172 08 00.0 S 067 20.0 E 4 Jan 96 259.6 523.4 1173 07 59.9 S 066 39.9 E 5 Jan 96 259.6 523.4 1174 07 59.8 S 066 00.0 E 5 Jan 96 259.6 523.4 1175 08 00.0 S 065 20.0 E 5 Jan 96 259.6 523.4 1176 07 60.0 S 064 38.8 E 5 Jan 96 259.6 523.4 1177 08 00.0 S 063 59.8 E 6 Jan 96 259.6 523.4 1178 08 00.0 S 063 20.0 E 6 Jan 96 259.6 523.4 1179 08 00.0 S 062 40.0 E 6 Jan 96 259.6 523.4 1180 08 00.0 S 062 00.0 E 6 Jan 96 259.6 523.4 1181 08 00.1 S 061 27.6 E 7 Jan 96 259.6 523.4 1182 08 00.0 S 060 39.9 E 7 Jan 96 259.6 523.4 1183 08 00.0 S 060 11.0 E 7 Jan 96 259.6 523.4 1184 08 00.0 S 059 50.3 E 7 Jan 96 259.6 523.4 1185 08 00.0 S 059 20.3 E 7 Jan 96 259.6 523.4 1186 08 00.0 S 058 41.9 E 8 Jan 96 259.0 523.4 1187 08 00.0 S 058 24.2 E 8 Jan 96 259.0 523.4 1188 07 59.8 S 058 00.2 E 8 Jan 96 259.0 523.4 1189 07 59.8 S 057 21.2 E 8 Jan 96 259.0 523.4 1190 08 00.0 S 056 39.9 E 9 Jan 96 259.0 523.4 1191 08 00.0 S 056 02.3 E 9 Jan 96 259.0 523.4 1192 08 00.0 S 055 20.0 E 9 Jan 96 259.0 523.4 1193 07 59.9 S 054 40.0 E 9 Jan 96 259.0 523.4 1194 07 59.9 S 053 60.0 E 10 Jan 96 259.0 523.4 1195 08 24.0 S 053 36.0 E 10 Jan 96 259.0 523.4 1196 08 35.9 S 053 24.0 E 10 Jan 96 259.0 523.4 1197 08 42.0 S 053 18.0 E 10 Jan 96 259.0 523.4 1198 08 48.0 S 053 12.0 E 10 Jan 96 259.0 523.4 1199 08 52.6 S 053 07.4 E 11 Jan 96 259.0 523.4 1200 08 57.0 S 053 02.8 E 11 Jan 96 259.0 523.4 1201 09 01.7 S 052 58.3 E 11 Jan 96 259.0 523.4 1202 09 06.0 S 052 54.0 E 11 Jan 96 259.0 523.4 1203 09 22.4 S 052 37.5 E 11 Jan 96 259.0 523.4 1204 09 28.0 S 052 15.2 E 12 Jan 96 258.5 522.9 1205 09 33.0 S 051 54.3 E 12 Jan 96 258.5 522.9 1206 10 08.0 S 051 50.0 E 12 Jan 96 258.5 522.9 1207 10 26.8 S 051 13.3 E 12 Jan 96 258.5 522.9 1208 10 45.0 S 051 15.0 E 13 Jan 96 258.5 522.9 1209 11 12.4 S 050 47.4 E 13 Jan 96 258.5 522.9 1210 11 39.9 S 050 20.0 E 13 Jan 96 258.5 522.9 1211 11 59.9 S 050 00.0 E 14 Jan 96 258.5 522.9 1212 12 06.0 S 049 53.9 E 14 Jan 96 258.5 522.9 1213 12 12.0 S 049 47.8 E 14 Jan 96 258.5 522.9 1214 12 16.8 S 049 43.0 E 14 Jan 96 258.5 522.9 1215 12 21.2 S 049 38.7 E 14 Jan 96 258.5 522.9 1216 12 06.0 S 048 53.2 E 14 Jan 96 258.5 522.9 1217 11 59.9 S 048 48.7 E 14 Jan 96 258.5 522.9 1218 11 54.0 S 048 44.2 E 15 Jan 96 258.5 522.9 1219 11 48.0 S 048 39.6 E 15 Jan 96 258.5 522.9 1220 11 42.0 S 048 34.8 E 15 Jan 96 258.5 522.9 1221 11 18.0 S 048 16.7 E 15 Jan 96 258.5 522.9 1222 10 47.4 S 047 53.4 E 15 Jan 96 259.6 523.8 1223 10 16.6 S 047 30.3 E 16 Jan 96 260.3 523.5 1224 09 46.2 S 047 07.0 E 16 Jan 96 260.3 523.5 1225 09 15.5 S 046 43.8 E 16 Jan 96 260.3 523.5 1226 08 44.9 S 046 20.9 E 16 Jan 96 260.3 523.5 1227 08 14.3 S 045 57.5 E 17 Jan 96 260.3 523.5 1228 07 38.0 S 045 57.5 E 17 Jan 96 260.3 523.5 1229 07 01.0 S 045 57.4 E 17 Jan 96 260.3 523.5 1230 06 24.2 S 045 57.5 E 18 Jan 96 260.3 523.5 1231 05 47.0 S 045 57.5 E 18 Jan 96 260.3 523.5 1232 05 10.2 S 045 57.5 E 18 Jan 96 260.3 523.5 1233 05 02.5 S 045 16.8 E 19 Jan 96 260.3 523.5 1234 04 55.0 S 044 30.2 E 19 Jan 96 260.3 523.5 1235 04 47.5 S 043 55.7 E 19 Jan 96 260.3 523.5 1236 04 40.0 S 043 15.1 E 19 Jan 96 260.3 523.5 1237 04 33.9 S 042 40.8 E 20 Jan 96 261.9 525.6 1238 04 27.8 S 042 06.7 E 20 Jan 96 261.9 525.6 1239 04 21.8 S 041 32.5 E 20 Jan 96 261.9 525.6 1240 04 15.6 S 040 58.3 E 21 Jan 96 261.9 525.6 1241 04 12.5 S 040 41.4 E 21 Jan 96 261.9 525.6 1242 04 09.6 S 040 24.2 E 21 Jan 96 261.9 525.6 1243 04 06.5 S 040 07.0 E 21 Jan 96 261.9 525.6 1244 04 03.5 S 039 49.5 E 21 Jan 96 261.9 525.6 C.8. Helium and Tritium Sampling During the I02 leg of WOCE Indian Ocean 370 helium/tritium sample pairs, one each helium and tritium taken from same bottle, were taken on 32 stations. The station spacing was approximately every 5 degrees of longitude along the 8°S line. The spacing was reduced to approximately every 1.5 degrees on the eastern and western boundaries and on the two short meridional lines near 88° & 72°E. These last two lines were sampled to further augment the overall spatial distribution of helium/tritium in the upper water column. The vertical distribution of the sampling was as follows: one station of 16 bottles sampled down to 1000m depth, followed by 8 bottle sampling down to a depth of 500m on the next helium/tritium station. On these same stations the deep helium sampling started where shallow helium/tritium