Aerosol and tropospheric ozone direct radiative impacts

This chapter describes the direct radiative effect (RE) over the Mediterranean region exerted by aerosols and tropospheric ozone. Recent results on the regional direct aerosol RE at the surface and at the top-of-the-atmosphere (TOA) are presented, together with trends in surface solar radiation. Absorption by aerosol particles within the troposphere affects heating rates and atmospheric stability, therefore playing a key role in the regional radiative impact of aerosols. In addition, the impact of aerosols on photochemistry and solar energy production over the Mediterranean region is also discussed with a focus on recent advances on the impact of the aerosol dimming on photovoltaic (PV) panels. Finally, the last section describes the regional RE of tropospheric ozone and drivers of its uncertainty.