A model for the atmospheric transport of sea-salt particles in coastal areas

Abstract

A model for the aerosol transport in the lower atmosphere is of great interest for studies on air and water quality. One of the difficulties of such a model is to provide the accurate source terms. In particular, for maritime environment, the production of particles generated at the air–sea interface by breaking waves largely varies in time and space (Piazzola et al., 2009). More particularly, near the coastal zone, the sea-spray aerosol fluxes depend on the development of the wave field. The present paper proposes some improvement of the model MACMod, published by Tedeschi and Piazzola (2011), which is dedicated to the transport of aerosol particles in the marine atmospheric boundary layer (MABL). Taking benefit of the experimental campaign MIRAMER conducted in the French Mediterranean in 2008, a new sea-spray source function has been introduced in the latter version of the model MACMod. This consists in a revisited version of the whitecap dependant formulation established by Monahan et al. (1986). The simulations were then validated using aerosol size distributions recorded on board the ship “Atalante” for different wind speeds. Error calculations show a good performance of the model since it predicts the aerosol concentration to within a maximum factor of 3 for particle radii between 0.5 to 5μm.