WHP Cruise Summary Information WOCE section designation I05P Expedition designation (EXPOCODE) 74AB29_1 Chief Scientist(s) and their affiliation John Toole, WHOI Dates 1987.11.12 - 1987.12.17 Ship CHARLES DARWIN Ports of call Durban, South Africa to Freemantle, Australia Number of stations 109 Geographic boundaries of the stations 34°10.09''S 30°21.02''E 114°49.06''E 29°00.02''S Floats and drifters deployed none Moorings deployed or recovered none Contributing Authors none listed A Trans-Indian Ocean Hydrographic Section at Latitude 32°S Data Report of RRS Charles Darwin Cruise #29 by: Margaret F. Cook, John M. Toole, and George P. Knapp Woods Hole Oceanographic Institution Woods Hole, Massachusetts 02543 Rana A. Fine and Zafer Top University of Miami Miami, Florida 33149 Joe C. Jennings, Jr. Oregon State University Corvallis, Oregon 97331 WHP Cruise and Data Information Instructions: Click on any highlighted item to locate primary reference(s) or use tools above. TABLE OF CONTENTS List of Tables List of Figures* Abstract Introduction Data Acquisition Systems, Water Sample Analysis, and Instrumentation Cruise Narrative Calibration of CTD/02 Profiles Acoustic Doppler Current Profiler Measurements Summary Presentations of the Final Data Set Acknowledgments References Description of Tables Tables 1--5 Figures* 1--27 Appendix A: Description of CTD #9 Data Adjustment Appendix B: Station Listing Description Station Listing Data Sheets Appendix C: Tritium, Helium, and Neon Observations LIST OF TABLES Table 1: List of Shipboard Personnel Table 2: CTD Station Summary Information Table 3: XBT Station Summary Information Table 4: Parameters of Algorithm Used to Calibrate CTD Oxygen Data Table 5: Average Along- and Across-Track ADCP Velocity Estimates LIST OF FIGURES Fig. 1*: Trans-Indian Ocean cruise track and CTD station locations. Fig. 2*: Block diagrams of the CTD data collection and processing systems Fig. 3*: Laboratory calibration data for the CTD temperature sensors. Fig. 4*: Laboratory calibration data for the CTD pressure sensors. Fig. 5*: Laboratory calibration data for the CTD conductivity sensors. Fig. 6*: Differences between calibrated CTD salinity and associated rosette data. Fig. 7*: Histograms showing the distribution of the salt and oxygen differences. Fig. 8*: Differences between calibrated CTD oxygen and associated rosette data. Fig. 9a*: Representative displays of the Acoustic Doppler Current Profiler data. Fig. 9b*: Representative displays of the Acoustic Doppler Current Profiler data. Fig. 9c*: Representative displays of the Acoustic Doppler Current Profiler data. Fig. 9d*: Representative displays of the Acoustic Doppler Current Profiler data. Fig. 10*: Potential temperature vs. salinity and oxygen plots from the Natal Valley. Fig. 11*: Potential temperature vs. nutrient data plots from the Natal Valley. Fig. 12*: Potential temperature vs. salinity and oxygen plots from Mozambique Basin. Fig. 13*: Potential temperature vs. nutrient data plots from Mozambique Basin. Fig. 14*: Potential temperature vs. salinity and oxygen plots from Madagascar Basin Fig. 15*: Potential temperature vs. nutrient data plots from Madagascar Basin. Fig. 16*: Potential temperature vs. salinity and oxygen plots from Crozet Basin. Fig. 17*: Potential temperature vs. nutrient data plots from Crozet Basin. Fig. 18*: Potential temperature vs. salinity and oxygen plots from Central Indian Basin. Fig. 19*: Potential temperature vs. nutrient data plots from Central Indian Basin. Fig. 20*: Potential temperature vs. salinity & oxygen plots: West Australian Basin. Fig. 21*: Potential temperature vs. nutrient plots: West Australian Basin. Fig. 22*: Temperature vs. depth section of trans-Indian Ocean section. Fig. 23*: Salinity vs. section. depth section of trans-Indian Ocean Fig. 24*: Oxygen vs. depth section of trans-Indian Ocean section. Fig. 25*: Nitrate vs. depth section of trans-Indian Ocean section. Fig. 26*: Phosphate vs. depth section of trans-Indian Ocean section. Fig. 27*: Silicate vs. depth section of trans-Indian Ocean section. ABSTRACT A trans-Indian Ocean hydrographic section employing CTD/O2 profilers was conducted between Africa and Australia during austral spring 1987. The cruise track ranged between 29°S and 34°S; the average latitude of the crossing was 32°S. The purpose of the cruise was to explore various aspects of the South Indian Ocean including the characteristics of the core water masses of this ocean, the strength of the subtropical gyre, the structure and transport of deep western-boundary currents, and the net meridional heat flux. A total of 109 CTD/O2 profiles with associated rosette water sample measurements and 347 XBT profiles were collected, supplemented by underway upper ocean velocity, bathymetric and sea surface temperature and salinity data. This report details the data collection, calibration, and reduction methods, and summarizes the hydrographic observations. INTRODUCTION A trans-Indian ocean hydrographic section along approximate latitude 32°S using Conductivity, Temperature, Depth, Dissolved Oxygen (CTD/O2) profilers was successfully completed during austral spring 1987. Water samples, collected with a rosette sampler attached to the CTD mounting frame, were analyzed for salinity, oxygen, dissolved nutrients, chlorofluorocarbons (CFC), tritium, and Me content. The expedition, conducted from the RRS Charles Darwin, a NERC (Natural Environment Research Council) /RVS (Research Vessel Services) vessel based out of Great Britain, departed Durban, South Africa on 12 November 1987 and made port at Fremantle, Australia on 17 December 1987. The cruise track covered an area between 29 and 34.11°S; several substantial ridge systems extend across the track, dividing the ocean into distinct basins (Figure 1*). The purpose of the cruise was to explore various aspects of the South Indian Ocean circulation including the characteristics of the core water masses of this ocean, the zonal extent of the subtropical gyre including the Agulhas Current and its recirculation zone, and the structure and transport of deep western-boundary currents. Cruise #29 of the RRS Charles Darwin was a multi-institution oceanographic effort. A U.S. contingent of thirteen joined by four shipboard technicians from NERC/RVS (Table 1) collected a total of 109 CTD/02 profiles (including test stations #1, 2, and 11). A summary of station information is given in Table 2. The NERC/RVS technicians operated the CTD winch and the permanent shipboard scientific equipment and computers. The Woods Hole Oceanographic Institution (WHOI) CTD Group staged, prepared and maintained the CTD and rosette equipment during the cruise. The WHOI Hydrography Group coordinated sampling and analysis of rosette salinity and oxygen data. WHOI personnel processed, quality controlled, and archived the collected data. A group from Oregon State University (OSU) analyzed water samples for dissolved nutrient concentrations (dissolved silica, phosphate, nitrite, and nitrate). A team from the University of Miami determined chlorofluorocarbon (CFC) concentrations (F11, F12) from selected rosette bottles at sea and also collected samples for subsequent processing in the laboratory of 3H and Me. Watchstanders deployed 347 expendable bathythermographs (XBTs) along the transect at nominal spacing of 15-20 km between CTD station positions (Table 3). All hands aided in the deployment and recovery of the instruments. Navigation data as well as continuous sea surface temperature, salinity, and upper ocean velocity were logged digitally throughout the cruise; bathymetry data were logged manually at 20-minute intervals with more frequent sampling over abrupt bottom topography. The data return from the cruise was exceptional, and the major cruise objectives were met due to hard work by both the scientific and shipboard personnel during the trip. Listings of the CTD observations at standard levels and the water sample observations form the bulk of this report, Appendix B. DATA ACQUISITION SYSTEMS, WATER SAMPLE ANALYSIS, AND INSTRUMENTATION Two EG&G/Neil Brown Instrument Systems (NBIS) Mark IIIB CTD/O2 (Conductivity/Temperature/Depth/Oxygen) profilers (WHOI instruments: #8, serial number 01-2252-01, and #9, serial number 01-2405-01) were employed on the cruise. A detailed description of the instrumentation can be found in the report by Brown and Morrison (1978). A 24-position, 10-liter rosette manufactured by Scripps Institution of Oceanography was the primary system for water sample collection; a 24-position 1.2-liter General Oceanics Inc. rosette system was available as a backup. The 10-liter bottle size was dictated by CFC sampling requirements. A 12-kHz pinger was mounted on each CTD underwater package to facilitate sampling close to the ocean bottom. The CTD data acquisition system employed the NBIS model 1150 deck unit (Figure 2*) which passed digital HEXASCII data to a 1/4" Kennedy cartridge tape drive. Data were graphically displayed and listed in real time by an HP-85 computer. Audio tape back-up analog recordings were also collected. Complete back-up sets of acquisition hardware were available on the cruise. Data transcription and processing were performed on Digital Equipment Corporation (DEC) MicroVAX II computer systems (Figure 2*). Acquisition data were loaded onto the MicroVAX system via Kennedy cartridge tape drives and displayed graphically using Zeta-8 plotters. Two independent MicroVAX systems were employed: the first devoted to basic processing, the second to data archiving, higher level processing and analysis. Nine-track and DEC TK50 cartridge tapes served as media for data archiving. Two Guildline Aut Sal Model 8400A salinometers were utilized to determine water sample salinities. These were installed in a portable laboratory capable of maintaining constant environmental temperature within ± 1°C. The nominal laboratory temperature was 22 C. A standardization check was performed once per day, using Standard Seawater Batch P-97. No drift of the Autosal was observed during the cruise, thus no standardization adjustments were made. It should be noted that, based upon a comparison of Batch P-97 and PSS78 DCL Standard, Mantyla (1987) has recommended a correction (which has not been made to these data) of + 0.0008 for rosette samples analyzed with this batch. The uncertainty in the rosette salinity data is believed to be ± 0.003 psu, the manufacturer s stated accuracy of the Aut Sal. Water sample dissolved oxygen analyses were also performed in the constant temperature laboratory using a modified Winkler titration technique. The measurements were conducted on 50 ml aliquots of the samples. A Metrohm Titroprocessor controlling a Metrohm Dosimat was used to titrate to an amperometric endpoint as described by Knapp et al. (1989). Standardization checks were performed prior to and following the use of each batch of titrant (typically every third day). No observable drift occurred between standardization checks. These data are reproducible to ± 0.02 ml/l with accuracy of better than 2%. The inorganic nutrient determinations were carried out by Dr. Louis I. Gordon's group from Oregon State University. Samples were analyzed for dissolved, reactive nutrients at sea using an Alpkem Corporation RFA-300 continuous, segmented flow analyzer (RFA). Nutrients analyzed included orthophosphate, silicic acid, nitrate plus nitrite, and nitrite. The phosphate method was basically that of Atlas et al. (1971), modified for the RFA. The remaining methods were those furnished by the Alpkem Corporation for use with the RFA (Alpkem, 1986; Patton, 1983). We have established that all other methods are linear to a few tenths of 1% and give results comparable to, or better than, the AutoAnalyzer-II-based methods we employed in the past (Atlas et al., 1971). The dissolved nutrients were measured at all station locations; in most cases, these analyses were performed immediately after each CTD cast and were completed within two to three hours after the cast. The short term precision (1 standard deviation), estimated from replicate analysis of the same sample and on occasions where two rosette bottles were tripped at the same depth, was approximately 0.2%, 0.5%, and 1.0% of regional deep water values for silicic acid, nitrate plus nitrite, and phosphate, respectively. Nitrite precision is typically 0.02 micromolar. Due to problems with the autosampler (mentioned below), long term precision and accuracy were estimated at 1-2% for silicic acid and nitrate plus nitrite, 3-5% for