Uptake of Anthropogenic CO2 and Its Impact on Saturation State of Calcium Carbonate in the Ulleung Basin, East/Japan Sea

Abstract

The East/Japan Sea is one of the marginal seas that actively take up atmospheric CO2 through deep water formation. Studies in relation to the change in anthropogenic CO2 uptake and its impact on saturation state of calcium carbonate were mainly conducted on the Japan Basin where deep water formation occurs. However, the importance of the other basins in the East/Japan sea on CO2 uptake has grown along with a recent transition from deep water to intermediate water formation due to global warming. We first report an uptake rate of anthropogenic CO2 in the Ulleung Basin using two time-series carbon data sets collected in year 1999 and 2012, and extended multi-linear regression method. Over the past 13 years, anthropogenic CO2 had penetrated to depths shallower than 1,700m and the uptake rate was 0.53 ± 0.38 mol C m-2 yr-1 which is comparable to that of the Atlantic Ocean (0.63 ± 0.16 mol C m-2 yr-1) for the period of 1983-2003. This substantial accumulation of anthropogenic CO2 in the Ulleung Basin has caused the saturation horizons for calcite and aragonite to move upward by 100