Southern Hemisphere Zonal Waves and Antarctic Sea Ice (Invited)

The Southern Hemisphere atmospheric circulation shows a remarkable degree of zonal symmetry, a result of the lack of mid-latitude landmasses and the location of Antarctica over the South Pole. Yet, there are significant asymmetries, and large-scale wave patterns play a critical role in the Southern Hemisphere general circulation at middle and higher latitudes. Zonal waves three and four account for approximately one third of the total daily variance in the middle and upper troposphere. This presentation will review the form of the Southern Hemisphere circulation, with a focus on the most prominent zonal wave patterns. It will also discuss the influence of the atmospheric circulation upon Antarctic sea ice extent, with a focus on trends in sea ice extent and the role of large-scale wave patterns in influencing those trends.