干旱区生态环境知识资源中心

A ground-based lidar observation was carried out in the northwest of China to validate the space-borne lidar CALIOP on 23 - 25 March 2009. Combining backscatter profiles of the ground-based lidar and CALIOP, lidar ratio (extinction to backscattering ratio) was retrieved for 532nm and 1064nm wavelengths by using performance function that minimizing the difference between the ground-based lidar and CALIOP for backscattering corfficient. The correlation coefficients between them were 0.98 for 532nm and 0.95 1064nm, respectively. Using the retrieved lidar ratio, the color ratio and aerosol optical depth (AOD) were calculated. The observed aerosols and clouds were classified into three groups (boundary layer dust, free tropospheric aerosol and cirrus cloud) according to a relationship between color ratio and 532nm-backscattering coefficient. We also validate the backscattering coefficient for CALIPSO level 2 data. The result shows that it is underestimated by 21 % compared to this study.