ORNL/CDIAC-86 NDP-054 CARBON DIOXIDE, HYDROGRAPHIC, AND CHEMICAL DATA OBTAINED IN THE CENTRAL SOUTH PACIFIC OCEAN (WOCE SECTIONS P17S AND P16S) DURING THE TUNES-2 EXPEDITION OF THE R/V THOMAS WASHINGTON, JULY AUGUST, 1991 Contributed by Taro Takahashi*, John G. Goddard*, Stephany Rubin*, David W. Chipman*, Stewart C. Sutherland*, and Catherine Goyet** *Lamont-Doherty Earth Observatory of Columbia University Palisades, New York **Woods Hole Oceanographic Institution Woods Hole, Massachusetts Prepared by Alexander Kozyr Carbon Dioxide Information Analysis Center Oak Ridge National Laboratory Oak Ridge, Tennessee Environmental Sciences Division Publication No. 4465 Date Published: March 1996 Prepared for the Global Change Research Program Environmental Sciences Division Office of Health and Environmental Research U.S. Department of Energy Budget Activity Number KP 05 02 00 0 Prepared by the Carbon Dioxide Information Analysis Center OAK RIDGE NATIONAL LABORATORY Oak Ridge, Tennessee 37831-6335 managed by LOCKHEED MARTIN ENERGY SYSTEMS, INC. for the U.S. DEPARTMENT OF ENERGY under contract DE-AC05-84OR21400 ABSTRACT Takahashi, T., J. G. Goddard, S. Rubin, D. W. Chipman, S. C. Sutherland, and C. Goyet. 1995. Carbon Dioxide, Hydrographic, and Chemical Data Obtained in the Central South Pacific Ocean (WOCE Sections P17S and P16S) During the TUNES-2 Expedition of the R/V Thomas Washington, July August, 1991. ORNL/CDIAC-86, NDP-054. Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, Oak Ridge, Tennessee. doi: 10.3334/CDIAC/otg.ndp054 This data documentation discusses the procedures and methods used to measure total carbon dioxide (TCO2), total alkalinity (TALK), and discrete partial pressure of CO2 (pCO2) during the Research Vessel (R/V) Thomas Washington TUNES Leg 2 Expedition in the central South Pacific Ocean. Conducted as part of the World Ocean Circulation Experiment (WOCE), the cruise began in Papeete, Tahiti, French Polynesia, on July 16, 1991, and returned to Papeete on August 25, 1991. WOCE Zonal Sections P17S along 135W and P16S along 150W were completed during the 40-day expedition. A total of 97 hydrographic stations were occupied. Hydrographic and chemical measurements made along WOCE Sections P17S and P16S included pressure, temperature, salinity, and oxygen measured by conductivity, temperature and depth sensor; bottle salinity; oxygen; phosphate; nitrate; nitrite; silicate; CFC-12; CFC-11; TCO2; TALK; and pCO2 measured at 20 C. The TCO2 concentration in 1000 seawater samples was determined with a coulometric analysis system, the TALK concentration in 139 samples was determined on shore at the laboratory of C. Goyet of Woods Hole Oceanographic Institution with an alkalinity titration system, and the pCO2 in 940 water samples was determined with an equilibrator/gas chromatograph system. In addition, 156 coulometric measurements for the Certified Reference Material (Batch #6) were made and yielded a mean value of 2303.2 +/-1.5 umol/kg. This mean value agrees within a standard deviation of the 2304.6 +/-1.6 umol/kg (N=9) value determined with the manometer of C. D. Keeling at Scripps Institution of Oceanography (SIO). Replicate samples from 11 Niskin bottles at 4 stations were also collected for later shore-based reference analyses of TCO2 and TALK by vacuum extraction and manometry in the laboratory of C. D. Keeling of SIO. The R/V Thomas Washington TUNES-2 Expedition data set is available free-of-charge as a numeric data package (NDP) from the Carbon Dioxide Information Analysis Center. The NDP consists of two oceanographic data files, two FORTRAN 77 data-retrieval routine files, a documentation file, and this printed documentation, which describes the contents and format of all files and the procedures and methods used to obtain the data. 1. 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 is unevenly distributed in the oceans because of complex circulation patterns and biogeochemical cycles, neither of which is completely understood, as well as the biological processes of photosynthesis and respiration. The oceans are estimated to hold 38,000 gigatons of carbon, 50 times more than that in the atmosphere and 20 times more than that held by plants, animals, and the soil. If only 2% of the carbon stored in the oceans were released, the level of atmospheric carbon dioxide (CO2) would double. Every year, more than 15 times as much CO2 is exchanged across the sea surface than the amount produced by burning of fossil fuels, deforestation, and other human activities (Williams 1990). To better understand the ocean s role in climate and climatic changes, several large experiments have already been conducted, and others are currently under way. The largest oceanographic experiment ever attempted is the World Ocean Circulation Experiment (WOCE). A major component of the World Climate Research Program, WOCE brings together the expertise of scientists and technicians from more