Surface active substance effect on marine aerosol fractionation as function of altitude.

Marine aerosol is one of the principal vehicles for the transport of organic and inorganic material from the bulk sea water into the atmosphere. In remote regions, such as Antarctic continent, marine aerosol represents one of the most important contributions to the local aerosol budget, especially in coastal regions. The marine aerosol composition, as well as, its distribution both in coastal zone and in inland zone, is in close relation with meteorological conditions and geographical characteristics (altitude). Taking into account the good relationship between the snow composition and the atmospheric aerosol composition during the precipitation event (scavenging effect), the analysis of snow samples let to have a good information about the local atmospheric composition. A proposed model (Spray Drop Adsorption Model - SDAM) consider the surfactant matter, adsorbed on the microdrop aerosol surface, the main responsible of the enrichment and of the transport of organic material and of all microcomponents able to interact with it. On the basis of SDAM, valuations concerning snow samples (from various Antarctic campaigns) both for fluorescence, rheological parameters acid for ionic composition, let to have a picture about the changing composition of marine aerosol with respect to the altitude.