Evaluating winter snowfall event distribution in a mountain watershed using differential airborne laser scanning

Abstract:

Knowledge of the spatial distribution of snowfall in mountain catchments is critical for estimation and simulation of snow water resources. Measurements of precipitation are sparse, and extrapolation of measurements to surrounding terrain is challenging, particularly in areas with high relief and complex topography.

The NASA Airborne Snow Observatory (ASO) offers a unique approach to quantifying snowfall distributions. The ASO is a combined airborne laser scanner (ALS) and hyperspectral imager designed to map snow depth, water equivalent, and albedo at high resolution in mountain basins. Over the past 3 winter seasons, the ASO has collected data on a nominally weekly basis over the full extent of the Tuolumne River Basin in the Sierra Nevada Mountains of California, offering an unprecedented opportunity to examine the spatial distribution of storm snowfall at high resolution in a mountain basin. Where snowfall events occurred between flights, the difference in ALS-derived elevations reveals the accumulation pattern. We demonstrate snow accumulation patterns for several snowfall events in 2013-15, and compare to other precipitation distribution products and methods.