 Very small sea salt aerosols, which are below the critical diameter for droplet activation at low supersaturations, can serve as nuclei for the growth of sulfate particles, while larger sea salt particles serve as a sink for gaseous hydrogen sulfate (H2SO4) molecules, reducing the amount of sulfate available for the formation of accumulation mode particles.Sea salt aerosols can alter the Earth radiation budget through directly scattering solar radiation (direct effect), and indirectly changing the cloud albedo by serving as CCN (indirect effect).Different models give different predictions of annual mean radiative forcing induced by sea salt direct effect, but most of the previous studies give a number around 0.6-1.0 W m−2.