Snow cover on Arctic Sea ice has thinned 30 to 50 percent

NASA | AUGUST 31, 2014

New research led by NASA and the University of Washington, Seattle, confirms that springtime snow on sea ice in the Arctic has thinned significantly in the last 50 years, by about a third in the Western Hemisphere and by half near Alaska.

Matthew Sturm of the University of Alaska Fairbanks, a co-author of this study, takes a snow measurement on sea ice in the Beaufort Sea in March 2012 during the BROMEX field campaign. Image credit: U.S. Army Cold Regions Research and Engineering Laboratory.

The new study tracks changes in snow depth over decades. It combines data from NASA's Bromide, Ozone, and Mercury Experiment (BROMEX) field campaign, NASA's Operation IceBridge flights, and instrumented buoys and ice floes staffed by Soviet scientists from the 1950s through the 1990s.

"The snow cover is like a shield that can insulate sea ice," said Son Nghiem of NASA's Jet Propulsion Laboratory in Pasadena, California, principal investigator for BROMEX and a coauthor of the new study. "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."

The researchers found that, since the Soviet period, the spring snowpack has thinned from 14 inches to 9 inches (35 centimeters to 22 centimeters) in the western Arctic and from 13 inches to 6 inches (33 centimeters to 14.5 centimeters) in the Beaufort and Chukchi seas, north and west of Alaska, despite notable uncertainty in the historical estimates.

The authors speculate that delayed freezing of the sea surface may contribute to the thinning trend, as heavy snowfalls in September and October now fall into the open ocean.

What thinner snow cover will mean for sea ice is not certain. "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.

YOU MAY ALSO LIKE

Plants can tell time even without a brain

Plants have circadian rhythms that help them tell the time of day, preparing plants for photosynthesis prior to dawn, turning on heat-protection mechanisms before the hottest part of the day, and producing nectar when pollinators are most likely to visit.

Extreme melt season leads to decade-long ecosystem changes in Antarctica's Dry Valleys

An abnormal season of intense glacial melt in 2002 triggered multiple distinct changes in the physical and biological characteristics of Antarctica's McMurdo Dry Valleys over the ensuing decade.

Researchers identify immune culprits linked to inflammation and bone loss in gum disease

An unhealthy population of microbes in the mouth triggers specialized immune cells that inflame and destroy tissues, leading to the type of bone loss associated with a severe form of gum disease.

Small Asteroid to Safely Pass Close to Earth Sunday

A small asteroid, designated 2014 RC, will safely pass very close to Earth on Sunday, Sept. 7, 2014. At the time of closest approach, based on current calculations to be about 2:18 p.m. EDT (11:18 a.m. PDT / 18:18 UTC), the asteroid will be roughly over New Zealand. From its reflected brightness, astronomers estimate that the asteroid is about 20 meters in size.

Cleaner Air Tied to Healthier Lungs in Kids

Researchers have linked a wide array of health effects to air pollution. Among these are reduced lung function, asthma, cardiovascular disease, preterm birth, and even death. The period between 11 and 15 years of age is particularly important for long-term lung function, as lungs are developing rapidly.

Potentially Habitable 'Super-Earths' Found Orbiting around Sun's near Neighbor

Two planets that orbit around a star like our own sun could support life.