phosphate, and 0.04 micromolar for nitrite. Data which seemed clearly in error were rejected during the post cruise quality control review of the data. Chlorofluorocarbon (CFC) samples (F11 and F12) were drawn from rosette bottles at about 70% of the stations. An analytical system similar to that of Bullister and Weiss (1988) was used. CFC concentrations are reported relative to the S1086 calibration scale (Weiss, personal communication). A combination bottle and handling blank was used to correct for contamination from the Niskin bottles, and from the collection and storage of samples. This blank was estimated by rotating Niskin bottles, double tripping them and measuring what was believed to be CFC-free water. For F11 the blanks varied throughout the cruise, generally decreasing with time. They ranged from 0.04 pmol/kg to zero. For F12 the blanks were zero; however, contamination problems preclude the use of some of the F12 data. We estimate our precision based on analysis of 166 duplicate samples from the same syringe. The standard deviation of the series of replicates for F11 was as follows: for concentrations in the range zero to 0.10 pmol/kg precision ± 0.004 pmol/kg, in the range 0.1-0.5 pmol/kg precision ± 0.007 pmol/kg, in the range 0.5-1.0 pmol/kg precision 0.012 pmol/kg, and greater than 1.0 pmol/kg precision 0.092 pmol/kg. The standard deviation of the series of replicates for F12 was as follows: for concentrations in the range zero to 0.10 pmol/kg precision ± 0.009 pmol/kg, in the range 0.1-0.5 pmol/kg precision ± 0.011 pmol/kg, in the range 0.5-1.0 pmol/kg precision ± 0.035 pmol/kg, and greater than 1.0 pmol/kg precision ± 0.04 pmol/kg. Marine airs for F11 were 224 ± 6 ppt. The water sample salinity, oxygen, nutrient, and CFC observations are presented in Appendix B of this report. Samples from stations 12, 15, 26, 33, 35, 39, 44, 50, 55, 62, 65, 69, 80, 88, 94, 97, 105, and 106 were analyzed for the following quantities: tritium, helium isotope ratio, total helium and neon. Two hundred and forty measurements each are available for helium isotope ratio, total helium and neon; there are 130 measurements for tritium. For the noble gas analyses, water samples (approximately 40 g) were collected in clamped copper tubes. These samples were also used for tritium analyses in the upper 500 m. For deep tritium samples, water samples (1 liter) were collected in glass bottles. Tritium measurements were made using the mass- spectrometric helium-3 regrowth technique with a precision of 0.01 TU. Helium isotope ratios, as well as absolute helium and neon concentrations, were measured mass-spectrometrically. Isotope ratios, expressed in the del notation (ratio anomaly with respect to the atmosphere), have a precision of 0.2%; absolute concentrations have a precision of 0.25%. These data are presented in listings appearing in Appendix C. The ship's equipment inventory included an Acoustic Doppler Velocity Profiling (ADCP) system (RD 150-kHz profiler with IBM AT acquisition computer) and a digital expendable bathythermograph (XBT) recorder (Bathysystems, Inc. with HP-85 computer). A thermosalinograph monitored surface temperature and salinity along track; data were logged to the ship's main computer system. This system also recorded navigation information (transit and GPS fixes) from which all CTD station navigation information was updated after the cruise. Wind speed and direction were recorded manually by each watch at the start of each station. All transit fixes were digitally logged in addition to GPS fixes every two minutes when available; all transit fixes were subsequently interpolated to form a one-minute position record using the ship velocity data. There were relatively few failures of equipment during the cruise. Upon set- up in Durban, CTD #9 was found to have a faulty FSK board, which was quickly identified and replaced before departure. At cruise start, there was a problem with the Scripps-modified General Oceanics rosette unit which was remedied by replacing a faulty pylon unit. The Kennedy Cartridge tape drives employed for acquisition experienced difficulty switching tracks efficiently; stations greater than 3000 db typically lost up to 15 db of data in mid- profile; data were subsequently interpolated across this gap during processing. At the beginning of the cruise, there was a failure of the nutrient RFA's autosampler. This was replaced by an older model autosampler which was only partly compatible with the RFA; this resulted in noisy and erratic phosphate results, particularly during the first third of the cruise. Late in the cruise one MicroVAX II nine-track tape drive failed; the remaining functional unit was shared between computer systems for the rest of the cruise. Several of the rosette bottles suffered breakage, a function of the difficulty handling such a large package. Many of the rosette bottles leaked; the problem was ultimately traced to old O-rings in the bottles. Careful editing has removed all suspect observations from the final data set. CRUISE NARRATIVE Staging of the ship was accomplished during a four-day period in Durban, South Africa. Two containers, one a WHOI portable laboratory (a temperature controlled, 20-foot long container equipped with salinity and oxygen analysis equipment), the other a shipping container used to transport the cruise equipment, were secured to the deck. CTD and CFC laboratories were established in the RRS Darwin's large main laboratory; two small adjacent laboratories housed the nutrient and shipboard computer operations. Departure from Durban was several hours late on November 12 due to a delayed air shipment containing the bulk of the University of Miami chemistry equipment. At 2100 hrs, the ship transited to a test station site roughly 100 km off the African coast in 3000 m of water. On the morning of November 13, CTD #9, mounted with the small 1.2-liter rosette package, was successfully deployed (station 1) to within 10 m of the ocean floor. Station 2 (the test station for CTD #8 mounted in the large rosette package) was aborted at 900 m depth when the CTD signal was lost. The remainder of that day was spent troubleshooting the problem. During this time, the scientific party was notified that the ship was required to return to Durban to put ashore the vessel's electrician because of a home emergency. The replacement electrician was scheduled to arrive Durban on the afternoon of the 15th. Complicating matters, the winds had increased to 40 knots with growing seas. Since the large rosette package was not yet functional, it was decided to work westward from the test station site and occupy the coastal stations of the proposed section using CTD #9 in the small, easily handled rosette package. Stations 3 through 10 make up an east-to-west transect back toward the African coast. A successful CTD #8 test station was subsequently occupied off the coast of Durban with the repaired large rosette system. The balance of the CTD casts were done with this underwater rosette package. The second departure from Durban occurred at 1700 hrs on 15 November. The ship steamed back to re-occupy the easternmost station position already collected (site of stations 1 and 2) and proceeded to work to the east. The CTD station schedule dictated high-resolution sampling at the western sides of basins and across rough topographic relief with an effort to sample any extraordinarily deep trenches. Larger station spacing intervals were planned over abyssal plains. The section began at the western boundary at 31°S where the Agulhas Current is located near the abrupt African shelf break. Stations were closely spaced down to the abyssal plain of the Natal Valley, spanning the full width of the Agulhas Current. The section then crossed the Mozambique Ridge and Basin, and up over the Madagascar Ridge near Walter's Shoal. High resolution stations were made at the eastern flanks of both ridges so as to observe any western intensification of the baroclinic gradients. Next, the cruise track turned slightly south to cross the Southwest Indian Ridge at approximate right angles, before sampling zonally across the Crozet Basin at latitude 34°S. In the eastern Crozet Basin the section jogged northward at the Southeast Indian Ridge to cross that feature at near right angles before sampling across the southern extremity of the Central Indian Basin along 29°S. The section continued along the crest of Broken Ridge then concluded by sampling across Naturaliste Plateau and up onto the Australian shelf, terminating in 55 m of water midway between Cape Leeuwin and Cape Naturaliste (Figure 1*). Upon arrival in Fremantle, gear was packed up into shipping vans within two days and surface freighted via Singapore (RRS Darwin's subsequent port of call) to the United States. During the cruise, the combination of the large underwater package and the slow winch speed (maximum 60 m/min) led to station times exceeding six hours. The first half of the cruise suffered average lowering/raising rates of 37 m/min. Fortunately, good weather afforded us with more time for CTD stations, and less time devoted to repairs; there were a total of five reterminations of the CTD underwater cable during the entire cruise, several of which occurred in poor weather during the last week. Selection of the primary CTD instrument for the cruise was based on the consistency with which the CTD sensors matched the analyzed water sample salinity data obtained on test stations and the initial casts. CTD #9 was used to collect the first group of stations (3-10) as noted above, while CTD #8 was employed on stations 11-15. Close scrutiny of these early data revealed that the potential temperature/salinity profiles for the two CTD/O2 instruments differed slightly; considering both instruments with pre-cruise calibrations applied, CTD #9 better described the hydrographic profile outlined by corresponding rosette water sample data. Thus, at station 16, CTD #9 was placed in the large rosette frame and subsequently employed on stations 16-94, and 96-109. CTD #8 was used once more at station 95 in the Western Australian Basin to confirm its deep-water sensor calibrations. Estimated accuracies of the final processed and calibrated data are +0.002°C for temperature, ±0.002 for salinity (with respect to the standard sea water used) and ±0.02 ml/l for dissolved oxygen concentration. The following sections detail the procedures used to reduce the CTD data to final form. All stations were collected to within 10 m of the ocean bottom; the deepest station (#91) extends to 5927 db in the Western Australian Basin. The warmest surface waters (T = 23.480°C) were found in the Agulhas Current at station 7; the coldest deep-water temperatures were found at station 50 in the Crozet Basin (T = 0.517°C, Theta = 0.094°C). CALIBRATION OF CTD/ O2 PROFILES Overview: Laboratory calibrations, performed before and after the cruise, provide the sole correction information for the CTD pressure and temperature sensors. Final CTD data have been pressure averaged at 2 db intervals with the appropriate pressure, temperature and conductivity calibrations. Note that temperature and pressure calibrations are used to scale both the data profiles and the CTD component of the rosette water sample data files. The pre-cruise laboratory calibrations of CTDs #8 and #9 appeared to described the at-sea instrumentation more accurately than post-cruise laboratory calibrations. Extended periods of time elapsed (three months prior, four months post) between CTD calibrations and data acquisition; it is likely that an event during post cruise shipment affected post cruise calibrations for CTD #8. In order to preserve a long-standing history on the stability of these sensors, no electronic adjustments were made to the sensor interface boards during laboratory calibrations. Instead, corrections, determined by polynomial least-square fits to the laboratory calibration data, were applied to the data. Temperature calibrations consisted of quadratic fits to seven temperature points ranging between 0 and 25°C in reference to a platinum thermometer standard (Figure 3*). Pressure calibrations were done using a dead-weight tester; data were sampled at 1000 psi intervals with both increasing and decreasing pressure between 0 and 10,000 psi. Data reduction employed a cubic calibration algorithm determined from a least-square fit to these data (Figure 4*). Conductivity calibrations were derived using the water sample salinity data which is traceable to the IOS Wormley standard sea