Direct and Semi‐Direct Aerosol Effects: a Modeled Study for Biomass Burning Aerosol Radiative Forcing in the Amazon Region

The effect of clouds on aerosol radiative forcing is examined by means of simulations considering the presence of a cloud layer above a homogeneous biomass burning aerosol layer. The forcings were calculated considering that aerosols can reduce cloud formation, the semi‐direct effect. A comparison of these results with the forcings calculated for clear sky condition shows that aerosol radiative forcing can be significantly altered by the semi‐direct effect, suggesting that this should be considerate in further studies of regional climate change.