Short-Wave Direct Radiative Effect of Aerosols in the Clear-Sky over Oceans from Satellites Observations

Short-wave radiative flux at top of atmosphere (TOA) changes due to aerosols. The analysis provides a new measurement perspective to an aerosol radiative effect problem dominated so far by models. Short-wave radiative fluxes at TOA from a satellite measurement CERES merged with the aerosol optical depth (AOD) from MODIS were used here to estimate direct radiative effect (DRE) of aerosols over cloud-free oceans. The results show that clear sky DRE at TOA is about 5plusmn1.2 Wm^-2 over global ocean, consistence with previous studies. The spatial distribution of aerosols AOD and DRE were clearly seen from satellite observations. The study is an independent measurement-based assessment of cloud-free aerosol radiative effect that could be used as a validation tool for numerical modeling studies.