This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: Climate patterns in the tropics help determine how much snow falls from year to year in Antarctica, one of the coldest, windiest and driest places on Earth. New research from the University of Utah shows that tropical conditions and the oceans also influence the continent's massive ice sheets.
By analyzing ice cores recovered from the West Antarctic Ice Sheet (WAIS) and 20th-century weather data, an interdisciplinary team of scientists demonstrated that what happens in the tropics, especially in the Pacific and Indian oceans, affects how much snow falls in West Antarctica. Tropical climate patterns, such as El Niño and the Madden–Julian Oscillation (MJO), send atmospheric ripples called Rossby waves south toward Antarctica. These waves alter wind patterns and storm tracks, influencing how much moisture reaches the ice sheet, according to Ella Hunter, a graduate student in atmospheric sciences.
Her recently published study documented the variability of snow accumulation on the ice sheet over the 20th century. "Our biggest takeaway was the influence of the tropics on snowfall in Antarctica. Rossby waves can affect temperature, winds and precipitation across the globe," said Hunter, first author of the paper in the Journal of Geophysical Research: Atmospheres.
"Tropical convection or heating in the tropics from sea surface temperatures can create storms that propagate these Rossby waves"—named for meteorologist Carl-Gustaf Rossby. "And they are really effective at transporting heat and moisture down to the Antarctic ice sheet," Hunter said. These findings are based on the research team's analysis of 25 ice cores, some of which were recovered by geography professor Summer Rupper of the U's School of Environment, Society & Sustainability, a co-author of the paper.
"What's unique about this study is leveraging all these cores together to look more carefully at the drivers of the variability, not just the trends. We tend to focus on the trends, but variability matters a lot for ice sheet stability," said Rupper, an expert on Earth's cryosphere, the parts covered in frozen water, such as glaciers, pack ice and ice sheets. Ancient ice preserves a record of past climate and atmospheric composition, and these frozen regions serve as bellwethers for ongoing climate change.
Much smaller than its eastern counterpart, the WAIS covers 760,000 square miles (2 million square kilometers), with an average ice thickness of 3,400 feet (1,040 meters). If it all melted, its water would raise global sea levels by more than 15 feet (4.6 meters). The U team analyzed West Antarctic ice cores that recorded snow accumulation between 1900 and 1999, along with historical climate datasets, to understand how the ice sheet's surface mass balance, or SMB, changed over time.
Extract — continue reading at the source.
