A preliminary classification of cirrus clouds over Sao Paulo city by systematic lidar observations and comparison with CALIPSO and AERONET data

Abstract

Cirrus clouds in the upper troposphere and the lower stratosphere have recently drawn much attention due to their important role and impact on the atmospheric radiative balance. To understand and quantify its impact on earth's atmosphere radiative transfer it is necessary to have information about its optical properties. Such a knowledge is necessary both for comparison with others datasets of cirrus measurements as well as for its influence on radiative transfer models. Cirrus clouds measurements have been performed since 2005 in the Metropolitan Sao Paulo, Brazil (23°33'S, 46o44'W). From MSP-lidar backscatter profiles at 532 nm, and eventually 355 nm, the cloud optical depth (COD) as well as the high of base and top of the clouds are retrieved. A preliminary climatology of cirrus clouds over Sao Paulo using this method has been set. The measurements from Aerosol Robotic Network (AERONET), the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) and GOES-10 observations are compared with a ground based lidar dataset for a wide range of cloud types.