Soil Moisture Retrieval From FY-3 Satellite Microwave Brightness Over The Tibetan Plateau And The Comparative Analysis

Soil moisture sdjusts and controls water vapor and energy exchange between the lower atmosphere and land by changing the surface albedo,soil heat capacity,sensible heat and latent,which has significant impacts on climate change and weather process.In this paper, we retrieved daily soil moisture data over the Tibet Plateau based on microwave data of FY-3B satellite using a radiative transfer model.Based on the in-situ datasets in Naqu,we improved the land surface temperature retrieval model in the LPRM,in order to improve the accuracy of the soil moisture data form LPRM model in the Tibetan Plateau.We compared the derived soil moisture data with VIC model and the Era-Interim reanalysis data using conventional statistical methods and TC method to analyze the soil moisture data form LPRMV06 over the Tibet Plateau.The main conclusions are as follows:(1)In terms of absolute magnitude,the deviation between the LPRM soil moisture and the in-situ data is large.The absolute deviation of the Era-Interim reanalysis data and VIC hydrological model are significantly lower than that of LPRM.The correlation coefficient between LPRM soil moisture data and the in-situ data is the highest,and the Era-Interim reanalysis data is the second,and VIC hydrological model is the lowest.This indicates that the LPRM soil moisture is the most consistent with the in-situ data.(2)In the time variation,through the comparison of the original LPRM during summer season inversion of soil moisture data and improved LPRM inversion of soil moisture data.The results show that the correlation coefficient does not change,but the absolute quantity is effectively reduced, and RMSD decreased 30%,ubRMSD decreased by 10%.(3)The LPRM soil moisture data,ECV soil moisture data and ERA-Interim soil moisture data show a decline trend from southeast to the northwest in the seasonal average distribution over the Tibet Plateau;while the TMI soil moisture data shows a decreasing trend from the southeast to the northwest.The LPRM soil moisture data shows the best temporal variation change with ECV soil moisture data in the Tibet Plateau,least consistent with ERA-Interim soil moisture data;In terms of the spatial distribution of soil moisture data,these four datasets show the different temporal variation of soil moisture in the eastern and Western regions ,for the TC results,LPRM soil moisture data is closely consistent with the assumed truth,ECV soil moisture is the second,the consistent between the ERA-Interim soil moisture data and the assumed truth in the Tibet Plateau is not very well..