Published In

Journal of Geophysical Research - Earth Surface

Document Type

Article

Publication Date

12-17-2008

Subjects

Surface energy, Meltwater -- Antarctica -- Taylor Valley, Glaciers -- Antarctica -- Taylor Valley, Mass budget (Geophysics)

Abstract

In the McMurdo Dry Valleys, Victoria Land, Antarctica, melting of glacial ice is the primary source of water to streams, lakes, and associated ecosystems. To understand geochemical fluxes and ecological responses to past and future climates requires a physically based energy balance model. We applied a one-dimensional model to one site on Taylor Glacier using 11 years of daily meteorological data and seasonal ablation measurements. Inclusion of transmission of solar radiation into the ice was necessary to accurately model summer ablation and ice temperatures. Results showed good correspondence between calculated and measured ablation and ice temperatures over the 11 years. Ablation (18 cm a??) was dominated by sublimation with very few occurrences of melt (42 days during 11 years). Results also indicated that above freezing air temperatures did not necessarily result in melt and, in turn, melt occurred during subfreezing air temperatures under some conditions. For air temperatures near freezing, low wind speed was critically important for melt initiation. According to the model, subsurface melt, away from rocks and sediment in the ice, occurred three times more frequently than surface melt; occurs no deeper than 50 cm below the glacier surface; and was small, never exceeding 8% by mass. The magnitude of subsurface melting and the energy balance indicate that Taylor

Description

Copyright 2008 American Geophysical Union.

DOI

doi:10.1029/2008JF001029

Persistent Identifier

http://archives.pdx.edu/ds/psu/7384

Publisher

American Geophysical Union

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