The Impact of Tropical Indian Ocean Warming on Southern Hemisphere Polar Climate

Dr. Judith Perlwitz
The impact of two distinct anthropogenic forcings on the Southern Hemisphere's (SH) polar climate is investigated using idealized climate model simulations. Chemical constituent changes are shown to drive a cooling of the polar stratosphere during spring and summer. Tropical Indian Ocean warming, itself a response to chemical constituent changes, drives a warming of the polar stratosphere, opposite to the local radiatively driven cooling. Our model experiments suggest that warming of the tropical Indian Ocean initiates a potent dynamical mechanism for changing high latitude climate, one that must be considered for accurate attribution of SH polar climate change.