ABSTRACT Chipman, D. W., T. Takahashi, D. Breger, and S. C. Sutherland. 1994. Carbon Dioxide, Hydrographic, and Chemical Data Obtained During the R/V Meteor Cruise 11/5 in the South Atlantic and Northern Weddell Sea Areas (WOCE sections A-12 and A-21). ORNL/CDIAC-55, NDP-045. Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, Oak Ridge, Tennessee. This document presents the procedures and methods used to obtain carbon dioxide (CO2), hydrographic, and chemical data during the R/V Meteor Expedition 11/5 in the South Atlantic Ocean, including the Drake Passage (Section A-12); the Northern Weddell Sea; and the Eastern South Atlantic Ocean (Section A-21). This cruise was conducted as part of the World Ocean Circulation Experiment (WOCE). The cruise started from Ushuaia, Argentina, on January 23, 1990, and ended at Capetown, South Africa on March 8, 1990. Samples were collected at 78 stations that covered the Drake Passage (56-63 S); the Northern Weddell Sea (45-35 W); a section along the 58 W parallel (25 W-prime meridian); and two segmented S-N sections between the Northern Weddell Sea and Capetown, South Africa. Measurements taken at WOCE sections A-12 and A-21 included pressure, temperature, salinity measured by the Conductivity, Temperature and Depth sensor (CTD); bottle salinity; oxygen; phosphate; nitrate; nitrite; silicate; total carbon concentration (TCO2); and partial pressure of CO2 (pCO2) measured at 20 C. In addition, potential density at 0 decibar (dbar) and potential temperature were calculated from the measured variables. The TCO2 concentration in seawater samples was measured using a coulometer with an estimated precision of approximately 1 umol/kg. The coulometer was calibrated frequently at sea by using a high- precision gas pipette and CO2 gas (99.998%). The pCO2 value in seawater samples was measured at 20 C by means of a constant volume (500 ml seawater) equilibrator and a gas chromatograph. CO2 in equilibrated gas was first converted to methane, by using a ruthenium catalyst, and then measured by a flame-ionization detector. The precision of pCO2 measurements has been estimated to be approximately 0.1%. The CO2 investigation during the R/V Meteor Cruise 11/5 was supported by a grant from the U.S. Department of Energy (No. DE-FGO2-90ER60943). The data set is available, free of charge, as a Numeric Data Package (NDP) from CDIAC. The NDP consists of seven data files and this printed documentation, which describes the contents and format of all data files as well as the procedures and methods used to obtain these data during the R/V Meteor Cruise 11/5. Keywords: Carbon dioxide; World Ocean Circulation Experiment (WOCE); South Atlantic Ocean; Weddell Sea; hydrographic measurements; carbon cycle. BACKGROUND INFORMATION The World Ocean plays a dynamic role in the Earth's climate: it captures heat from the sun, transports it, and releases it thousands of miles away. These oceanic-solar-atmospheric interactions affect winds, rainfall patterns, and temperatures on a global scale. The oceans also play a major role in global carbon cycle processes. Carbon in the oceans is unevenly distributed because of complex circulation patterns and biogeochemical cycles, neither of which is completely understood. In addition to circulation patterns, biological processes (i.e., photosynthesis and respiration) play a crucial role in the carbon cycle. The oceans are estimated to hold 38,000 gigatons of carbon, which is 50 times more carbon than that in the atmosphere and 20 times more carbon than that held by plants, animals, and the soil (Williams 1990). Thus, if only 2% of the carbon stored in the oceans is released, the level of atmospheric carbon dioxide (CO2) would double (Williams 1990). Furthermore, every year more than 15 times as much CO2 is exchanged across the sea surface than the amount produced by the burning of fossil fuels, deforestation, and other human activities (Williams 1990). Several large experiments were conducted in the past, and others are currently under way, attempting to better understand the oceans and their role in climate and the global carbon cycle. One of the earliest large-scale oceanographic projects was the Geochemical Ocean Section Study (GEOSECS). The goal of GEOSECS was to study geochemical properties of the oceans with respect to large-scale circulation problems. The project, which covered the Atlantic (1972-73), Pacific (1973-74), and Indian (1977-78) oceans, officially started in 1971 and was noted for its use of equipment and techniques that were at the forefront of modern technology and knowledge. The Transient Tracers in the Ocean (TTO) project (1982) was designed