Tropical weather patterns drive West Antarctic snowfall

New research published in JGR Atmospheres by a team from the University of Utah has demonstrated that tropical climate patterns significantly influence snowfall on the West Antarctic Ice Sheet (WAIS).

By analyzing 25 ice cores collected from the 760,000-square-mile ice sheet alongside 20th-century weather data, scientists found that tropical convection and sea surface temperatures in the Pacific and Indian oceans drive atmospheric Rossby waves. These large-scale atmospheric undulations propagate south toward Antarctica, altering wind patterns and storm tracks. This process effectively transports heat and moisture to the continent, influencing the surface mass balance of the ice sheet.

The study also noted regional disparities in accumulation, revealing that the eastern sector of the West Antarctic Ice Sheet receives approximately twice as much annual snowfall as the western sector. The use of shallow ice core drilling helped researchers bridge observational gaps caused by the difficulty of maintaining weather stations in extreme Antarctic environments.