water. Additional information on CTD calibration methodology and data processing procedures can be found in the report by Fofonoff, Hayes, and Millard (1974) and Millard (1982). Pressure: For both CTD instruments, the pressure bias term applied to each CTD cast was set equal to the pre-lowering deck unit pressure reading (du) The following downcast (0-6000 db range) pressure calibration algorithm was applied to the CTD #8 profiles. CTD #8: P = -(du) + (.996485E^-1) P(raw) + (.204213E^-7) P(raw) -2 - (.203510E^-12)P^3 (raw) where P(raw) is the raw counts of the pressure channel. The downcast pressure calibration algorithm for CTD #9 derived from laboratory measurements is listed below: CTD #9: P = -(du) + (.997789E^-1) P(raw) + (.146634E^-7) P^2 (raw) -(.199288E^-12) P^3 (raw) This calibration equation was adjusted with a cubic term which increases the pressure of the CTD trace by 15 db at 6000 db but introduces negligible change for for P < 3000 db. This step was taken to correct a problem with the pressure gauge which resulted in an uncharacteristically salty (.002) CTD trace in the deep water (see Appendix A). The equation for the laboratory pressure calibration plus the adjustment is: CTD #9: P = -(du) + (.99934049E^-1) P(raw) + (.2878124E^-8) P^2 (raw) + (.229295E^-13) P^3 (raw) In similar fashion, cubic calibration curves were constructed from the decreasing pressure (upcast) laboratory calibration data. For CTD #8, a weighted combination of the pre-cruise downcast and upcast pressure calibrations was applied to the CTD component of the rosette water sample data (Millard, 1982). CTD # 8: P(up) = -.661953E^1 + (.993626E^-1) P(raw) + (.358650E^-7) P^2 (raw) -(.370163E^-12) P^3 (raw) P(dn) = -.408372E^1 + (.996485E^-1) P(raw) + (.204213E^-7) P^2 (raw) -(.203510E^-12) P^3 (raw) For CTD #9 observations, the upcast pressure calibration algorithm alone (with adjustment described above) was applied to the upcast CTD component of the rosette water sample data. This method of scaling helped minimize discrepancy in the CTD #9 deep-ocean salinity data. CTD # 9: P(up) = .296106E^1 + (.9946015E^-1) P(raw)+ (.2208452E^-7) P^2 (raw) - (.1510815E^-12) P^3 (raw) Temperature: The following pre-cruise temperature calibrations were used for the calibration of CTD downcast and water sample rosette data collected with CTD #8. A time lag correction of 0.250 seconds between the C and T sensors (deduced during the cruise) was also made. CTD #8: T = .481378E^-2 + (.499839E^-3) T(raw) + (.183211E^-11) T^2 (raw) where T(raw) is the raw counts of the temperature channel. A comparison of CTD #9 pre- and post-cruise temperature calibrations indicated that the temperature sensor remained very stable during the cruise and shipping time period; therefore, a combination of the two laboratory calibrations was used to determine the correction formula. The following was applied to the data along with a time lag correction of 0.150 seconds: CTD #9: T = .993360E^-2 + (.499908E^-3) T(raw) + (.120247E^-11) T^2 (raw) Conductivity: Linear conductivity calibration algorithms, derived from pre-cruise laboratory data (Figure 5*), were used to plot and list CTD data during acquisition. The algorithms employed were: CTD #8: C = .844399E^-2 + (.100041E^-2)C(raw) [1 + a(T - TO) + b(P - PO)] CTD #9: C = -.148379E^-2 + (.100002E^-2) C(raw) [1 + a(T - TO) + b(P - PO)] where: C(raw) is the raw counts of the conductivity channel; a (alpha) is the temperature correction coefficient (-.65E-5°C^-l); b (beta) is the coefficient of cell contraction with pressure (1.*5E-8 db"'-l); T is scaled temperature; TO is 2.8°C; P is scaled pressure; PO is 3000 db. CTD #8 pre-cruise scaling factors resulted in a huge offset (.01 psu) between the CTD and the rosette water sample salinity data. CTD #9 pre-cruise scaling factors described the CTD conductivity cell extraordinarily well, which motivated use of this instrument on the bulk of the stations. It was not until much later in the cruise that a .002 psu inconsistency between CTD #9 and water sample salinity was revealed at very deep stations. Non-standard manipulations of the pressure and conductivity scaling factors were ultimately needed in order to describe the deep ocean accurately (Appendix A). The final conductivity calibrations applied to the data were determined from multiple regression fits of the CTD data with their respective rosette salinity water samples. CTD #8 stations were calibrated using standard multiple regression fitting methods for conductivity (Millard, 1982). First, a multiple regression fit was done over a homogeneous station group (one in which the differences between water sample and nominally scaled CTD salinities were roughly constant), fitting for conductivity bias and conductivity slope through the entire water column. The resultant bias was next removed from the data, and a second multiple regression fit for conductivity slope was done for the same station group in the deep water. Stations 2 and 11-15 formed a homogeneous calibration group. Station 95 required an independent fit to its corresponding water sample data. The stations which utilized CTD #8 subsequently required a manual adjustment to bring the CTD downcast salinity trace 0.002 psu fresher for consistency with surrounding casts made with CTD #9 and with the upcast water sample data. Stations 2, 11-15: C = .16271899E^-1 + (.99980617E^-3) C(raw) (1 + a(T - TO) + b(P - PO)] Station 95: C = .11818043E^-1 + (.99985533E^-3) C(raw) [1 + a(T - TO) + b(P - PO)] CTD #9 conductivity scaling coefficients were derived in essentially the same manner as those for CTD #8. As previously mentioned, a deep-water cubic pressure adjustment was made to the CTD #9 data. In addition, the cell contraction coefficient, beta ("b"), was set to zero in order to describe the subtle uncharacteristic properties of the CTD #9 conductivity cell. Three calibration groups were identified in the CTD #9 data set; the resulting algorithms that were applied are: Stations 1-10: C = .12371505E^-1 + (.99949753E^-3) C(raw) [1 + (T - TO)] Stations 16-80: Stations 81-109: C = .88715050E^-2 + (.99949753E^-3) C(raw) [1 + a(T - TO)] C = .61719213E^-2 + (.99968088E^-3) C(raw) [1 + a(T - TO)] Uncertainty in the final CTD salinity data may be measured by differences between CTD and water sample salinity data. Absolute CTD salinity accuracy of course hinges on the accuracy of the water sample data which in turn is tied to the Wormley standard water. Two measures of CTD/water-sample consistency were prepared (Figures 6, 7*). The time series plot of salinity differences as a function of station number shows the final data to be uniformly calibrated. The histogram of the salinity differences for the data below 2000 decibars is essentially Gaussian with a mean of 0.0003; the standard deviation of the population of 645 points is 0.0085 psu. Oxygen: Coefficients in the CTD oxygen sensor calibration algorithm were derived from in situ water sample oxygen data according to Owens and Millard (1985). The algorithm is: Oxm= [a(Oc + b(delta Oc/delta))+C] Oxsat (T,S) e^(D [T + E (To-T)] + F P) OR LOOK AT THIS AND SEE WHICH WAY YOU WANT IT: Oxm= (a * (Oc + b * (dOc/dt)) + C] * Oxsat (T,S)e** D*[T+E*(TO-T)I+F*P where, Oc is the oxygen current measurement; P & T are CTD pressure (dbar) and temperature (°C); To is the oxygen sensor temperature (°C); S is salinity computed on the 1978 practical salinity scale; a (alpha) is the oxygen current slope adjustment, b (beta) is the oxygen sensor lag in seconds; and C is the oxygen current bias adjustment. Parameters D, E, F appearing in the exponential represent adjustments for the permeability of the teflon membrane of the oxygen cell with temperature and pressure. Oxsat (T,S) is the oxygen saturation value as calculated by Weiss (1970). Stations were first subdivided into groups which appeared to have homogeneous calibration characteristics. A multiple regression technique was then used to define the coefficients. Note that the regression is between downcast CTD oxygen sensor data and water sample observations obtained on the upcast. (This is because erroneous CTD oxygen data are obtained when the underwater package is stopped to close a rosette bottle. As well, the oxygen sensor typically exhibits excessive up-down hysteresis.) Oxygen sensor characteristics changed markedly in time on the trans-Indian cruise. Regression groups were typically small, and frequently consisted of single stations. We have no explanation for the lack of sensor stability. Table 4 details the algorithm coefficients used to generate the final data. As was the case for the salinity data, a measure of CTD-derived oxygen data uncertainty is given by comparison with the water sample data (Figures 7, 8*), but the absolute accuracy depends directly on the water sample accuracy. The population of oxygen difference data below 2000 decibars (678 points) has a standard deviation of 0.037 ml/l with a mean of 0.008 ml/l. ACOUSTIC DOPPLER CURRENT PROFILER MEASUREMENTS Upper ocean velocity profile data from the hull mounted ADCP instrument were vector averaged in 10-minute blocks and archived to floppy disk with the standard RDI software package. A default configuration of 8-m ping length and 8-m bin length was specified, with a ping rate of 1 Hz. As noted above, ship navigation data were recorded on a separate computer. Post-cruise processing of the data initially involved merging these data using time as the common denominator. This entailed correction for a linear drift of 24 seconds/day in the ADCP system time data. The other major correction applied to the data involved determination of the ADCP transducer orientation relative to the ship's gyro. Reciprocal runs of 30-45-minute duration were carried out midway through the cruise. A study of the resulting data indicates that a transducer rotation angle of 4.9° is appropriate. Work is continuing to refine this estimate. Representative summary plots of the relative ADCP measurements are given in Figures 9a-d*. The top panels in each case denote with bold line the ship position corresponding to each subset of the data shown. The 10-minute average east and north relative velocity profiles are displayed in "waterfall" format in the middle panels. The bottom panels present the time series of depth-averaged relative velocity (east is the bold curve). As is apparent from the figures, the ADCP velocity profiles are characterized by structures with short vertical scales, having small horizontal scale. Table 5 presents estimates of the ADCP- derived absolute across-track velocity averaged horizontally between CTD stations, and in the vertical between 100 and 200 m. For comparison, the table also shows the differences between the ADCP data and the geostrophic velocity relative to 1500 db averaged over the same vertical interval. There is qualitative agreement between ADCP and geostrophic velocities; mean and standard deviation of the difference between them are 1.729 E^-2 m/s and 8.035 E^-2 m/s, respectively. Understanding the sources of these differences is an ongoing research topic. SUMMARY PRESENTATIONS OF THE FINAL DATA SET As noted in the INTRODUCTION, the bathymetry of the South Indian Ocean is quite complex. To a large degree, the water property characteristics on the RRS Darwin trans-Indian section reflect the underlying bathymetry; significant property differences are seen from basin to basin. As a means of summarizing the observations, potential temperature--property diagrams were constructed from selected stations in each of the major basins sampled on the cruise (Figures 10-21*). Six property vs. depth sections (Figures 22-27*) of the trans-Indian Ocean section were prepared. Vertical distortion of the full-depth profiles is 500:1, while the expanded shallow sections have a vertical distortion of 1250:1. The continuous bottom topography shown on these profiles is based on depth recordings made approximately every 20 minutes when the ship was underway. Depths have been corrected for variations in the speed of sound in seawater (Carter, 1980). Profiles of potential temperature, salinity, and dissolved oxygen are based on the calibrated CTD data. The black dots on the SiO2, PO4 and NO3 profiles represent bottle positions. All isopleths are interpolated linearly between observations, and contoured by hand. ACKNOWLEDGMENTS The officers and crew of the RRS Charles Darwin are to be commended for their fine work. The British NERC seagoing technicians worked closely with the American scientific staff to insure a safe and successful