Researchers confirmed snow has thinned significantly in the Arctic over the past century.
The study looked at data collected by ice buoys and NASA aircraft and compared it with historic ice floes recorded by Soviet scientists from the late 1950s through the early 1990s, the University of Washington reported.
These earlier researchers used meter sticks and handwritten logs to record snow depth, today researchers use an automated probe comparable to a ski pole to make airborne measurements.
"When you stab it into the ground, the basket move up, and it records the distance between the magnet and the end of the probe," said first author Melinda Webster, a UW graduate student in oceanography. "You can take a lot of measurements very quickly. It's a pretty big difference from the Soviet field stations."
Results showed snowpack had thinned from 14 inches to nine inches in the western Arctic and from 13 inches to six inches in the Beaufort and Chukchi seas, west and north of Alaska. This represents a decline of about a third in the western arctic and snowpack in the Beaufort and Chukchi seas are less than half as thick as they once were.
"Knowing exactly the error between the airborne and the ground measurements, we're able to say with confidence, Yes, the snow is decreasing in the Beaufort and Chukchi seas," said co-author Ignatius Rigor, an oceanographer at the UW's Applied Physics Laboratory.
Researchers are unsure what the thinner snow will mean for ice in the region. Deeper snow shields ice from cold air, so a thinner coat could actually allow ice to grow thicker in the winter.
"This confirms and extends the results of that earlier work, showing that we continue to see thinning snow on the Arctic sea ice," Rigor said.
The findings have been accepted for publication by the Journal of Geophysical Research: Oceans.
