The Validation Of The Precipitable Water Vapor Of Multisensor Satellites And The Impact Of AOD Retrieve In China

Water vapor and Aerosols are two kinds of atmospheric components that have an important impact on climate change and human life.It is found that the retrieval of the satellite aerosol is often affected by the atmospheric water vapor,so the accurate detection of atmospheric water vapor(also known as Precipitable Water Vapor,PWV)has an important influence on the aerosol optical thickness of the satellite.Ground-based observations(2014~2015)indicated that the PWV in China exhibited large spatial and temporal variations.The annual mean PWV values ranged from 4.0 ± 2.9 mm to 42.3 ± 10.6 mm from the Qinghai-Tibet Plateau to the South China Sea,and the seasonal variation ranged from 1.9 ± 1.2 mm to 50.5 ± 5.4 mm.The accuracies of MODIS,VIRR and MERSI data varied widely with relative errors from 10% to 899%.VIRR performed the best in the humid southern coastal regions of China(RE<6.3%)where the annual PWV was as high as 35 mm.MERSI was more suitable in the dry western region of China(10 mm<PWV<15 mm),with RE< 1.3%.MODIS PWV products could be accurately in the city and urbanized areas of the eastern China Plain(20 mm<PWV<30 mm),with RE of 0.64%~13.8%.The accuracy of VIRR and MERSI is poor.In the north China desert and the Qinghai-Tibet plateau(PWV<18 mm),and the VIRR is overestimated by 161~899%;In the southeastern coastal areas of China(PWV>35 mm),and MERSI underestimated by 10~30%.In general,the accuracy of MOD05 and MOD07 products of NASA's MODIS satellite is higher than that of FY satellite,and the accuracy of MOD07 is higher than that of MOD05.In related research,MOD07 products are recommended.The study of MOD07 PWV effects on MODIS AOD in eastern China shows that: In the land area of eastern China,when PWV<1.5,MODIS AOD had a good correction with the AERONET AOD,and the correlation coefficient is greater than 0.9;in the case of large PWV(PWV>1.5),the retrival result of MODIS AOD is reduced.For the southeast coastal areas of China,MODIS AOD algorithm is not accurate in the sea land border,and the PWV is high in the southeast China,in the PWV<3,the MODIS AOD result is good,with the correlation coefficient as high as 0.94,and when the PWV>3,there was a larger deviation.