Sensitivity analysis on surface soil moisture to the time parameter of land surface variables: Application with remote sensing data

Soil moisture is an important variable for understanding hydrology and climate. This paper aims to analyze the sensitivity of surface soil moisture to the time parameter of land surface variables(Land Surface Temperature and Net Surface Shortwave Radiation) in the day time, thus to develop a new method to derive surface soil moisture with the time parameter. Firstly, time series of LST and NSSR were simulated by CoLM (Common Land Model) with different soil moistures and soil textures. Further study mainly dealt with the sensitivity analysis on time parameter according to the simulated data, and based on these, a general model was developed to retrieve surface soil moisture with the time different Δt (Δt =t_{max, LST}-t_{max, NSSR}). The validation was conducted with the simulated data with different soil textures and different atmospheric conditions. Finally, the model was applied to MSG (METEOSAT Second Generation) data to map regional soil moisture.