Combining space-based active and passive microwave observations to improve global snowfall estimates

Snowfall provides a significant source of freshwater for ecological and human needs at higher latitudes and represents a significant component of the energy and water cycles in northern climate systems. Furthermore, seasonal runoff from snowmelt, along with over-ocean snowfall, contributes to freshening in the Arctic and high-latitude North Atlantic oceans that can have a significant impact on global ocean circulations. Despite this importance, much of the region in which snowfall occurs is poorly monitored by surface observations. As a result, satellite measurements of falling snow are essential for providing large-scale estimates of this important component of the hydrologic cycle. This presentation will outline the latest techniques for identifying and inferring the intensity of falling snow using spaceborne radar. The dominant sources of uncertainty in these techniques will be highlighted and the potential for reducing these uncertainties using passive microwave constraints will be explored.