应用改进模式从FY2H卫星数据估算OLR

The OLR Estimation from FY2H VISSR Data with an Improved Regression Model

射出长波辐射(OLR)是大气科学研究领域的关键参量,并在辐射相互作用、气候变化和灾害监测等方面发挥重要作用。2018年6月5日静止气象卫星FY2H成功发射,OLR产品是FY2H的业务产品之一。在原有FY2系列OLR反演算法基础上,参考国际上NOAA/HIRS OLR反演算法,结合FY2H/VISSR 3个红外通道设置,建立适合FY2H的OLR反演算法。利用该算法处理FY2H/VISSR的L1级观测数据,生成实时及日、旬、月平均的OLR产品。FY2H的OLR产品与CERES均匀性下垫面的瞬时视场OLR产品对比,RMSE=3.38 W/m^2,R=0.99,Bias=0.77 W/m^2;与CDR日平均OLR产品对比,RMSE为5~7 W/m^2,R为0.97~0.98,Bias为-2.2~1.9 W/m^2;与CDR旬平均OLR产品对比,RMSE为3~5 W/m^2,R=0.99,Bias为-1.1~0.4 W/m^2;与CDR月平均OLR产品对比,RMSE为2~4 W/m^2,R=0.99,Bias为-1.1~0.4 W/m^2。这表明FY2H OLR改进算法达到了较高的精度,可满足卫星设计和应用研究精度需求。

The outgoing longwave radiation(OLR)is a crucial parameter in the atmospheric science,and it also plays an important role in radiative interaction process,climate change,and disaster monitoring,etc.On June 5,2018,the geostationary meteorological satellite FY2H was successfully launched and the OLR product is one of its operational products.Based on the OLR inversion algorithm of the FY2 satellite series,this paper establishes an OLR inversion algorithm suitable for FY2H by referring to the international HIRS OLR inversion algorithm and combining three infrared channel settings of FY2H/VISSR.Then,this algorithm is used to process the FY2H VISSR L1 data,and the real time,hourly,daily,dekad and monthly average OLR products of FY2H are produced.The qualities of the FY2H OLR products are examined by comparing them with the CERES OLR and NOAA CDR OLR products.The validation results are as follows:When compared with the CERES instantaneous OLR on the homogeneous scenes,RMSE=3.38 W/m^2,R=0.99,Bias=0.77 W/m^2;when compared with the NOAA CDR daily average OLR,the RMSE values are between 5 and 7 W/m^2,R values are between 0.97 and 0.98,Bias values are between-2.2 and 1.9 W/m^2;when compared with the NOAA CDR dekad average OLR,RMSE values are between 3 and 5 W/m^2,R=0.99,Bias values are between-1.1 and 0.4 W/m^2;and when compared with the NOAA CDR monthly OLR,RMSE values are between 2 and 4 W/m^2,R=0.99,Bias values are between-1.1 and 0.4 W/m^2.These results indicate that good quality of the FY2H OLR products has been achieved by means of the improved algorithm,so it can fully satisfy the accuracy requirement of satellite design and application research.