ended to give complete helium profiles. This pattern of alternating 500m them 1000m samplings was carried out the whole length of the 8šS line including boundaries. The processing of the helium and tritium samples was carried out on board using "standard" high vacuum techniques. Both the helium extraction and the tritium degassing procedures involved using rotary mechanical pumps to achieve rough vacuum followed by diffusion pumping. The Varian pumps were charged with a poly phenyl ether based oil (Santovac 5), in conjunction with a cryogenic trapping of the water vapor. This procedure achieves pressures in the low to mid x10^-7 torr range. Once this starting pressure was reached on the all stainless steel vacuum system the samples were introduced into the system. The helium extraction was carried out using water vapor pumping as the means to strip and contain the helium sample until it could be sealed in a glass ampoule for storage. The tritum degassing system uses the same principle, water vapor pumping of the head space above the sample, stripping it of all gases, then shaking of the water sample to reequilibrate the head space. This procedure of stripping and reequilibration is repeated until head space pressure are in the low x10^-6 torr range. At this point the remaining degassed water sample is sealed in a glass bulb for storage. The helium and tritium samples are then transported back to the Helium Isotope Laboratory at the Woods Hole Oceanographic Institution for analysis by mass spectrometry. C.9. Deep Helium Sampling Report C.9.1 Sampling Eight hundred and sixteen deep helium samples were collected from Niskin bottles in stainless steel cylinders which are approximately 40 ml in volume. A total of 53 stations were sampled, spaced two degrees apart, with one degree spacing across spreading zones and through flow areas. Sixteen samples were taken at each station in an array between 1000 meters depth and the bottom of the cast. In some cases the sea floor was too shallow to permit sixteen samples, so all bottles fired in the given interval were sampled. C.9.2 Sample preparation methods Each water sample was stripped of dissolved gases using both high and ultra high vacuum technologies. A rotary pump was used to create the initial high vacuum (approximately 5.0 E-3 torr) and an oil diffusion pump using Santovac 5 (pentaphenyl ether) was used to create the ultra high vacuum (approximately 5.0 E-7 torr). A "water vapor pump" was created by applying a temperature gradient of 100 degrees across the evacuated space. The dissolved gases were pumped into glass ampoules and held there by the resulting pressure gradient until the ampoules were closed by flame sealing. The ampoules are being shipped back to the Lamont-Doherty Earth Observatory for analysis by mass spectrometer. C.10. Radiocarbon Sampling The Princeton University Ocean Tracers Lab was responsible for collecting samples for carbon 14 analysis on WOCE line I02. The data from this line together with data from the far western Pacific and other WOCE Indian Ocean lines will be used to characterize the water masses at particular points of interest. Such points include mapping the through flow of the deep boundary current along the 90°E Ridge, the deep flow around 3° 00'S across the Chagos-Laccadive Ridge and a mapping of the northern branch of the South Equatorial Current. This was a detailed leg and other locations were documented as well. Six hundred and fifty five samples were collected at 29 stations on this line. Full water profiles were collected at 14 stations; shallow profiles, 1800m or less, were collected at 15 stations. The samples will be analyzed at a later date in the land based Atomic Mass Spectrometry lab at Woods Hole Oceanographic Institution. C.11. Radium Sampling As a side project the Princeton University Ocean Tracers Lab has been collecting surface samples at various stations along the I02 track for analysis of radium 226 and 228. Samples are collected on stations of depths greater than 2500m to give the fiber, for 228 measurement, time to soak. Samples are collected about once a day if they are deep enough. The method for collection is as follows. For the surface soak, fiber is placed in a flow through, netted, cloth bag and cast over the side attached to a