Washington, Aug 18 (IANS): In an alarming revelation, NASA has confirmed that the 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.

The research by NASA and University of Washington, Seattle recorded changes in snow depth over decades by combining data from various sources.

In the study, they took measurements of snow depth on sea ice to thoroughly validate the US space agency'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 snow cover is like a shield that can insulate sea ice," said Son Nghiem from NASA's Jet Propulsion Laboratory in Pasadena, California.

They found that since the Soviet period, the spring snowpack has thinned from 14 inches to nine inches in the western Arctic and from 13 inches to six inches in the Beaufort and Chukchi seas, north and west of Alaska.

However, researchers are not sure about the possible impact of thinner snow cover on sea ice.

"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," added first study author Melinda Webster, an oceanography graduate student at University of Washington.

The 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, researchers concluded.

The study was published in the Journal of Geophysical Research.