A PSL team, snow-level radar network

Dave Carter, Dave Costa and Paul Johnston are three outstanding CIRES scientists who have teamed up to design, prototype, build, and deploy a new network of snow-level radars for California. The snow level, the altitude in the atmosphere where snow changes into rain, is a critical parameter influencing runoff in mountainous watersheds because it determines the surface area of the watershed that will be exposed to rain versus snow. When the snow level is above most or all of the terrain in a watershed, a storm is more likely to produce enough rapid runoff to cause flooding. On the other hand, if the snow level is low in a watershed, then the storm increases the snowpack, providing valuable storage of water for potential later use. The radar instruments typically used to measure snow level are prohibitively expensive, particularly for state-wide monitoring of water resources and flood control issues. In response to this need, the nominees employed modernized frequency-modulated, continuous wave (FMCW) technology as part of a project with the California Department of Water Resources (CADWR). By innovating a new radar design using FM-CW technology, the nominees built a prototype snow-level radar for about one tenth of the cost of one of the conventional instruments. This new network of snow-level radars implemented by the nominees will allow scientists to monitor this key variable over time. The nominees designed creative ways to process the data and generate radar profiles, and the new technology is already being applied to new fields, including wind profiling.