than 30 nations. In the United States, WOCE is supported by the federal government under the Global Change Research Program. The multi-agency U.S. effort is led by the National Science Foundation and supported by major contributions from the National Oceanic and Atmospheric Administration, the U.S. Department of Energy (DOE), the Office of Naval Research, and the National Aeronautics and Space Administration. Although total carbon dioxide (TCO2) is not an official WOCE measurement, a coordinated effort, supported in the United States by the DOE, is being made on WOCE cruises (through 1998) to measure the global, spatial, and temporal distributions of TCO2 and other carbon-related parameters. The goal of the CO2 survey include estimation of the meridional transport of inorganic carbon in the Pcific Ocean in a manner analogous to the oceanic heat transport (Bryden and Hall 1980; Brewer et al. 1989; Roemmich and Wunsch 1985), evaluation of the exchange of CO2 between the atmosphere and the ocean, and preparation of a database suitable for carbon-cycle modeling and the subsequent assessment of the anthropogenic CO2 increase in the oceans. The final data set is expected to cover ~23,000 stations. This report presents CO2-related measurements obtained during the 40-day Leg 2 of the Research Vessel (R/V) Thomas Washington TUNES Expedition (TUNES-2) along the WOCE Sections P17S and P16S, which are located in the central part of the South Pacific Ocean along the 135W (between 6S and 33S) and 150W (between 17.5S and 37.5S) meridians respectively. In addition to TCO2, parameters measured include total alkalinity (TALK); discrete partial pressure of CO2 (pCO2) measured at 20 C; pressure, temperature, salinity, and oxygen measured by conductivity, temperature, and depth sensor (CTD); bottle salinity; oxygen; nutrients; chlorofluorocarbons (CFCs); tritium; and helium. Scientists from the following institutions participated in the cruise: Scripps Institution of Oceanography (SIO), Woods Hole Oceanographic Institution (WHOI), Lamont-Doherty Earth Observatory (LDEO), Rosenstiel School of Marine and Atmospheric Science (RSMAS), University of Hawaii (UH), and Princeton University (PU). The CO2 investigation during the TUNES-2 Expedition was supported by a grant (No. DE-FGO2-90-ER60983) from the U.S. DOE. 2. DESCRIPTION OF THE EXPEDITION 2.1 R/V Thomas Washington TUNES-2 Expedition Information R/V Thomas Washington TUNES-2 Expedition information is as follows: Ship name Thomas Washington Cruise/leg TUNES/2 Expocode 31WTTUNES/2 WOCE Sections P17S/P16S Ports of call Papeete, Tahiti, French Polynesia (round trip) Dates July 16 August 25, 1991 Chief Scientist James H. Swift, (SIO) Master A. Arsenault Parameters measured Institution Principal investigators CTD, oxygen, and nutrients (P17S) SIO L. Talley, M Tsuchiya CTD, oxygen, and nutrients (P16S) SIO J. Swift Drifters SIO Pearn Niiler ALACE floats SIO R. Davis Tritium and helium WHOI W. Jenkins TCO2 and pCO2 (shipboard) LDEO D. Chipman, T Takahashi TCO2 and TALK (shore) SIO C. D. Keeling TALK (shore) WHOI C. Goyet pCO2 (underway) SIO R. Weiss CFCs RSMAS R. Fine ADCP UH P. Hacker 14C, 226Ra/228Ra, and Ba PU R. Key Participating Institutions SIO Scripps Institution of Oceanography (University of California, San Diego) WHOI Woods Hole Oceanographic Institution LDEO Lamont-Doherty Earth Observatory (Columbia University) RSMAS Rosenstiel School of Marine and Atmospheric Science (University of Miami) UH University of Hawaii PU Princeton University 2.2 Brief Cruise Summary Scientific work for the first portion of the TUNES-2 Expedition (Section P17S) was proposed by Lynne Talley and Mizuki Tsuchiya (both SIO); the second portion (P16S) was planned by James Swift (SIO). The overall purpose of both sections was to contribute to a planned WOCE Hydrographic Program multi-cruise examination of the meridional circulation and water mass transportation in the Pacific Ocean, in this case emphasizing the central subtropical gyros of the North and South Pacific. After departure from Papeete, Tahiti, on July 16, 1991, WOCE Section P17S began on July 21, 1991, with the occupation of Station 124 at 6S and 135W and continued south along 135W meridian with stations every 30 nm. The P17S track, which followed the ridge extending from the East Pacific Rise to the Tuanotu Islands, was shifted slightly to the east, then back again, in order to cross the rise at a saddle. The planned southern Station 179 (33 03'S and 135 01'W) of the P17S line was reached without major problems on August 8, 1991, and the vessel steamed for 83 hours to the southern end of the P16S line. In general, the weather was relatively good during the work on the P17S line. A total of 56 stations were occupied. WOCE Section P16S began on August 11, 1991, with the occupation of Station 180 at 37 30'S and 150 28'W, and continued north along 150W meridian with stations spaced every 30 nm. The weather was still remarkably favorable considering that operations were being carried out during the middle of the austral winter. Although some instrument problems that could potentially affect CTD data quality occurred during this section of the cruise, researchers managed to complete every planned station. The last station of the TUNES-2 Expedition, station 210, was occupied on August 25, 1991, at 17 31'S and 150 30'W, and the same day R/V Thomas Washington arrived back at Papeete, Tahiti. A total of 41 stations were occupied during Section P16S. 3. DESCRIPTION OF VARIABLES AND METHODS The data file tun2.dat (see description in Part 2) in this numeric data package (NDP) contains the following variables: station numbers; cast numbers; sample numbers; bottle numbers; CTD pressure, temperature, salinity, and oxygen; potential temperature; bottle salinity; concentration of dissolved oxygen, silicate, nitrate, nitrite, and phosphate; CFC-11; CFC-12; TCO2 and TALK concentration; pCO2 measured at 20 C; and data quality flags. The station inventory file tun2sta.inv (see Part 2) contains the expocode, section number, station number, latitude, longitude, sampling date (i.e., month, day, year), sampling time, and bottom depth for each station. 3.1 Hydrographic Measurements The hydrographic measurements and water sampling were conducted by the staff of the SIO Oceanographic Data Facility (ODF). During the expedition, a 24/12 double-ring 36-bottle CTD/rosette sampler was used for sampling. An ODF-modified Neil Brown Mark III CTD, a Benthos altimeter, and a Sea Tech transmissometer were mounted on the rosette frame. Seawater samples were collected in PVC 10-L Niskin and ODF bottles. A full description of CTD and bottle hydrographic measurements is provided in Takahashi et al. (1993 - a reprint is provided in Appendix B of a printed NDP-054). 3.2 CFC-11 and CFC-12 Measurements Concentrations of the dissolved chlorofluorocarbons (CFC-11 and CFC-12) were measured by shipboard electron-capture gas chromatography using the methods described by Bullister and Weiss (1988). The measurements were carried out by the group at the University of Miami under the direction of Dr. Rana A. Fine with the assistance of a technician from LDEO, Columbia University. A total of 1847 water analyses were carried out, 23 of which were duplicate analyses as tabulated in Table 1. The mean values of duplicate analyses are reported in the data file and are assigned a quality flag of 6 according to the WOCE Operations Manual (Joyce and Corry, 1994). 3.3 Shipboard CO2 Measurements The TCO2 concentration in 1000 seawater samples (Fig. 2) was determined with a coulometric analysis system similar to the one described by Johnson et al. (1985). This system consists of a coulometer (Model 5011) manufactured by UIC, Inc. (Jolliet, Ill.) and a sample introduction/CO2 extraction system of LDEO design. The pCO2 in 940 water samples was determined with a fully automated equilibrator-gas chromatograph system that has been described by Chipman et al. (1993). A full description of shipboard TCO2 and pCO2 measurements is provided in Appendix B of NDP-054. 3.4 Shore-based CO2 Analyses The TALK concentration in 139 samples was determined on shore at the laboratory of C. Goyet of WHOI. Samples were collected in 250-mL, standard borosilicate glass, screw-cap bottles and poisoned with 50 L of saturated solution of HgCl2. The samples were stored at room temperature and sent to WHOI for TALK analysis. TALK was determined by potentiometric titration; the method used was derived from one first described by Dyrssen (1965) and later modified by Bradshaw et al. (1981). The automated titration was performed in a closed cell maintained at constant temperature (25 0.1 C). To be similar to seawater, the ionic strength of the hydrochloric acid solution (0.1 N) was adjusted with NaCl. The ratio of the acid normality over the cell volume was calibrated before and after the sample analysis. The calibration consisted of preparing solutions of known TALK concentration and measuring them as described by Brewer et al. (1986). The precision of the measurements was estimated to be better than 0.1%. The replicate samples from 11 Niskin bottles at 4 stations were collected for shore-based reference analyses at the laboratory of C. D. Keeling of SIO. The TCO2 measurements were produced by vacuum extraction/manometric analysis and the TALK values by potentiometric titration. Both measurements were performed in controlled laboratory conditions using standards. Samples were collected from the same Niskin bottles used to collect samples for shipboard analyses of TCO2. The shore laboratory analyses of TCO2 and TALK employed a precise and proven methodology to provide information on the quality of the shipboard analyses (Guenther et al. 1994). For all shore-based analyses, a replicate s of 1.43 umol/kg for eleven unflagged pairs was calculated, with no deltas greater than 3s. The