to measure the distribution of CO2 and hydrographic properties in the North Atlantic Ocean. The World Ocean Circulation Experiment (WOCE) started in 1990 and is currently under way. WOCE is the first research program of sufficient scope to mount a true global study of the ocean. WOCE brings together the expertise of scientists and technicians from many nations in an oceanographic experiment that is larger than any ever attempted. Another multinational program currently under way is the Joint Global Ocean Flux Study (JGOFS). The purpose of JGOFS is to investigate the processes controlling marine biogeochemical cycles, specifically carbon and nutrient cycles. During the lifetime of the WOCE project, from 1990 to 1997, approximately 23,000 stations will be sampled in oceans around the world. This document provides and describes data collected during a 45-day expedition in the South Atlantic Ocean, Northern Weddell Sea, and Drake Passage aboard the German research vessel Meteor. The cruise, referred to as cruise number 11, leg 5 (11/5), was conducted during the austral summer. It started at Ushuaia, Argentina, on January 23, 1990, and ended at Capetown, South Africa, on March 8, 1990. Seventy-eight stations were occupied along the WOCE sections A-21 and A-12. The CO2 investigation during the R/V Meteor Cruise 11/5 was supported by a grant from the U.S. Department of Energy (DOE) No. DE-FGO2-90ER60943. 2. DESCRIPTION OF THE EXPEDITION 2.1 R/V Meteor, Technical Details and History The research vessel Meteor is owned by the Federal Republic of Germany and is operated by the Federal Ministry for Research and Technology. The basic features of the vessel are described below. Port of registration: Hamburg Call sign: DBBH Classification: GL+100A4E2+MC Auto Operator: University of Hamburg, Institute for Ocean Research Built: 1985 86 at Schlichting Werft, Travemunde Basic dimensions: GRT: 3990, NRT 1284; Displacement: 4780t; Length o.a.: 97.50 m; Beam: 16.50 m; Draught: max. 5.60 m; Service speed: 12 kn; Depth main deck: 7.70 m Personnel: Crew: 32; Scientists: 30 Main engine: 4 X Mak6M 322 = 4 X 1,000kW at 750 rpm Propulsion: Diesel-electrical, Tandem-Motor = 2 X 1,150 kW Fuel consumption: approximately 12.0 t IFO 80 per day at service speed Maximum cruise duration: 60 days Nautical equipment: Integrated navigation system with data transfer to position computer, echosounder synchronization and supervision, data-processing facility Science quarters: 20 laboratories on the main deck with approximately 400 m2 of working space for multidisciplinary research The original Meteor (I) was constructed in 1925; it was the first research and survey vessel of that name. R/V Meteor was owned by the German navy and was based in Wilhelmshaven. One of the Meteor's first expeditions was the German Atlantic Ocean Expedition of 1925-27, which was organized by the Institute of Marine Research in Berlin. Thereafter, the vessel was used for German physical, chemical, and microbiological marine investigations and for navy surveying and fisheries protection duties. The Meteor (II) was planned since the end of the 1950s and was operated by the Deutsche Forschungsgemeinschaft (German Science Community) in Bad Godesberg and the Deutsches Hydrographisches Institut (German Hydrographic Institute) in Hamburg. Meteor (II) was commissioned in 1964 and participated in the International Indian Ocean Expedition. It was replaced by the newly built, multipurpose vessel Meteor (III), which was completed in 1986. The Hamburg-based Meteor (III) is used for German ocean research worldwide and for cooperative efforts with other nations in this field. The vessel serves scientists of all marine disciplines in all of the world's oceans. 2.2 R/V Meteor Cruise 11/5 Information The following is the cruise information: Ship Name: Meteor Cruise/Leg: 11/5 Location: Ushuaia, Argentina, to Cape Town, South Africa Dates: January 23-March 8, 1990 Funding: German Science Community Federal Ministry of Research and Technology, Bonn, Germany Chief Scientist: Dr. Wolfgang Roether University of Bremen, Germany Parameters measured, institution, and responsible Principal Investigators (PI): Parameter Institution PI CTD, Salinity Alfred Wegner Institute, Bremerhaven G. Rohardt, E. Fahrbach Nutrients, Oxygen Scripps Institution of Oceanography (SIO) J. Swift, F. Delahoyde CFM's University of Bremen W. Roether Tritium, 3He University of Bremen W. Roether 14C (L-V and AMS) University of Heidelberg P. Schlosser, K. O. Munnich 39Ar University of Bern H. H. Loosli 85Kr Lamont-Doherty Earth Observatory W. M. Smethie TCO2 and pCO2 Lamont-Doherty Earth Observatory D. Chipman, T. Takahashi 