Reconstructs the Earth's complex climate history using the chemical and physical properties preserved in ice cores collected from polar ice sheets and high mountain glaciers. Has led eight expeditions to Antarctica and six to Greenland. Established Antarctica's most extensive and longest-running snow accumulation network at South Pole Station. Her current research focuses on reconstruction of climate and accumulation histories from the Greenland ice sheets and the Antarctic Peninsula. Both regions are very sensitive to the ongoing warming and are potential contributors to sea level rise.