string on the ship. It soaks for the duration of the station and is then brought up, placed in a baggie, which is labeled and stored for shipment back to the Ocean Tracers Lab for processing and analysis. This is a large volume sample. Small volume samples are placed in 7 x 3/4 inch clear plastic tubes. A 25 liter jug with a spigot is then filled with surface water collected with a bucket cast over the side. The fiber tube is attached to the spigot with a flexible tube and the water in the jug is trickled through the fiber over an 8 to 12 hour period. When this is done this sample is also placed in a baggie, labeled and stored for shipment back to the lab. For LV (large volume) samples the fiber is leached and formed into a precipitate which is put into a small tube and measured in a gamma counter. SV samples are measured on a radon board by forcing gas through and measuring decay counts in special cells with photaic properties. The fiber is actually acrylic fiber that has been "cooked" at 100°C in potassium permanganate. The radium attaches to the manganate, and thus the reason long soaking times are needed. About 30 samples each of SV and LV were collected on I02 for later analysis back at Princeton. C.12. Total CO2 and Alkalinity Analyses C.12.1 Overall Objective: Documentation of the CO2 partial pressure, total inorganic carbon content and alkalinity of the ocean to discern the forces modulating rise in atmospheric CO2. These parameters were measured in conjunction with the overall program of measurements for the WOCE I02 leg. C.12.2 Sample Collection: Documentation of the CO2 partial pressure, total inorganic carbon content and alkalinity of the ocean to discern the forces modulating rise in atmospheric CO2. These parameters were measured in conjunction with the overall program of measurements for the WOCE I02 leg. C.12.3 Equipment and Methods: Total inorganic carbon (TCO2) and total alkalinity (TA) were measured on a total of 166 stations (75 full profiles/91 surface). A total of 3001 samples were analyzed for TCO2 (including replicates). A total of 3070 samples were analyzed for TA (including replicates). The analytical techniques employed are described in Dickson and Goyet (1994). A short description is as follows: TCO2- A known amount of seawater is dispensed into a stripping chamber, where it is acidified and purged with an inert gas. This gas stream is coulometrically titrated and compared to known amounts of CO2 gas. The final concentration is expressed in micromole/Kg of seawater. TA- A known amount of seawater is placed in a closed, thermostated, titration cell and titrated with a solution of hydrochloric acid. The titration is monitored by using a glass electrode/reference electrode and a non-linear least squares approach is applied to the resultant e.m.f. data. The final concentration is expressed in micromole/kg of seawater. C.12.4 Data: Data were reported as specified in the WOCE Operations Manual, WHP Office Report WHPO 91-1. Internal Data Quality Indicators incorporated into the sampling plan included field replicates and Certified Reference Materials. Review of these data indicated that the instrumentation performed within acceptable control limits throughout the cruise. The few minor instrumentation difficulties encountered during the cruise were quickly fixed and did not impact our ability to adhere to our original sampling/analysis scheme. D. Acknowledgments We are indebted to the officers and crew of R/V Knorr for their good- natured and unflagging support for the scientific work on the I02 leg of the WOCE Hydrographic Program Indian Ocean Expedition. The good spirit of the entire ship's company throughout this long voyage contributed greatly to making it such a pleasant and successful one. E. References Bullister, J. L. and R. F. Weiss. 1983. Anthropogenic chlorofluoromethanes in the Greenland and Norwegian Seas. Science, Vol. 221, pp. 265-268. Bullister, J. L. and R. F. Weiss. 1988. Determination of CCl3F and CCl2F2 in sea water and air. Deep-Sea Research, Vol. 35, No. 5, pp. 839-853. Dickson, A.G. and C. Goyet. 1994. Handbook of Methods for the Analysis of the Various Parameters of the Carbon Dioxide System in Sea Water, Ver.2. DOE. Fisher, J. and M. Visbeck. 