Earth radiation budget - general purpose data base Final report

Earth Radiation Budget (ERB) satellite missions using broadband scanning radiometers on low polar orbits provide accurate instantaneous observations of the energy exchange between Earth/atmosphere and space. However, the poor coverage of the diurnal cycle from polar orbits constitutes an important error source for monthly mean ERB estimates. As this time sampling error depends on the orbit characteristics it distorts the results of interannual comparison studies using data from different satellite missions. Information on the diurnal variation of regional ERB components can be successfully extracted from Meteosat B2-data and incorporated into the ERBE-Diurnal Time Integration Model. Time-sampling-synergy-algorithms for the solar and terrestrial ERB components, combining ERBE and Meteosat measurements, have been established. Their validation is performed by application to ERBE NOAA-10 measurements and a subsequent comparison with the ERBE multi-satellite estimate for January 1987. Both algorithms are globally applicable (with respect to the Meteosat disk) to either ERBE or ScaRaB data for any orbit or orbit combination and are suitable for operational application to future ERB missions. The highest efficiency of the time-sampling-synergy procedures is obtained for application to single-satellite ERB-scanner measurements. The longwave algorithm effects a considerable reduction - if not a complete removal - of the time sampling error in monthly means of the Outgoing Longwave Radiation (OLR). In particular, errors up to 10 Wm"-"2 are removed for some desert areas as well as for land regions affected by the Innertropical Convergence Zone. On global scale, the monthly longwave time sampling error is decreased by more than 50%. The shortwave algorithm, although slightly suffering from the coarse 3-hourly temporal resolution of the B2-data format, leads to a reduction of the regional monthly time sampling error by about 25%. (orig./KW)SIGLEAvailable from TIB Hannover: RR 1857(27) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman