This paper presents a comprehensive analysis of the basin‐wide inventory of anthropogenic CO2 in the Atlantic Ocean based on high‐quality inorganic carbon, alkalinity, chlorofluorocarbon, and nutrient data collected during the World Ocean Circulation Experiment (WOCE) Hydrographic Program, the Joint Global Ocean Flux Study (JGOFS), and the Ocean‐Atmosphere Carbon Exchange Study (OACES) surveys of the Atlantic Ocean between 1990 and 1998. Anthropogenic CO2 was separated from the large pool of dissolved inorganic carbon using an extended version of the ΔC* method originally developed by Gruber et al. [1996]. The extension of the method includes the use of an optimum multiparameter analysis to determine the relative contributions from various source water types to the sample on an isopycnal surface. Total inventories of anthropogenic CO2 in the Atlantic Ocean are highest in the subtropical regions at 20°–40°, whereas anthropogenic CO2 penetrates the deepest in high‐latitude regions (>40°N). The deeper penetration at high northern latitudes is largely due to the formation of deep water that feeds the Deep Western Boundary Current, which transports anthropogenic CO2 into the interior. In contrast, waters south of 50°S in the Southern Ocean contain little anthropogenic CO2. Analysis of the data collected during the 1990–1998 period yielded a total anthropogenic CO2 inventory of 28.4 ± 4.7 Pg C in the North Atlantic (equator‐70°N) and of 18.5 ± 3.9 Pg C in the South Atlantic (equator‐70°S). These estimated basin‐wide inventories of anthropogenic CO2 are in good agreement with previous estimates obtained by Gruber [1998], after accounting for the difference in observational periods. Our calculation of the anthropogenic CO2 inventory in the Atlantic Ocean, in conjunction with the inventories calculated previously for the Indian Ocean [Sabine et al., 1999] and for the Pacific Ocean [Sabine et al., 2002], yields a global anthropogenic CO2 inventory of 112 ± 17 Pg C that has accumulated in the world oceans during the industrial era. This global oceanic uptake accounts for approximately 29% of the total CO2 emissions from the burning of fossil fuels, land‐use changes, and cement production during the past 250 years.

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Temperature, salinity, chlorophyll a (Chl-a), nitrate, and sea-air differences of CO 2 partial pressure (ΔpCO 2 ) were extensively investigated in the northern East China Sea (ECS) during seven research cruises from 2003 to 2009. The ΔpCO 2 showed large intraseasonal variation in the spring and summer. In spring, the areal mean ΔpCO 2 in May 2004 was almost half of that in April 2008, probably associated with differences in sea surface temperature (SST). In summer, the areal mean ΔpCO 2 in August 2003 was also twice as large as that in July 2006. In addition, ΔpCO 2 exhibited large seasonal variation with positive values in autumn and negative values in other seasons. The positive ΔpCO 2 in autumn was ascribed to vertical mixing with CO 2 -enriched subsurface waters and relatively high SST in this season. The annually integrated sea-air CO 2 flux in the northern ECS was -2.2 ± 2.1 mol m -2 yr -1 , indicating CO 2 absorption from atmosphere to the sea, which was more than two times lower than the previous estimate (Shim et al. 2007) reported for the same region. This large difference was presumably responsible for the underestimation of winter CO 2 influx by Shim et al. (2007) and the large interannual variation of CO 2 flux. The CO 2 influx in the ECS was twice that estimated for continental shelves worldwide, suggesting that the ECS acts as a strong sink of atmospheric CO 2 compared to other continental shelves.

Fugacity of CO 2 (fCO 2 ), temperature, salinity, nutrients, and chlorophyll-a were measured in the surface waters of southwestern East Sea/Japan Sea in July 2005. Surface waters were divided into three waters based on hydrographic characteristics: the water with moderate sea surface temperature (SST) and high sea surface salinity (SSS) located east of the front (East water); the water with high SST and moderate SSS located west of the front (West water); and the water with low SST and SSS located in the middle part of the study area (Middle water). High fCO 2 larger than 420 µatm were found in the West water. In the Middle water, CO 2 was undersaturated with respect to the atmosphere, with values between 246 and 380 µatm. Moderate f CO 2 values ranging from 370 to 420 µatm were observed in the East water. For the East and West waters, estimates of temperature dependency of f CO 2 (12.6 and 15.1 µatm o C −1 , respectively) were rather similar to a theoretical value, indicating that SST is likely to be a major factor controlling the surface f CO 2 distribution in these two regions. In the Middle water, however, the estimated temperature dependence was somewhat lower than the theoretical value, and relatively high concentrations of surface chlorophyll-a coincided with the low surface f CO 2 , implying that biological uptake may considerably affect the f CO 2 distribution. The net sea-to-air CO 2 flux of the study area was estimated to be 0.30±4.81 mmol m −2 day −1 in summer, 2005.

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