average difference for eleven comparisons of single replicate samples cpmparing ship and shore TCO2 values was -3.5 +/-2.0 umol/kg. Only two surface water and two deep water comparisons exist for the TUNES-2 Expedition. These represent too few data points for meaningful comparative analysis. Figure 3 in NDP-054 displays the one set of profile differences from Station 180 of the TUNES-2 Expedition. There are eight comparisons from Niskin bottles at 300 m and deeper. After the one shallowest comparison (a replicate singlet) was omitted, the remaining seven are characterized by an average difference of -4.3 +/-1.6 umol/kg. The consistency of the four deeper comparisons, all with excellent bottle pair agreement, is striking. Tables 1 and 2 summarize the replicate shore-based measurements of TCO2 and TALK. Table 1. Summary of total CO2 replicate data collected during R/V Thomas Washington TUNES-2 Expedition THE CARBON DIOXIDE PROJECT OF THE SCRIPPS INSTITUTION OF OCEANOGRAPHY TUNES Leg 2 1991 Pacific WOCE Lines P17S/P16S ----------------------------------------------- S.I.O. RUN BOTTLE BOTTLE "NISKIN" LDEO LDEO LEG LAT. CAST DEPTH SAMPLE EXTRAC ANALYSIS MANO SAMPLE RUN DELTA TCO2 DELTA AVG TCO2 -S.I.O. STN LONG. NISK (M) DATE DATE DATE TYPE BOTTLE RUN FLAG ----------------- ( MOLES/KG SW) --------------------- 2 23-43S 1 19 909 01AUG91 11DEC91 11DEC91 M S4158 001 2208.25 2208.25 160 132-33W 11DEC91 20DEC91 S S4158 001 2208.73 2208.73 11DEC91 12DEC91 M S4159 001 2207.96 2207.96 -0.29 2208.10 2206.1 -2.00 11DEC91 20DEC91 S S4159 001 2208.23 2208.23 -0.50 2208.48 2206.1 -2.38 2 30-32S 1 61 4 06AUG91 03DEC91 04DEC91 M R4548 001 2023.46 2023.46 174 134-20W 03DEC91 09DEC91 S R4548 001 2022.97 2022.97 03DEC91 04DEC91 M R4549 001 2023.77 2023.77 +0.31 2023.61 2024.2 0.59 03DEC91 09DEC91 S R4549 001 2024.61 2024.61 +1.64 2023.79 2024.2 0.41 1 33 3081 03DEC91 03DEC91 M R4546 001 2301.42 2301.42 03DEC91 06DEC91 S R4546 001 2303.27 2303.27 03DEC91 03DEC91 M R4547 001 2302.64 2302.64 +1.22 2302.03 2299.0 -3.03 03DEC91 06DEC91 S R4547 001 2302.94 2302.94 -0.33 2303.10 2299.0 -4.10 2 37-30S 2 69 315 12AUG91 04DEC91 06DEC91 S R4565 001 2121.42 2121.42 2121.42 2125.5 4.08 180 150-30W 2 11 469 11DEC91 11DEC91 M R4562 001 2134.64 2134.64 11DEC91 19DEC91 S R4562 001 2133.70 2133.70 11DEC91 11DEC91 M R4563 001 2130.68 2130.68 -3.96 2132.66 2126.2 -6.46 11DEC91 19DEC91 S R4563 001 2129.14 2129.14 -4.56 2131.42 2126.2 -5.22 2 13 622 16DEC91 17DEC91 M R4560 001 2138.07 2138.07 16DEC91 20DEC91 S R4560 001 2137.74 2137.74 16DEC91 17DEC91 M R4561 001 2133.80 2133.80 -4.27 2135.94 2132.5 -3.44 16DEC91 20DEC91 S R4561 001 2134.91 2134.91 -2.83 2136.32 2132.5 -3.82 2 16 931 06MAY92 17JUL92 E R4558 001 2169.51 06MAY92 17JUL92 E R4558 002 2168.19 -1.32 2168.85 06MAY92 17JUL92 E R4559 001 2168.22 06MAY92 17JUL92 E R4559 002 2168.53 +0.31 2168.38 -0.47 2168.61 2167.2 -1.41 2 18 1188 05MAY92 17JUL92 E R4556 001 2207.85 05MAY92 17JUL92 E R4556 002 2207.82 -0.03 2207.84 05MAY92 17JUL92 E R4557 001 2207.12 05MAY92 17JUL92 E R4557 002 2206.20 -0.92 2206.66 -1.18 2207.25 2202.9 -4.35 2 20 1543 04DEC91 04DEC91 M R4554 001 2258.59 2258.59 04DEC91 09DEC91 S R4554 001 2259.74 2259.74 04DEC91 05DEC91 M R4555 001 2258.58 2258.58 -0.01 2258.59 2253.9 -4.69 04DEC91 09DEC91 S R4555 001 2257.71 2257.71 -2.03 2258.73 2253.9 -4.83 2 37-30S 2 22 2052 12AUG91 05MAY92 10JUL92 E R4552 001 EX 2299.71 180 150-30W 05MAY92 10JUL92 E R4552 002 2294.57 2294.57 05MAY92 10JUL92 E R4553 001 2295.61 05MAY92 10JUL92 E R4553 002 2295.46 -0.15 2295.54 +0.97 2295.06 2290.4 -4.66 2 26 3051 04MAY92 10JUL92 E R4550 001 2309.37 04MAY92 10JUL92 E R4550 002 2309.74 +0.37 2309.56 04MAY92 10JUL92 E R4551 001 2308.23 04MAY92 10JUL92 E R4551 002 EX 2299.35 2308.23 -1.33 2308.90 2303.7 -5.20 2 21- 0S 1 3 62 23AUG91 12DEC91 13DEC91 M S4118 001 1997.57 1997.57 213 150-30W 12DEC91 19DEC91 S S4118 001 1998.22 1998.22 12DEC91 13DEC91 M S4119 001 1995.37 1995.37 -2.20 1996.47 1992.9 -3.57 12DEC91 20DEC91 S S4119 001 1995.98 1995.98 -2.24 1997.10 1992.9 -4.20 ----------------------------------------------------------------------------------------------------------------------------------- MANOMETER TYPE: FLAGS: M = CONSTANT VOLUME MERCURY MANOMETER DATUM F: No Hg found in bottle S = QUARTZ SPIRAL MANOMETER DATUM G: Severe bottle leak E = ELECTRONIC CONSTANT-VOLUME MANOMETER DATUM EX: Data excluded from analysis BOTTLE TYPE: R = RODAVISS S = S TYPE NOTE: Dilution factor of 1.000170 has been applied. Table 2. Summary of total alkalinity replicate data collected during R/V Thomas Washington TUNES-2 Expedition THE CARBON DIOXIDE PROJECT OF THE SCRIPPS INSTITUTION OF OCEANOGRAPHY TUNES Leg 2 1991 WOCE Pacific Line P17S/P16S ---------------------------------------------- S.I.O. TRIAL BOTTLE BOTTLE "NISKIN" LEG LAT. CAST DEPTH SAMPLE ANALYSIS TITR SAMPLE FLAG TRIAL DELTA ALK DELTA AVG STN LONG. NISK (M) DATE DATE SYST BOTTLE TRIAL ----------------- ( EQUIV/KG SW) ------ 2 23-43S 1 19 909 01AUG91 20JAN92 V S4158 1 2300.18 2300.18 160 132-33W 20JAN92 V S4159 1 2302.05 2302.05 +1.87 2301.11 2 30-32S 1 61 4 06AUG91 10JAN92 V R4548 1 2318.15 2318.15 174 134-20W 10JAN92 V R4549 1 2324.19 2324.19 +6.04 2321.17 1 33 3081 10JAN92 V R4546 1 2395.78 2395.78 10JAN92 V R4547 1 2396.62 2396.62 +0.84 2396.20 2 37-30S 2 69 315 12AUG91 14JAN92 V R4564 1 2277.74 2277.74 180 150-30W 14JAN92 V R4565 1 2280.79 2280.79 +3.05 2279.27 2 11 469 14JAN92 V R4562 1 2275.55 2275.55 14JAN92 V R4563 1 2273.45 2273.45 -2.10 2274.50 2 13 622 17JAN92 V R4560 1 2275.23 2275.23 17JAN92 V R4561 1 2281.82 2281.82 +6.59 2278.53 2 16 931 22JUN92 V R4558 1 2290.65 2290.65 22JUN92 V R4559 1 2285.23 2285.23 -5.42 2287.94 2 18 1188 22JUN92 V R4556 1 2304.57 2304.57 22JUN92 V R4557 1 2304.45 2304.45 -0.12 2304.51 2 20 1543 13JAN92 V R4554 1 2343.31 2343.31 13JAN92 V R4555 1 2343.93 2343.93 +0.62 2343.62 2 22 2052 18JUN92 V R4552 1 2380.77 2380.77 18JUN92 V R4553 1 2382.52 2382.52 +1.75 2381.65 2 26 3051 18JUN92 V R4550 1 2403.47 2403.47 18JUN92 V R4551 1 2404.50 2404.50 +1.03 2403.99 2 21- 0S 1 3 62 23AUG91 20JAN92 V S4118 1 2365.81 2365.81 213 150-30W 20JAN92 V S4119 1 2366.34 2366.34 +0.53 2366.08 --------------------------------------------------------------------------------------------------------------------- TITRATION SYSTEM: FLAGS: G = GRAVIMETRIC F: No Hg found in bottle V = VOLUMETRIC X: Titrator malfunction BOTTLE TYPE: EX: Data excluded from analysis R = RODAVISS S = S TYPE NOTE: Dilution factor of 1.000170 has been applied. 4. DATA CHECKS AND PROCESSING PERFORMED BY CDIAC An important part of the 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 that involve examining the data for completeness, reasonableness, and accuracy. Although they have common objectives, these reviews are tailored to each data set and often require 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 information summarizes the data-processing and QA checks performed by CDIAC on the data obtained during the R/V Thomas Washington TUNES-2 Expedition in the South Pacific Ocean (WOCE Sections P17S and P16S). 1. Carbon-related data and preliminary hydrographic measurements were provided to CDIAC by Taro Takahashi Stewart Sutherland of LDEO and Catherine Goyet of WHOI. The final hydrographic and chemical measurements and the station information files were provided by the WOCE Hydrographic Program Office after quality evaluation. A FORTRAN 77 retrieval code was written and used to merge and reformat all data files. 2. The designation for missing values, given as -9.0 in the original files, was changed to -999.9. 3. To check for obvious outliers, all data were plotted with a PLOTNEST.C program written by Stewart C. Sutherland (LDEO). 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. Several outliers were identified and removed after consultation with the principal investigators. 4. To identify noisy data and possible systematic, methodological errors, property-property plots for all parameters were generated, carefully examined, and compared with plots from previous expeditions in the South Pacific Ocean. 5. All variables were checked for values exceeding physical limits, such as sampling depth values that are greater than the given bottom depths. 6. Dates and times were checked for bogus values (e.g., values of MONTH < 1 or > 12, DAY < 1 or > 31, YEAR < or > 1991, TIME < 0000 or > 2400. 7. Station locations (latitudes and longitudes) and sampling times were examined for consistency with maps and cruise information supplied by Takahashi et al. (1993). 5. HOW TO OBTAIN THE DATA AND DOCUMENTATION This database is available on request in machine-readable form, without charge, from CDIAC. CDIAC will also distribute subsets of the database as needed. It can be acquired on 9-track magnetic tape; on 8-mm tape; on 150-mB, quarter-inch tape cartridge; on MAC- or 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 required by the user to access the data (e.g., 1600 or 6250 BPI, labeled or nonlabeled, ASCII or EBCDIC characters, and variable- or fixed-length records; 3.5- or 5.25-in. floppy diskettes, high or low density; and 8200 or 8500 format, 8-mm tape). Magnetic tape requests not accompanied by specific instructions will be filled on 9-track, 6250-BPI, non-labeled tapes with ASCII 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: (423) 574-0390 or (423) 574-3645 Fax: (423) 574-2232 Electronic Mail: INTERNET: cdiac@ornl.gov The data files can also be 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 user ID, Enter your electronic mail address as the password (e.g., alex@alex.esd.ornl.gov ), Change to the directory /pub/ndp054 , and Acquire the files using the FTP get or mget command. or World Wide Web URL: http://cdiac.esd.ornl.gov 6. REFER ENCES Bradshaw A. L., P. G. Brewer, D. K. Shafer, and R. T. Williams. 