January 1, 1999 Journal article Open Access

Sea-spray and marine biogenic seasonal contribution to snow composition at Terra Nova Bay, Antarctica

Giovanni Piccardi; S. Vermigli; Emiliano Castellano; Roberto Udisti; Silvia Becagli; Rita Traversi

AbstractPrimary and secondary marine aerosol contributions to snow composition in Terra Nova Bay Antarctica, were evaluated by chemical analysis of surface and snow-pit samples. A seasonal pattern of marine inputs, very clear for secondary aerosol (mainly constituted by nssSO4- and methanesulphonic acid (MSA) coming from phytoplanktonic activity) and less evident for sea spray (Na+, CF, Mg2+) was shown by snow-pit samples. Altitude and distance from the coast were found to be the main parameters affecting seasonal change in the composition of snow collected within about a 200 km radius of the Terra Nova Bay Italian base. Using Na+ as a sea-spray indicator and MSA as a biogenic marker, fractionating aerosol effects (which are altitude-induced) as well as source contributions for Cl- and nssSO42- were found. A nssSO42- /MSA ratio of 2.7 (w/w), indicating their distribution from the common source dimethylsulphide, was calculated from Analysis of fresh summer snow collected in horizontal and vertical transects in northern Victoria Land.