Using spaceborne lidar for snow depth retrievals: Best practices and recommendations for future studies

Lidar is an effective tool to measure snow depth over key watersheds across the United States. Lidar-derived snow depth observations from airborne platforms have demonstrated centimeter-level accuracy at high spatial resolution. However, ground-based and airborne lidar surveys are costly and limited in space and time, so repeat observations over large spatial domains are infrequent. In recent years, there has been an emerging interest in using spaceborne lidar to estimate snow depth. Preliminary results from spaceborne lidar altimeters such as NASA’s Ice, Clouds, and Land Elevation Satellite-2 (ICESat-2) can provide routine snow depth retrievals over mid-latitude watersheds, though further research on accuracy, coverage, and operational potential is needed.

In this presentation, we outline the current status of research using spaceborne lidar to derive snow depth. We focus on the currently operational ICESat-2 mission, with a summary of snow observations gathered during the SnowEx 2022/2023 campaigns in Alaska. We also outline best practices for spaceborne lidar snow depth retrievals, based on findings from the SnowEx campaigns and recent studies. We conclude with a discussion of ongoing challenges for spaceborne lidar, with suggestions for future studies and requirements for future mission concepts.