Soil Moisture-Precipitation Coupling in the Central United States: Results from Soil Moisture Active-Passive (SMAP) and the Thunderstorm Observation by Radar (ThOR) Algorithm

Development of a process-based understanding of the role of the land surface in the initiation of convective precipitation has been inhibited by the lack of soil moisture data at appropriate spatial and temporal scales. Recent advances in soil moisture remote sensing, such as the Soil Moisture Active-Passive (SMAP) mission, provide the opportunity to enhance our understanding of soil moisture-precipitation coupling and the role of land surface heterogeneity on deep convection initiation. In this study we use the Thunderstorm Observation by Radar (ThOR) algorithm to identify tens-of-thousands convective events in the central United States. Soil moisture from SMAP, as well as other remotely sensed soil moisture products, are used to identify areas exhibiting statistically significant preferences for convection initiation over relatively dry or wet soils. Additionally, SMAP L4 and merged SMAP/Sentinel-1 datasets are used to determine the spatial gradient or pattern of soil moisture immediately surrounding points of convection initiation.