Downscaling of Satellite Soil Moisture Products and its Applications in Drought Monitoring

Soil moisture is one of the most important land surface variables that controls not only water balance at land surface, but also land surface energy budget. As more and more satellite sensors are launched in recent years, a number of satellite soil moisture products are operationally produced with different spatial and temporal coverage and quality. However, the application of these products is usually limited by their spatial resolutions that is determined by their native sensor footprint sizes, which are usually tens of kilometers. To broaden the range of satellite soil moisture applications, products with finer resolution are in great need. This paper explores a soil moisture downscaling algorithm and its potential for drought monitoring at local scales. Downscaled soil moisture product is compared with soil moisture products produced from airborne measurements. The results show that the quality of the downscaled soil moisture product is comparable with the coarser resolution product but catches much more spatial details, which is very beneficial to applications such as drought monitoring.