Concentrations and size distributions of aerosol particles in coastal zone

This paper presents the behaviour of aerosol size distributions and number concentrations with respect to specific meteorological conditions, deduced from experiments conducted over a period of 3 yr, in the Mediterranean coastal zone. Specific meteorological conditions, “East” wind and “Mistral” wind lead to specific size distributions and total number concentrations. In an “East” wind situation (steady winds, weak sunniness, high humidity), the size distributions are characterized by only accumulation and coarse particle modes. “Mistral” wind situations (gusty winds, strong sunniness, low humidity), lead to greater concentrations and the corresponding size distributions are often characterized by an Aitken peak but no accumulation peak. After a specific time-lag which depends on the particle size and meteorological conditions, the concentrations of coarse particles are well correlated with the wind velocity. In case of high “Mistral” winds, particles in the Aitken range and the wind velocity also are well correlated. It seems likely that the wind, by bursting small bubbles at the sea-air interface, is the major generation mechanism for these particles.