Fluctuations and trends in mountain snowpack and their climatic causes Philip Mote
JISAO/SMA Climate Impacts Group, University of Washington

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Observations of snow water equivalent taken once to several times per year since the 1930s show a substantial decline in mountain snowpack since the 1950s, especially in spring. The decline is most pronounced at lower elevations, consistent with observed increases in winter and spring temperature. By regressing interannual fluctuations on seasonal mean temperature and precipitation from nearby climate stations, a clearer picture emerges of the climatic causes of this decline and of an apparent increase between the 1920s and the 1950s.

To augment these observations, we use long-term gridded climatalogical fields and a macroscale hydrology model to simulate snow accumulation and ablation. The hydrology model, the Variable Infiltration Capacity (VIC) model, has been well-validated in previous studies of streamflow, and has been implemented here over the Columbia River basin at a spatial resolution of 1/8 degree. Where snow observations are available, we compare variability and trends in simulated and observed snowpack. Implications for climate monitoring and water resources will be discussed.

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11 July, 2003
1:30 PM/ DSRC 1D 403
(Note: special time and day)

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