1981. Measurements of total carbon dioxide and alkalinity by potentiometric titration in the GEOSECS program. Earth Planet. Sci. Lett. 55:99 115. Brewer, P. G., A. L. Bradshaw, and R. T. Williams. 1986. Measurements of total carbon dioxide and alkalinity in the North Atlantic Ocean in 1981. pp. 358 81. In D. Reiche (ed.), The Global Carbon Cycle: Analysis of the Natural Cycle and Implications of Anthropogenic Alterations for the Next Century. Springer, New York. Brewer, P. G., C. Goyet, and D. Dyrssen. 1989. Carbon dioxide transport by ocean currents at 25 N latitude in the Atlantic Ocean. Science 246:477 79. Bryden, H. L., and M. M. Hall. 1980. Heat transport by ocean currents across 25 N latitude in the North Atlantic Ocean. Science 207:884. Bullister, J.L. and R.F. Weiss. 1988. Determination of CCl3F and CCl2F2 in seawater and air. Deep-Sea Res. 35:839 53. Chipman, D. W., J. Marra, and T. Takahashi. 1993. Primary production at 47 N and 20 W in the North Atlantic Ocean: A comparison between the 14C incubation method and the mixed layer carbon budget. Deep-Sea Res. 40:151 69. Dyrssen D. 1965. A gran titration of sea water on board SAGITTA. Acta Chemica Scand. 19:1265. Guenther, P. R., C. D. Keeling, and G. Emanuele III. 1994. Oceanic CO2 Measurements for the WOCE Hydrographic Survey in the Pacific Ocean, 1990 1991: Shore Based Analyses. SIO Reference Series, Ref. No. 94 28. University of California. Johnson, K. M., A. E. King, and J. McN. Sieburth. 1985. Coulometric TCO2 analyses for marine studies: An introduction. Mar. Chem. 16:61 82. Joyce, T., and C. Corry (eds.). 1994. Requirements for WOCE Hydrographic Programme Data Reporting. Rew. 2. Woods Hole Oceanographic Institution, Woods Hole, Mass. Roemmich, D., and C. Wunsch. 1985. Two transatlantic sections: Meridional circulation and heat flux in the subtropical North Atlantic Ocean. Deep-Sea Res. 32:619 64. Takahashi, T., J. G. Goddard, S. Rubin, D. W. Chipman, and S. C. Sutherland. 1993. Investigation of Carbon Dioxide in the Central South Pacific Ocean (WOCE Sections P-16C and P-17C) during the TUNES/2 Expedition of the R/V Thomas Washington, July August, 1991. Final Technical Report for grant DE-FGO2-90-ER60983, LDEO of Columbia University, Palisades, N.Y. Williams, P. J. 1990. Oceans, carbon, and climate change. Scientific Committee on Oceanic Research (SCOR), Halifax, Canada. 7. FILE DESCRIPTIONS This section describes the content and format of each of the five files that comprise this NDP (see Table 3). Because CDIAC distributes the data set in several ways (e.g., via anonymous FTP, on floppy diskette, and on 9-track magnetic tape), each of the five files is referenced by both an ASCII file name, which is given in lower-case, bold-faced type (e.g., ndp054.txt), and a file number. The remainder of this section describes (or lists, where appropriate) the contents of each file. The files are discussed in the order in which they appear on the magnetic tape. Table 3. Content, size, and format of data files File number, name, Logical File size Block Record and description records in bytes size length 1. ndp054.txt: 1,008 60,305 8,000 80 a detailed description of the cruise network, the two FORTRAN 77 data retrieval routines, and the two oceanographic data files 2. stainv.for: 32 1,006 8,000 80 a FORTRAN 77 data retrieval routine to read and print tun2sta.inv (File 4) 3. tun2dat.for: 50 2,239 8,000 80 a FORTRAN 77 data retrieval routine to read and print tun2.dat (File 5) 4. tun2sta.inv: 108 7,850 4,100 41 a listing of the station locations, sampling dates, and sounding bottom depths for each of the 97 stations 5. tun2.dat: 3,479 653,054 16,000 160 hydrographic, carbon dioxide, and chemical data from 97 stations _____ ______ Total 4,677 724,454 ndp054.txt (File 1) This file contains a detailed description of: the data set, the two FORTRAN 77 data retrieval routines, and the two oceanographic data files. It exists primarily for the benefit of individuals who acquire this database as machine-readable data files from CDIAC. stainv.for (File 2) This file contains a FORTRAN 77 data retrieval routine to read and print tun2sta.inv (File 4). The following is a listing of this program. For additional information regarding variable definitions, variable lengths, variable types, units, and codes, please see the description for tun2sta.inv. c**************************************************************** c* FORTRAN 77 data retrieval routine to read and print the * c* file named "tun2sta.inv" (File 4) * c**************************************************************** INTEGER stat, depth REAL lat, lon CHARACTER expo*11, sect*8, date*8, time*4 OPEN (unit=1, file='tun2sta.inv') OPEN (unit=2, file='tun2stat.inv') write (2, 5) 5 format (3X,'EXPOCODE',4X,'SECTION',3X,'STNNBR',3X,'LATDCM', 1 4X,'LONDCM',6X,'DATE',2X,'TIME',1X,'DEPTH',/) read (1, 6) 6 format (///////////) 7 CONTINUE read (1, 10, end=999) expo, sect, stat, lat, lon, date, 1 time, depth 10 format (A11, 3X, A8, 6X, I3, 2X, F7.3, 2X, F8.3, 2X, A8, 1 2X, A4, 2X, I4) write (2, 10) expo, sect, stat, lat, lon, date, 1 time, depth GOTO 7 999 close(unit=1) close(unit=2) stop end tun2dat.for (File 3) This file contains a FORTRAN 77 data retrieval routine to read and print tun2.dat (File 5). The following is a listing of this program. For additional information regarding variable definitions, variable lengths, variable types, units, and codes, please see the description for tun2.dat. c**************************************************************** c* FORTRAN 77 data retrieval routine to read and print the * c* file named "tun2.dat" (File 5). * c**************************************************************** CHARACTER qualt*14 INTEGER sta, cast, samp, bot REAL pre, ctdtmp, ctdsal, ctdoxy, theta, sal, oxy, silca REAL nitrat, nitrit, phspht, cfc11, cfc12, tcarb, talk REAL pco2, pco2tmp OPEN (unit=1, file='tun2.dat') OPEN (unit=2, file='tunes2.dat') write (2, 5) 5 format (2X,'STNNBR',2X,'CASTNO',2X,'SAMPNO',2X,'BTLNBR',2X, 1 'CTDPRS',2X,'CTDTMP',2X,'CTDSAL',2X,'CTDOXY',3X,'THETA',4X, 2 'SALNTY',2X,'OXYGEN',2X,'SILCAT',2X,'NITRAT',2X,'NITRIT',2X, 3 'PHSPHT',3X,'CFC-11',3X,'CFC-12',2X,'TCARBN',2X,'ALKALI',4X, 4 'PCO2',1X,'PCO2TMP',9X,'QUALT1',/, 5 36X,'DBAR',2X,'ITS-90',2X,'PSS-78',1X,'UMOL/KG',3X,'DEG C', 6 4X,'PSS-78',1X,5('UMOL/KG',1X,),1X,'PMOL/KG',2X,'PMOL/KG',1X, 7 2('UMOL/KG',1X,),3X,'UATM',3X,'DEG C'14X,'*',/,25X,'*******', 8 17X,2('*******',1X,),10X,6('*******',1X,),1X,'*******', 9 2X,4('*******',1X,),21X,'*',/) read (1, 6) 6 format (////////////) 7 CONTINUE read (1, 10, end=999) sta, cast, samp, bot, pre, ctdtmp, 1 ctdsal, ctdoxy, theta, sal, oxy, silca, nitrat, nitrit, 2 phspht, cfc11, cfc12, tcarb, talk, pco2, pco2tmp, qualt 10 format (5X, I3, 7X, I1, 6X, I2, 5X, I3, 1X, F7.1, 1X, F7.4, 1 1X, F7.4, 1X, F7.1, 1X, F7.4, 1X, F9.4, 1X, F7.1, 1X, F7.2, 2 1X, F7.2, 1X, F7.2, 1X, F7.2, 1X, F8.3, 1X, F8.3, 1X, F7.1, 3 1X, F7.1, 1X, F7.2, 1X, F7.2, 1X, A14) write (2, 20) sta, cast, samp, bot, pre, ctdtmp, 1 ctdsal, ctdoxy, theta, sal, oxy, silca, nitrat, nitrit, 2 phspht, cfc11, cfc12, tcarb, talk, pco2, pco2tmp, qualt 20 format (5X, I3, 7X, I1, 6X, I2, 5X, I3, 1X, F7.1, 1X, F7.4, 1 1X, F7.4, 1X, F7.1, 1X, F7.4, 1X, F9.4, 1X, F7.1, 1X, F7.2, 2 1X, F7.2, 1X, F7.2, 1X, F7.2, 1X, F8.3, 1X, F8.3, 1X, F7.1, 3 1X, F7.1, 1X, F7.2, 1X, F7.2, 1X, A14) GOTO 7 999 close(unit=1) close(unit=2) stop end tun2sta.inv (File 4) This file provides station inventory information for each of the 97 stations occupied during the R/V Thomas Washington TUNES-2 Expedition. Each record of the file contains an expocode, section number, station number, coordinate, sampling date, sampling time, and sounding depth. The file is sorted by station number and can be read by using the following FORTRAN 77 code (contained in stainv.for, File 2): INTEGER stat, depth REAL lat, lon CHARACTER expo*11, sect*8, date*8, time*4 read (1, 10, end=999) expo, sect, stat, lat, lon, date, 1 time, depth 10 format (A11, 3X, A8, 6X, I3, 2X, F7.3, 2X, F8.3, 2X, A8, 1 2X, A4, 2X, I4) Stated in tabular form, the contents include the following: Variable Variable Variable Starting Ending type width column column expo Character 11 1 11 sect Character 8 15 22 stat Numeric 3 29 31 lat Numeric 7 34 40 lon Numeric 8 43 50 date Character 8 53 60 time Character 4 63 66 depth Numeric 4 69 72 where expo is the expocode of the cruise; sect is the WOCE section number; stat is the station number (values range from 124 to 220); lat is the latitude of the station (in decimal degrees; negative values indicate the Southern Hemisphere); lon is the longitude of the station (in decimal degrees; negative values indicate the Western Hemisphere); date is the sampling date (month/day/year); time is the sampling time (GMT); depth is the sounding depth of the station (in meters). tun2.dat (File 5) This file provides hydrographic, carbon dioxide, and chemical data for the 97 stations occupied during the R/V Thomas Washington TUNES-2 Expedition. Each record contains a station number; cast number; sample number; bottle number; CTD pressure, temperature, salinity, and oxygen; potential temperature; bottle salinity; concentrations of oxygen, silicate, nitrate, nitrite, phosphate, CFC-11, CFC-12, and TCO2; TALK; pCO2; pCO2 temperature; and data quality flags. The file is sorted by station number and pressure and can be read by using the following FORTRAN 77 code (contained in tun2dat.for, File 3): CHARACTER qualt*14 INTEGER sta, cast, samp, bot REAL pre, ctdtmp, ctdsal, ctdoxy, theta, sal, oxy, silca REAL nitrat, nitrit, phspht, cfc11, cfc12, tcarb, talk REAL pco2, pco2tmp read (1, 10, end=999) sta, cast, samp, bot, pre, ctdtmp, 1 ctdsal, ctdoxy, theta, sal, oxy, silca, nitrat, nitrit, 2 phspht, cfc11, cfc12, tcarb, talk, pco2, pco2tmp, qualt 10 format (5X, I3, 7X, I1, 6X, I2, 5X, I3, 1X, F7.1, 1X, F7.4, 1 1X, F7.4, 1X, F7.1, 1X, F7.4, 1X, F9.4, 1X, F7.1, 1X, F7.2, 2 1X, F7.2, 1X, F7.2, 1X, F7.2, 1X, F8.3, 1X, F8.3, 1X, F7.1, 3 1X, F7.1, 1X, F7.2, 