Error And Impact Factor Analysis Of Global Solar Radiation Reanalysis Products

Solar radiation refers to the energy that the sun transmits to the space through electromagnetic waves.It is the main driving force for energy exchange between the atmosphere and the earth’s surface,and it is also the most important source of energy on the surface of the earth.The solar radiation data of global reanalysis products has the characteristics of long time series and wide spatial coverage,and is often used in large-scale meteorological research.Since the solar radiation data of the reanalysis product depends on the assimilation data and the assimilation system,it still has some error.Therefore,when users use reanalysis products for scientific research,it must be giving priority to error assessment to fully understand the applicability of different products.Supported by China Postdoctoral Science Foundation Project "2018M632281"and the National Natural Science Foundation of China(41871293),this research evaluated three typical global reanalysis products(ERA-Interim,JRA-55,NCEP-DOE)using 10 years of ground-based solar radiation observatory data(GEBA,CMA)from 1 January 2000 to 31 December 2009 and error assessment on different temporal scales.The results of the assessment showed that the solar radiation data of the three reanalysis products were overestimated by actual solar radiation.The annual scale deviations of ERA-Interim,JRA-55 and NCEP-DOE are 14.86W/m2,22.61 W/m2,31.85 W/m2,and the seasonal scale deviations are 15.08W/m2 and 21.21 W/m2,36.69 W/m2,the monthly scale deviations were 15.17 W/m2,21.29 W/m2,and 36.91 W/m2,respectively.According to the error evaluation results of different time scales,ERA-Interim products performed best,followed by JRA-55,and NCEP-DOE products performed the worst.On the spatial scale,this paper uses the Koppen climate zones to divide the world into five climatic zones,namely tropical zone,cold zone,arid zone,polar zone and temperate zone.According to the research results,different reanalysis products have different performances in different climatic zones.The three reanalysis products performed poorly in the temperate climate zone,while the ERA-Interim products performed better in the cold zone and the JRA-55 and NCEP-DOE products performed better in the arid zones and tropical zones.Based on the assessment results of three products,the impact factors of the three products were analyzed using aerosol,cloud and water vapor data released by MODIS products.According to the analysis results of the error impact factors of the three products,it can be seen that the solar radiation data errors of the three reanalysis products are mainly affected by the cloud,and secondly,the effects of aerosol and water vapor are also significant.Further exploration of the error analysis of the cloud data of the reanalysis products can be found that although the cloud cover will affect the solar radiation data of the reanalysis products,the interaction between the aerosol and the water vapor and the cloud cover will also lead to the evaluation error of the solar radiation reanalysis products.