Analysis of cirrus from airborne lidar and radiometer observations

Lidar and passive radiance sensing data on cirrus clouds gathered in instrumented high altitude aircraft flights are analyzed, with emphasis on cirrus emittance characteristics. The data were collected with a U-2 aircraft flying at about 19 km altitude. Lidar data defined the vertical structure of the cloud which, when combined with independent atmospheric temperature data, permitted radiance to be derived from thermal radiance data. Sample return lidar images are provided of cirrus and cirrostratus clouds, along with the calculated emittance data.