Published In

Antarctic Science

Document Type

Article

Publication Date

1-1-2008

Subjects

Paleoclimatology -- Antarctica -- McMurdo Dry Valleys, Glacial climates -- Antarctica, Glacial landforms -- Antarctica, Hydrologic cycle -- Climatic factors -- Antarctica

Abstract

The meteorological characteristics and hydrological response of an extreme warm, and cold summer in the McMurdo Dry Valleys are compared. The driver behind the warmer summer conditions was the occurrence of down-valley winds, which were not present during the colder summer. Occurrence of the summer down-valley winds coincided with lower than typical mean sea level pressure in the Ross Sea region. There was no significant difference in the amount of solar radiation received during the two summers. Compared to the cold summer, glaciological and hydrological response to the warm summer in Taylor Valley included significant glacier mass loss, and 3- to nearly 6000-fold increase in annual streamflow. Lake levels decreased slightly during the cold summer, and increased between 0.54 and 1.01 m during the warm summer, effectively erasing the prior 14 years of lake level lowering in a period of three months. Lake level rise during the warm summer was shown to be strongly associated with and increase in degree days above freezing at higher elevations. We suggest that strong summer down-valley winds may have been responsible for the generation of large glacial lakes during the Last Glacial Maximum when ice core records recorded annual temperatures significantly colder than present.

Description

Copyright 2008 Antarctic Science Ltd. The original publication is available at http://journals.cambridge.org.

DOI

10.1017/S0954102008001272

Persistent Identifier

http://archives.pdx.edu/ds/psu/7385

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