Validation of FY-4A Temperature Profiles by Radiosonde Observations in Taklimakan Desert in China

The atmospheric temperature profiles (ATPs) retrieved through the geostationary Interferometric Infrared Sounder (GIIRS) onboard FY-4A satellite (GIIRS/FY-4A) can effectively fill gap of scarce conventional sounding data in Taklimakan Desert (TD), second largest desert world, with an area 330,000 square kilometers. In this study, we take experimental radiosonde observations (RAOB) from one RAOB station hinterland TD and seven radiosondes oasis region around as true values analyze bias distribution characteristics GIIRS/FY-4A ATPs quality control (QC) flags 0 or 1 for region. addition, a comparison is made ATPs, fifth generation ECMWF reanalysis global climate (ERA5) ATPs. results show that (1) Missing measurements are most frequent near-surface layer, accounting more than 80% all grid points. averaged total proportion QC marks about 33.06%. (2) root mean error (RMSE) less 3 K, smaller ERA5 RMSE exceed 10 K hinterland. absolute biases are, respectively, 2 former being slightly larger. correlation coefficients higher 0.98 0.99, between inferior to latter. (3) overall by 0.08 RAOB, on average, while 0.13 lower indicating profile obtained integrating may be much closer (4) probability density ATP generally follows Gaussian so it assimilated 3-D variational assimilation modules. not different. However, due fusion analysis relatively rich multi-source observation stations, at stations nearer hinterland, where enough, distributions alike. Therefore, GIIRS FY4A contribute accurate estimation