Ongoing development of the Terrestrial Snow Mass Mission

Freshwater delivered by seasonal snow melt is a commodity of the utmost importance for health and well-being, supports all sectors of the economy, sustains ecosystems, and poses risks through floods or sustained drought events. At present, surface snow mass observing networks are sparse; current satellite observing systems lack the capability to derive terrestrial snow water equivalent (SWE, the amount of liquid water stored in solid form by snow) at the spatial resolution, synoptic sensitivity, global coverage, and accuracy required for environmental monitoring, climate services, and hydrological prediction. The required combination of revisit time, spatial coverage, measurement resolution, and sensitivity to the mass of snow on the ground necessitates a new spaceborne observing concept. To address this observing gap, Environment and Climate Change Canada (ECCC), the Canadian Space Agency (CSA), industrial partners, and international scientific collaborators are developing a new Ku-band radar mission primarily focused on seasonal snow. Following technical trade-off studies, a concept capable of providing dual-polarization (VV/VH), moderate resolution (500 m), wide swath (~250 km), and high duty cycle (~25% SAR-on time) Ku-band radar measurements at two frequencies (13.5; 17.25 GHz) was identified. Ku-band radar is a viable approach for a terrestrial snow mission because these measurements are sensitive to (1) SWE through the volume scattering properties of dry snow and (2) the wet/dry state of snow cover. These two parameters characterize the key aspects of snow relevant to hydro-climatological applications. This presentation will provide an overview of the Ku-band radar technical concept, ongoing activities to advance the scientific readiness, and the programmatic status of the mission.