Assessing the effects of multiple soil physics parameterizations on continental scale soil moisture patterns.

This work presents an analysis of how different representations of soil hydrology and soil hydraulics within Noah-MP may improve continental scale spatial-temporal soil moisture patterns. We evaluate a mixed-form Richards' equation solver with spatially variable soil depth and topographic index (TI) data in Noah-MP. This new solver presumably better represents variably saturated soil moisture, surface ponding, infiltration, and groundwater recharge. Our results also include how different parameterizations of the soil water retention curve (SWC), including Van-Genuchten and Brooks & Corey equations may influence overall model performance. We evaluate the modeling results against soil moisture estimates of (i) SMAP continental scale estimates and (ii) a large dataset of in-situ soil moisture sensors from the International Soil Moisture Network (ISMN). Our results show the potentials of implementing more physically based representations in land surface models, alongside with its implications on continental-scale soil moisture dynamics and land-atmosphere fluxes.