Surface pH and pC0 2 distributions in the Bellingshausen Sea, Southern Ocean, during the early Austral summer

Abstract

Measurements of the carbon dioxide system (pH, pC0 2) from the Bellingshausen Sea, Southern Ocean are discussed in relation to varying biological activity and hydrography. pH was determined using on-line indicator spectrophotometry and varied between 7.65 and 7.85 (at 25°C) and between 8.04 and 8.25 at in situ temperatures. Except for the Bransfield Strait, pCO 2 was below atmospheric pCO 2 for the duration of the cruise, with the average level being 295 ± 32 μatm (1 SE). Large mesoscale variability with no single control on the surface seawater carbon dioxide system was observed, although the majority of the study area was predominantly influenced by the hydrography of the circumpolar waters. The most significant exception being a region with high chlorophyll concentration south of the Southern Polar Front.