Comparative Analysis Of Multi-source Land Surface Albedo Data In China

Land surface albedo is an important land surface parameter in climate models,numerical weather prediction models,and land surface process models with different spatial and temporal scales.To analyze the surface albedo data from different sources in China,we must first analyze and evaluate its accuracy,especially in the Tibetan Plateau.This paper uses years of China's meteorological radiation observation data to compare it with the surface albedo of MODIS,GLASS,ECMWF,analyzes the characteristics of each data and the differences between them,and analyzes the reason for the accuracy that affects surface albedo satellite remote sensing inversion in the Tibetan Plateau.Specifically include the following work:(1)Firstly,we use ground observation data of 17 stations obtained from the daily dataset of China Meteorological Radiation Fundamentals from 2000 to 2012,MODIS(MODerate-resolution Imaging Spectroradiometer)surface albedo data MCD43C3,GLASS(Global LAnd Surface Satellites)surface albedo data GLASS02B06,and ECMWF(European Centre for Medium-Range Weather Forecasts)ERA-Interim reanalysis data for comparative analysis.The land surface albedo observations,MODIS land surface albedo and GLASS land surface albedo are the same,but there are significant differences in the values.The surface albedo of MODIS and GLASS can reflect the change of actual surface state to some extent.The ECMWF land surface albedo data fluctuate around 0.2 at each station,showing a periodic variation curve,which makes it difficult to reflect changes in surface conditions.(2)Then,using the 2009 China Regional MODIS,GLASS,and ECMWF land surface albedo data,the spatial distribution of the three are compared and analyzed.The results show that the spatial distribution trends of MODIS,GLASS,ECMWF land surface albedo data are overall consistent.The land surface albedo of MODIS and GLASS has little difference in spatial distribution.GLASS land surface albedo is slightly higher than MODIS land surface albedo.The land surface albedo data of ERA-Interim and MODIS are quite different.Especially in the Tibetan Plateau and northern winter,the highest difference with MODIS is 0.65,the highest difference with GLASS is 0.7.In northern China it is lower than the land surface albedo of MODIS and GLASS,and in southern region it is higher than MODIS and GLASS land surface albedo.The ECMWF land surface albedo data is relatively flat in temporal and spatial variations and cannot reflect more complex surface changes,such as the Tibetan Plateau,while MODIS and ECMWF land surface albedo can reflect this change.(2)The accuracy of land surface albedo products of MODIS and GLASS in the Qinghai-Tibet Plateau was evaluated,and the factors that affected the product's accuracy were discussed.The accuracy of these two products was evaluated with the high-precision ground observation data obtained from four stations during the CAMP/Tibet experiments.Furthermore,the factors that affect the accuracy of these two products was analyzed through the artificial visual interpretation of the MODIS land surface albedo data MOD09GA,MYD09GA combining with the MODIS snow product MOD10A1,MYD10A1,and the reasons for affecting the accuracy of the two products were analyzed in depth.The results are as follows:These two products have good consistency with land surface albedo ground measurements during the most retrieval periods,and accurately reflect the abnormal changing processes of land surface albedo.The patchy snow is an important factor that affects the accuracy of these two products.The inversion algorithm of the GLASS land surface albedo has great advantage over that of the MODIS land surface albedo under the snow condition.