Water Resources Research

This research focuses on estimating surface heat fluxes, which are critical components of the Earth's water and energy balance. These fluxes influence various environmental processes, including ecology and meteorology. Traditional methods for measuring these fluxes are either costly, limited in scope, or difficult to implement over large areas due to variations in land surface characteristics. This study proposes a novel methodology to map surface heat fluxes by combining satellite data from the Soil Moisture Active Passive (SMAP) mission for soil moisture and the Geostationary Operational Environmental Satellite (GOES) for land surface temperature. These data are assimilated into a dual-source model using an advanced particle assimilation strategy. The method addresses the challenges posed by the different spatial and temporal resolutions of the satellite data. Assessments against ground-based observations show that the assimilation process improves the accuracy of soil moisture and land surface temperature estimates. The results indicate a reduction in the Root Mean Square Deviation (RMSD) for both sensible and latent heat flux estimates, highlighting the effectiveness of this integrated approach. Furthermore, the study emphasizes the crucial role of assimilating soil moisture data, even with its coarser resolution, for achieving robust flux estimations, especially when model uncertainties are high.