Occurrence And Trends of Pollution in the Arctic Troposphere

The chemical composition of the troposphere (0 to ~8 km above msl) in the Arctic is distinctly different than it is in the Antarctic. As pointed out in previous reviews (Barrie, 1986; Barrie et al, 1992; Barrie, 1993; Barrie, 1995), the Arctic is surrounded by populated continents from which pollution is released to the atmosphere and is transported readily to the north. In contrast, the Antarctic region is entirely surrounded by the southern Pacific ocean and is remote from human activities. Thus, it comes as no surprise that the tropospheric concentration of many anthropogenic aerosols and gases is much higher in the Arctic than in the Antarctic. What may be less obvious is that atmospheric trace constitutents of natural origin are found to have a different chemical climatology in the Arctic than in the Antarctic. Substances derived from sea spray, wind blown dust, marine biogenic activity and volcanoes generally have different seasonal variations and concentrations in the Arctic compared to the Antarctic.