1993. Deep velocity profiling with self- contained ADCPs. J. Atmos. Oceanic Technol., 10, 764-773. Gammon, R. H., J. D. Cline and D. P. Wisegarver. 1981. Chlorofluoromethanes in the Northeast Pacific Ocean: measured vertical distributions and application as transient tracers of upper ocean mixing. Journal of Geophysical Research, Vol. 87, pp. 9441-9454. Gordon, L. I., J. C. Jennings, Jr., A. A. Ross and J. M. Krest. 1994. A suggested protocol for continuous flow automated analysis of seawater nutrients (phosphate, nitrate, nitrite and silicic acid) in the WOCE Hydrographic Program and the Joint Global Ocean Fluxes Study. In WOCE Operations Manual, WOCE Report No. 68/91. Revision 1, 1994. Knapp, G. P., M.C. Stalcup & R.J. Stanley. 1990. Automated Oxygen Titration and Salinity Determination. Woods Hole Oceanographic Institution Tech. Rep. WHOI-90-33, 25 pages. Millard, R. C. and K. Yang. 1993. CTD Calibration and Processing Methods Used At Woods Hole Oceanographic Institution. Woods Hole Oceanographic Institution Tech. Rep. WHOI-93-44, 96 pages. Oceansoft MKIII/SCTD Acquisition Software Manual. 1990. P/N Manual 10239. EG&G Marine Instruments. WHPO, 1991 WOCE Operations Manual. WHP Office Report WHPO 91-1 WOCE Report No 68/91. Woods Hole Mass, USA. F. Figure Captions Figure 1*. WOCE Hydrographic Program Section I02 station locations (dots) with the 3000m isobath. Every fifth station number is shown for clarity. Figure 2*. Vertical section of bottle positions for WOCE Hydrographic Program Section I02. Vertical exaggeration is 750:1. the longitude locations (°E) are plotted parametrically along the bottom axis. The station locations are plotted parametrically along the top axis. the bathymetry is plotted only at station locations. -------------------------------------------------------------------------------- 8 July 1997 I02 QC Report: Nutrients I Methods The analysts, from Oregon State University (OSU) used an analytical system based upon the Technicon Industrial AutoAnalyzer II (AAII). The Oceanographic Data Facility (ODF) of the Scripps Institution of Oceanography furnished the system. It contained an autosampler developed and constructed at ODF. A Keithley data acquisition system (DAS), model 575, digitized the analog absorbance data. OSU's software, DATABEEP, controlled the DAS and stored the data in digital format. The absorbance data were converted to concentrations using OSU's NUTCALC software. The OSU group supplied all calibration standards, chemical reagents and other consumables. Gordon et al. (1994) described the protocols used. The nutrient analysts sampled all CTD/rosette casts at stations 1077 to 1244 using nominal 50 ml HDPE centrifuge tubes after rinsing at least three times with at least 20 ml of sample. Without any additional transfers these tubes were placed in the ODF autosampler. Nutrient sampling followed that for CFC, helium, tritium, dissolved oxygen, carbon dioxide, alkalinity and, in some cases, salinity. When possible the analysts started the AAII system before sampling to keep sample degradation to a minimum. In many cases difficulties with the silicate analysis delayed the actual beginning of the analytical run by more than an hour. (See "Problems" section, this document). Following analysis the sample tubes were rinsed twice with deionized water (DIW) and soaked every other day in 10% hydrochloric acid. II. Instrument calibration For reagent blanks the analysts used DIW prepared using a Barnstead Nanopure deionizer with feed water from the ship's evaporator. The NUTCALC program applied corrections for the difference in refractive index between DIW and seawater. The calibration standards were prepared in a matrix solution consisting of aged, low-nutrient surface seawater and appropriate aliquots of primary and secondary calibration solutions. The OSU calibration protocols followed those of Gordon et al. (1994) including comparison with "matrix solutions." The matrix solutions consisted of the same natural, low-nutrient seawater, filtered and aged, as used to make up the working, calibration standard solutions but to which no nutrient stock standards were added. To prepare the primary calibration solutions the analysts used high purity dried and pre-weighed, crystalline standard materials. They employed the sequence of sequential, stock, calibration solutions as