Inland transport of marine aerosols in southern Sweden

Abstract

The transport of marine aerosols across southern Sweden was studied using six meteorological stations in a transect from west- to east-coast. Measurements were made during dry westerlies on 10 occasions during 1995. The concentration and flux of salt in the air was measured using “salt vanes”. It is concluded that marine salt is transported along the whole transect at all occasions and that the concentration and flux of salt decrease with downwind distance from the coast as an inversed power function. The two easternmost stations show a slight increase towards the east-coast. Variability of the data is high on the west coast due to strong influence from the coastal production of aerosols. This effect diminishes along downwind forming lower, less variable concentration further inland. Statistical models based on the data are in relatively good agreement with previous models and data. Further, salt content on Scots Pine ( Pinus sylvestris, L) needles after two westerly gale occasions, in profiles from west- to east-coast, were analysed. The Cl −/Na +, Ca 2+/Na +, K +/Na +, Mg 2+/Na + and SO 4 2−/Na + ratios were studied revealing a clear downwind decrease in Ca 2+/Na + and Mg 2+/Na +, a close to sea water ratio for Cl −/Na + and an excess of SO 4 2− along the profile. Also, the importance of degree of exposure was studied concluding that the roughness of the upwind surface is an important factor for the deposition onto trees in forest edges.