226/228Ra Princeton University, Univ. of Kiel R. Key, M. Rhein XBT Alfred Wegner Institute, Bremerhaven U. Schauer, E. Farhrbach ADCP Alfred Wegner Institute, Bremerhaven E. Farhrbach CTD-intercomparison AWI, SIO G. Rohardt, F. Delahoyde ALACE Drifter SIO, Texas A&M University R. Davis, W. D. Nowlin 2.3 Brief cruise summary The R/V Meteor left Ushuaia on the morning of January 23, 1990. The next morning, sampling started southwest of Cape Horn and continued south-ward at 30-nm station spacing. Basic equipment included a Neil Brown Mark IIIB CTD (AWI, calibrated at SIO Oceanographic Data Facility) and a 24 12 liter General Oceanic rosette system. Large-volume stations were placed between the fronts in order to characterize the four principle hydrographic zones of the passage (Sievers and Nowlin 1984). Apart from pCO2, which became operative only toward the end of the section, all measurements were carried out successfully. Measurements of salinity, oxygen, and nutrients (nitrate, nitrite, silicate, and phosphate) were made in the standard fashion. The weather was advantageous for all of the Drake Passage section work. After 3 days of station work, the winch computer system malfunctioned. The ship crew managed to provide makeshift operation for the CTD/Rosette winch, and the trawl winch operation for large-volume sampling was similarly resumed 2 days later. It was decided to continue the section and then return to Ushuaia for repairs. The section was concluded after sampling near the South Shetland Arc shelf off Smith Island. During the section, 13 standard and 4 large-volume stations were occupied. However, the large-volume samples in the Polar Frontal Zone were collected on the way back to Ushuaia (i.e. not simultaneously with the corresponding main CTD/Rosette work). In total, at least 4 days were lost as a result of the winch malfunction. After the vessel left Ushuaia (February 3, 1990) the second time, station work resumed on February 6, 1990, with a short section north and east of the South Orkney Islands (Stations 122 131). On February 12, 1990, after rounding Southern Thule of the South Sandwich Islands, sampling began on WOCE section A-12 (stations 132 179), and continued up to the African shelf until the morning of March 8, 1990, when R/V METEOR entered Cape Town. A historic comment: From January 21 to March 10, 1926, the original Meteor (I) also explored a transect from Ushuaia to Cape Town, which was leg 5 of its famous South Atlantic survey. The scientific topic, i.e. hydrography, was quite similar. A total of 34 stations were sampled (6 across Drake Passage), 3 properties were measured (temperature, salinity, and oxygen), and 26 depths typically were sampled (in 3 casts) (Roether et al. 1990). 3. DESCRIPTION OF VARIABLES Data file m115.dat in this numeric data package contains the following variables: station numbers; cast numbers; sample numbers; bottle numbers; CTD pressures; CTD temperatures; CTD salinities; potential temperatures; bottle salinities; concentrations of dissolved oxygen, silicate, nitrate, nitrite, phosphate; total CO2 concentrations; partial pressures of CO2 at 20 C; potential densities at 0 dbar; and quality flags. Station inventory file m115sta.inv contains section numbers; station numbers; latitude, longitude, sampling date (i.e., day, month, and year), and bottom depth for each station. The temperature and pressure readings of the Neil Brown IIIB CTD unit were corrected through the use of 4-6 pairs of reversing thermometers; the electrical conductivity readings were corrected by using the salinity values determined aboard the ship for all 24 Niskin samplers. A Guildline Autosal 8400A salinometer and the Wormley Salinity Standards were used for the determination of salinity in the discrete water samples. The precision of the measurements obtained by the CTD unit has been estimated to be 0.002 C for temperature and 0.002 PSS for salinity. Potential temperature and potential density values were computed through the use of the potential temperature algorithm of Fofonoff (1980), the International Equation of State for Seawater (Millero et al. 1980), and Bryden's (1973) formulation for the adiabatic temperature gradient. The concentration of dissolved oxygen was determined by means of the Winkler titration method. A molar volume at STP of 22.385 liter/mole (Kester 1975) was used to convert oxygen concentrations from milliliter per liter to micromoles per kilogram of seawater at the in situ temperature. The concentrations of nitrate, nitrite, phosphate, and silicate dissolved in the seawater samples were determined through the use of standard calorimetric