**Determining Aerosol Radiative Effect Using Satellite Retrievals**
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Kolmonen, Pekka ^{1}; Sogacheva, Larisa^{1}; Rodriguez, Edith^{1}; Virtanen, Timo^{1}; Sundström, Anu-Maija^{2}; de Leeuw, Gerrit^{3}
^{1}Finnish Meteorological Institute, FINLAND; ^{2}University of Helsinki, FINLAND; ^{3}Finnish Meteorological Institute, University of Helsinki, FINLAND
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In climate studies the reliable estimate of radiative effect (or forcing) by atmospheric aerosols is a very important parameter that is related to Earth's energy budget. Usually the estimate is obtained from model simulations. This study discusses an alternative method to determine the effect. Satellite retrieval of the needed parameters to compute the effect is described. These parameters include e.g. aerosol loading, aerosol optical properties, aerosol size distribution, and surface reflectance. The described method is able to give good estimates of the instantaneous effect as the use of aggregated model or climatological data is avoided as much as possible. The method is described and examples of its use are given. Furthermore, the application of the determined instantaneous aerosol radiative effect for estimating the short-wave radiative effect (daily, wide spectral range, measurement geometry independent) is discussed. The method is being developed for AATSR (in future also SLSTR) satellite data.