The Estimation Of Downward Long-wave And Short-wave Radiation In Polar Regions

Downward radiation consists of the downward long-wave radiation(4?100um)and downward short-wave radiation(0.2?4um).Downward radiation surface radiation balance is not only an important component of the surface energy balance also an important factor in the surface energy balance and the earth-atmosphere system.Due to the particularity of the polar region,the long and short wavelength radiation in the region has more practical value in understanding and studying the global climate change,the radiation balance of the surface,the stability of the ecological environment,hydrology and agricultural meteorology.The existing radiation products in the low latitude area has been widely used,and the accuracy has also been verified,but in the polar regions is less.In this paper,by verifying the downward long and short wavelength radiation in the existing radiation products,it is found that the accuracy of the existing radiation products in the polar regions is low.Analysis of the reasons:First,the spatial resolution is low,the second is the use of a relatively single algorithm,the third is the polar regions of the climate and environmental conditions are more complex.This article in view of the existing radiation products low precision in the polar regions,by the team of algorithm combined with MODIS products for the polar regions(arctic downward short-wave radiation and the Antarctic downward longwave radiation)downward radiation has carried on the estimate.Longwave radiation,MODIS products and ground observation data basic in 0.6 above,the correlation coefficient between the standard deviation between 34 to 39 W/m2,root mean square error between 32 to 42 W/m2,the average deviation between 19 to-32 W/m2,compared with the existing radiation products,MODIS radiation products of various index is relatively stable.Average daily shortwave irradiance average deviation of only 3.28 W/m2,deviation range is 24.48W/m2 to 39.81 W/m2;Root mean square error is 55.85 W/m2;Minimum correlation coefficient is 0.72,the maximum is 0.92.The precision of the polar regions of MODIS products relative to the existing radiation products are improved.