Evidence of ice shelf melt in the Bellingshausen Sea from seal-borne observations
The inflow of warm Circumpolar Deep Water (CDW) onto the Antarctic continental shelf contributes to basal melting of ice shelves in the Amundsen Sea. The Bellingshausen Sea (BS) also hosts several major ice shelves, but observations regarding the trends of shelf water properties are limited, especially in the western BS. Here we analyze 489 hydrographic profiles near the continental shelf break in the western and central BS obtained from CTD-Satellite Relay Data Loggers deployed on southern elephant seals from April to August 2010, collected under seasonal sea ice. ARGO floats in nearby regions are used for calibration purposes. The hydrographic data show the intrusion of CDW onto the continental shelf, and a poleward shift of the CDW core with respect to historical profiles from 1994. Furthermore, a new source of bottom water, likely due to basal melting of the Venable Ice Shelf, is identified. The temporal variability of shelf water properties and the presence of a strong geostrophic shelf break current are also discussed.