Published In

Antarctic Science

Document Type

Article

Publication Date

3-1-2017

Subjects

McMurdo Dry Valleys (Antarctica) -- Environmental conditions, Evolutionary paleoecology -- Antarctica, Paleoclimatology --Antarctica, Antarctica -- Hydrologic models, Föhn

Abstract

Large glacial lakes, including Glacial Lake Washburn, were present in the McMurdo Dry Valleys, Antarctica, during the Last Glacial Maximum (LGM) despite a colder and drier climate. To address the mechanism capable of generating enough meltwater to sustain these large lakes, a conceptual model was developed based on the warming potential of infrequent contemporary föhn winds. The model suggests that föhn winds were capable of generating enough meltwater to sustain large glacial lakes during the LGM by increasing degree days above freezing (DDAF) and prolonging the melt season. A present-day relationship between infrequent summer föhn winds and DDAF was established. It is assumed that the Taylor Dome ice core record represents large-scale palaeoclimatic variations for the McMurdo Dry Valleys region. This analysis suggests that because of the warming influence of the more frequent föhn winds, summer DDAF in the McMurdo Dry Valleys during the LGM were equivalent to present-day values, but this enhanced summer signal is not preserved in the annually averaged ice core temperature record. © Antarctic Science Ltd 2017

Description

To the best of our knowledge, this work was authored as part of the Contributor's official duties as an Employee of the United States Government and is therefore a work of the United States Government.

This is the publishers PDF. The definitive version can be found here.

DOI

10.1017/S0954102017000062

Persistent Identifier

http://archives.pdx.edu/ds/psu/19874

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