operation. Support for WHOI involvement in data collection was provided by the National Science Foundation grant number OCE 86-14497. REFERENCES Alpkem Corporation, 1986. Nitrate and nitrite nitrogen A303-S170. Preliminary RFA/2 Rapid Flow Analyzer Operator's Manual, looseleaf, 11 pp. Atlas, E. L., S. W. Hager, L. I. Gordon, and P. K. Park. 1971. A practical manual for use of the Technician Autoanalyzer in seawater nutrient analysis: Revised. Technical Report 215, Reference 71-22, Department of Oceanography, Oregon State University, 49 pp. Brown, N. L., and G. K. Morrison, 1978. WHOI/Brown Conductivity, Temperature and Depth Microprofiler. Woods Hole Oceanographic Institution Technical Report No. WHOI-78-23, 246 pp. Bryden, H. L., 1973. New polynomials for thermal expansion, adiabatic temperature gradient and potential temperature of seawater. Deep-Sea Research, 20, 401-408. Bullister, J. L., and R. F. Weiss, 1988. Determination of CCL3F and CCL2F2 in seawater and air. Deep-Sea Research, 35, 839-853. Carter, D. J. T., 1980. Echo-Sounding Correction Tables. Hydrographic Department, U.K., NP-139, 150 pp. Fofonoff, N. P., 1962. Physical properties of sea water. In: The Sea, Volume I, Editor, M. N. Hill, Interscience Publishers, New York, pp. 3-30, pp. 336-338. Fofonoff, N. P., 1962. Dynamics of ocean currents. In: The Sea, Volume I, Editor, M. N. Hill, Interscience Publishers, New York, pp. 323-395. Fofonoff, N. P., 1985. Physical properties of seawater: a new salinity scale and equation of state for seawater. Journal of Geophysical Research, 90, 3332-3342. Fofonoff, N. P., S. P. Hayes, and R. C. Millard, 1974. WHOI/Brown CTD Microprofiler: Methods of calibration and data handling. Woods Hole Oceanographic Institution Technical Report WHOI-74-89, 64 pp. Knapp, G. P., M. C. Stalcup, and R. J. Stanley, 1989. Dissolved oxygen measurements in sea water at the Woods Hole Oceanographic Institution. WHOI Technical Report, WHOI-89-23, 14 pp. Mantyla, A. W., 1987. Standard seawater comparisons updated. Journal of Physical Oceanography, 17, 543-548. Millard, R. C., Jr., 1982. CTD calibration and data processing techniques at WHOI using the 1978 practical salinity scale. In: Proceedings of the International STD Conference and Workshop, La Jolla, California, 8-11 February 1982; Marine Technology Society, 19 pp. Millard, R. C., W. B. Owens, and N. P. Fofonoff, 1990. On the calculation of the Brunt-Vaaeisaaelaae frequency. Deep-Sea Research, 37, 167-181. Owens, W. B., and R. C. Millard, Jr., 1985. A new algorithm for CTD oxygen calibration. Journal of Physical Oceanography, 15, 621-631. Patton, C. J., 1983. Design, characterization and applications of a miniature continuous flow analysis system. Ph.D. Thesis, Michigan State University, University Microfilms International, Ann Arbor, Michigan, 150 pp. Unesco, 1983. Algorithms for computations of fundamental properties of seawater. Unesco Technical Report 44, 53 pp. Unesco, 1988. The acquisition, calibration, and analysis of CTD data. Unesco Technical Report 54, 92 pp. Weiss, R. F., 1970. The solubility of nitrogen, oxygen, and argon in water and seawater. Deep-Sea Research, 17, 721-735. Wilson, W. D., 1960. Speed of sound in seawater as a function of temperature, pressure and salinity. Journal of the Acoustical Society of America, 32, 641-644. DESCRIPTION OF TABLES Table 1: RRS Charles Darwin Cruise #29 Shipboard Personnel. Table 2: RRS Charles Darwin Cruise #29 CTD Station Summary Information. Table 3: RRS Charles Darwin Cruise #29 XBT Station Summary Information. Table 4: Parameters of the CTD Oxygen Algorithm Used to Calibrate RRS Darwin Cruise #29 CTD Oxygen Data. Oxm= [a(Oc + b(delta Oc/delta))+C] Oxsat(T,S) e^(D [T + E (To-T)] + F P) where, Oc is the oxygen current measurement; P & T are CTD pressure (dbar) and temperature (°C); To is the oxygen sensor temperature (°C); S is salinity computed on the 1978 practical salinity scale; a (alpha) is the oxygen current slope adjustment, b (beta) is the oxygen sensor lag in seconds; and C is the oxygen current bias adjustment. Table 5: RRS Charles Darwin Cruise #29 Average Along- and Across-Track ADCP Velocity Estimates. [Velocities are between 96 and 208 db as computed between consecutive station positions. The last column shows the difference between the actual (ADCP) and computed (geostrophic) velocities between station pairs.] Table 1: RRS Charles Darwin Cruise #29 Shipboard Personnel Woods Hole Oceanographic Institution: Dr. J. Toole Co-Principal Investigator Dr. B. Warren Co-Principal Investigator A. Morton WHOI CTD Group Manager J. Kinder WHOI CTD Group Hardware Technician M. Francis Software Technician - Data Processor R. Stanley Rosette Oxygen Analyst G. Knapp Rosette Salt Analyst J. Zemba Watchstander Oregon State University: J. Jennings Rosette Nutrient Analyst J. Johnson Rosette Nutrient Analyst University of Miami: Dr. R. Fine Co-Principal Investigator K. Sullivan Rosette CFC Analyst L. Pope Rosette CFC Analyst NERC/RVS: G. Miller Instrumentation Technician G. Knight Computer System Manager R. Griffiths Mechanical Technician K. Smith Mechanical Technician Officers and Engineers: Crew: S. Mayl (Master) C. Woods G. Harries A. Olds S. Sykes D. Buffery G. Procter M. Metcalfe J. Baker K. Peters D. Anderson P. Bishop A. Greenhorn J. McKeown W. Groody A. Philp J. Coleman I. Gibb G. Pook P. Hough Table 2: RRS Charles Darwin Cruise #29 CTD Station Summary Information Stn Cast Day/Mo/Yr St GMT End GMT Latitude Longitude P Max Depth CTD 1-test 0 13/11/87 0625 0746 -31 35.07 31 10.56 3127 3107 9 2-test 0 13/11/87 1000 1100 -31 34.86 31 09.55 889 3071 8 2-test 1 13/11/87 1350 1420 -31 34.86 31 09.55 911 3071 8 2-test 2 13/11/87 1652 1723 -31 35.13 31 08.09 1505 3071 9 3 0 13/11/87 2035 2140 -31 22.54 30 50.10 2951 2931 9 4 0 14/11/87 0125 0230 -31 15.59 30 39.30 2935 2926 9 5 0 14/11/87 0546 0658 -31 12.09 30 35.84 2655 2675 9 6 0 14/11/87 0929 1025 -31 09.14 30 32.08 2247 2306 9 7 0 14/11/87 1219 1300 -31 06.12 30 27.82 1783 1739 9 8 0 14/11/87 1440 1508 -31 02.91 30 24.17 893 905 9 9 0 14/11/87 1637 1649 -31 02.95 30 22.07 247 290 9 10 0 14/11/87 1720 1729 -31 02.31 30 21.21 65 90 9 11-test 0 15/11/87 0332 0415 -30 18.46 31 19.84 1175 1178 8 12 0 16/11/87 0148 0303 -31 34.73 31 09.67 3107 3091 8 13 0 16/11/87 1138 1249 -31 56.62 31 36.31 3567 3535 8 14 0 16/11/87 1947 2122 -32 11.67 32 30.13 3581 3551 8 15 0 17/11/87 0442 0610 -32 32.75 33 24.74 3501 3491 8 16 0 17/11/87 1214 1310 -32 41.54 34 10.30 2461 2481 9 17 0 17/11/87 1849 1930 -32 53.96 35 00.12 1615 1593 9 18 0 17/11/87 2330 0008 -33 00.14 35 35.04 1469 1474 9 19 0 18/11/87 0340 0421 -32 59.37 36 04.75 2011 2006 9 20 0 18/11/87 0656 0750 -33 00.87 36 20.65 2603 2591 9 21 0 18/11/87 1029 1130 -33 00.69 36 30.87 3315 3304 9 22 0 18/11/87 1416 1551 -33 00.32 36 40.49 4755 4744 9 23 0 18/11/87 2033 2213 -32 59.65 37 04.82 5165 5108 9 24 0 19/11/87 0608 0742 -33 00.39 37 59.97 5127 5062 9 25 0 19/11/87 1802 1935 -32 59.42 39 29.43 5145 5092 9 26 0 20/11/87 0540 0714 -33 00.32 41 00.34 5097 5010 9 27 0 20/11/87 1752 1915 -32 59.71 42 44.81 4417 4352 9 28 0 20/11/87 2304 2350 -32 59.87 43 02.46 2337 2331 9 29 0 21/11/87 0420 0443 -32 59.95 43 40.13 909 906 9 30 0 21/11/87 0911 0933 -32 59.64 44 29.41 959 964 9 31 0 21/11/87 1815 1853 -33 12.41 46 04.79 2201 2196 9 32 0 21/11/87 2227 2321 -33 18.70 46 30.25 2673 2660 9 33 0 22/11/87 0302 0401 -33 22.78 46 54.98 3187 3147 9 34 0 22/11/87 0832 0940 -33 29.94 47 26.84 3629 3591 9 35 0 22/11/87 1538 1653 -33 33.66 48 14.68 4033 3976 9 36 0 23/11/87 0123 0245 -33 45.01 49 30.39 4397 4323 9 37 0 23/11/87 1135 1257 -33 59.75 50 55.55 4393 4336 9 38 0 23/11/87 2039 2206 -33 59.54 52 10.57 4587 4484 9 39 0 24/11/87 0249 0415 -33 59.91 52 44.66 4555 4444 9 40 0 24/11/87 0904 1032 -34 00.42 53 10.22 4687 4607 9 41 0 24/11/87 1522 1649 -34 00.45 53 36.86 4613 4586 9 42 0 24/11/87 2148 2309 -34 00.73 54 07.11 4455 4393 9 43 0 25/11/87 0919 1052 -33 59.46 55 46.98 4387 4291 9 44 0 25/11/87 1945 2117 -33 58.35 57 02.08 5207 5129 9 45 0 26/11/87 0221 0401 -33 59.68 57 29.09 5433 5299 9 46 0 26/11/87 0953 1124 -33 59.93 58 10.05 5201 5093 9 47 0 26/11/87 1725 1842 -33 59.73 58 53.63 4011 3905 9 48 0 27/11/87 0218 0357 -33 59.61 59 56.99 5207 5150 9 49 0 27/11/87 0940 1124 -33 59.67 60 34.15 5447 5346 9 50 0 27/11/87 2102 2248 -33 59.37 61 59.67 5195 5125 9 51 0 28/11/87 1024 1146 -33 59.53 63 59.93 4755 4649 9 52 0 28/11/87 2340 0100 -33 59.81 66 00.21 4587 4582 9 53 0 29/11/87 1200 1321 -34 00.14 67 59.86 4619 4547 9 54 0 30/11/87 0120 0242 -33 59.95 70 00.33 4397 4302 9 55 0 30/11/87 1435 1606 -34 00.10 71 59.84 5063 4987 9 56 0 01/12/87 0133 0250 -33 19.52 73 20.15 4133 4109 9 57 0 01/12/87 1224 1330 -32 40.09 74 39.66 3789 3678 9 58 0 01/12/87 2354 0055 -31 59.89 76 00.09 3419 3380 9 59 0 02/12/87 0826 0923 -31 30.03 76 59.91 3033 2962 9 60 0 02/12/87 1510 1609 -31 07.67 77 44.36 3073 3003 9 61 0 02/12/87 2212 2313 -30 45.01 78 29.81 3557 3471 9 62 0 03/12/87 0522 0631 -30 22.43 79 15.32 3795 3739 9 63 0 03/12/87 1241 1345 -30 00.44 80 00.14 3565 3476 9 64 0 03/12/87 2125 2242 -29 30.23 80 59.51 4219 4129 9 65 0 04/12/87 0633 0739 -29 00.23 82 00.09 4173 4124 9 66 0 04/12/87 1816 1932 -29 09.41 83 29.55 4447 4368 9 67 0 05/12/87 0500 0613 -29 19.23 84 59.44 3993 3885 9 68 0 05/12/87 1315 1437 -29 27.94 85 58.69 4527 4470 9 69 0 05/12/87 2205 2311 -29 32.16 86 55.20 3587 3562 9 70 0 06/12/87 0540 0609 -29 39.75 87 50.08 1355 1228 9 71 0 06/12/87 1030 1107 -29 49.81 88 34.84 1843 1844 9 72 0 06/12/87 1649 1731 -30 04.66 89 29.86 2283 2282 9 73 0 07/12/87 0011 0046 -30 20.00 90 30.30 1663 1670 9 74 0 07/12/87 0825 0902 -30 40.05 91 49.63 1935 1928 9 75 0 07/12/87 1720 1746 -30 50.29 93 24.64 1237 1248 9 76 0 08/12/87 0101 0131 -31 10.82 94 26.11 1559 1571 9 77 0 08/12/87 0731 0755 -31 33.96 95 27.31 1213 1223 9 78 0 08/12/87 1401 1429 -31 59.70 96 29.67 1293 1305 9 79 0 08/12/87 2136 2210 -32 00.06 97 44.79 1619 1617 9 80 0 09/12/87 0451 0535 -31 59.88 99 00.12 2105 2089 9 81 0 09/12/87 1102 1147 -31 59.61 99 58.56 2423 2407 9 82 0 09/12/87 1822 1906 -31 59.94 100 59.48 2235 2228 9 83 0 10/12/87 0036 0128 -32 14.54 101 49.73 2873 2842 9 84 0 10/12/87 0429 0538 -32 20.11 102 00.03 3785 3740 9 85 0 10/12/87 0953 1105 -32 24.90 102 29.69 4069 4014 9 86 0 10/12/87 1356 1520 -32 29.73 102 39.41 4633 4544 9 87 0 10/12/87 1917 2045 -32 35.90 102 59.45 4855 4779 9 88 0 11/12/87 0109 0248 -32 44.88 103 24.00 5341 5261 9 89 0 11/12/87 0824 1003 -32 54.91 103 59.00 5559 5467 9 90 0 11/12/87 1519 1658 -33 05.54 104 30.27 5535 5508 9 91 0 11/12/87 2207 2353 -33 14.90 105 00.14 6053 5927 9 92 0 12/12/87 0646 0826 -33 26.35 105 44.89 5417 5415 9 93 0 12/12/87 1524 1717 -33 39.61 106 29.47 5607 5514 9 94 0 13/12/87 0013 0204 -33 53.66 107 13.45 5385 5302 9 95 0 13/12/87 0846 0958 -34 09.78 107 59.77 5065 4984 8 96 0 13/12/87 1514 1701 -34 09.85 108 34.38 5545 5452 9 97 0 13/12/87 2226 0014 -34 10.00 109 09.05 5145 5014 9 98 0 14/12/87 0514 0620 -34 09.89 109 42.30 3303 3260 9 99 0 14/12/87 0920 1018 -34 09.92 110 00.08 2589 2572 9 100 0 14/12/87 1647 1736 -34 09.80 110 59.81 2123 2123 9 101 0 15/12/87 0012 0109 -34 09.66 112 09.72 2635 2627 9 102 0 15/12/87 1201 1259 -34 09.26 113 29.39 3041 3023 9 103 0 15/12/87 1613 1709 -34 10.10 113 43.81 2223 2208 9 104 0 15/12/87 1945 2023 -34 10.06 113 59.84 1503 1508 9 105 0 15/12/87 2240 2307 -34 10.93 114 14.53 1069 1078 9 106 0 16/12/87 0049 0111 -34 10.22 114 24.64 685 700 9 107 0 16/12/87 0220 0226 -34 09.71 114 30.26 141 160 9 108 0 16/12/87 0353 0358 -34 10.27 114 44.85 111 130 9 109 0 16/12/87 0438 0440 -34 09.52 114 49.64 41 55 9 Table 3: RRS Charles Darwin Cruise #29 XBT Station Summary Information XBT # JDAY Time Latitude Longitude Surftemp Surfsalt Comment (1987) (GMT) (S) (E) (C) (psu) 7-2A 320 0753 31 46.89 31 07.69 20.9 - - - 7-3A 320 0855 31 48.76 31 11.58 21.0 - - - 7-4A 320 0953 31 51.14 31 20.71 21.0 - - - 7-5A 320 1052 31 53.46 31 29.22 20.9 - - - 7-6A 320 1546 32 59.00 31 41.80 20.8 - - - 7-7A 320 1655 32 03.98 31 53.61 20.7 - - - 7-8A 320 1749 32 07.13 32 05.98 20.7 - - - 7-9A 320 1846 32 09.50 32 17.70 20.7 - - - 7-10A 320 2351 32 13.71 32 36.47 20.5 - - - 7-11A 321 0045 32 17.81 32 46.22 20.3 - - - 7-12A 321 0146 32 23.32 32 55.55 20.1 - - - no good 7-13A 321 0215 32 24.45 33 00.00 20.0 - - - redo 7-14A 321 0316 32 28.42 33 10.30 20.0 - - - no good 7-15A 321 0336 32 30.18 33 13.54 20.1 - - - redo 7-16A 321 0909 32 36.43 33 36.19 19.9 - - - 7-17A 321 1004 32 39.01 33 45.57 19.9 - - - no good 7-18A 321 1005 32 39.01 33 45.57 19.9 - - - redo 7-19A 321 1108 32 40.96 33 57.75 