David H. Bromwich

The Ohio State University

Multi-decadal Climate Variability and Change in Antarctica

Room 811 AOSS, Monday, May 7, 2007, 3:30 PM

Abstract

Despite increases globally and especially in the Arctic, Antarctic station temperatures apart from those on the Antarctic Peninsula have changed little since modern records began in the International Geophysical Year of 1957-1958. A positive trend in the Southern Hemisphere Annular Mode (SAM), which may be due to greenhouse gas increases and stratospheric ozone depletion over Antarctica, appears to provide a negative feedback that buffers Antarctic temperature change.

Recent work has focused on spatially and temporally extending Antarctic snowfall and temperature records, as well as temporally extending the SAM index. These syntheses allow us to assess current Antarctic climate in a complete, multi-decadal context, and to examine whether the signal of anthropogenic forcing can be distinguished from the natural variability of the climate system. Further, such reconstructions provide a means of assessing global climate model simulations (IRCC AR4) over Antarctica and to infer the confidence attached to their projections for the future.