Rapid Subsurface Warming of West Antarctic Peninsula Waters by East Antarctic Coastal Winds

Massive mass loss and accelerated Antarctic glacial flows in recent decades is generally linked with warmer ocean water at the base of the floating ice shelves. However, the physical mechanisms responsible for changing the subsurface ocean heat content on the Antarctic continental shelf remain largely unknown. This talk explores the magnitude and causes of subsurface Antarctic coastal ocean temperature variability on annual to decadal time scales. Ocean model simulations using the GFDL MOM5 ¼ degree model reveal that intense subsurface ocean warming (>2C at 200-700m depth) can rapidly (<1yr time-scale) result from changes in both local and distant (>10,000km away) Antarctic coastal winds. The local wind response is driven by changes in near-shore Ekman pumping, while the distant wind response is driven by Antarctic coastal Kelvin waves. The Bellingshausen and Amundsen seas and the western side of the Antarctica Peninsula are particularly susceptible to Southern Annular Mode like wind changes in East Antarctic coastal winds.