(Credit: NASA/Michael Studinger) Greenland is a giant ice sheet covered in snow. Its snowline — the border where snow cover and bare ice abut — migrates with the seasons, sliding to lower elevations in the winter and shifting up in the summer. Now researchers find that not only does the snowline move much more dramatically than they thought, but it also accelerates melting of the ice sheet. That’s a problem because the Greenland ice sheet is melting into the ocean and contributing to global sea level rise. The new finding could change climate model predictions, the researchers say. "We found that [climate] models don't reproduce snowlines very well, which adds an uncertainty to future projections," Jonathan Ryan, a glaciologist at Brown University in Providence, Rhode Island, who led the new research, said in a statement.
In Greenland, summer’s melting snow exposes bare ice. Whereas snow is bright and reflective, ice ...
