The Snow Science Traverse—Alaska Region team and their snowmobiles and sleds. The covered sled is heated and houses the computers that are used in a number of tests performed on the snow at each station. Credit: National Science Foundation

The words “snow” and “Arctic” are almost interchangeable. But the white stuff that blankets the frozen north is incredibly complex and may hold several clues to what lies in store for a warmer tundra, scientists say.

In the Arctic, snow lasts eight to 10 months of the year and is one of the most important elements of the climate system. It insulates the ground, preserves the permafrost and reduces winter temperatures because it is such a good reflector of heat from the Sun. If scientists can understand the patterns of snow distribution and properties in the current climate, they will be in a much better position to model how this critical element in the Arctic landscape may change along with changes in climate.

For 35 days, the six-member Snow Science Traverse—Alaska Region (SnowSTAR 2002) crossed the state on snowmobiles to analyze the chemistry and composition of snow along the route and to determine the snow’s source. The traverse was part of an ongoing larger project to understand Arctic climate change, called ATLAS (Arctic Transitions in Land Atmosphere System), and sponsored by NSF's Office of Polar Programs. 

Matthew Sturm, principal investigator of the SnowSTAR expedition. Credit: National Science Foundation

Beginning in March 2002, the expedition covered roughly 700 miles—from Nome, northeast through the Brooks mountain range to Barrow—sampling snow at more than 75 locations. According to Matthew Sturm of the U.S. Army's Cold Regions Research and Engineering Laboratory at Fort Wainwright, Alaska, and team leader, snow is so elemental to the Arctic ecosystem that such painstaking detail is easily justified.

By tracing the sources of the snow’s chemical constituents, such as calcium, magnesium and various isotopes like boron and deuterium, the team hoped to pinpoint where the snow originated and its atmospheric history. The data gathered during the traverse will help show how key meteorological events determine snow characteristics.

At journey’s end, the team had produced 33,000 snow-depth measurements, recorded the layering of snow from 415 snow pits and made more than 800 measurements of the water content of the snow. They also conducted several hundred experiments on snow density and its reflective properties.

The data is the most comprehensive ever collected on snow properties, and scientists are continuing their analysis.