Variability and stability of anthropogenic CO.sub.2 in Antarctic Bottom Water observed in the Indian sector of the Southern Ocean, 1978-2018

Antarctic Bottom Water (AABW) is known as a long-term sink for anthropogenic CO.sub.2 (C.sub.ant ), but the sink is hardly quantified because of the scarcity of observations, specifically at an interannual scale. We present in this paper an original dataset combining 40 years of carbonate system observations in the Indian sector of the Southern Ocean (Enderby Basin) to evaluate and interpret the interannual variability of C.sub.ant in the AABW. This investigation is based on regular observations collected at the same location (63.sup." E-56.5.sup." S) in the framework of the French observatory OISO from 1998 to 2018 extended by GEOSECS and INDIGO observations (1978, 1985 and 1987).