20.1 - - - 7-20A 321 1510 32 43.61 34 17.76 20.2 - - - 7-21A 321 1530 32 45.18 34 21.30 20.3 - - - 7-22A 321 1629 32 49.36 34 32.30 20.2 - - - 7-23A 321 1727 32 52.30 34 43.24 20.1 - - - 7-24A 321 1815 32 54.57 34 54.04 20.1 - - - 7-25A 321 2133 32 56.37 35 14.16 20.1 - - - 7-26A 321 2230 32 58.48 35 25.60 19.3 - - - 7-27A 322 0204 33 00.00 35 48.48 19.7 - - - no good 7-28A 322 0216 33 00.00 35 51.00 19.7 - - - redo 7-29A 322 1132 33 00.87 36 32.91 19.9 - - - 7-30A 322 1930 32 59.42 36 52.96 19.2 - - - 7-31A 323 0138 33 00.06 37 12.24 19.0 - - - 7-32A 323 0244 33 01.18 37 24.12 18.9 - - - 7-33A 323 0343 33 00.48 37 34.18 19.0 - - - 7-34A 323 0442 33 00.42 37 45.36 19.0 - - - 7-35A 323 1122 32 59.83 38 07.79 19.1 35.76 7-36A 323 1227 33 02.98 38 20.91 19.8 35.62 7-37A 323 1330 33 02.42 38 33.48 19.3 35.72 7-38A 323 1429 33 03.00 38 47.48 18.9 35.74 7-39A 323 1529 33 02.54 39 00.48 18.9 35.62 7-39B 323 1630 33 01.60 39 12.90 19.1 - - - 7-40A 323 2330 32 59.56 39 45.02 19.1 35.71 7-41A 324 0024 33 00.89 39 56.27 19.0 35.71 7-42A 324 0129 33 00.54 40 10.30 18.8 35.74 7-43A 324 0140 33 00.48 40 12.54 18.7 35.74 7-44A 324 0244 33 00.24 40 27.12 18.8 35.74 7-45A 324 0344 32 59.54 40 40.12 18.8 35.74 7-46A 324 0445 33 00.06 40 53.12 18.7 35.74 7-47A 324 1026 33 00.11 41 10.10 19.3 35.70 7-48A 324 1128 33 00.08 41 22.70 18.9 35.70 7-48B 324 1128 33 00.08 41 22.70 18.9 35.70 7-49A 324 1337 33 02.40 41 52.30 20.7 - - - 7-50A 324 1429 33 02.70 42 03.20 19.6 - - - 7-51A 324 1606 33 01.54 42 24.06 20.7 - - - 7-52A 324 1619 33 01.48 42 27.06 20.9 - - - 7-53A 324 1720 33 00.28 42 39.49 19.9 - - - 7-54A 324 2200 33 00.16 42 51.67 20.7 35.59 7-55A 325 0214 32 59.85 43 17.27 19.2 35.65 7-56A 325 0319 32 59.48 43 30.36 19.2 35.62 7-57A 325 0614 33 00.38 43 50.29 19.1 35.62 7-58A 325 0715 32 59.04 44 06.50 19.9 - - - 7-59A 325 0815 32 59.30 44 20.39 19.7 - - - 7-60A 325 1131 33 00.73 44 45.69 19.7 35.66 7-60B 325 On data tape, but not listed in station log with all information 7-61A 325 1306 33 04.73 45 04.00 18.9 35.63 7-62A 325 1410 33 08.37 45 16.34 18.8 35.62 7-63A 325 1526 33 11.00 45 30.54 18.7 35.64 7-64A 325 1546 33 11.28 45 34.48 19.2 35.63 7-65A 325 1648 33 12.70 45 48.50 18.8 - - - 7-66A 325 2100 33 14.88 46 14.98 19.3 35.57 7-66B 325 2100 33 14.88 46 14.98 19.3 35.57 7-67B 326 0721 33 25.36 47 13.12 19.4 - - - no good 7-68A 326 0751 33 26.36 47 18.36 19.3 - - - 7-69A 326 1220 33 30.30 47 36.70 19.2 - - - 7-70A 326 1258 33 30.54 47 44.18 20.0 - - - 7-71A 326 1328 33 33.55 47 51.15 20.0 - - - 7-72A 326 1349 33 33.54 47 54.30 - - - - - - 7-73A 326 1448 33 33.60 47 06.20 - - - - - - 7-74A 326 1952 33 37.66 48 26.11 - - - - - - 7-75A 326 2056 33 38.67 48 37.86 19.3 35.55 7-76A 326 2202 33 40.33 48 51.08 19.3 35.56 7-77A 326 2303 33 41.58 49 04.10 19.3 35.57 7-78A 327 0003 33 43.00 49 16.06 19.6 35.62 7-79A 327 0558 33 47.50 49 43.16 20.3 - - - 7-80A 327 0700 33 49.64 50 56.18 20.2 - - - 7-81A 327 0857 33 56.62 50 22.41 20.6 35.75 7-82A 327 1002 33 57.04 50 37.36 20.1 35.76 7-83A 327 1055 33 58.18 50 48.64 20.7 35.77 7-84A 327 1600 33 59.19 51 09.09 21.5 - - - 7-85A 327 1700 34 00.48 51 29.91 21.1 - - - 7-86A 327 1800 34 01.30 51 37.19 20.8 - - - 7-87A 327 1900 34 01.01 51 50.85 20.0 - - - 7-88A 328 0058 33 59.12 52 21.54 20.1 35.78 7-89A 328 0204 34 00.06 52 35.54 20.0 35.76 7-90A 328 0701 33 59.32 52 51.57 20.2 - - - 7-91A 328 1340 33 59.44 53 21.54 20.1 35.75 7-92A 328 2003 34 00.69 53 52.09 19.5 35.74 7-93A 328 2100 34 01.27 54 03.69 20.0 35.74 7-94A 329 0223 34 01.30 54 18.54 20.2 35.75 7-95A 329 0322 34 00.54 54 29.24 19.7 35.74 7-96A 329 0430 34 00.95 54 46.50 19.5 35.77 7-97A 329 0530 34 01.00 54 59.00 19.1 35.72 7-80B 329 0631 34 01.35 55 11.58 18.9 35.73 7-81B 329 0802 34 01.32 55 31.76 20.0 35.77 7-98A 329 1517 3359.59 55 59.77 - - - - - - 7-99A 329 1615 3359.95 5611.91 19.2 35.73 7-100A 329 1715 33 59.65 56 26.34 19.1 35.77 7-101A 329 1815 34 00.62 56 35.49 19.5 35.71 7-102A 329 1915 34 01.02 56 52.50 18.7 35.70 7-103A 330 0029 34 00.24 57 07.12 18.7 35.69 7-104A 330 0128 34 00.24 57 19.18 18.3 35.69 7-105A 330 0730 34 00.68 57 40.17 19.0 35.72 7-106A 330 0830 34 00.07 57 53.21 19.0 35.72 7-107A 330 1439 33 59.42 58 19.54 18.8 35.65 no good 7-109A 330 1506 33 59.10 58 25.20 18.7 - - - redo 7-115A 331 1015 34 00.00 60 34.00 - - - - - - no good 7-118A 331 1653 33 59.60 61 11.00 18.9 35.64 7-120A 331 1943 34 00.83 61 45.37 19.1 35.62 7-121A 331 2000 34 00.87 61 48.50 19.2 35.64 7-122A 332 0158 33 59.54 62 11.00 18.9 35.60 7-124A 332 0428 34 00.12 62 40.42 19.1 35.65 7-127A 332 0656 34 01.06 63 14.34 19.3 35.67 7-128A 332 0754 34 01.09 63 28.02 19.3 35.68 7-129A 332 0856 34 00.36 63 41.97 19.4 35.65 7-130A 332 1500 33 58.72 64 13.82 19.5 35.77 7-131A 332 1600 34 00.29 64 27.39 19.2 35.66 7-132A 332 1700 34 00.74 64 39.37 19.1 35.68 7-133A 332 1800 34 02.09 64 52.44 19.2 35.67 7-134A 332 1922 34 02.39 65 08.87 18.8 35.64 7-135A 332 2013 34 01.18 65 19.55 18.9 35.62 7-136A 332 2111 34 00.07 65 30.89 19.3 35.72 7-137A 332 2200 33 59.96 65 41.03 19.6 35.83 7-138A 333 0358 34 00.90 66 10.33 19.0 35.75 7-139A 333 0500 34 00.75 66 22.29 18.9 35.75 7-140A 333 0600 34 01.01 66 36.47 18.9 35.75 7-141A 333 0704 34 00.64 66 51.21 19.1 35.75 7-142A 333 0800 34 00.96 67 05.38 19.3 35.78 7-143A 333 0858 34 00.61 67 18.82 19.4 35.80 7-144A 333 0959 34 00.24 67 32.82 19.8 35.84 7-145A 333 1101 33 59.36 67 47.18 19.8 35.84 7-146A 333 1631 33 58.64 68 11.92 19.1 35.73 7-147A 333 1730 33 59.94 68 24.50 19.1 35.73 7-148A 333 1828 34 00.23 68 36.71 18.3 35.66 7-149B 333 1925 34 00.27 68 48.91 18.3 35.65 redo 7-150A 333 2028 34 00.00 69 02.41 18.2 35.61 7-151A 333 2126 33 59.99 69 14.48 18.1 35.59 7-152A 333 2226 33 59.77 69 25.87 18.1 35.60 7-153A 333 2322 33 59.24 69 37.42 18.6 35.68 7-154A 334 0027 34 00.06 69 51.00 19.0 35.78 7-155A 334 0529 34 00.65 70 11.15 18.9 35.78 7-156A 334 0630 34 00.06 70 22.55 18.8 35.78 7-157A 334 0727 34 00.42 70 34.67 18.4 35.73 7-158A 334 0828 34 00.43 70 46.91 17.9 35.54 7-159A 334 0923 34 00.42 70 58.29 17.7 35.55 7-160A 334 1021 34 00.07 71 08.94 17.9 35.58 7-161A 334 1130 34 00.06 71 22.42 17.7 35.54 7-163A 334 1243 34 00.50 71 37.20 17.9 34.44 7-164A 334 1331 34 00.18 71 47.24 17.8 35.48 7-165A 334 1923 33 55.03 72 11.04 17.9 35.51 7-166A 334 2022 33 49.53 72 21.30 18.0 35.55 7-167A 334 2121 33 46.80 72 36.55 18.5 35.85 7-168A 334 2222 33 40.65 72 47.42 18.5 35.89 7-169A 334 2330 33 33.20 72 58.10 18.3 35.88 7-170A 335 0031 33 25.48 73 09.18 18.4 35.86 7-171A 335 0530 33 15.71 73 28.18 18.6 35.92 7-172A 335 0630 33 10.29 73 38.14 18.6 35.92 7-173A 335 0721 33 05.50 73 50.79 18.4 35.70 7-174A 335 0823 32 59.38 74 02.73 18.8 35.74 7-175A 335 0921 32 54.10 74 12.72 19.1 35.83 7-176A 335 1022 32 48.21 74 23.69 19.3 35.96 7-177A 335 1121 32 45.24 74 31.30 19.2 35.97 7-178A 335 1630 32 36.08 74 51.11 19.1 35.99 7-179A 335 1730 32 31.21 75 00.12 19.3 35.98 7-180A 335 1831 32 26.07 75 09.35 19.3 35.98 7-181A 335 1922 32 22.03 75 16.53 19.3 35.97 7-182A 335 2021 32 16.93 75 24.87 19.2 35.95 7-183A 335 2123 32 11.89 75 37.87 18.9 35.94 7-184A 335 2223 32 06.92 75 47.38 19.3 35.98 7-185A 336 0330 31 55.73 76 07.76 18.8 35.95 7-186A 336 0430 31 51.78 76 20.56 18.9 35.97 7-187A 336 0530 31 46.43 76 31.79 19.0 35.97 7-188A 336 0630 31 40.80 76 41.72 19.8 35.96 7-189A 336 0722 31 35.80 76 51.29 18.7 35.82 7-190A 336 1147 31 25.48 77 07.18 19.3 35.99 7-191A 336 1243 31 21.42 77 19.48 19.6 36.04 7-192A 336 1358 31 14.54 77 31.18 19.0 36.03 7-193A 336 1455 31 08.29 77 42.30 19.7 35.99 7-194A 336 1825 31 03.82 77 53.01 20.1 36.00 no record 7-194B 336 1922 30 59.36 78 03.71 20.0 36.00 7-195A 336 2028 30 53.63 78 14.04 19.4 36.02 7-196A 336 2122 30 48.36 78 23.27 19.3 36.03 7-197A 337 0144 30 40.42 78 37.06 19.4 36.01 7-198A 337 0245 30 35.83 78 48.51 19.1 36.01 7-199A 337 0345 30 30.41 78 58.89 19.2 36.01 7-200A 337 0446 30 24.89 79 10.84 18.9 35.82 7-201A 337 0825 30 21.59 79 16.78 19.7 35.93 7-202A 337 0926 30 17.15 79 27.45 20.3 35.99 7-203A 337 1030 30 12.06 79 37.24 20.2 35.99 7-207A 337 1130 30 06.50 79 49.20 20.1 35.72 7-208A 337 1231 30 00.24 79 59.18 20.1 35.99 7-209A 337 1600 29 57.78 80 04.74 20.0 36.00 7-210A 337 1700 29 52.86 80 16.06 19.9 36.00 7-211A 337 1759 29 48.38 80 25.06 19.8 36.02 7-212A 337 1856 29 43.67 80 36.08 19.7 36.02 7-213A 337 1958 29 38.42 80 45.89 19.6 36.07 7-214A 337 2059 29 30.84 80 56.30 19.8 36.01 7-215A 338 0144 29 25.06 81 07.30 19.0 35.94 7-216A 338 0245 29 20.39 81 19.49 18.9 35.84 7-217A 338 0347 29 15.34 81 29.71 19.5 35.93 7-218A 338 0445 29 09.12 81 42.93 19.6 35.97 7-219A 338 0545 29 03.74 81 54.20 19.8 35.89 7-220A 338 0930 28 59.10 82 02.13 21.0 35.97 7-221A 338 1049 29 01.48 82 18.48 21.2 35.89 7-222A 338 1147 29 05.00 82 29.36 21.0 35.92 7-223A 338 1245 29 07.00 82 40.42 21.2 35.89 7-224A 338 1349 29 08.56 82 53.77 21.6 35.81 7-225A 338 1445 29 09.32 83 05.14 21.8 35.83 7-226A 338 1545 29 10.25 83 18.76 22.0 35.78 7-227A 338 2220 29 10.94 83 38.46 21.2 35.85 7-228A 338 2322 29 13.06 83 51.06 21.2 35.82 7-229A 339 0022 29 14.42 84 03.30 21.6 35.82 7-230A 339 0122 29 16.00 84 15.00 21.6 35.79 7-231A 339 0230 29 17.62 84 30.41 21.4 35.81 7-232A 339 0330 29 19.18 84 42.66 21.4 35.95 7-233A 339 0900 29 20.95 85 08.73 22.0 36.01 7-234A 339 1101 29 26.24 85 33.42 22.4 36.07 7-235A 339 1217 29 27.48 85 49.12 22.5 35.97 7-236A 339 1731 29 27.94 86 07.15 21.5 36.03 7-237A 339 1827 29 28.70 86 17.57 21.4 36.03 7-238A 339 1928 29 29.60 86 28.83 21.5 36.04 7-239A 339 2022 29 33.29 86 39.60 21.7 36.03 7-240A 339 2128 29 33.57 86 50.11 21.5 36.01 7-241A 340 0205 29 35.34 87 07.03 21.3 36.00 7-242A 340 0300 29 36.79 87 17.98 21.3 35.94 7-243A 340 0400 29 38.99 87 31.13 21.6 35.95 7-244A 340 0500 29 39.87 87 43.53 21.6 36.00 7-245A 340 0721 29 42.75 87 55.26 21.7 36.99 7-246A 340 0825 29 45.45 88 10.15 21.5 36.00 7-247A 340 0926 29 47.96 88 22.93 22.0 36.00 7-248A 340 1316 29 52.90 88 50.60 21.3 36.00 7-249A 340 1415 29 56.30 89 01.80 21.3 37.02 7-250A 340 1515 29 59.63 89 12.80 21.1 36.02 7-251A 340 1615 30 03.44 89 24.32 21.1 36.01 7-252A 340 1922 30 07.13 89 38.07 21.0 35.99 7-253A 340 2030 30 10.98 89 50.92 20.5 35.96 7-254A 340 2130 30 14.00 90 00.68 20.8 35.94 7-255A 340 2231 30 16.12 90 12.24 20.6 36.01 7-256A 340 2330 30 18.00 90 23.18 21.3 36.01 7-257A 341 0230 30 22.16 90 40.81 21.1 36.04 7-258A 341 0330 30 25.00 90 53.39 21.2 36.05 7-259A 341 0430 30 28.81 91 04.98 21.4 36.03 7-260A 341 0530 30 31.66 91 16.84 21.0 36.05 7-261A 341 0622 30 34.55 91 27.08 20.5 35.94 7-262A 341 0724 30 36.73 91 40.28 20.8 35.93 7-263A 341 1110 30 42.30 92 02.20 20.8 - - - 7-264A 341 1230 30 45.20 92 19.10 20.4 35.95 7-265A 341 1332 30 46.12 92 30.48 20.3 35.98 7-267A 341 1432 30 46.92 92 41.91 19.5 35.85 7-268A 341 1530 30 48.21 92 53.40 19.5 35.85 7-269A 341 1630 30 49.12 92 05.56 19.5 35.85 7-270A 341 1930 30 54.09 93 26.84 19.6 35.95 7-271A 341 2024 30 56.73 93 37.21 19.6 35.91 7-272A 341 2126 30 59.51 93 48.22 19.3 35.92 7-273A 341 2231 31 03.00 93 59.12 20.0 36.02 7-274A 341 2331 31 06.10 94 10.60 20.0 36.03 7-275A 342 0030 31 08.70 94 21.10 20.0 36.05 7-276A 342 0330 31 18.48 94 41.29 19.4 35.89 7-277A 342 0430 31 21.28 94 51.93 19.7 35.95 7-278A 342 0523 31 25.53 95 02.59 19.7 35.95 7-279A 342 0627 31 31.54 95 15.51 19.7 35.95 7-280A 342 0930 31 38.48 95 39.48 19.5 35.99 7-281A 342 1030 31 43.30 95 52.20 19.5 35.99 7-282A 342 1129 31 47.36 96 02.54 18.9 35.66 7-283A 342 1226 31 52.24 96 12.30 19.2 35.81 7-284A 342 1330 31 58.11 96 24.68 19.1 35.82 7-285A 342 1527 32 00.52 96 33.29 18.7 35.89 7-286A 342 1629 32 00.27 96 45.81 19.1 35.65 7-287A 342 1732 32 00.46 96 57.93 18.2 35.59 7-288A 342 1824 32 00.19 97 08.04 18.3 35.61 7-289A 342 1925 31 59.98 97 19.80 18.7 35.58 7-290A 342 2025 32 01.03 97 32.11 19.3 35.82 7-291A 343 0002 32 00.60 97 55.80 19.0 36.02 7-292A 343 0115 32 00.45 98 10.61 19.2 36.05 7-293A 343 0212 32 00.79 98 24.35 18.8 36.04 7-294A 343 0330 32 00.51 98 42.29 19.2 36.05 7-295A 343 0430 31 59.90 98 56.01 19.3 36.05 7-296A 343 0730 32 00.10 99 12.96 19.1 36.07 7-297A 343 0826 32 59.72 99 25.55 19.2 36.02 7-298A 343 0929 32 00.00 99 40.06 19.4 36.02 7-299A 343 1031 31 59.30 99 53.60 18.3 35.68 7-300A 343 1330 31 59.77 100 06.34 17.9 35.65 7-301A 343 1430 32 00.00 100 18.21 18.1 35.63 7-302A 343 1530 32 01.19 100 28.54 18.5 35.84 7-303A 343 1630 32 00.71 100 40.19 17.5 35.64 7-304A 343 1726 32 00.89 100 50.66 17.8 35.50 7-305A 343 2027 32 01.65 101 02.73 18.3 35.84 7-306A 343 2132 32 05.00 101 16.12 18.2 35.90 7-307A 343 2229 32 09.06 101 25.48 18.4 35.88 7-308A 343 2330 32 12.30 101 37.60 18.0 35.74 no good 7-309A 344 0828 32 22.34 102 14.04 18.0 35.74 