outlined in the protocol by Gordon et al. (1994). The crystalline materials can be traced to US-NIST, primary standard materials. The silicate standard material can be traced to ultra-high purity, silicon dioxide used in the semiconductor industry and to an ultra-high purity silicon metal sample provided by Dr. Shier Berman, Director of Environmental Measurement Science, National Research Council, Canada. The analysts used the following, specific materials: Phosphate standard: J.T. Baker potassium di-hydrogen phosphate lot 3246. Nitrate standard: Alfa potassium nitrate lot 121881. Silicic acid standard: J. T. Baker sodium silicofluoride lot 21078 10A. Nitrite standard: MCB sodium nitrite lot 4205. Eppendorf Maxipettors were used to make up the calibration standards and all volumetric ware had been gravimetrically calibrated prior to the expedition. The primary calibration solutions contained nitrate, phosphate and silicate (silicic acid) at concentrations designed to approximate deep-water concentrations in the final, working calibration solutions. The analysts added aliquots of nitrite primary solutions directly to the final, working calibration solutions. They prepared the working calibration solutions immediately before analyzing each station's samples in almost all cases. They stored the primary and intermediate calibration solutions in the refrigerator when not in use. The data supplied to the WOCE Hydrographic Programme Office are in units of micromoles per liter. They must be converted to micromoles per kg when the salinity data can be used, together with the laboratory temperature of 25 Ò3C to calculate the sample densities needed. III. Precision and bias The analysts drew replicate samples at each cast for measurement of short-term precision on the order of minutes to one or two hours). They placed the replicates both adjacent to each other and separated by the rest of the samples of each run. As a quality control measure to monitor the stability of working-standard, calibration solutions they kept the preparation left over after most stations to compare with that prepared for the next. Typical time lags between preparations amounted to four to eight hours. The analysts achieved the WOCE specifications for precision for phosphate and nitrate in virtually all cases. Only a very few cases as noted later exceeded these specifications. Instrumental problems introduced very severe problems into the silicate and nitrite analyses for many stations throughout the leg. Because of its low concentrations most of the time, the nitrite problems presented only relatively minor challenges to evaluate and correct the errors. The silicate problems affected as many as 30% of the stations. The magnitude of the errors was typically 1 - 4 % and required a great deal of post-cruise data workup to evaluate and correct the data. When finished, for the most part, we achieved between station precision in the deep-water values of ca. one per cent. We were able to salvage most of the data and note where this was possible and where not. Although there are no WOCE specifications for accuracy in the nutrient analyses, we urge users of this data set to be cautious in use of the silicate data! We are available to consult with users of these data on the problems and probable errors. Following the post cruise data editing we computed estimates of short-term (within station) precision by examining a random subset of the replicate sample determinations. These estimates are given below for phosphate, nitrate and silicate. They report the absolute mean difference between deep water samples run at the beginning of a sample run and rerun again at the end in units of micro moles per liter. Analysis: phosphate nitrate silicate Mean difference 0.0148 0.123 0.44 Stnd deviation 0.0090 0.093 0.26 For nitrite, we estimate the precision for stations 1077 - 1166 to be ca. 0.003 micromoles per liter. IV. Problems There were no major equipment failures in the AAII system, but there were two significant analytical problems with the silicic acid and nitrite data. The analysts at sea were aware of these problems but were unable to resolve them satisfactorily during the cruise. The problems and the post-cruise treatment of the data follow. A. Silicate: The silicate problem resulted from an