Aerosol optical properties derived from lidar observations using cluster analysis

We present the distributions of the lidar observable optical properties for dust, continental pollution and marine aerosols using the Cloud Physics Lidar (CPL, ef.) measurements. This study uses CPL measurements during CRYSTAL-FACE off the coast of Florida to extract probability distribution functions (PDFs) of the lidar depolarization ratios (delta), and the ratio of the backscatter at 1064 nm to 532 nm (chi, referred to as the color ratio) for dust, continental pollution, and marine aerosols. The aerosol types are identified using a clustering algorithm. In this study, cluster analysis by partitioning is used to categorize the CPL data set based on the backscatter and depolarization ratio. The cluster results for clouds and aerosols are compared to the other classification schemes and observations. The results of the aerosol clusters are verified using in situ measurements where these are available