The impact of sea spray evaporation in a numerical weather prediction model

Strong winds above the sea lead to large amounts of spray in the lowest par t of the boundary layer. Through their evaporation, spray droplets influenc e the exchange of sensible and latent heat between sea and air. In this stu dy, the impact of spray on the atmosphere is investigated using the numeric al weather prediction high-resolution limited-area model HiRLAM. The effect of spray is taken into account via modified surface heat fluxes. The impac t on forecasts is then investigated in two case studies of intense midlatit ude storms. A general consequence of spray is a significantly cooler and mo ister surface layer. Indirect effects are reported as well, such as enhance d precipitation, and associated midlevel latent heat release. The second ca se study, which deals with a rapidly deepening depression, indicates that i ncluding spray leads to a marginal intensification of the depression.