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janrinok writes:

An abnormal season of intense glacial melt in 2002 triggered multiple distinct changes in the physical and biological characteristics of Antarctica's McMurdo Dry Valleys over the ensuing decade.

The findings suggest that even abrupt, short-lived climate events can cause long-term alterations in polar regions that unfold over the span of several years and subsequently change the overall trajectory of an ecosystem.

The new research appears in the journal Nature Ecology and Evolution.

The McMurdo Dry Valleys (MDV) are the largest ice-free region of Antarctica and are considered a polar desert environment due to their low humidity and scarce precipitation. Now in its 25th year, the National Science Foundation's McMurdo Dry Valleys Long-Term Ecological Research (LTER) has provided a continuous multi-decade record of atmospheric and ecological data at the MDV research site.

Between 1987 and 2000, the MDV region experienced a period of cooling, during which mean summer temperatures steadily declined while solar radiation gradually increased. The trend resulted in expected changes to most biological variables, including decreased streamflow and increased thickness of permanent ice covers on lakes.

In 2002, however, the MDV experienced an abnormally warm and sunny summer season, triggering the greatest amount of glacial meltwater since 1969. The abrupt event prompted numerous changes in the lakes, streams and soils of the MDV over the following decade.

Journal Reference:
Michael N. Gooseff, et. al., Decadal ecosystem response to an anomalous melt season in a polar desert in Antarctica. Nature Ecology & Evolution, 2017; DOI: 10.1038/s41559-017-0253-0

Original Submission