methods with an Auto-Analyzer. Determinations were generally made within 6 hours of collection. The water samples were stored in a refrigerator at 4 C before analysis. All of the concentration values are expressed in units of per kilogram of seawater, although analytical samples were isolated by volumetric means. For the conversion from the volume to the mass of seawater sample, the density of each water sample was computed by using the International Equation of State for Seawater (Millero et al. 1980) and the measured salinity and the temperature at which the volumetric measurements were made. The total CO2 concentration in approximately 1300 seawater samples and the CO2 partial pressure in approximately 870 seawater samples collected at 76 stations were determined aboard the ship. The TCO2 concentration in seawater samples was determined by the use of a coulometric system, which was modified from that described by Johnson et al. (1985). For analysis, the seawater was introduced into the stripping chamber using fixed-volume syringes. The sample was acidified with 1 ml of 8.5% phosphoric acid while it was in the stripping chamber, where the evolved CO2 gas was swept from the sample and transferred with a stream of CO2-free air into the electrochemical cell of the CO2 coulometer (UTC-Coulometric Model-5011). In the coulometer cell, the CO2 was quantitatively absorbed by a solution of ethanolamine in dimethylsulfoxide (DMSO). Reaction between the CO2 and the ethanolamine formed the weak hydroxyethylcarbamic acid. The pH change of the solution associated with the formation of the acid resulted in a color change of the thymophthalein pH indicator in the solution. The color change, from deep blue to colorless, was detected by a photodiode, which continually monitored the transmissivity of the solution. The electronic circuitry of the coulometer, on detecting the change in the color of the pH indicator, caused a current to be passed through the cell generating hydroxyl (OH-) ions from a small amount of water in the solution. The OH- that was generated titrated the acid, returning the solution to its original pH (and hence color); the circuitry then interrupted the current flow. The product of current passed through the cell and time was related by the Faraday constant to the number of moles of OH- generated to titrate the acid and hence to the number of moles of CO2 absorbed to form the acid. The volumes delivered by the constant-volume syringes were determined by repeatedly weighing distilled water dispensed in the same manner as a sample; the volume was calculated from the delivered weight by using the density of pure water at the temperature of the measurement and a buoyancy correction for the air displaced by the water (amounts to approximately 0.1% of the weight of the water). The density of the seawater in the pipet was calculated at the temperature of injection by using the International Equation of State (Millero et al. 1980). The coulometer was calibrated by introducing research-grade CO2 gas (99.998%) into the carrier gas line upstream of the extraction tube, using a pair of fixed-volume sample loops on a gas-sampling valve and measuring the gas pressure in the loops as the gas was vented to the ambient atmosphere, and determining the barometric pressure by means of the electronic barometer used with the pCO2 system. The loop temperature was measured to 0.05 C with a thermometer calibrated against one traceable to the National Institute of Standards and Technology (NIST), and the non-ideality of CO2 was incorporated in the computation of the loop contents. The volume of the calibration loop had previously been determined by weighing empty loops and then loops filled with mercury. The volumes of these loops have additionally been checked by comparing the amount of CO2 introduced by them with the amount derived from gravimetric samples of calcium carbonate and sodium carbonate. They were found to be accurate to within 0.1%. During the expedition, the coulometer was calibrated several times daily by using the calibrated loop and pure CO2 gas. In order to evaluate the long-term reproducibility and precision of the coulometric determination of CO2 in seawater, a number of sample bottles were filled with a homogeneous sample of surface water and deep water. Bottles made of Pyrex glass and PET plastic (500 ml and 1000 ml, respectively) were used. Bottled samples were poisoned with mercuric chloride solutions (200 ul for each 500-ml water sample) and analyzed for total CO2 during the expedition. On the basis of these measurements, the precision of TCO2 measurements during this expedition was estimated