Impact of Stratospheric Ozone on Antarctica and the Southern Ocean

Johns Hopkins University, Baltimore MD

Investigators

Abstract

The impact of stratospheric ozone depletion, and its anticipated subsequent recovery this century, on several aspects of the climate and weather of the Antarctic and Southern Ocean regions is of considerable interest in the study of high-latitude climate dynamics. This modeling study seeks to use best available observations (i.e. reanalysis products) and the ensemble output of several contemporary coupled chemistry climate models (CCMs) to project the past and present impact of ozone depletion on Southern Hemisphere (SH) tropospheric and oceanic circulation features. Of particular interest is the projected evolution of these in the 21st century as high latitude ozone recovers (due to the Montreal protocols), and yet while greenhouse gases (GHGs) continue to increase. Modeling studies suggest that the influence of SH ozone extend to much more than general atmospheric circulation. Trends in polar stratospheric temperature, the location of polar tropospheric jets, the intensity of the Southern Annular Mode (SAM), high latitude precipitation, poleward shifts of subtropical dry zones, Antarctic surface temperatures and other changes have been suggested to show dependencies on O3 concentrations in model climate simulations. Attention will be paid to the examination of impacts of stratospheric ozone on synoptic weather systems at high latitudes. Both the interpretation of future IPCC climate projections and WMO/UNEP high latitude ozone assessments represent the main societal impact in the outcome of this work.