Retrieval Of Surface Energy Flux In Taklimakan Desert Based On Multi-source Remote Sensing And Reanalysis Data

Because of the unique underlying surface type and land surface physical process,Taklimakan Desert plays an important role in the arid region of Northwest China.Its unique land-atmosphere interactions process directly affects the atmospheric circulation in China and even the world.As a significant parameter in the surface energy balance equation,the surface energy flux is a physical quantity that characterizes the underlying surface forcing and the strength of the interaction between the atmosphere and the near-surface.Therefore,get large-scale surface energy flux and quantitative analysis of each energy flux and energy balance closure have important research value for the heat exchange process,numerical prediction in the Taklimakan Desert.This paper is based on geostationary meteorological satellite data(FY-2F),polar-orbiting satellite Data(MODIS),and China Meteorological Forcing Dataset(CMFD)to derive 3-hourly surface energy flux at a spatial resolution of 0.1°in Taklimakan Desert,then,temporal and spatial variation characteristics of the various components of the surface energy flux are analyzed,the energy balance closure of the surface energy flux is evaluated,finally,comparison between SMAP datasets and Simulation results of surface energy flux,The main conclusions are as follows:(1)This article uses geostationary satellite FY-2F,polar-orbiting satellite MODIS land surface product data,and reanalysis data(CMFD)to obtain surface emissivity,surface albedo,land surface temperature,downward shortwave radiation,air temperature,and air pressure,The above parameters have a better fit with the measured values,all coefficients of determination are above 0.8.(2)The surface energy flux of the Taklimakan desert accurate results shows that:the estimated values are all in good agreement with the measured value,all coefficients of determination are above 0.8,the root means square error are 29.193 W·m^-2,11.477 W·m^-2,4.515 W·m^-2,and 8.960 W·m^-2,respectively.(3)Except latent heat flux,the diurnal variation of surface energy flux was smooth inverted U-shaped curves.The seasonal change characteristics of net radiant flux,soil heat flux,and sensible heat flux are similar,the largest daily mean values in summer,followed by spring and autumn,and the smallest in winter,the change of latent heat flux is not drastic throughout the year.For spatial distribution,the oasis and farmland have the highest value,followed by desert hinterland,Kunlun Mountain and Altun Mountain area have the lowest value.(4)Three energy balance closure evaluation methods were used to evaluate the energy balance closure of the surface energy flux.The degree of energy closure in the Taklimakan Desert has obvious seasonal changes,the degree of energy closure in spring and summer is better than in autumn and winter,the energy closure rate is the highest in spring with a value of 96%,and the energy closure rate in winter is the lowest with a value of 59.7%.The overall energy balance residual value fluctuates between-50 and 100W·m^-2,the daily peak value of each season was ranked as winter>autumn>spring>summer.(5)The simulation results and the SMAP remote sensing surface energy flux product data were compared with the measured sites in the Tazhong for quantitative analysis.The results shows that the simulation effect of surface energy flux is better than that of SMAP remote sensing product data.