Soil Moisture Sensitivity to NRL-Blend High-Resolution Precipitation Products: Analysis of Simulations With Two Land Surface Models

We examine the Naval Research Laboratory (NRL) blended satellite (NRL-Blend) High-Resolution Precipitation Product (HRPP) as a proxy for a Global Precipitation Mission (GPM)-era HRPP by using the NRL-Blend for precipitation forcing in land surface models (LSM). We use the existing (late 2008) constellation of low Earth orbiting (LEO) microwave-based satellite platforms as a baseline to examine the impact of omitting several satellite and sensor types from future GPM-era HRPPs. A response of 1-m soil water content (SWC) to different precipitation forcing represented by six NRL-Blend satellite/sensor omission scenarios was investigated using simulations over the central United States with the Noah and Mosaic land surface models (LSM). The LSMs were integrated over a domain encompassing the Arkansas-Red River basin, using the North American Land Data Assimilation System (NLDAS) atmospheric forcing (except for precipitation). Both spatial and temporal statistical properties of the SWC response were examined. Both LSMs predicted a rather consistent geographical response of the 1-m SWC to different precipitation inputs, having positive/negative SWC monthly mean anomalies in western/eastern parts of the domain. The biggest impact was due to the omission of either the crosstrack microwave sounders, or the morning local time crossing satellites. On the other hand, omission of afternoon local time crossing satellites in the NRL-Blend resulted in the smallest impact upon the soil moisture simulated both with the Noah and Mosaic models. Although the relative magnitude of these SWC changes is small, these results suggest the importance of the crosstrack microwave sounders for future GPM constellations.