Using Ultra-high Spectral Resolution Atmospheric Infrared Detection (airs) Atmospheric Temperature Profile Retrieval Test

Atmospheric Infrared Sounder(AIRS)is on board on the EOS-2/ Aqua satellite,lauched in May 4, 2002. It is now the modern atmospheric remote sensing instrument withhigh spectral resolution in the world. AIRS can observe atmospheric state and change onglobal scale with inproved accuracy. To study AIRS data processing is important in scienceand application.The computation and analyses of AIRS spectral characteristics indicate that the wingsof absorption bands have fine information structure. Therefore, it can provide atmosphericparameters with high vertical resolution and more accuracy.Collocated AIRS brightness temperature and the corresponding T213 temperatureanalyses field are used to compute the regression coefficients. The studies include: theoptimal of eigenvectors number, regression coefficients computation, spectral channelsselecting, more predictors determing and retrieval result comparison. Research resultsindicate that 1) the optimal of eigenvectors number relates to the number of the channelsused in retrieval;2) respective computing regression coefficients for day and night canimprove the atmospheric temperature retrieval accuracy;3)it is very essential to choose thechannels rationally when retrieving atmospheric temperature with the high spectralresolution instrument;4) AIRS can significant increase the retrieval accuracy introposphere middle – up level and tropopause, in the troposphere lower, especially near thesurface, the accuracy is not ideal enough;5) The facts reflecting surface radiationnatures,such as surface temperature, surface emissivity and topography, are used asadditional predictors can improve the accuracy near the surface;6) AIRS retrieval accuracyis better than ATOVS in troposphere middle – up level and tropopause. The improvementof accuracy in the troposphere lower needs to consider the joining of microwave data.In general speaking our study has some key points as follows:1. It illustrates that the vertical resolution of absorption band wing can be increasedby computing spectral channel weighting function when the wing of the spectral channelnarrow down. It can be used for selecting suitable channels in developing Chinese highspectral infrared atmospheric sounder.2. Computing regression coefficients for day and night individually for differentseason and area with large difference of day and night can improve the atmospherictemperature retrieval accuracy.3. The facts reflecting surface radiation natures are used as additional predictors canimprove the accuracy near the surface.4. Based on the comparison, AIRS can significant increase the retrieval accuracy introposphere middle – up level and tropopause. The improvement of accuracy in thetroposphere lower needs to consider the joining of microwave data.5. Computing the regression coefficients with AIRS brightness temperature and thecorresponding T213 temperature analyses field make for AIRS operational retrieval.