COCS - Cirrus Optical properties derived from CALIOP and SEVIRI during day and night time

Abstract

Significant progress in cirrus cloud observation has been achieved with spaceborne active remote sensing techniques, e.g. the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) aboard the polar-orbiting Cloud-Aerosol Lidar and Infrared Pathfinder Satellite (CALIPSO). With its high vertical and horizontal resolution CALIOP provides high detailed profiles of optical properties especially of cirrus clouds. But to deliver information on the lifecycle of cirrus clouds high temporal resolution is needed. These observations are performed by the Spinning Enhanced Visible and Infrared Imager (SEVIRI) aboard MSG every 5-15 minutes providing high detailed information (e.g. brightness temperatures of seven infrared channels) making a day and night time observation of clouds possible. In the following, the COCS algorithm (Cirrus Optical properties derived from CALIOP and SEVIRI) combining the advantages of both satellite instruments, some preliminary results, intercomparisons and examples of its application are presented. COCS provides the cloud optical thickness (COT) and the cloud top altitude (CTA) of cirrus clouds.