Atmospheric sulfur cycle over continents

An atmospheric sulfur inventory for the whole European continent has been recently constructed by E. Meszaros et al. (1978). These authors show on the basis of the comparison of anthropogenic sulfur emission (Semb, 1978) and sulfur advection from the Atlantic that the sulfur gained by advection is small. 70-85 % of the sulfur emitted and imported is removed over the continent equally by dry (mostly in form of S02) and wet deposition. Meszaros and his associates have estimated the dry deposition of S02 by using an average European S02—S concentration calculated from data in Table 13 (3.2 /tg m-3) and a dry deposition velocity of 1cm s (Garland, 1978). The value of wet deposition was based on precipitation chemistry measurements. It follows from this quantitative calculation that Europe contributes 15-30 % of its sulfur emission to the tropospheric sulfur cycle of other areas. 

The two regions used for sulfur budget studies over N. W. Europe (Rodhe, 1972b). (By courtesy of Tellus) 

Atmospheric sulfur inventoryover two regionsofN. W. Europe (see Fig. 20) according to Rodhe (1972b) 

Region. Wet deposition minus natural anthropogenic of anthropogenic 

One can clearly see from the data tabulated that the preponderance of trace gases is of biological origin. They are mostly produced by microbiological processes (for further details see Schlegel, 1974). This means that the biosphere plays an important role not only in cycling the main atmospheric constituents, but also in the 

---

As well as the sulfur cyde, there are other cycles in nature water, nitrogen, phosphorus and carbon. Man has influenced them all, but the sulfur cycle is the most disturbed among aU these cydic processes. Fossil fuels are burned in order to warm up houses and to provide cars, power stations and industries with energy. Then the sulfur that was built into coal, oil and natural gas, millions of years ago, is set free. It is transported as sulfur dioxide to the atmosphere, the SO content of which has increased considerably compared to the equilibrium content of the natural cyde. The acid gas is transported by the winds over the continents, and, long distances from a specific source, people experience a rain of sulfuric acid . This acid rain not only attacks the needles and leaves of trees but also damages the roots of plants. In acidified lakes the ability of fish to reproduce is disturbed. If acidification is not neutralized by liming, metal ions may be leached from rocks and damage animal life. 

Andreae MO, Jaeschke WA. Exchange of sulfur between biosphere and atmosphere over temperate and tropical regions. In Horwarth RW, Stewart JWB, Ivanov MV, eds. Sulfur Cycling on the Continents. Chichester Wiley 1992 27-61. 

---