Polarization lidar for identifying indirect aerosol effects on clouds

Polarization lidar is uniquely suited for detecting and identifying aerosols as well as cloud particle phase. We show lidar evidence from Utah and southern Florida, US, that the aerosols from both the Asian and African Saharan dust storms are effective ice nucleating agents capable of forming cirrus clouds and glaciating mildly supercooled liquid clouds that come into contact with the transported dust layers.