Extreme weather phenomena called atmospheric rivers were behind intense snowstorms recorded in 2009 and 2011 in East Antarctica. The resulting snow accumulation partly offset recent ice loss from the Antarctic ice sheet, report researchers from KU Leuven. Atmospheric rivers are long, narrow water vapour plumes stretching thousands of kilometres across the sky over vast ocean areas. They are capable of rapidly transporting large amounts of moisture around the globe and can cause devastating precipitation when they hit coastal areas.