The Intercomparison of Cloud Parameters Derived Using Multiple Satellite Instruments

Cloud optical thickness (COT) has been retrieved using multiple optical instruments onboard ENVISAT and compared for consistency for a single cloud field over central Europe. To match the spatial resolution of the Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY), the results of retrievals from higher resolution instruments have been averaged on the scale of 30 times 60 km. It was found that the Medium Resolution Imaging Spectrometer (MERIS), Advanced Along Track Scanning Radiometer (AATSR), and SCIAMACHY (all onboard ENVISAT) give close values of COT and, therefore, cloud albedo. Similar results have been obtained for Moderate Resolution Imaging Spectroradiometer onboard the Terra satellite. This suggests that these instruments can be used for synergetic retrievals of cloud properties from space. For instance, the high spectral resolution of SCIAMACHY can be used to enhance MERIS or AATSR retrievals of cloud top height and other cloud characteristics