anomalous response when the AAII was switched from deionized water to seawater, with the initial seawater absorbance being unusually high and tapering off over time. This occurred at the beginning of the sample run for many stations. Our calibration standards were prepared in low nutrient seawater and corrected for the absorbance due to the seawater alone, leading to the standards being over corrected. The computed sample concentrations were then erroneously high. The magnitude of the error was ca. 1 to 4 (M. We have attempted to reproduce this problem in the lab, but have been unable to do so; the cause remains unknown. To correct the problem, we chose and objective approach based on our experience of the constancy of nutrient concentrations in aged LNSW. The silicate concentration of LNSW should be quite constant over time, yet in the affected stations it was apparently changing within the time span of a sample run (< 2hours). We plotted the seawater (LNSW) absorbance minus deionized water (DIW) absorbance at the start and finish of each sample run. Normally, this absorbance arises from small amounts of silicate present in the LNSW and from optical effects; it should be constant for any given batch of LNSW. For stations where the apparent LNSW silicate concentration was more than 1.0 (M too large, we corrected the LNSW absorbances to equal the mean low values for the appropriate batch of LNSW. This lowered the calculated silicate concentrations at the questionable stations and resulted in much improved grouping of theta/silicate plots. Fifty-one stations were recalculated after editing to correct the anomalous LNSW readings in the silicate channel. B. Nitrite The second significant analytical problem involved apparent shifts in the response of the nitrite channel, usually following the calibration standards run at the start of each sample run. These shifts led to anomalously high apparent nitrite concentrations in the deep water, often accompanied by obvious and non-linear drift in the absorbance signal. The analysts at sea recognized the problem but were unable to eliminate the drift, so they elected to cease reporting nitrite concentrations following station 1166. Post cruise inspection of the AAII stripchart recordings showed that the deep- water nitrite samples all had essentially the same absorbance. Since deep- water nitrite concentrations are expected to be essentially zero, the wandering nature of the deepwater absorbance peaks is obviously erroneous. Therefore we edited all deep-water concentrations to zero for stations 1166 - 1244. Where primary and secondary nitrite maxima clearly appeared, at shallower depths, we calculated nitrite concentrations using the differences in absorbances of these peaks from the apparent seawater background of the adjacent samples. Our acceptance criterion for "zero" nitrite concentration was 0.1 ÊM. V. References Gordon, L. I., J. C. Jennings, Jr., A. A. Ross and J. M. Krest. 1994. A suggested protocol for continuous flow automated analysis of seawater nutrients (phosphate, nitrate, nitrite and silicic acid) in the WOCE Hydrographic Program and the Joint Global Ocean Fluxes Study. In WOCE Operations Manual, WOCE Report No. 68/91. Revision 1, 1994. VI. Post cruise data editing: Silicate concentrations were recalculated for the following stations after editing anomalous LNSW responses described previously in this document, and for station 1166 for a problem unrelated to the LNSW response 1077 1078 1079 1080 1081 1084 1093 1103 1108 1109 1110 1115 1116 1122 1123 1131 1134 1135 1144 1145 1146 1147 1148 1157 1158 1160 1162 1163 1164 1165 1180 1181 1182 1183 1187 1188 1190 1191 1192 1201 1202 1211 1224 1226 1228 1229 1230 1231 1236 1237 1238 Nitrate concentrations were recalculated for the following stations. The problems were mostly due to inconsistent (noisy) readings by the data acquisition system. 1102 1113 1115 1119 1127 1135 1136 1139 1144 1157 1159 1163 1165 1200 1205 1206 1210 1213 1224 1225 Phosphate concentrations were recalculated at the following stations. 1136 1142 1143 1144 1175 1179 1180 1190 In addition to the nitrite problems described earlier, the following stations were recalculated with minor editing after the cruise. 1144 1163 1164 Figure 1* Figure 2* * All figures shown in PDF file.