敦煌辐射校正场典型气溶胶垂直廓线的激光雷达观测

Vertical Profile of Atmospheric Aerosol Observed by Lidar in Dunhuang Radiometric Calibration Site

激光雷达可以获取气溶胶的三维信息。在2010年中国辐射校正场（Chinese Radiometric Calibration Site,CRCS2010）试验中,利用一部米散射激光雷达获取了敦煌辐射校正场区域15天的观测数据,利用经典的Fernald反演方法得到了这一区域的大气气溶胶消光系数垂直廓线并分析了其对辐射定标的影响。观测结果表明敦煌地区在从近地面到2~4 km处存在着一层气溶胶浓度高值层。用于辐亮度辐射定标的飞机飞行高度需要大于此高度,以避开气溶胶高浓度层的影响。并利用MODTRAN（MODerate resolution atmospheric TRANsmission）辐射模式中的气溶胶廓线与实测气溶胶廓线分别进行辐射模拟,对于FY3/MERSI各可见-近红外通道都有不同程度的差异,其中蓝通道（〈500 nm）有4%~5%的辐射差异。

Lidar can obtain three-dimensional aerosol information.In 2010,the Mie-scattering lidar was used to acquire the observation data for 15 days during the China Radiometric Calibration Site（CRCS2010） field experiment.Fernald inversion method was used to retrieve vertical profile of atmospheric aerosol extinction coefficient in this region.Its impacts on the radiometric calibration are analyzed.Observations results indicate that there is an aerosol layer of high concentration values from the near-surface layer to 2~4 km in Dunhuang area.The aircraft for radiometric calibration should fly above this altitude to avoid the effect of the high concentrations aerosol layer.On the basis of the aerosol profiles of MODTRAN（MODerate resolution atmospheric TRANsmission） radiative transfer model and the measured aerosol profiles,the radiation simulation was carried out respectively.The results showed that,different degrees of differences existed among FY3A/MERSI,all visible-near infrared channels,whereas the blue channels（〈500 nm） had 4%~5% of the radiation difference.