Fractionating phenomena, altitude induced, on snow composition in Northern Victoria Land (Antarctica).

The chemical analysis of snow and firn samples collected from snow pits and coring at different altitude stations has revealed fractionating phenomena of the atmospheric aerosol and has identified principal and secondary sources of some environmental notable components. Using sodium as sea spray source indicator and methanesulphonic acid as biogenic marine tracer, it has been possible to evaluate the contribution of the altitude of the station, and consequently the size of aerosol particles, on the snow composition and on the progressive importance of fractionating phenomena. As the elevation of the station increases (and the paricle size decreases) evidence of secondary sources of K, Ca and non sea salt sulphates has been noted.The dating of the snow layers sampled has shown the seasonal character of the principal and secondary sources of some of the components studied.