Warmer air is only part of the story when it comes to Greenland’s rapidly melting ice sheet. New research by scientists at Woods Hole Oceanographic Institution (WHOI) highlights the role ocean circulation plays in transporting heat to glaciers.
Greenland’s ice sheet has lost mass at an accelerated rate over the last decade, dumping more ice and fresh water into the ocean. Between 2001 and 2005, Helheim Glacier, a large glacier on Greenland’s southeast coast, retreated 5 miles (8 kilometers) and its flow speed nearly doubled.
A research team led by WHOI physical oceanographer Fiamma Straneo discovered warm, subtropical waters deep inside Sermilik Fjord at the base of Helheim Glacier in 2009. “We knew that these warm waters were reaching the fjords, but we did not know if they were reaching the glaciers or how the melting was occurring,” says Straneo, lead author of the new study on fjord dynamics published online in the March 20 edition of the journal Nature Geoscience: Rapid circulation of warm subtropical waters in a major glacial fjord in East Greenland
The team returned to Greenland in March 2010, to do the first-ever winter survey of the fjord. Using a tiny boat and a helicopter, Straneo and her colleague, Kjetil Våge of University of Bergen, Norway, were able to launch probes closer to the glacier than ever before—about 2.5 miles away from the glacier’s edge. Coupled with data from August 2009, details began to emerge of a complicated interaction between glacier ice, freshwater runoff and warm, salty ocean waters.