Direct Effect of Aerosols on Solar Radiation Over the Eastern Mediterranean Basin on a Daily 1° by 1° Resolution

The climatically sensitive Mediterranean basin, which is characterized by high solar radiation amounts and aerosol loadings, is the focus of this study that aims to determine the direct effect of aerosols on solar radiation (DRE) over the eastern basin. The objective is to reveal detailed patterns of aerosol DRE that are smoothed when obtained at coarse resolution. Therefore, computations of DRE are performed at a concurrent spatial and temporal resolution that has not been achieved to date. The DREs are computed for 1×1° latitude-longitude grids with the FORTH detailed spectral radiative transfer model (RTM) using daily input data for various atmospheric and surface parameters, such as clouds, water vapor, ozone and surface albedo, taken from the NASA-Langley Global Earth Observing System database. Key aerosol optical properties, namely aerosol optical depth, single scattering albedo and asymmetry parameter, necessary for the RTM runs, are taken from combined climatologies, like the Global Aerosol Data Set, and the satellite-derived datasets of Total Ozone Mapping Spectrometer and Advanced Very High resolution Radiometer that satisfy daily availability at the RTM required spectral and 1×1° resolution. The aerosol DREs are computed at the surface, the top-of-atmosphere and within the atmosphere, over the period 1985–1995.