During the 1990s, ocean sampling expeditions were carried out as part of the World Ocean Circulation Experiment (WOCE), the Joint Global Ocean Flux Study (JGOFS), and the Ocean Atmosphere Carbon Exchange Study (OACES). Subsequently, a group of U.S. scientists synthesized the data into easily usable and readily available products. This collaboration is known as the Global Ocean Data Analysis Project (GLODAP). Results were merged into a common format data set, segregated by ocean. For comparison purposes, each ocean data set includes a small number of high‐quality historical cruises. The data were subjected to rigorous quality control procedures to eliminate systematic data measurement biases. The calibrated 1990s data were used to estimate anthropogenic CO2, potential alkalinity, CFC watermass ages, CFC partial pressure, bomb‐produced radiocarbon, and natural radiocarbon. These quantities were merged into the measured data files. The data were used to produce objectively gridded property maps at a 1° resolution on 33 depth surfaces chosen to match existing climatologies for temperature, salinity, oxygen, and nutrients. The mapped fields are interpreted as an annual mean distribution in spite of the inaccuracy in that assumption. Both the calibrated data and the gridded products are available from the Carbon Dioxide Information Analysis Center. Here we describe the important details of the data treatment and the mapping procedure, and present summary quantities and integrals for the various parameters.

Water column inventories are calculated for bomb radiocarbon at all the stations occupied during the GEOSECS and NORPAX expeditions and for the available TTO stations. The pattern of global inventories obtained in this way suggests that a sizable portion of the bomb radiocarbon that entered the Antarctic, the northern Pacific, and the tropical ocean has been transported to the adjacent temperate zones. A strategy for utilizing these inventory anomalies as constraints on global ocean circulation models is presented. Essential to this strategy are the improvement of our knowledge of the pattern of wind speed over the ocean, the establishment of the wind speed dependence of the rate of gas exchange between the atmosphere and sea, and the continued mapping of the distribution of bomb‐produced radiocarbon in the sea.

An improved method has been developed for the separation of the natural and bomb components of the radiocarbon in the ocean. The improvement involves the use of a very strong correlation between natural radiocarbon and dissolved silica. This method is applied to radiocarbon measurements made on samples collected during the Geochemical Ocean Sections Study (GEOSECS), Transient Tracers in the Ocean (TTO) and South Atlantic Ventilation Experiment (SAVE) expeditions. On the basis of this new separation we provide not only an estimate of the global inventory of bomb 14C at the time of the GEOSECS survey but also the distribution of bomb radiocarbon along four thermocline isopycnals in each ocean. We also document the evolution of the bomb 14C inventory and penetration along thermocline isopycnals in the North Atlantic Ocean between the times of the GEOSECS (1972–1973) and TTO (1980–1982) surveys and in the South Atlantic Ocean between the times of the GEOSECS (1973) and SAVE (1987–1989) surveys. In addition, we show that the bomb tritium to bomb 14C ratio (expressed in the tritium unit (TU) 81 units/100‰) for waters entering the thermocline of the northern hemisphere is about 9 times higher than for those entering the southern hemisphere thermocline. This contrast offers long‐term potential as an indicator of inter‐hemispheric transport of upper ocean waters.

The only viable explanations put forth to date for the glacial to interglacial change in atmospheric CO2 content suggested from measurements of the CO2 content of gas extracted from ice cores involve changes in the ocean's nutrient cycles. Any nutrient change capable of creating the 80 µatm changes in atmosphere CO2 pressure suggested by the ice core results also creates significant change in the deep ocean's CO3= content. Evidence from deep sea sediments suggests that these CO3= changes are compensated on the time scale of a few thousand years by reductions or increases in amount of CaCO3 accumulating in deep sea sediments. This compensation process has two important consequences. First, it significantly increases the magnitude of the CO2 change per unit of nutrient forcing. Second, it causes a delay in the response of the atmospheric CO2 change. While the first of these consequences is a boon to those seeking to explain the CO2 change, the second may prove to be a curse. The ice core CO2 record shows no evidence of a significant lag between the CO2 response and the polar warming. In any case it is important that we improve our knowledge of the magnitude and timing of the CaCO3 preservation events which mark the close of episodes of glaciation and of the dissolution events which mark the onset of these episodes.

Gas exchange rate studies carried out in the laboratory suggest that the stagnant film model is adequate t o relate the transfer coefficients of most gases between the atmosphere and sea t o an accuracy of f 15 ' $6. Estimates of the average film thickness prevailing for the world ocean based on the distribution of natural radiocarbon, bombproduced radiocarbon, and radon are in good agreement. Radon data from the BOMEX area and from station PAPA lend support t o Kanwisher's suggestion that gas exchange rates should vary in proportion to the square of the wind velocity. These observations permit a number of generalizations regarding the potential of the ocean as a source and sink for trace gases to be made. They also permit the more complicated situation for carbon dioxide to be assessed.

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Gas exchange rate studies carried out in the laboratory suggest that the stagnant film model is adequate to relate the transfer coefficients of most gases between the atmosphere and sea to an accuracy of ±15%. Estimates of the average film thickness prevailing for the world ocean based on the distribution of natural radiocarbon, bomb‐produced radiocarbon, and radon are in good agreement. Radon data from the BOMEX area and from station PAPA lend support to Kanwisher's suggestion that gas exchange rates should vary in proportion to the square of the wind velocity. These observations permit a number of generalizations regarding the potential of the ocean as a source and sink for trace gases to be made. They also permit the more complicated situation for carbon dioxide to be assessed.

This work presents an estimate of anthropogenic CO2 in the Pacific Ocean based on measurements from the WOCE/JGOFS/OACES global CO2 survey. These estimates used a modified version of the ΔC* technique. Modifications include a revised preformed alkalinity term, a correction for denitrification, and an evaluation of the disequilibrium terms using an optimum multiparameter analysis. The total anthropogenic CO2 inventory over an area from 120°E to 70°W and 70°S to 65°N (excluding the South China Sea, the Yellow Sea, the Japan/East Sea, and the Sea of Okhotsk) was 44.5 ± 5 Pg C in 1994. Approximately 28 Pg C was located in the Southern Hemisphere and 16.5 Pg C was located north of the equator. The deepest penetration of anthropogenic CO2 is found at about 50°S. The shallowest penetration is found just north of the equator. Very shallow anthropogenic CO2 penetration is also generally observed in the high‐latitude Southern Ocean. One exception to this is found in the far southwestern Pacific where there is evidence of anthropogenic CO2 in the northward moving bottom waters. In the North Pacific a strong zonal gradient is observed in the anthropogenic CO2 penetration depth with the deepest penetration in the western Pacific. The Pacific has the largest total inventory in all of the southern latitudes despite the fact that it generally has the lowest average inventory when normalized to a unit area. The lack of deep and bottom water formation in the North Pacific means that the North Pacific inventories are smaller than the North Atlantic.