The snow that shields Arctic sea ice has become little more than a thin veil over the past 50 years, according to a new US study that was aided in part by data from Soviet-era scientists.
Arctic snow cover has fallen by nearly a third in the western hemisphere and by more than half near Alaska over the past half century, according to the study by Nasa and the University of Washington.
The researchers say this sweeping change in the Arctic could alter weather patterns, such as precipitation levels, but the full extent of the repercussions are not yet known.
The snow melt is part of a larger trend caused by global warming. Ice and snow cover is generally in retreat at the planet’s poles, and is likely to cause havoc with the world’s climate, according to a myriad of studies.
Published in the Journal of Geophysical Research, the study tracked changes in snow depth over decades using data (which you can see here and here) from Nasa and from specially-equipped Soviet buoys and ice floes from the 1950s through to the 1990s.
“The snow cover is like a shield that can insulate sea ice,” Son Nghiem of Nasa’s Jet Propulsion Laboratory in Pasadena, California and a co-author of the report, said in a statement. “In this study, we had thousands of measurements of snow depth on sea ice to thoroughly validate NASA’s aircraft observations.
“We knew Arctic sea ice was decreasing, but the snow cover has become so thin that its shield has become a veil.”
A delay in the freezing of Arctic ice may be contributing to the thinning snow trend as heavy snowfalls in September and October now fall into the open ocean, the researchers said.
What the disappearing snow cover will mean for the region is uncertain. “The delay in sea ice freeze-up could be changing the way that heat is transported in the Arctic, which would, in turn, affect precipitation patterns. That’s going to be a very interesting question in the future,” said first author Melinda Webster, an oceanography graduate student at the University of Washington.
The full paper is online here.