Collaborative Research: SAM's Contribution to Increased Ocean Heat Content on the Continental Shelf of the Western Antarctic Peninsula
The dynamics of a warming Southern Ocean and its interactions with Antarctic continental shelf circulation patterns brought about by the intensification of the Southern Hemisphere westerlies, circumpolar winds which prevail between 30 and 60 0 S, remains uncertain in several respects. Current global climate models (e.g. IPCC/AR4) attribute intensification of the westerlies to anthropogenic increases in greenhouse gases in the troposphere along with decreased levels of stratospheric ozone, seasonally observed as the polar ozone hole. Other dynamical oceanic processes may also be involved.
This numerical and analysis project seeks to further evaluate the contribution of oceanic heat content to the accelerating warming and sub-glacial melting currently being observed in the terminal ice streams in the Amundsen and Bellingshausen Seas, and the adjacent rapidly warming Western Antarctic Peninsula (WAP). Use of the Palmer Station LTER data set, which extends back to 1993, provides a observational series which in part covers the time period where changes in atmospheric circulation and air temperatures are most likely to have taken place. Use of a regional oceanic numerical model (3-D, fully dynamic) under contrasting wind regimes corresponding to observed (more positive) trends in the Southern Annular Mode will shed light on the dynamics of climate change in these sensitive continental shelf regions of the continent.
The impact of melting glaciers and ice sheets on global sea level rise is an acknowledged area of uncertainty in the most recent IPCC assessment, and would be a direct impact of climate change on society in this century.
OUTCOMES: One journal publication. Found that Upper Circumpolar Deep Water isopycnals are already at their maximum tilt so increasing wind speeds will not affect them.