A quantitative understanding of snow accumulation on glaciers is essential to understanding glacier mass balance and provides insights into a wide range of scientific and resource management topics. The USGS Alaska Science Center is using 500 MHz ground penetrating radar (GPR) to map snow accumulation at multiple glaciers. This spatial variability allows scientists to quantify the importance of regional controls, such as distance from moisture sources and rain-shadow effects from topographic features, as well as local controls that include terrain parameters such as elevation, aspect, slope, and shelter from prevailing winds. Multi-variable regressions with terrain parameters on a glacier-by-glacier basis indicate that elevation is always the dominant local control, while other terrain parameters vary in importance. Although local parameters describe much of the variation in snow, 20–40% of the observed variability is not explained by these models, suggesting that additional processes are important.
End-of-season distributed Snow Water Equivalent (SWE) at six glaciers throughout the Gulf of Alaska region. Radar-observed SWE on survey tracks is overlaid for comparison. Both variables are plotted on the same color scale within each subplot, although each glacier has a different scale to show the basin scale variability.