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Regional patterns and proximal causes of the recent snowpack decline in the Rocky Mountains, U.S.

Geophysical Research Letters

By:
, ,
DOI: 10.1002/grl.50424

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Abstract

We used a first-order, monthly snow model and observations to disentangle seasonal influences on 20th century,regional snowpack anomalies in the Rocky Mountains of western North America, where interannual variations in cool-season (November–March) temperatures are broadly synchronous, but precipitation is typically antiphased north to south and uncorrelated with temperature. Over the previous eight centuries, regional snowpack variability exhibits strong, decadally persistent north-south (N-S) antiphasing of snowpack anomalies. Contrary to the normal regional antiphasing, two intervals of spatially synchronized snow deficits were identified. Snow deficits shown during the 1930s were synchronized north-south by low cool-season precipitation, with spring warming (February–March) since the 1980s driving the majority of the recent synchronous snow declines, especially across the low to middle elevations. Spring warming strongly influenced low snowpacks in the north after 1958, but not in the south until after 1980. The post-1980, synchronous snow decline reduced snow cover at low to middle elevations by ~20% and partly explains earlier and reduced streamflow and both longer and more active fire seasons. Climatologies of Rocky Mountain snowpack are shown to be seasonally and regionally complex, with Pacific decadal variability positively reinforcing the anthropogenic warming trend.

Geospatial Extents

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Regional patterns and proximal causes of the recent snowpack decline in the Rocky Mountains, U.S.
Series title:
Geophysical Research Letters
DOI:
10.1002/grl.50424
Volume
40
Issue:
9
Year Published:
2013
Language:
English
Publisher:
AGU
Contributing office(s):
Northern Rocky Mountain Science Center
Description:
6 p.
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
First page:
1811
Last page:
1816
Country:
United States
Other Geospatial:
Rocky Mountains