1X, F7.2, 1X, A14) Stated in tabular form, the contents include the following: Variable Variable Starting Ending Variable type width column column sta Numeric 3 6 8 cast Numeric 1 16 16 samp Numeric 2 23 24 bot Numeric 3 30 32 pre Numeric 7 35 40 ctdtmp Numeric 7 42 48 ctdsal Numeric 7 50 56 ctdoxy Numeric 7 58 64 theta Numeric 7 66 72 sal Numeric 9 74 82 oxy Numeric 7 84 90 silca Numeric 7 92 98 nitrat Numeric 7 100 106 nitrit Numeric 7 108 114 phspht Numeric 7 116 122 cfc11 Numeric 8 124 131 cfc12 Numeric 8 133 140 tcarb Numeric 7 142 148 talk Numeric 7 150 156 pco2 Numeric 7 158 164 pco2tmp Numeric 7 166 172 qualt Character 14 174 187 where sta is the station number; cast is the cast number; samp is the sample number; bot* is the bottle number; pre is the CTD pressure (in dbar); ctdtmp is the CTD temperature (in deg C); ctdsal* is the CTD salinity [on the Practical Salinity Scale (PSS)]; ctdoxy* is the CTD oxygen consentration (in umol/kg); theta is the potential temperature (in deg C); sal* is the bottle salinity; oxy* is the oxygen concentration (in umol/kg); silca* is the silicate concentration (in umol/kg); nitrat* is the nitrate concentration (in umol/kg); nitrit* is the nitrite concentration (in umol/kg); phspht* is the phosphate concentration (in mol/kg); cfc11* is the trichlorofluoromethane-11 concentration (CCl3F) (in pmol/kg); cfc12* is the dichlorodifluoromethane-12 concentration (CCl2F2) (in pmol/kg); tcarb* is the total carbon dioxide concentration (in umol/kg); talk* is the total alkalinity (in umol/kg); pco2* is the partial pressure of CO2 (in atm and measured at pco2tmp); pco2tmp is the temperature of equilibration of the pCO2 samples in the equilibrator (in C); qualt is a 14-digit character variable that contains data-quality flag codes for parameters marked with an asterisk (*) in the output file. Quality flags are defined as follows: 1 = Sample for this measurement was drawn from water bottle but results of analyses were not received; 2 = Acceptable measurement; 3 = Questionable measurement; 4 = Bad measurement; 5 = Not reported; 6 = Mean of replicate measurements; 7 = Manual chromatographic peak measurement; 8 = Irregular digital chromatographic peak integration; 9 = Sample was not drawn for this measurement from this bottle. 8. VERIFICATION OF DATA TRANSPORT The data files contained in this numeric data package can be read by using the FORTRAN 77 data retrieval programs provided. Users should visually examine each data file to verify that the data were correctly transported to their systems. To facilitate the visual inspection process, partial listings of each data file are provided in Tables 4 and 5. Each of these tables contains the first and last five lines of a data file. Table 4. Partial listing of tun2sta.inv (File 4) First five lines of the file: 31WTTUNES-2 WOCE_P17 124 -6.005 -135.003 07/21/91 2322 4562 31WTTUNES-2 WOCE_P17 125 -6.498 -135.000 07/22/91 0550 4475 31WTTUNES-2 WOCE_P17 126 -6.998 -135.003 07/22/91 1227 4393 31WTTUNES-2 WOCE_P17 127 -7.503 -135.002 07/22/91 1929 4400 31WTTUNES-2 WOCE_P17 128 -7.998 -135.000 07/23/91 0208 4525 Last five lines of the file: 31WTTUNES-2 WOCE_P16 216 -19.500 -150.498 08/24/91 0811 4264 31WTTUNES-2 WOCE_P16 217 -19.000 -150.500 08/24/91 1433 3356 31WTTUNES-2 WOCE_P16 218 -18.508 -150.497 08/24/91 2027 4201 31WTTUNES-2 WOCE_P16 219 -18.002 -150.498 08/25/91 0215 3659 31WTTUNES-2 WOCE_P16 220 -17.502 -150.498 08/25/91 0804 3604 Table 5. Partial listing of tun2.dat (File 5) First five lines of the file: 124 1 2 2 53.2 27.3959 35.1756 216.4 27.3836 35.1817 214.8 2.73 4.81 0.08 0.53 1.673 0.888 2000.6 -999.9 313.20 20.00 22622222228292 124 1 3 3 78.5 27.4009 35.1940 213.6 27.3827 35.1999 213.8 2.71 4.91 0.08 0.54 1.539 0.839 2003.4 -999.9 297.66 20.00 22622222228292 124 1 4 4 98.0 27.3409 35.4125 206.3 27.3182 35.4790 209.2 2.69 4.56 0.08 0.59 1.564 0.837 2015.1 -999.9 318.35 20.00 22622222228292 124 1 5 5 114.0 25.9565 35.9781 193.4 25.9310 35.9803 196.4 2.48 3.08 0.11 0.63 1.768 0.993 2047.4 -999.9 304.50 20.00 22222222228292 124 1 6 6 128.9 24.2842 36.0574 185.1 24.2567 36.0313 186.6 2.27 2.52 2.02 0.67 0.794 0.431 2080.4 -999.9 359.24 20.00 22222222244292 Last five lines of the file: 220 1 30 30 3038.2 1.6449 34.6718 167.2 1.4213 34.6738 166.7 125.79 34.50 0.00 2.41 -999.900 -999.900 -999.9 -999.9 -999.90 -999.90 22222222299595 220 1 31 31 3243.1 1.5769 34.6782 170.1 1.3348 34.6785 170.4 127.26 34.31 0.00 2.40 -999.900 -999.900 2295.1 -999.9 1104.49 20.00 22222222299292 220 1 33 33 3450.9 1.5390 34.6823 170.9 1.2769 34.6828 173.1 126.77 34.11 0.00 2.38 -999.900 -999.900 2295.0 -999.9 1111.84 20.00 22222222299292 220 1 32 32 3451.1 1.5400 34.6824 170.9 1.2778 34.6822 173.2 127.46 34.11 0.00 2.38 -999.900 -999.900 -999.9 -999.9 -999.90 -999.90 22222222299595 220 1 38 38 3636.3 1.5220 34.6839 -999.9 1.2412 34.6848 175.1 125.50 34.01 0.00 2.37 -999.900 -999.900 -999.9 -999.9 -999.90 -999.90 22922222299595