Constraining Physical Controls on Snow Hydrology Along the Wasatch Front, UT,

TitleConstraining Physical Controls on Snow Hydrology Along the Wasatch Front, UT,
Publication TypeConference Proceedings
Year of Conference2017
AuthorsS. Skiles, McKenzie, Clark Steven, Andreini Jeremy, Olson Matt, and Peterson Hannah
Conference Name85th Annual Western Snow Conference
Date Published2017
Conference LocationBoise, Idaho

Like much of the Western US, the million plus people that live in the Salt Lake City metropolitan area,
located along the Wasatch Front, UT, depend on snowmelt to meet water demands. A persistent reduction in the
mountain snowpack would introduce stress into the current water delivery system. Impacts to snow water storage
during accumulation are mainly due to increasing temperatures; more precipitation falls as rain instead of snow.
Impacts to storage during ablation are mainly due to increasing net solar radiation, controlled by albedo, which
drives snowmelt in almost all snow covered environments. Combined, a shallower, warmer snowpack has a lower
albedo, which shifts snowmelt timing and magnitude, and further reduces water yields via increased
evapotranspiration. Deposition of light absorbing aerosols, which accumulate in the snowpack through the winter
and concentrate at the surface as snow melts, further compounds albedo decay. The Wasatch snowpack is at risk for
deposition of both black carbon, particularly in the winter during persistent cold air pools (inversions), and dust,
particularly in the spring when regional wind speeds and dust emission peak. Current snowmelt forecasting methods
are not capable of accounting for the physical processes that control snow accumulation and melt, which limits their
ability to adapt to changing snowmelt regimes. This is mainly due to the lack of observations to document processes,
establish relationships based on first principles, and validate physically based snow energy balance models. During
Water Year 2017 fieldwork efforts in the four main watersheds that dominate water deliveries to Salt Lake City, UT
were aimed at addressing this paucity of data to better constrain physical controls on snow hydrology along the
Wasatch Front. Here, initial results from fieldwork efforts completed between Jan-Jun 2017 are presented, as well
as a remote sensing analysis to assess historical variation in snow line elevation.