No abstract

Analyses of 37 precipitates from Blidö in the archipelago of Stockholm collected 1984–1987 reveal distinct seasonal variations. Particularly, P and K but also Mn, Ba, Ca, and Mg are enriched in rain during the early growth season, whereas Na is enriched in rains at the end of the year due to storm activity at sea. Semiconservative mixing models involving seawater (SW), plant matter (PLM), terrigenous matter (TM), and coal emissions (CEM) suggest that PLM supplies 99–20% of P, K, Mn, Ba, Ca, Sr, and Mg, SW explains 99–35% of Na and Mg, and TM the major fraction of Al, Fe, Ti, and Si. However, 90–65% of S and Zn are in excesses compared to the models: probably these elements arrive in volatile anthropogenic phases. These mixing models explain the complex sources of rain components better than conventional enrichment factors. The results appear representative for Northern Europe, but other areas of the world probably show different input ratios of PLM, SW, etc.

No abstract