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INSTAAR Seminar: Remote sensing and modeling of the Sierra Nevada snowpack under hydrologic extremes

Monday, February 20, 2017, 12:00PM - 1:00PM


Noah Molotch


SEEC room 228

Full title

Remote sensing and modeling of the Sierra Nevada snowpack under hydrologic extremes: Transformative information at the interface of environmental science and management


In California, the mountain snowpack is the main source of the State’s surface water, with downstream hydrologic processes and interactions with ecosystems controlled by processes at higher elevations.  Changes in climate and rapid population growth drive the need for new understanding of the processes that control snow accumulation and melt.  Over rugged terrain, snow distribution is highly variable in time and space, motivating studies that integrate models with observations acquired at multiple scales (e.g. using intensive field campaigns and remote sensing).  In this regard, a new method for snowpack characterization will be presented in which multi-spectral remotely sensed data are used to reconstruct the distribution of snow water equivalent (SWE) at unprecedented levels of accuracy (~25% of observations).  In this regard, the SWE reconstruction approach mathematically integrates snow-atmosphere energy exchange retrospectively to resolve the distribution of maximum winter snow accumulation.  The approach leverages previously under-used remotely sensed snow cover data and reduces reliance on poorly constrained precipitation estimates that have plagued previous works in this area. The resulting high-resolution snow estimates improve knowledge of the processes that control snow distribution, snowmelt, and hydrologic sensitivity to climate change.  These estimates have relevance for seasonal water supply forecasts under abnormal climatic conditions.  Examples of water management applications will be presented in the context of the California drought and recent mega-snowstorms.  In addition, the improved estimates of snowmelt derived from these data have transformed understanding of hydrologic flowpaths, forest productivity response to interannual climate variability, and the transport of atmospheric pollutants through aquatic ecosystems.  These various scientific discoveries will be presented to illustrate the importance of snowpack processes within integrated atmospheric, surface, and subsurface processes and associated fluxes of water, energy, carbon and nitrogen.   


Free and open to the public.