Large-Scale Hydrological Fluxes as Revealed by Data from the Soil Moisture Active-Passive Mission

摘要

Given that the near-surface soil acts as a “gateway” for many hydrological processes (e.g., infiltration into the soil, evaporation from the soil), and given that the Soil Moisture Active-Passive (SMAP) passive radiometer can sense soil moisture in the top 5 cm of soil at regular intervals, SMAP soil moisture retrievals offer the potential for providing useful information on large-scale hydrological fluxes, including precipitation and streamflow. This idea is explored here through the joint analysis of SMAP soil moisture retrievals, gauge-based precipitation data, and stream gauge measurements covering the warm seasons (June-September) of the years 2015-2017. Results are presented for two representative hydrological basins. SMAP-based estimates of 10-day precipitation and streamflow averages in these basins are found to be reasonably accurate as long as the precipitation and/or streamflow occurring in nature is not too extreme.