to be approximately 1 umol/kg. Additional details on the TCO2 measurements are discussed in Chipman et al. (1992). A fully automated equilibrator-gas chromatograph system was used during the expedition to determined the pCO2 exerted by the seawater samples. Prior to analysis, the sample flasks were brought to 20 C in the thermostated water bath, and approximately 45 ml of seawater was displaced with air that had a known CO2 concentration. The air in the flasks and in the tubing connecting the flasks to the sample loop of the gas chromatograph was recirculated continuously for approximately 20 minutes; the gas disperser about 1 cm below the water surface provided a large contact area between the water and air bubbles. At the end of the equilibration period, the circulation pump was switched off, and the air pressure throughout the system was allowed to equalize. A 1-ml aliquot of the equilibrated air was isolated from the equilibration subsystem and injected into the carrier gas stream of the gas chromatograph by cycling the gas sampling valve to which the sample loop was attached. After chromatographic separation, the CO2 was converted into methane and water vapor through a reaction with the hydrogen carrier in the catalytic converter. The methane produced by this reaction was then measured with a precision of 0.05% (one standard deviation) by the flame ionization detector. The concentration of CO2 in the sample was determined through comparison with the peak areas of known amounts of CO2 from injections of three reference gas mixtures, which were calibrated against the World Meteorological Organization standards created by C. D. Keeling. The reference gas mixtures were injected into the gas chromatograph by means of the same sample loop used for the equilibrated air samples; the pressure of the gas in the sample loop at the time of injection was determined by venting the loop to atmospheric pressure and measuring that pressure by means of a high-accuracy electronic barometer (Setra Systems, Inc., Model 270, accuracy 0.3 millibar; calibration traceable to the NIST provided by the manufacturer). The sample loop was located within the well-controlled temperature environment of the column oven of the gas chromatograph; hence, all injections were made at a constant temperature. The equilibrated air samples were saturated with water vapor at the temperature of equilibration and had the same pCO2 as the water sample. By injecting the air aliquot without removing the water vapor, the partial pressure of CO2 was determined directly, without the need to know the water vapor pressure (Takahashi et al. 1982). However, was necessary to know the pressure of equilibration, which was controlled by keeping the equilibrator flask at atmospheric pressure. The atmospheric pressure was, in turn, measured with the electronic barometer at the time each equilibrated air sample was injected into the gas chromatograph. Corrections were required to account for the change in pCO2 of the sample water as a result of the transfer of CO2 to or from the water during equilibration with the recirculating air. The overall precision of the pCO2 measurement is estimated to be about 0.10%, based on the reproducibility of replicate equilibrations. Greater details on the pCO2 measurements are discussed in Chipman et al. (1992). 4. DATA CHECKS PERFORMED BY CDIAC An important part of the numeric data package (NDP) process at the Carbon Dioxide Information Analysis Center (CDIAC) involves the quality assurance (QA) of data before distribution. Data received at CDIAC are rarely in a condition that would permit immediate distribution, regardless of the source. To guarantee data of the highest possible quality, CDIAC conducts extensive QA reviews. Reviews involve examining the data for completeness, reasonableness, and accuracy. Although they have common objectives, these reviews are tailored to each data set, often requiring extensive programming efforts. In short, the QA process is a critical component in the value-added concept of supplying accurate, usable data for researchers. The following summarizes the checks performed by CDIAC on the data obtained during the R/V Meteor 11/5 Expedition in the South Atlantic Ocean and Northern Weddell Sea areas. 1. These data were provided to CDIAC in three files: CO2 measurements, along with downgraded hydrographic and chemical data, provided by Taro Takahashi and David Chipman from Lamont-Doherty Earth Observatory; hydrographic and chemical measurements, and station information files provided by the WOCE Hydrographic Program Office (WHPO) after quality evaluation; FORTRAN 77 retrieval code written and used to merge and reformat the first two data files. 