March 25, 2002

CROSSING ALASKA BY SNOWMOBILE IN SEARCH OF CLIMATE-CHANGE CLUES

A group of scientists left Nome, Alaska, late last week on a 35-day snowmobile traverse to scour the Alaskan tundra for clues to the role snow cover plays in climate change. The team also will analyze the chemistry and composition of snow along the route to determine the source of the snow, and how much it has been affected by arctic haze.

Supported by the National Science Foundation (NSF), the six-member Snow Science Traverse ? Alaska Region (SnowSTAR 2002) expedition plans to cover 1,100 kilometers (700 miles) -- from Nome, northeast through the Brooks mountain range to Barrow. The team plans to sample snow at more than 75 locations.

The traverse is part of an ongoing larger project to understand climate change in the arctic, titled ATLAS (Arctic Transitions in Land Atmosphere System) and sponsored by the Arctic System Science program within NSF?s Office of Polar Programs. Matthew Sturm, of the Army's Cold Regions Research and Engineering Laboratory at Fort Wainwright, Alaska will lead the team.

The team will measure snow depth, density and layering during the traverse, and will make detailed measurements of snow layering or stratigrapy. These measurements will be used to determine regional trends in the snow properties.

Several lines of evidence indicate that climate change is likely to be amplified in the arctic and therefore easier to detect there than at lower latitudes. Air temperatures in the Alaskan arctic have increased two to four degrees Celsius in the past 30 years, and evidence suggests changes are already occurring in terrestrial ecosystems. Snow covers the arctic for seven to 10 months of the year and is thought to play a key role in this process of change.

The researchers will be looking at two processes: the role of key weather events in the development of the snow pack, and the interaction of the snow and vegetation. Previous studies have shown that arctic snow pack consists of between five and eight layers of snow deposited by a like number of storms.

Chemical sampling of the snow will help determine if there is a difference between the winter precipitation source for the arctic slope versus south of the Brooks Range and if the precipitation source changes through the winter as the Chukchi, Beaufort, and Bering Seas freeze. By tracing the snow?s chemicals, such as calcium, magnesium, and various isotopes such as Boron and Deuterium, the team hopes to pinpoint where the snow originated and its atmospheric history. The data gathered during the traverse will help show how key meteorological events determine the characteristics of the snow.

The studies related to snow and vegetation are motivated by previous findings that the presence of shrubs may promote further shrub growth by increasing the amount of snow on the ground. Climate warming also promotes increased plant production, so the two processes may feed back in complex ways.

Snow measurements will be taken along the tundra-forest boundary between Council and Ambler, a small village on the Kobuk River. North of the Brooks Range, measurements will be taken on the tundra. The tundra north of the Brooks Range is much less shrubby than the tundra of the south range.

April Cheuvrant, a teacher at Table Rock Middle School in Morganton, N.C., will accompany the traverse as part of NSF?s Teachers Experiencing the Arctic and Antarctic (TEA) Program. She will assist in conducting sampling and interacting with Native Alaskans in villages along the traverse route.

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Contacts:
Peter West
National Science Foundation
703-292-8070
pwest@nsf.gov

This text derived from http://www.nsf.gov/od/lpa/news/02/pr0220.htm

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