Lessons Learned and Looking Ahead: Supporting Operational Water Resources Decision-Making with NASA Airborne Snow Observatory

One-third of California's water supply comes from snowpack in the Sierra Nevada, yet despite over 100 years of manual snow surveys and ground measurements, water managers still have two pressing questions: how much snow is there and when is it going to melt? Ground measurements are sparsely located, challenging to access, and are generally located at low to mid-elevations, leaving water managers without little insight into the remaining snowpack after the last ground measurement sites have melted out in the late spring and early summer. NASA's Airborne Snow Observatory (ASO), developed in partnership with California Department of Water Resources, addresses this challenge by providing high resolution measurements of snow depth, snow albedo, and snow water equivalent on hydrologic basin-wide scale, answering the question of how much snow there is. ASO data is also being assimilated into the USDA iSnobal physically-based distributed snowmelt model and USDA's Automated Water Supply Model (AWSM), answering the second question of when is the snow going to melt.

This presentation will provide a brief history and technical overview of ASO, the process and challenges of getting water managers to accept, adopt, and utilize ASO and AWSM data on an operational decision-making basis, and pathways for long term sustainability and operability of the ASO and AWSM data.