Applicability validation and evaluation of AIRS retrievals in the Taklimakan Desert
MA Yu-fen;PAN Hong-lin;ZHANG Hai-liang;LIU Jun-jian;LI Man;DU Juan;Institute of Atmospheric Physics,Chinese Academy of Sciences;Institute of Desert Meteorology,China Meteorological Administration;Center of Central Asia Atmospheric Science Research;
The temporal and spatial distribution features of air temperatures and humidity in Taklimakan Desert,south Xinjiang,China,could hardly be learned by the seven sounding sites there,while the high resolution atmospheric infrared sounder( AIRS) data can effectively make up for the vacancy. However,the quality of AIRS retrievals suffers from complex topographic condition and land-surface emissivity,it is necessary to do the quality validation before applying them in this desert region. This study mainly focused on quality validation of AIRS retrieved air temperature,geopotential height as well as water vapor mixing ratio by comparing them with the field experimental soundings in both Taklimakan Desert and other seven traditional sounding sites over oasis region at nightfall and in the morning respectively. It is showed that,Firstly,the temperature data in the AIRS satellite data set are in good agreement with the radiosonde observation( RAOB). The temperature data are relatively small in the hinterland of the desert,and higher in the surrounding oasis regions,especially in the upper level. The AIRS inversion of temperature in the tower of the desert hinterland,the deviation of each layer in the morning is obviously greater than that at nightfall,and the other stations have little deviation in the morning and nightfall. Secondly,the geopotential height data measured by AIRS satellite is almost the same as RAOB,which is the best factor in the comparative study. The detection level of AIRS can reach 1 h Pa,which is much higher than that of RAOB. Thirdly,mixing ratio of AIRS data coincides with the upper RAOB of 300 hPa,and smaller in the middle layers,higher in the lower layers. Finally,the statistical results showed that in the morning,the AIRS inversion temperature deviation over Tazhong sounding station in each layer were higher than that over the other 7 oasis stations,warmer above 500 h Pa and cooler below,and the higher the warmer. While the AIRS inversion temperature over the remaining 7 oasis sounding station is generally higher than soundings above 500 hPa and lower below. The RMSE of the AIRS inversion temperature over the selected seven oasis sounding sites is decreased with the height being increased. The RMSE of the AIRS inversion temperature over desert sites is acceptably small,but presents a comparatively larger bias in the morning possibly due to the great emissivity there and its location in the center of the Tarim Basin.
【Fund】： 中亚大气科学研究基金(CAAS201815);; 国家自然科学基金新疆联合基金项目(A-N2015007);国家自然科学基金(41575008 41805075);; 新疆维吾尔自治区科技支撑项目(201433112)
【CateGory Index】： P407
【CateGory Index】： P407