Meteorological Controls on Snow Accumulation and Chemistry in the St. Elias Mountains

This Project is supported by a generous grant from the
Dan and Betty Churchill Exploration Fund

July 6th to 24th, 2006
Journal entries and photos

Nate Vogan
The Arctic plays a prominent role in global climate change research because of both its sensitivity to changing climate and because of the relative wealth of paleoenvironmental proxy records available. Proxy records developed through physical and chemical analyses of ice cores provide the highest resolution and most direct view of Earth’s paleoatmosphere over time scales ranging from single seasons to hundreds of thousands of years. Recent research efforts have focused on developing high resolution ice core records from the St. Elias Mountains in southwestern Yukon Territory and southeastern Alaska. During the summers of 2001 and 2002, scientists from the Geological Survey of Canada (GSC), National Institute for Polar Research in Tokyo, University of New Hampshire (UNH), and University of Maine (UMaine) recovered ice cores from three different glaciers in the St. Elias Mountains, southwestern Yukon Territory. On the Eclipse Icefield (∼30 km northeast of the Logan Massif) an UNH/UMaine team recovered a 345 m core along with three other shallower cores.

Previous work on an ice core recovered in 1980 from Mt. Logan (Holdsworth et al, 1991, Holdsworth and Krause, 2002) has shown that major discontinuities in the variation of the water stable isotope ratios with altitude, which are believed to be derived from a multilayered atmosphere during precipitation events on high altitude glacier sites. To properly interpret the glaciochemical records developed from the new St. Elias ice cores, calibration of snow properties with meteorological data (temperature, precipitation, and sea level pressure) is critical. At the Divide Site, two automatic weather stations (AWS) have been operating since 2002, collecting snow depth as well as standard meteorological data. Therefore, the timing of snow accumulation over the past 4 years is known precisely, providing a unique opportunity to investigate the atmospheric controls on snow deposition and chemistry in the St. Elias Mountains.

heric controls on snow deposition and chemistry in the St. Elias Mountains.