Scientists looked at the snow accumulation through the decades by compiling data from NASA's IceBridge air surveys, collected from 2009 to 2013, as well as data from buoys frozen into ice sheets by the U.S. Army Corps of Engineers. The more recent data was pooled and then compared and contrasted to historic ice flow data collected by Russian scientists from 1954 to 1991.
The numbers confirm that spring snow in many regions of the arctic is anywhere from one-third to half as thick as it was in the 1950s, when Russian scientists first started measuring.
Washington researchers also trekked out onto ice sheets to hand measure (using a high tech probe) the thickness of the snow in order to confirm the data collected by NASA's IceBridge airplane. Their work is detailed in the latest issue of the Journal of Geophysical Research: Oceans.
"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," explained study co-author Ignatius Rigor, an oceanographer at Washington's Applied Physics Laboratory.
Rigor and his colleagues aren't exactly sure what the thinning snow means for the arctic and the climate at large. The snow blankets that rest atop the arctic's ice sheets have a thermos-like effect, shielding the ice from the arctic air. A thinner blanket may mean the ice can accumulate thicker and faster in the winter, but melt easier in the spring and summer.
Researchers say more research is needed to understand the long-term implications, but less protected could affect the regions weather as well as the ecosystem. Low-light microscopic plants that grow underneath the ice and benefit from the snow's protection for the base of the arctic's food web, and animals used the snow to build dens for shelter from the elements.