Researchers Document Widespread Melting on Antarctica’s Huge Ross Ice Shelf

Large-scale melting of snow and ice on Antarctica’s massive Ross Ice Shelf, brought about by an unusually warm stretch of weather in the summer of 2016, is one of the first documented cases of widespread surface melting of the Ross Ice Shelf and other regions of West Antarctica, according to a new study

An area twice the size of California was partially melted when warm winds from an especially strong El Niño blew over western Antarctica for more than two weeks in January 2016. Satellite data showed a mix of melted snow and ice over most of the Ross Ice Shelf, which covers an area the size of France and is the largest floating ice shelf in the world.

West Antarctica, showing the number of melt days in January 2016.

West Antarctica, showing the number of melt days in January 2016. JULIEN NICOLAS/LEAD AUTHOR

More frequent melting would accelerate the general deterioration of the West Antarctic Ice Sheet, which is located to the west of the Ross Ice Shelf, explained David Bromwich of Ohio State team, co-author of a paper on the findings in Nature Communications. “Because we expect stronger, more frequent El Niños in the future with a warming climate, we can expect more major surface melt events in West Antarctica,” he cautioned.

Researchers have documented that the West Antarctic Ice Sheet is melting from below because of warming ocean waters. But the January 2016 melt event affected the surface of large areas of western Antarctica, which could mean that a major portion of Antarctica’s vast ice sheet — which holds 90 percent of the world’s ice — will experience intensified melting from the air above and the sea below.

“The story of melt all over the ice shelf rattled through the science community as it happened,” added Robin Bell, Antarctic researcher at the Lamont-Doherty Earth Institute at Columbia University who was not involved in the study. “Melting is thought to be death to ice shelves. This is the first well documented melt event where we can see how it happened.”