2. All data were plotted by using a PLOTNEST.C program written by Stewart C. Sutherland (LDEO) to check for obvious outliers. The program plots a series of nested profiles, using the station number as an offset; the first station is defined at the beginning, and subsequent stations are offset by a fixed interval. Some outliers were identified and removed after consultation with the principal investigators. 3. Property-property plots for all parameters were generated, carefully examined, and compared with plots from previous expeditions in the South Atlantic Ocean to identify "noisy" data and possible systematic, methodological errors. 4. All variables were checked for values exceeding physical limits, such as sampling depth values that are greater than the given bottom depths. 5. Station locations (latitudes and longitudes) and sampling times were examined for consistency with maps and with cruise information supplied by Chipman et al. (1992). 6. The designation for missing values, given as -9.0 in the original files, was changed to -999.9. 5. HOW TO OBTAIN THE DATA AND DOCUMENTATION This data base is available in machine-readable form, on request, from CDIAC free of charge. CDIAC will also distribute subsets of the data base as needed. It can be acquired on 9-track magnetic tape; 8-mm tape; 150-mB, quarter-inch tape cartridge; IBM-formatted floppy diskettes; or from CDIAC's anonymous File Transfer Protocol (FTP) area via Internet (see FTP address below). Requests should include any specific media instructions (i.e., 1600 or 6250 BPI, labeled or nonlabeled, ASCII or EBCDIC characters, and variable- or fixed-length records; 3.5- or 5.25-inch floppy diskettes, high or low density; 8200 or 8500 format, 8-mm tape) required by the user to access the data. Magnetic tape requests not accompanied by specific instructions will be filled on 9-track, 6250 BPI, standard-labeled tapes with EBCDIC characters. Requests should be addressed to: Carbon Dioxide Information Analysis Center Oak Ridge National Laboratory Post Office Box 2008 Oak Ridge, Tennessee 37831-6335 U.S.A. Telephone: (615) 574-0390 or (615) 574-3645 Fax: (615) 574-2232 Electronic Mail: BITNET: CDP@ORNLSTC INTERNET: CDP@STC10.CTD.ORNL.GOV OMNET: CDIAC The data files can be also acquired from CDIAC's anonymous FTP account via Internet: FTP to cdiac.esd.ornl.gov (128.219.24.36) Enter "ftp" or "anonymous" as the userid Enter your electronic mail address as the password (e.g.,"alex@alex.esd.ornl.gov") Change to the directory "/pub/ndp045" Acquire the files using the FTP "get" or "mget" command 6. REFERENCES Bryden, H. L. 1973. New polynomials for thermal expansion, adiabatic temperature gradient and potential temperature of seawater. Deep-Sea Research 20: 401 08. Chipman, D., T. Takahashi, D. Breger, S. Sutherland. 1992. Investigation of carbon dioxide in the South Atlantic and Northern Weddell Sea Areas (WOCE Sections A-12 and A-21) during the Meteor Expedition 11/5, January March 1990. Lamont-Doherty Geological Observatory of Columbia University, Palisades, N.Y. Clark, W. C. 1982. Carbon dioxide review. Clarendon Press and Oxford Press, Oxford, England, and New York. Fofonoff, N. P. 1980. Computation of potential temperature of seawater for an arbitrary reference pressure. Deep-Sea Research 24: 489 91. Johnson, K. M., A. E. King, and M. Sirburth. 1985. Coulometric TCO2 analyses for marine studies: An introduction. Marine Chemistry 16: 61 82. Kester, D. R. 1975. Dissolved gases other than CO2. pp. 497 556. In 2nd Edition, J.P. Riley, G. Skirrow (eds.), Chemical Oceanography. Academic Press, London. Vol.1. Millero, F. J., C.-T. Chen, A. Bradshaw and K. Schleicher. 1980. A new high-pressure equation of state for seawater. Deep-Sea Research 27: 225 64. Roether, W., M. Sarnthein, T. J. M ller, W. Nellen und D. Sahrhage. 1990. S DATLANTIC- ZIRCUMPOLARSTORM, Reise Nr. 11. 3 October 1989 - 11 M rz 1990. Meteor-Berichte, Universit t Hamburg. Sievers, H. A., and W. D. Nowlin. 1984. The stratification and water masses at Drake Passage. Journal of Geophysics Research 89: 10489 514. Takahashi, T., D. Chipman, N. Schechtman, J. Goddard, and R. Wanninkof. 1982. Measurements of the partial pressure of CO2 in discrete water samples during the North Atlantic Expedition, the Transient Tracers of Oceans Project. Technical Report to NSF. Lamont-Doherty Earth Observatory, Palisades, N.Y. U.S. WOCE Implementation Plan. 1991. U.S. Implementation Report No. 1, U.S. WOCE Office, College Station, Tex. Williams, P. J. 1990. Oceans carbon, and climate change. Scientific Committee on Oceanic Research (SCOR), Halifax, Canada.