The Southern Hemisphere mid- to high-latitudes have undergone large changes over the past 30-50 years. The extratropical atmosphere has seen a shift to a more positive phase of the Southern Annular Mode and a stronger and more poleward eddy-driven jet, particularly in austral summer. These altered winds have been associated with changes in rainfall patterns, ocean warming and Antarctic sea-ice.

Robust evidence based on theoretical arguments as well as simple and comprehensive climate models has built a strong case for the dominance of ozone depletion in driving the summertime mid-latitude wind changes. However, recent research has highlighted the influence of tropical sea surface temperature variability, on both interannual and decadal timescales, in understanding changes in recent decades as well as individual years. For example, the rapid decline in Antarctic sea-ice in spring 2016 has been linked to record convective heating in the tropical Indian Ocean and western Pacific. With the ozone hole beginning its recovery, understanding and predicting internal variability in tropical SSTs, as well as their interaction with increasing greenhouse gases, will be critical to understanding future changes in the Southern Hemisphere mid- to high-latitudes. Recent work in understanding the link between the tropics and high latitudes on interannual to decadal timescales will be presented.