Field investigations on the snow chemistry in central and southern California—I. Inorganic ions and hydrogen peroxide

Abstract

Measurements of various inorganic species in snow collected in central and southern California during the winter of 1987–1988 indicate a combined influence of anthropogenic and maritime sources, depending on the meteorological conditions and wind patterns. Ion balance calculations revealed that organic acids are significant contributors to the overall chemical budget in snow samples. 60–95% of the total SO 4 2− was calculated to habe been derived from S(IV) oxidation. H 2O 2 concentrations up to 7.4 μmole ℓ −1 were analyzed in fresh snow. No systematic trends in the concentrations of H 2O 2 were observed during collection periods in marked contrast to the behavior of inorganic species (e.g. Na +, Cl −, SO 4 2-, NO 3 −). H 2O 2 concentrations found in snow were 2–3 times lower than those found in rainwater collected during the same events at a lower elevation site, whereas inorganic ion levels were 2–7 times lower in snow. In an accumulated season snowpack a decrease of [H 2O 2] and an increase of [SO 4 2−] with depth was observed.