Retrieval of cirrus cloud optical thickness and top altitude from geostationary remote sensing

摘要

A novel approach for the detection of cirrus clouds and the retrieval ofoptical thickness and top altitude based on the measurements of the SpinningEnhanced Visible and Infrared Imager (SEVIRI) aboard the geostationaryMeteosat Second Generation (MSG) satellite is presented. Trained with 8 000 000 co-incident measurements of the Cloud-Aerosol Lidar with OrthogonalPolarization (CALIOP) aboard the Cloud-Aerosol Lidar and Infrared PathfinderSatellite Observations (CALIPSO) mission the new "cirrus optical propertiesderived from CALIOP and SEVIRI algorithm during day and night" (COCS)algorithm utilizes a backpropagation neural network to provide accuratemeasurements of cirrus optical depth τ at λ = 532 nm and topaltitude z every 15 min covering almost one-third of the Earth's atmosphere.The retrieved values are validated with independent measurements of CALIOPand the optical thickness derived by an airborne high spectral resolutionlidar.