New early winter fCO(2) data reveal continuous uptake of CO2 by the Weddell Sea

The Antarctic Ocean has been thought to be unimportant for the uptake of CO 2 since upwelling of CO2-enriched deep waters would favour outgassing. Here we present the first direct f(co2) measurements obtained in early winter u nder the ice which, combined with estimated entrainment rates, show that th e Weddell Sea, an area of intense upwelling manifested by the doming struct ure of the cyclonic gyre, has the capability to be almost continuously a si nk fur atmospheric CO2. A Bur, effective after the ice cover disappears, is estimated to be -0.74+/-0.7 mmol m(-2) d(-1). Combined with a flux estimat e in late autumn (- 2.0 mmol m(-2) d(-1)) integrated over the area of the c entral Weddell Gyre, a carbon uptake of 0.24 x 10(13) gC y(-1) (approximate to 24 x 10(-3) GtC y(-1) being approximate to 1 parts per thousand of glob al uptake) is computed, which is about a third of the strength of the biolo gical pump of the Weddell Sea.