Improvement of AMSR2 soil moisture algorithm with considering temperature profile effects in dry soil: A case study in Heihe basin

Soil moisture is an important variable in the Earth system. Reliable estimation of soil moisture, especially in regional and global scale, is essential for climatic, meteorological and hydrological researches. This study presents a revised soil moisture retrieval algorithm of ASMR2 that aims to improve soil moisture estimate in dry regions through including the vertical profile effects of soil temperature into the radiative transfer model. In situ observations of soil moisture and temperature profile, measured during HIWater Experiment intensive observation period, were used to formulate profile functions. By comparing the results of new algorithm against ground observations, the feasibility and capability of the revised algorithm were verified. The application of this algorithm in wide regions also demonstrated that our method could alleviate the overestimation-in-desert problem of original JAXA AMSR2 soil moisture products.