7-310A 344 2400 32 39.66 103 12.05 17.6 35.75 7-311A 345 0601 32 47.66 103 34.13 18.1 35.92 7-312A 345 0655 32 50.67 103 43.92 17.9 35.91 7-313A 345 1344 32 59.95 104 13.47 17.9 35.98 7-314A 345 2013 33 09.12 104 41.65 18.3 35.93 7-315A 345 2115 33 16.50 104 52.00 17.9 35.94 7-316A 346 0330 33 18.00 105 10.70 18.0 35.91 7-317A 346 0430 33 21.94 105 22.08 18.1 35.93 7-318A 346 1210 33 28.84 105 57.11 19.3 36.01 7-319A 346 1310 33 32.52 106 07.10 19.3 36.02 7-320A 346 1410 33 36.49 106 16.45 19.1 36.01 7-321B 346 2057 33 44.24 106 40.18 18.7 36.00 no good 7-322A 346 2129 33 46.30 106 45.30 18.7 36.00 due to bad 7-322B 346 2144 33 47.18 106 47.54 18.6 36.00 launcher 7-777A 346 - - - - - - - - - - - - - - - - - - - test/cal stn 94 7-323A 347 0530 33 58.42 107 26.95 17.4 35.84 7-324A 347 0628 34 02.38 107 36.86 17.4 35.84 7-325A 347 0724 34 05.87 107 47.10 17.3 35.85 7-326A 347 1310 34 10.00 108 11.26 17.1 35.83 7-327A 347 1413 34 10.15 108 23.05 17.1 35.83 7-328A 347 2023 34 10.18 108 47.06 17.2 35.79 7-329A 347 2120 34 10.42 108 58.06 17.3 35.79 7-330A 348 0340 34 10.50 109 24.07 17.3 35.80 7-331A 348 0430 34 10.82 109 35.23 17.3 35.80 7-332A 348 0845 34 09.48 109 54.36 17.4 35.79 7-332B 348 1159 34 09.92 110 05.43 17.3 35.77 7-333A 348 1258 34 10.58 110 17.81 17.2 35.77 7-334A 348 1400 34 19.93 110 27.84 16.9 35.67 7-335A 348 1500 34 11.00 110 40.88 16.8 35.70 7-336A 348 1600 34 10.69 110 51.98 17.2 35.72 7-337A 348 1923 34 09.80 111 09.00 18.0 35.89 7-338A 348 2029 34 10.30 111 23.42 18.0 35.89 7-339A 348 2129 34 10.30 111 36.06 18.0 35.89 7-340A 348 2229 34 10.18 111 48.42 18.0 35.90 7-341A 348 2330 34 10.00 111 58.60 18.0 35.89 7-342A 349 0300 34 10.32 112 19.33 17.9 35.77 7-343A 349 0405 34 10.79 112 33.99 17.9 35.85 7-344A 349 0828 34 09.54 112 47.48 17.8 36.65 7-345A 349 0930 34 09.80 113 00.70 - - - - - - 7-346A 349 1027 34 10.24 113 12.54 18.9 35.93 7-347A 349 1129 34 10.10 113 24.30 18.9 35.93 Table 4: Parameters of the CTD Oxygen Algorithm Used to Calibrate RRS Charles Darwin Cruise #29 CTD Oxygen Data Stations C alpha a D E F beta b 1 0.163 0.532 0.1456E-03 -0.1107E-01 0.3594E+00 0.8115E+01 3-5 0.061 0.666 0.1581E-03 -0.2037E-01 0.1019E+01 0.8000E+01 6-7 0.007 0.767 0.1557E-03 -0.2738E-01 0.9145E+00 0.6274E+01 11-12 -0.020 0.798 0.1954E-03 -0.2367E-01 0.1943E+00 0.1780E+02 13-15 -0.003 0.795 0.1701E-03 -0.2317E-01 0.8059E+00 0.8016E+01 16-19 0.040 0.660 0.1887E-03 -0.2089E-01 0.5664E+00 0.3696E+01 20-22 0.024 0.744 0.1509E-03 -0.2653E-01 0.8161E+00 0.4182E+01 23-24 0.026 0.748 0.1455E-03 -0.2537E-01 0.1252E+01 0.8000E+01 25 0.009 0.801 0.1478E-03 -0.3024E-01 0.7307E+00 0.8000E+01 26 0.023 0.794 0.1390E-03 -0.2896E-01 0.8505E+00 0.7994E+01 27 0.049 0.725 0.1434E-03 -0.2417E-01 0.8776E+00 0.8000E+01 28-36 0.028 0.755 0.1462E-03 -0.2562E-01 0.9920E+00 0.4370E+01 37 0.108 0.648 0.1215E-03 -0.2436E-01 0.4646E+00 0.7990E+01 38 0.113 0.651 0.1227E-03 -0.2101E-01 0.5163E+00 0.7973E+01 39-42 0.038 0.747 0.1413E-03 -0.2674E-01 0.8302E+00 0.2819E+01 43-47 0.050 0.720 0.1400E-03 -0.2352E-01 0.1068E+01 0.4720E+00 48-55 0.036 0.748 0.1428E-03 -0.2513E-01 0.8710E+00 0.7999E+01 56 0.038 0.746 0.1427E-03 -0.2753E-01 0.7105E+00 0.7994E+01 57-58 0.053 0.719 0.1402E-03 -0.2225E-01 0.8985E+00 0.6000E+01 59-60 0.026 0.758 0.1525E-03 -0.2478E-01 0.9031E+00 0.8000E+01 61-64 0.037 0.739 0.1472E-03 -0.2357E-01 0.9310E+00 0.8005E+01 65-67 0.043 0.729 0.1457E-03 -0.2326E-01 0.7681E+00 0.8000E+01 68-69 0.046 0.725 0.1421E-03 -0.2223E-01 0.8972E+00 0.8000E+01 70-81 0.028 0.706 0.1784E-03 -0.2004E-01 0.7328E+00 0.8000E+01 82-83 0.036 0.711 0.1665E-03 -0.2107E-01 0.5484E+00 0.8000E+01 84-88 0.009 0.807 0.1471E-03 -0.2730E-01 0.8875E+00 0.8000E+01 89-91 0.029 0.777 0.1409E-03 -0.2612E-01 0.7450E+00 0.8001E+01 92-93 0.037 0.763 0.1394E-03 -0.2631E-01 0.7288E+00 0.7996E+01 95 -0.017 1.445 0.1000E-03 -0.2231E-01 0.7375E+00 0.8000E+01 96 0.049 0.757 0.1348E-03 -0.2692E-01 0.5672E+00 0.8000E+01 97-102 0.037 0.763 0.1394E-03 -0.2631E-01 0.7288E+00 0.7996E+01 Table 5: RRS Charles Darwin Cruise #29 Average Along- and Across-Track ADCP Velocity Estimates Station Along-Track Across-Track Across-Track Number Average ADCP Average ADCP ADCP-GEOST Velocity m/s Velocity m/s Velocity m/s 3 12 -0.220 -0.390 -0.096 4 3 -0.223 -0.649 0.031 5 4 -0.153 -0.731 -0.117 6 5 0.048 -0.890 0.327 7 6 -0.203 -1.040 0.315 8 7 -0.027 -0.917 0.398 9 8 -0.359 -0.289 0.086 12 13 0.031 -0.353 -0.087 13 14 0.067 -0.026 0.026 14 15 0.040 -0.072 -0.060 15 16 -0.112 -0.050 0.013 16 17 -0.030 0.092 0.048 17 18 0.054 0.128 0.046 18 19 0.111 0.026 -0.026 19 20 0.013 -0.035 0.001 20 21 -0.035 -0.032 0.083 21 22 -0.143 -0.088 0.124 22 23 -0.086 -0.040 0.136 23 24 -0.271 0.048 0.003 24 25 -0.167 -0.025 -0.046 25 26 -0.007 0.086 -0.039 26 27 0.106 -0.023 0.032 27 28 0.000 -0.058 0.262 28 29 0.039 -0.045 -0.096 29 30 0.112 0.112 0.063 30 31 -0.186 0.171 0.132 31 32 -0.089 0.040 0.006 32 33 -0.033 -0.030 -0.081 33 34 -0.062 0.074 0.051 34 35 -0.093 -0.023 -0.022 35 36 -0.065 -0.070 -0.008 36 37 0.067 -0.032 0.023 37 38 0.237 -0.008 0.010 38 39 0.204 -0.027 -0.074 39 40 0.345 0.047 0.036 40 41 0.181 -0.012 -0.057 41 42 0.224 0.015 0.031 42 43 0.055 0.023 0.016 43 44 -0.313 0.094 0.083 44 45 -0.059 -0.021 0.017 45 46 -0.003 -0.126 -0.033 46 47 -0.236 -0.114 -0.101 47 48 -0.342 0.003 -0.053 48 49 -0.152 0.105 -0.014 49 50 -0.041 -0.028 -0.052 50 51 0.031 -0.041 -0.038 51 52 -0.078 -0.108 -0.088 52 53 0.032 -0.014 -0.008 53 54 0.140 -0.003 -0.025 54 55 0.067 0.051 -0.024 55 56 0.027 0.055 0.048 56 57 0.038 -0.038 0.060 57 58 -0.059 0.000 0.003 58 59 0.019 0.095 0.059 59 60 0.013 0.081 0.013 60 61 0.071 0.017 0.034 61 62 0.083 0.030 -0.036 62 63 0.094 0.000 0.030 63 64 0.115 0.062 -0.001 64 65 0.067 0.042 0.030 65 66 0.040 -0.051 0.001 66 67 0.091 0.004 -0.017 67 68 0.015 0.123 -0.006 68 69 0.013 -0.082 0.066 69 70 0.108 -0.099 -0.097 70 71 0.305 0.029 -0.014 71 72 0.188 0.044 -0.057 72 73 0.218 -0.089 -0.033 73 74 0.103 0.023 -0.022 74 75 -0.065 -0.016 -0.003 75 76 0.017 -0.078 -0.040 76 77 0.071 -0.106 -0.010 77 78 -0.035 0.132 0.021 78 79 0.007 -0.074 -0.037 79 80 0.213 -0.074 0.026 80 81 0.360 0.175 -0.001 81 82 0.092 0.043 0.034 82 83 0.153 0.019 -0.019 83 84 -0.002 -0.044 0.048 84 85 0.020 -0.046 0.029 85 86 0.194 -0.023 -0.053 86 87 0.071 0.087 -0.017 87 88 0.067 0.075 0.034 88 89 0.057 0.031 0.028 89 90 0.022 0.037 0.005 90 91 0.018 -0.041 0.039 91 92 -0.097 0.101 0.037 92 93 -0.354 0.069 0.021 93 94 -0.129 -0.033 0.017 94 95 -0.179 -0.026 0.038 95 96 -0.076 0.079 0.038 96 97 0.106 0.020 0.057 97 98 0.245 0.069 0.011 98 99 0.121 0.068 0.055 99 100 0.102 0.147 0.062 100 101 0.328 0.078 -0.019 101 102 0.221 -0.015 0.024 102 103 -0.025 0.077 0.044 103 104 0.021 0.024 0.036 104 105 0.041 -0.094 0.026 105 106 0.055 -0.157 0.000 FIGURES Fig. 1* The trans-Indian ocean cruise track and CTD station locations of RRS Charles Darwin cruise #29 from Africa to Australia. Note the many ridges and basins traversed by the cruise track. Fig. 2* Block diagrams of the CTD data collection and processing systems employed on the RRS Charles Darwin trans-Indian cruise. Fig. 3 Laboratory calibration data for the CTD temperature sensors along with quadratic least-square fits to the data used to reduce the CTD data. Fig. 4* Laboratory calibration data for the CTD pressure sensors along with cubic least-square fits to the data used to reduce the CTD data. Fig. 5* Laboratory calibration data for the CTD conductivity sensors along with linear least-square fits to the data used to reduce the CTD data. Fig. 6* Below: Differences between calibrated CTD salinity data and associated rosette data over the entire ocean profile: RRS Charles Darwin cruise #29. Above: Differences between deep (greater than 2000 db) calibrated CTD salinity data and associated rosette data: RRS Charles Darwin cruise #29. Fig. 7* Histograms showing the distribution of the salt and oxygen differences (CTD vs. rosette samples) for: Below: all stations at all depths. Above: all stations at depths greater than 2000 db. Fig. 8* Below: Differences between calibrated CTD oxygen data and associated rosette data over the entire ocean profile: RRS Charles Darwin cruise #29. Above: Differences between deep (greater than 2000 db) calibrated CTD oxygen data and associated rosette data: RRS Charles Darwin cruise #29. Fig. 9* (a). Representative displays of the Acoustic Doppler Current Profiler data obtained on the trans-Indian cruise. Four subsections of the data set are presented (Figures* 9a, b, c, and d). In each case, the top panel denotes with bold line where along the cruise track the data were collected. Panels 2 and 3 contain the relative east and north velocity profiles in "waterfall" format where successive profiles are offset to the right. The profiles were biased to have zero vertical mean. The bottom panels give the east (bold line) and north (thin line) components of the depth-averaged relative velocity. Fig. 9* (b). Representative displays of the Acoustic Doppler Current Profiler data obtained on the trans-Indian cruise. Four subsections of the data set are presented (Figures* 9a, b, c, and d). In each case, the top panel denotes with bold line where along the cruise track the data were collected. Panels 2 and 3 contain the relative east and north velocity profiles in "waterfall" format where successive profiles are offset to the right. The profiles were biased to have zero vertical mean. The bottom panels give the east (bold line) and north (thin line) components of the depth-averaged relative velocity. Fig. 9* (c). Representative displays of the Acoustic Doppler Current Profiler data obtained on the trans-Indian cruise. Four subsections of the data set are presented (Figures* 9a, b, c, and d). In each case, the top panel denotes with bold line where along the cruise track the data were collected. Panels 2 and 3 contain the relative east and north velocity profiles in "waterfall" format where successive profiles are offset to the right. The profiles were biased to have zero vertical mean. The bottom panels give the east (bold line) and north (thin line) components of the depth-averaged relative velocity. Fig. 9* (d). Representative displays of the Acoustic Doppler Current Profiler data obtained on the trans-Indian cruise. Four subsections of the data set are presented (Figures* 9a, b, c, and d). In each case, the top panel denotes with bold line where along the cruise track the data were collected. Panels 2 and 3 contain the relative east and north velocity profiles in "waterfall" format where successive profiles are offset to the right. The profiles were biased to have zero vertical mean. The bottom panels give the east (bold line) and north (thin line) components of the depth-averaged relative velocity. Fig.10* Typical potential temperature vs. salinity and oxygen plots from the Natal Valley during RRS Charles Darwin cruise #29. Symbols represent rosette water sample data for those particular casts. The bottom plots are expanded scale to show deep theta/property consistency. Fig.11* Typical potential temperature vs. nutrient data plots from the Natal Valley during RRS Charles Darwin cruise #29. Phosphate data are represented by triangles, N+N by circles, and silicate by diamonds. The ordinates (potential temperature axes) are at the same scales as Figure 10*. Fig.12* Typical potential temperature vs. salinity and oxygen plots from the Mozambique Basin during RRS Charles Darwin cruise #29. Symbols represent rosette water sample data for those particular casts. The bottom plots are expanded scale to show deep theta/property consistency. Fig.13* Typical potential temperature vs. nutrient data plots from the Mozambique Basin during RRS Charles Darwin cruise #29. Phosphate data are represented by triangles, N+N by circles, and silicate by diamonds. The ordinates (potential temperature axes) are at the same scales as Figure 12*. Fig.14* Typical potential temperature vs. salinity and oxygen plots from the Madagascar Basin during RRS Charles Darwin cruise #29. Symbols represent rosette water sample data for those particular casts. The bottom plots are expanded scale to show deep theta/property consistency. Fig.15* Typical potential temperature vs. nutrient data plots from the Madagascar Basin during RRS Charles Darwin cruise #29. Phosphate data are represented by triangles, N+N by circles, and silicate by diamonds. The ordinates (potential temperature axes) are at the same scales as Figure 14*. Fig.16* Typical potential temperature vs. salinity and oxygen plots from the Crozet Basin during RRS Charles Darwin cruise #29. Symbols represent rosette water sample data for those particular casts. The bottom plots are expanded scale to show deep theta/property consistency. Fig.17* Typical potential temperature vs. nutrient data plots from the Crozet Basin during RRS Charles Darwin cruise #29. Phosphate data are represented by triangles, N+N by circles, and silicate by diamonds. The ordinates (potential temperature axes) are at the same scales as Figure 16*. Fig.18* Typical potential temperature vs. salinity and oxygen plots from the Central Indian Basin during RRS Charles Darwin cruise #29. Symbols represent rosette water sample data for those particular casts. The bottom plots are expanded scale to show deep theta/property consistency. Fig.19* Typical potential temperature vs. nutrient data plots from the Central Indian Basin during RRS Charles Darwin cruise #29. Phosphate data are represented by triangles, N+N by circles, and silicate by diamonds. The ordinates (potential temperature axes) are at the same scales as Figure 18*. Fig.20* Typical potential temperature vs. salinity and oxygen plots from the West Australian Basin during RRS Charles Darwin cruise #29. Symbols represent rosette water sample data for those particular casts. The bottom plots are expanded scale to show deep theta/property consistency. Fig.21* Typical potential temperature vs. nutrient data plots from the West Australian Basin during RRS Charles Darwin cruise #29. Phosphate data are represented by triangles, N+N by circles, and silicate by diamonds. The ordinates (potential temperature axes) are at the same scales as Figure 20*. Fig.22* Temperature vs. depth section of trans-Indian Ocean section. Vertical distortion of the full depth profiles is 500:1, while for the expanded shallow sections it is 1250:1. Fig.23* Salinity vs. depth section of trans-Indian Ocean section. Vertical distortion of the full depth profiles is 500:1, while for the expanded shallow sections it is 1250:1. Fig.24* Oxygen vs. depth section of trans-Indian Ocean section. Vertical distortion of the full depth profiles is 500:1, while for the expanded shallow sections it is 1250:1. Fig.25* Nitrate vs. depth section of trans-Indian Ocean section. Vertical distortion of the full depth profiles is 500:1, while for the expanded shallow sections it is 1250:1. Fig.26* Phosphate vs. depth section of trans-Indian Ocean section. Vertical distortion of the full depth profiles is 500:1, while for the expanded shallow sections it is 1250:1. Fig.27* Silicate vs. depth section of trans-Indian Ocean section. Vertical distortion of the full depth profiles is 500:1, while for the expanded shallow sections it is 1250:1. -------------------------------------------------------------------------------- Appendix A: Description of CTD #9 Data Adjustment Careful examination of deep (T < 4°C) potential temperature/ salinity data obtained with WHOI CTD #9 on the 320S trans-Indian Ocean section revealed a small discrepancy with the water sample measurements. As depicted in Figure Al, standard CTD data calibration techniques yielded CTD profiles which diverged from the water sample data below 0.8°C potential temperature by upwards of 0.002 psu. Salinity, computed from CTD data, is dependent on temperature, conductivity and pressure observations: each of which is subject to error. The relative sensitivity of calculated salinity to these variables is approximately 0.001°C, 0.001 mmho and 2.5 db per 0.001 psu change (based on EOS 80 and nominal values of 1.5°C, 34.7 psu and 4500 db.) Review of the temperature calibration data for CTD #9 from the pre- and post-cruise laboratory measurements indicated that the salinity discrepancy probably was not the product of error in the temperature calibration. The two laboratory calibrations were internally consistent over the full range of calibration temperatures to better than 0.002°C, and we believe the laboratory measurements have an absolute accuracy of 0.002°C. More importantly, because the salinity error occurred over a rather small temperature interval, the required adjustment of the temperature calibration curve to remove the salinity discrepancy would have induced strong change of curvature to the calibration curve below 1°C. Such structure in a calibration curve is outside our experience with CTD instruments. We therefore concluded that the temperature channel was not the source of the observed salinity problem. A change in the deep-water conductivity calibration algorithm was also ruled out. In order to match the water sample salinity data, a nonlinear conductivity correction would have been required. The NBIS CTD conductivity sensor, however, is inherently a linear device (N. Brown, personal communication, 1988). Some improvement between CTD and water sample data was obtained by setting to zero the coefficient of conductivity cell deformation with pressure. While full agreement might have been achieved by allowing this coefficient to be negative, we did not pursue this course as it implied non-physical behavior of the CTD sensor (cell expanding with increasing pressure). Hence by default, we concluded the salinity error was the product of pressure error. Using the figures above, a salinity error of 0.002 psu would result from a pressure error of 5 db. We suspect that residual temperature sensitivity in the pressure sensor was responsible for the pressure error, but we were unable to confirm this in the laboratory. Reduction of the data to final form utilized a modified cubic pressure calibration algorithm. The algorithm agreed with that derived from the polynomial least-square fit to the laboratory data at pressures less than 3000 db. At higher pressures, the final pressures were greater than those generated by the laboratory- derived calibration formula by the amount needed to force the CTD potential temperature/salinity curve to overlie the water sample data; the algorithm is reported in the main section of the text. For the bulk of the deep trans-Indian Ocean data, the adjustment caused an increase of bottom pressure by 10 db or less. Checks were made to insure that the resulting bottom pressure data were consistent with the acoustic depth recorded at each station. The pressure adjustments that were made were within the uncertainty of the acoustic depth data. Finally it should be noted that because this adjustment was made uniformly to all stations occupied with CTD #9, no spurious signal was introduced into the thermal wind shear field of the ocean interior. Potential does exist for shear error at the transitions between stations which used instruments #9 and #8 (station pairs 3-12 and 15-16). However, bottom pressures at these sites were 3000 db or less, levels where the pressure adjustment of CTD #9 was negligible. Figure A1*: Potential temperature vs. CTD salinity plot showing the discrepancy between CTD#9 data and corresponding rosette data in the very deep water. All CTD #9 data was subsequently adjusted as described in Appendix A. ------------------------------------------------------------------------ Appendix B: Station Listing Description Individual station listings have been created with the following information for the trans-Indian cruise. A description of the Fortran algorithms for computing all parameters except those involving integrals and gradients are documented in Unesco TR 44 "Algorithms for computation of fundamental properties of seawater" by N. P. Fofonoff and R. C. Millard. Starting at the left, the station variables are categorized in four groups as follows. The observed variables: temperature, salinity, and oxygen are vertically filtered values at the pressure level indicated. The standard Woods Hole Oceanographic Institution 2 db pressure-averaged CTD data are centered on odd pressure intervals (1,3,5,7,...) while the adopted pressure listing levels axe at even pressure values with the exception of 75 and 125 db. The 2 db temperature, salinity, and oxygen data were smoothed with a binomial filter (Unesco TR 54) and then linearly interpolated as required to the standard levels. The potential temperature, potential density anomaly, and potential density anomaly referenced to 2000 and 4000 db that follow in the listings were computed using the Fortran algorithms of Unesco TR 44. The dynamic height and potential energy are integral quantities from the surface to the pressure interval indicated. These assume that the value of the specific volume anomaly of the first level of the 2 db CTD data profile can be extrapolated to the sea surface. A trapezoidal integration method was employed. The next quantities: potential temperature and salinity gradients, potential vorticity, and Brunt- Väisälä frequency, involve the calculation of vertical gradients. Gradient quantities were estimated from a centered linear least squares fit calculated over half of the neighboring listing intervals. The calculated depth involves a dynamic height correction and a latitude dependent gravity correction. The header of each station listing contains the beginning time and position for the station. Positions are determined from a transit satellite navigator or by dead reckoning from last fix. The speed of sound is an average value computed from averaged travel time of the profile (Wilson, 1960). The water depth is from an echo sounder, corrected using the Carter tables. The columns of the station listing are: PRES DBAR Pressure (P) level in decibars. TEMP °C Temperature (T) in degrees Celsius calibrated on the 1968 International Practical Temperature Scale (IPTS 1968). SALT PSU Salinity (S) computed from conductivity (C), temperature, and pressure according to the 1978 practical salinity scale. (Unesco TR 44, pp. 6-12). C(35,15,0) = 42.914 mmho/cm. OXYG ML/L Oxygen in units of milliliters per liter. The partial pressure of oxygen is computed from the polargraphic electrode measurements using an algorithm described by Owens and Millard (1985). PTEMP °C Potential temperature theta in degrees Celsius computed by integrating the adiabatic lapse rate after Bryden (1973) (see Unesco TR 44, pp. 42-45). The reference level, Pr, for the calculation is 0.0 db. theta= theta (S, T, P, Pr). SIGTH kg/m^3 Potential density anomaly in kilograms/m^3. Obtained by computing the density anomaly gamma (S, T, P) (density - 1000 kg/m^3) at 0 pressure replacing the in situ temperature with potential temperature theta = theta (S, T, P, 0.0) referenced to 0 db. gamma-theta = gamma(S, theta, 0.0). SIGM2 kg/m^3 Potential density anomaly referenced to 2000 db in kilograms/m^3. Obtained by computing the density anomaly gamma (density - 1000 kg/m^3) at 2000 db using potential temperature referenced to 2000 db theta = theta (S, T, P, 2000), gamma-theta = gamma (S, theta, 2000). SIGM4 kg/m^3 Potential density anomaly referenced to 4000 db in kilograms/m^3. Obtained by computing the density anomaly 7 (density - 1000 kg/m') at 4000 db with potential temperature referenced to 4000 db theta = theta (S, T, P, 4000). gamma- theta = gamma (S, theta, 4000). DYN-HT 10(J/kg) Dynamic height in units of dynamic meters (10 Joules/kg) is the integral with pressure of specific volume anomaly (see The Sea, Volume I, p. 336 by Fofonoff 7 1962). POT. E 10^-5(J/m^2) Potential energy anomaly in 10^-5 Joules/m^2 is the integral with pressure of the specific volume anomaly multiplied by pressure (see The Sea, Volume I, p. 338 by Fofonoff, 1962). GRD-PT 10^3(°C/db) Potential temperature gradient in units of millidegrees Celsius per decibar. Estimated from the least squares temperature gradient over half the surrounding pressure intervals minus the center pressure adiabatic lapse rate. GRD-S 10^3(psu/db) Salinity gradient in psu per decibar. Estimated from the least squares salinity gradient over half the surrounding pressure intervals. POT-V 10^-12 ms^-1 Planetary potential vorticity in m^-1*s^-1. This is defined as f E, where f is the Coriolis frequency and E is the stability parameter (Millard et al., 1990) estimated over half the surrounding pressure intervals. B-V (1/hr) Brunt-Väisälä frequency in cycles per hour. This is the natural frequency of oscillation of a water parcel when vertically displaced from a rest position assuming no exchanges of heat or salt with surroundings. This calculation uses the adiabatic leveling of steric anomaly (Fofonoff, 1985; Millard et al., 1990). DEPTH (m) The depth of the pressure interval including the local gravity and dynamic height (see DYN-HT definition) corrections (see Unesco TR 44, pp. 25-28). ------------------------------------------------------------------------ Appendix C: Tritium, Helium, and Neon Observations INDIAN OCEAN 32S ST12 DEPTH T pot. SALINITY DELTA He DELTA Ne DELTA TRITIUM T-He3 db deg C permil He3 % ccSTP/g He % ccSTP/g Ne % TU AGE years 8.8 20.830 200 17.022 35.631 0.00 3.85 1.9 13.41 4.5 0.640 4.7 598 11.596 35.021 0.338 949 7.007 34.558 0.016 1148 4.756 34.465 2.60 4.10 3.5 17.87 4.8 57.0 1400 3.799 34.591 -0.003 1800 2.795 34.700 5.80 4.15 4.1 17.55 3.8 0.000 2202 2.417 34.774 6.50 4.28 5.9 18.48 5.5 2400 2.308 34.792 4.28 7.1 18.62 6.2 IND OCEAN 32 S ST 15 32 32.7S 33 24E ST 15 100 17.873 35.662 -0.7 3.82 1.2 15.83 2.6 0.910 2.1 200 17.048 -0.5 3.78 3.4 15.63 3.8 0.861 1.3 601 12.606 35.149 0.4 0.420 901 8.893 6.2 4.16 4.4 18.38 5.1 1502 3.652 34.546 7.8 4.46 12.0 19.11 10.3 1804 3.158 34.668 2001 2.780 34.708 6.2 4.18 4.7 18.45 5.7 3525 1.142 34.760 7.9 4.14 3.0 18.27 3.2 INDIAN OCEAN 32S 33 03S, 41 00E ST 26 6.8 19.172 35.706 -1.8 3.75 -0.2 15.79 2.7 0.685 -0.6 100 17.116 35.636 -1.3 3.95 4.2 16.01 3.0 0.793 0.5 200 15.939 35.529 -0.5 3.95 3.7 16.42 4.9 0.840 4.9 300 14.800 35.428 1.0 4.02 5.1 16.37 3.8 0.710 3.5 450 13.228 35.241 2.1 4.04 4.9 16.91 6.3 0.547 5.9 600 11.639 35.021 4.8 4.07 5.0 16.90 4.8 0.440 10.8 800 9.178 34.722 6.3 4.00 2.2 17.15 4.1 1000 6.225 34.474 6.4 4.11 3.8 17.63 4.2 0.178 1200 4.278 34.412 5.7 4.19 5.4 18.04 4.7 1500 3.244 34.553 7.3 4.15 4.0 18.19 4.6 1800 2.751 0.297 2100 2.487 34.747 0.123 2400 2.316 34.793 6.0 4.35 8.8 18.50 5.5 3300 1.740 34.797 0.005 4500 0.375 34.705 0.025 4900 0.229 34.695 5.8 4.41 10.3 18.60 5.9 5088 0.192 34.691 0.003 INDIAN OCEAN 32S ST 33 33 22.7S, 46 54E ST 33 0 19.068 35.577 3.77 0.2 15.56 1.1 0.711 0.1 54 17.338 35.580 -1.6 3.95 2.8 16.21 4.4 0.792 0.1 150 15.35 35.496 -1.1 3.98 4.3 16.54 3.6 0.8 350 13.396 35.276 -0.7 3.99 3.7 16.52 4.2 0.644 1.5 450 12.538 35.142 -1.2 4.01 3.9 16.87 5.3 0.402 1.2 850 7.604 34.717 4.3 4.12 4.7 17.72 5.5 1500 2.927 34.525 8.2 4.14 3.8 18.15 4.0 2100 2.287 34.724 4.20 5.2 18.31 4.3 2503 2.052 34.784 14.8 4.31 7.8 18.88 7.1 2701 1.819 34.784 4.33 8.3 3090 1.428 34.756 12.2 4.33 8.1 18.84 6.4 INDIAN OCEAN 32S ST35 33 33.6S, 48 14E ST35 0 19.594 35.532 -1.2 3.85 2.7 16.02 4.3 0.756 0.7 100 15.849 35.539 -2.0 3.87 1.8 16.12 2.9 0.680 -0.4 200 14.884 35.444 0.4 3.84 3.5 16.57 5.2 2.8 300 13.818 35.323 0.4 3.95 3.1 16.33 2.9 0.805 2.4 400 12.936 35.211 0.8 4.02 4.4 16.75 4.9 0.464 4.7 600 10.804 34.919 0.0 4.06 4.5 16.92 4.2 0.409 3.8 1000 5.341 34.461 2.8 4.14 4.3 17.90 5.0 10.9 1200 3.901 34.451 3.2 4.13 3.8 18.02 4.1 0.288 12.0 1400 3.169 34.489 5.2 4.12 3.2 18.09 3.9 1700 2.608 34.615 6.8 4.18 4.7 18.30 4.6 0.195 2400 2.004 34.739 16.9 4.30 7.6 18.53 5.3 2800 1.667 34.749 14.9 4.33 8.2 18.67 5.7 3200 1.227 34.731 9.6 4.34 8.2 18.88 6.4 3205 1.227 34.731 10.8 4.36 8.8 18.97 6.9 3782 0.842 34.721 6.8 4.29 6.8 18.78 5.4 0.000 4029 0.756 34.713 6.8 4.46 11.3 0.017 INDIAN OCEAN 32S ST39 33 59.9S, 52 44E ST39 10.1 19.350 35.625 -1.8 3.88 3.3 16.00 4.1 0.794 -0.1 200 15.488 35.507 -1.5 3.87 1.6 16.42 2.9 0.692 0.3 300 14.442 35.404 -1.6 3.97 3.6 16.45 4.1 0.707 0.1 500 12.676 35.172 5.1 4.00 3.7 16.45 2.8 700 10.373 34.867 4.8 4.04 3.9 16.70 2.5 0.577 8.8 900 7.499 34.569 5.0 4.05 3.0 17.43 4.3 1300 3.839 6.8 4.09 2.8 18.16 3.9 1500 3.174 34.482 7.9 4.14 4.0 18.18 4.4 0.144 1903 2.479 34.646 5.1 4.22 5.6 18.47 5.4 0.178 2801 1.640 34.742 7.8 4.31 7.8 18.17 4.9 3400 1.104 34.725 7.1 4.38 9.2 18.78 5.7 0.032 4001 0.840 34.716 5.6 4.43 10.3 19.30 8.3 4201 0.802 34.713 5.4 4.34 8.1 18.83 5.6 0.044 4402 0.773 4.8 4.27 6.4 18.58 4.2 INDIAN OCEAN 32S ST44 33 58.3S, 57 02E ST44 250 14.336 35.398 -0.3 3.90 1.8 15.96 0.9 0.758 1.8 400 13.333 35.276 0.3 3.95 2.7 16.53 3.8 0.742 2.5 500 12.289 35.104 1.6 4.02 4.0 16.78 4.5 0.705 4.2 600 11.308 34.969 1.2 4.00 3.3 16.51 2.1 4.3 800 8.717 34.675 1.8 4.09 4.4 17.18 3.9 5.9 1000 5.918 34.457 1.7 4.16 5.0 17.76 4.7 0.377 7.3 1200 4.350 34.401 3.4 4.07 2.2 17.67 2.6 0.033 40.0 1400 3.399 5.8 4.14 3.9 18.26 5.1 0.177 1600 2.978 34.525 6.6 4.16 4.3 0.000 2000 2.355 34.670 6.1 4.19 4.8 18.40 4.9 0.099 2600 1.908 34.734 6.8 4.26 6.6 18.55 5.3 0.129 3200 1.333 34.733 7.7 4.31 7.6 18.61 5.0 0.328 3800 0.533 34.705 6.9 4.33 7.9 19.05 4.8 0.105 4099 0.465 34.703 6.0 4.37 8.7 18.89 5.6 0.019 56.3 4401 0.376 34.700 0.004 4741 0.289 34.693 4.7 4.27 6.3 18.78 4.7 0.510 9.8 5103 0.210 34.690 6.0 4.40 9.4 19.09 6.4 0.393 13.2 5197 0.206 34.691 4.43 10.2 19.18 6.8 0.000 5197 0.209 34.691 4.37 8.7 19.01 5.9 INDIAN OCEAN 32S ST50 '33 59.3S, 61 59E ST 50 3.2 19.015 35.550 -1.6 3.85 2.4 16.23 5.3 0.898 0.1 200 14.193 35.400 -1.2 3.87 1.1 16.28 2.9 0.774 0.6 300 13.867 35.344 -0.8 4.00 4.3 16.62 4.8 0.481 1.8 600 11.328 34.962 1.8 4.07 5.0 16.89 4.4 0.412 7.0 800 8.718 34.671 2.1 4.11 4.9 17.29 4.6 1100 4.629 34.372 3.0 4.20 5.8 18.09 5.3 0.040 1200 3.946 34.368 0.103 1400 3.183 34.454 6.4 4.09 2.5 18.13 4.1 2400 1.904 34.726 8.9 4.25 6.3 18.80 6.7 3000 1.514 34.737 8.8 4.37 9.2 18.75 6.0 3300 1.352 34.726 7.2 4.30 7.4 18.04 1.8 0.034 3600 1.070 34.725 0.028 3900 0.708 34.709 6.6 4.28 6.6 18.76 5.1 0.157 25.0 4200 0.463 34.700 5.8 4.29 6.9 18.60 3.9 0.111 28.0 4500 0.285 34.692 0.010 4800 0.159 5.6 4.30 7.2 19.09 6.3 0.000 5187 0.096 34.686 5.9 4.25 5.7 18.69 3.9 INDIAN OCEAN 32S ST55 34 01S, 71 59E ST55 1.5 17.815 35.416 -1.4 3.86 2.0 16.03 3.4 0.624 0.5 70 15.823 35.437 -1.3 3.88 2.4 16.24 3.6 0.926 0.4 150 13.390 35.262 -1.5 4.00 4.1 16.61 4.3 0.809 0.2 250 12.689 35.224 -2.1 3.97 3.2 16.32 2.0 0.541 -0.1 350 12.102 35.077 4.00 3.6 16.73 4.1 0.333 450 11.501 34.982 -1.2 3.78 5.3 17.04 5.5 2.4 550 10.653 34.863 4.07 4.7 17.25 6.1 700 8.920 34.678 1.2 4.10 4.8 17.31 4.9 0.210 10.3 900 6.102 34.444 1.8 4.08 3.2 17.39 2.7 1300 3.238 34.438 3.8 4.26 6.8 18.33 5.3 1500 2.789 34.529 7.7 4.20 5.0 18.55 6.2 2200 1.917 34.726 14.7 4.22 5.4 18.50 5.1 3500 1.135 34.716 10.3 4.20 4.8 18.72 5.4 4100 0.771 34.708 7.2 4.31 7.4 18.82 5.5 0.169 24.5 4700 0.672 34.705 7.1 4.29 6.9 18.72 4.8 5055 0.668 34.705 5.6 4.19 4.3 18.44 3.3 INDIAN OCEAN 32S ST62 30 22.4S, 79 15E ST62 22 18.897 35.772 -1.4 3.95 5.0 16.13 4.8 0.636 0.5 100 16.265 35.622 3.1 3.88 2.1 16.24 4.0 0.762 5.4 200 13.646 35.335 5.3 3.98 3.8 16.27 2.4 0.645 8.5 300 12.301 35.121 5.7 4.06 5.2 16.45 2.5 0.608 9.3 400 11.377 34.975 8.7 4.06 4.7 16.86 4.4 0.741 10.4 500 10.666 34.875 6.6 4.00 3.0 16.45 1.2 0.603 10.2 700 9.183 34.686 8.8 3.99 2.1 17.59 6.8 800 8.235 9.8 4.19 6.8 17.30 4.2 1000 5.294 34.410 9.4 4.14 4.5 17.65 3.5 1100 4.332 34.408 7.2 4.19 5.3 17.60 2.3 1300 3.583 34.493 11.1 4.27 7.4 17.78 2.5 1500 3.169 34.572 9.0 4.20 5.4 18.02 3.5 2300 2.017 34.729 14.9 4.53 13.2 18.72 6.4 2700 1.576 34.742 10.9 4.42 10.3 18.69 5.7 2900 1.400 34.735 8.2 4.46 11.4 19.04 7.5 3100 1.258 34.732 6.4 4.20 4.9 18.68 5.3 3500 1.137 34.726 5.0 4.25 6.0 18.25 2.8 3792 1.121 34.726 5.5 4.32 7.8 18.83 6.0 INDIAN OCEAN 32S ST65 29 02S, 82E ST65 17 19.482 35.917 -1.2 3.84 2.5 15.93 3.8 0.706 0.7 100 16.089 35.593 3.8 3.87 1.9 15.97 2.3 0.707 6.5 200 13.485 35.283 4.8 4.10 6.8 16.74 5.2 0.679 7.7 301 12.229 35.102 5.5 4.04 5.1 0.782 7.5 400 11.340 34.971 9.4 4.06 4.7 16.77 3.8 0.767 10.6 500 10.539 34.863 6.9 4.09 5.0 16.98 4.3 0.767 8.7 700 8.752 34.651 8.1 4.18 6.6 17.37 5.1 1001 4.696 34.411 7.0 4.24 6.8 18.09 5.5 1100 4.110 34.418 6.6 4.21 5.9 18.32 5.8 1200 3.716 34.477 10.3 4.31 8.2 18.40 6.2 2000 2.290 34.708 12.4 4.31 7.8 18.56 5.8 2500 1.737 34.732 11.9 4.28 7.0 18.65 5.7 3100 1.263 34.735 7.0 4.31 7.6 18.86 6.0 4000 1.057 34.722 6.8 4.25 5.9 18.72 5.3 4167 1.049 0 5.9 4.17 4.0 18.65 4.9 INDIAN OCEAN 32S ST69 29 32.1S, 86 55E ST69 2.6 21.593 36.528 -1.5 3.74 0.9 15.59 2.9 0.599 0.3 100 18.010 35.853 -0.9 3.91 3.6 15.91 3.0 0.635 1.2 200 14.776 35.492 0.6 4.00 4.5 16.50 4.8 0.712 3.0 300 12.632 35.177 4.04 7.4 16.82 5.1 0.652 400 11.408 34.989 1.8 4.02 3.9 16.84 4.2 0.783 4.0 500 10.519 34.865 0.9 4.04 4.0 17.06 4.8 4.6 600 9.746 34.765 4.3 4.07 4.3 17.10 4.4 0.406 10.8 700 8.971 34.665 5.8 4.09 4.5 17.37 5.2 0.000 800 7.894 34.567 7.9 4.11 5.0 17.36 4.3 900 6.339 34.461 9.5 4.13 4.8 17.82 5.5 0.080 1000 4.808 34.403 9.3 4.24 6.8 18.13 5.8 0.040 1100 4.238 34.464 10.2 4.14 4.1 17.76 3.1 1300 3.463 34.529 9.8 4.27 7.2 18.05 3.9 0.058 1700 2.702 34.653 10.9 4.27 6.9 18.49 5.8 0.340 2300 1.940 34.724 11.2 4.30 7.5 18.67 6.0 0.086 2700 1.575 34.730 13.7 4.31 7.8 18.79 6.3 3300 1.197 34.724 12.0 4.29 7.0 18.85 6.2 3585 1.069 34.721 11.5 4.33 8.0 18.92 6.6 INDIAN OCEAN 32S ST80 31 59.8S, 99E ST80 8.4 18.875 35.984 -1.7 3.88 3.3 15.91 3.5 0.674 -0.3 60 17.503 35.961 -1.7 3.85 2.1 16.04 3.6 0.649 -0.3 120 16.482 35.874 -1.1 3.99 5.2 15.99 2.7 0.754 0.8 200 15.846 35.759 -0.3 3.94 4.0 16.51 5.6 0.793 1.7 300 13.651 35.391 4.8 4.09 6.7 16.23 2.2 0.529 9.4 400 11.856 35.089 0.502 500 10.648 34.871 6.3 4.10 5.4 16.85 3.6 0.345 14.9 700 9.040 34.653 6.3 4.18 6.9 17.43 5.7 800 8.539 34.595 6.5 4.19 6.6 17.28 4.3 901 7.324 34.509 6.6 4.14 5.1 17.51 4.6 1000 5.582 34.415 5.8 4.15 4.8 17.73 4.1 1198 3.873 34.421 0.000 1600 2.945 34.584 6.8 4.34 8.8 18.28 4.8 0.401 14.0 1800 2.649 34.645 1950 2.482 34.674 5.1 4.24 6.1 18.72 6.9 2104 2.241 34.704 6.9 4.16 4.1 18.35 4.5 INDIAN OCEAN 32S ST88 32 44.8S 103.24E ST88 9.8 17.530 35.709 -1.4 3.85 1.9 16.05 3.6 0.718 0.4 102 14.208 35.474 -0.4 3.94 2.9 16.36 3.4 0.846 1.5 200 12.434 35.158 1.8 4.08 5.8 16.81 4.9 0.851 3.7 300 10.983 34.923 4.2 4.02 3.6 16.89 4.1 400 10.352 34.825 7.2 4.17 7.0 17.41 6.8 500 9.631 34.726 9.7 4.17 6.8 17.37 5.9 0.409 700 8.323 34.594 8.6 4.11 4.8 17.36 4.7 898 5.600 34.404 9.3 4.17 5.3 17.83 4.8 0.000 1100 3.912 34.403 9.6 4.31 8.4 18.26 5.6 0.009 1300 3.364 34.512 10.1 4.28 7.4 18.21 4.9 0.000 1500 3.025 34.581 1797 2.609 34.662 9.6 4.31 7.9 18.52 5.9 0.212 2101 2.229 34.703 2401 1.929 34.730 8.4 4.41 10.3 18.87 7.1 0.076 2703 1.653 34.736 3000 1.413 34.737 10.0 4.35 8.5 18.83 6.4 3300 1.131 34.729 3600 0.929 34.721 8.5 4.38 9.2 18.82 5.7 3906 0.761 34.717 8.5 4.41 9.9 19.02 6.7 0.009 4208 0.661 34.711 4501 0.606 34.707 7.9 4.28 6.7 18.56 4.1 4806 0.573 34.705 5102 0.550 34.705 7.5 4.31 7.4 18.81 5.2 5336 0.539 34.700 8.2 4.35 8.2 19.12 6.9 0.242 21.3 INDIAN OCEAN 32S ST94 33 53.6S. 107 13E ST94 13.4 17.901 35.893 -1.6 3.87 2.8 16.02 3.9 0.649 0.2 100 15.703 35.700 0.0 3.86 1.6 16.17 3.3 0.806 2.0 200 13.466 35.350 2.1 4.01 3.3 16.77 4.2 0.682 4.9 300 11.210 34.963 0.8 4.12 6.4 17.10 5.6 0.060 21.5 400 9.983 34.771 3.7 4.08 4.8 17.14 4.8 500 9.347 34.686 4.9 4.11 5.2 17.10 4.0 600 8.687 34.611 7.8 4.18 6.7 17.35 4.9 700 8.001 34.552 8.4 4.17 6.1 17.52 5.3 800 6.610 34.464 8.1 4.21 6.6 17.78 5.5 900 5.147 34.396 7.9 4.22 7.4 18.15 6.2 1000 4.269 34.396 8.8 4.28 7.7 18.06 4.8 1200 3.509 34.482 7.6 4.38 9.8 18.55 6.9 1800 2.475 34.665 7.9 4.21 5.4 18.27 4.3 2600 1.752 34.728 8.8 4.32 8.1 18.67 5.8 3400 1.220 34.731 15.0 4.24 5.9 18.86 6.3 4200 0.817 34.715 6.4 4.29 6.9 18.66 4.7 4900 0.558 34.705 10.9 4.27 6.3 18.58 3.9 5375 0.507 34.707 8.6 4.31 7.2 18.86 5.4 INDIAN OCEAN 32S ST97 34 10S, 109 09E ST97 100 14.903 35.595 -1.0 3.95 3.6 16.40 4.2 200 13.782 35.394 -0.8 3.94 2.8 16.47 3.8 300 12.067 35.092 -1.2 4.05 4.9 16.64 3.5 400 10.084 34.770 -1.6 4.05 3.9 17.10 4.6 0.313 0.3 500 9.479 34.697 0.2 4.15 6.1 17.19 4.7 600 8.918 34.638 2.3 4.15 6.0 17.43 5.5 700 8.302 34.563 6.3 4.13 5.5 17.39 4.8 800 7.186 34.488 7.1 4.23 7.4 17.43 4.0 900 5.766 0.000 9.1 4.27 7.8 18.01 6.1 1000 4.508 34.370 10.8 4.30 8.3 18.30 6.4 1300 3.284 0.000 11.4 4.23 6.2 18.32 5.3 0.055 1900 2.400 34.677 11.8 4.26 6.7 18.39 4.9 2500 1.844 34.727 12.4 4.29 7.3 18.54 5.2 3100 1.453 34.732 12.1 4.23 5.8 18.58 5.0 3800 1.020 34.725 11.4 4.33 7.9 18.63 4.7 4000 0.898 34.716 10.5 4.35 8.4 18.92 6.2 5138 0.515 34.702 9.7 4.27 6.2 18.89 5.6 INDIAN OCEAN 32S ST105 ST105 2.5 19.145 35.880 -1.8 3.80 1.1 15.65 1.9 100 16.182 35.696 -1.1 4.09 7.9 16.64 6.6 200 14.235 35.446 -0.2 4,02 5.1 16.48 4.2 400 9.452 34.704 4.06 3.9 17.15 4.4 500 8.643 34.608 -0.6 4.07 4.0 17.17 3.8 600 7.711 34.524 2.1 4.12 4.8 17.35 4.0 700 6.156 34.437 4.13 4.4 17.83 5.3 800 4.902 34.394 8.2 4.13 4.1 17.68 3.3 900 4.231 34.413 10.4 4.21 5.8 17.74 2.9 1000 3.999 34.473 10.8 4.12 3.6 17.95 3.9 1080 3.877 34.482 11.1 4.12 3.6 17.94 3.8 INDIAN OCEAN 32S ST106 ST 106 3.5 19.395 35.855 -1.5 3.86 3.1 15.78 2.8 0.698 0.3 100 16.957 35.769 -0.9 4.10 8.3 16.47 5.9 0.477 1.6 200 16.425 35.734 0.0 4.00 5.4 16.29 4.5 0.341 4.4 300 12.389 4.01 4.2 16.90 4.5 400 9.542 34.718 4.08 4.6 17.03 3.8 500 8.659 34.618 0.5 4.12 5.1 17.26 4.3 600 7.199 34.510 2.5 4.11 4.5 17.41 3.9 687 6.062 34.437 6.9 4.15 4.9 17.79 5.0 Precision + - 0.2 0.01 1 0.04 1 0.010 HELIUM AND NEON COLUMNS *1E-8 * All figures shown in PDF file.