The cloud analysis tool APOLLO Improvements and validations

Abstract

During its more than twelve years of existence, the 'AVHRR processing scheme over clouds, land and ocean' (APOLLO) has been modified and extended. The intention of this paper is to document the present state of APOLLO and to summarize the experiences gained. The scope of the processing scheme is reviewed and the actual state of the day time and night time algorithms are presented. The reason for the modifications are discussed. Validations of the modifications include comparisons with surface observations, with data from the 'international satellite cloud climatology project' (ISCCP) and with model simulations of the cloud liquid water path. APOLLO is now a robust and versatile cloud analysis tool. It is presently used to establish a cloud climatology in central Europe, based on processing of 15 years of daily AVHRR data. (orig.)29 refs.Available from TIB Hannover: RR 6341(126) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman