Snow as a Vital Link in the Hydrologic Cycle

Snow is life. It is the water we drink and is necessary to grow food that we require. Atmospheric clouds redistribute water around our Earth and when conditions are right, falling snow reaches the surface. Mountains collect and store snow in winter, and spring snowmelt feeds streams and reservoirs that supply water to people and crops, and it also generates electricity. The white blanket of snow cover drives climate processes and cools the planet.

But changes in snow quantity and snowmelt timing are underway and have serious consequences. However, the quantity of snow stored across the prairies and tundra, in the mountains, on sea ice, and in the forests remains difficult to measure, hindering efforts to understand how, why and where this precious resource is changing. Airborne and satellite remote sensing provides a means of measuring these changes in a consistent manner over large areas on a regular basis, but developing the optimal instruments to measure snow requires an investment of dollars and a long-term (several decades) effort. NASA seeks to measure global snow cover using multiple approaches including aircraft and field campaigns as well as through modeling and data assimilation, all derived from competitively-selected research activities.  These important efforts will culminate in an improved understanding that will enable development and launch of a satellite dedicated to snow research. We need to make these investments now to enable water resource managers, who base their decisions on historical records, to optimize hydrological forecasts during changing hydrologic conditions.

To begin, we need to conduct a series of community-wide field experiments that spans a range of snow types and during which we deploy multiple remote sensing technologies. The results of this work will enable informed choices about optimal instrument synergy to move forward for development of a satellite dedicated to snow research.

Credit: Got Snow