Air Pollution measured at the NOAA, Barrow Atmospheric Baseline Observatory (71<sup>0</sup> N, 156<sup>0</sup> W, 11 m asl) arrives predominately in easterly winds with the pollution originating in Eastern Europe and northern Russia. The pollution is highly stratified and concentrated above the Arctic marine boundary layer. As such, surface concentrations of pollution are generally much lower than those measured above the marine boundary layer (aircraft profiles). Since the early 1980’s, the concentrations of springtime pollution aerosols measured at the Barrow Observatory have been in general decline while CO<sub>2</sub> and CH<sub>4</sub> have steadily increased. Occasionally in spring, westerly winds bring dust and air pollution from Asia that has traveled over the Bering Sea into Alaska north of the Brooks Range. This air is fairly well mixed which reduces the strength of the marine boundary layer. As such, aerosol concentrations measured at the surface better represent concentrations aloft. Forest fires, especially those in Alaska and northern Canada, occasionally flow past the Barrow Observatory and may markedly reduce the solar radiation reaching the surface. Forest fire smoke flowing over the Barrow Observatory has also been measured some days later flowing past the Summit Greenland Observatory (72<sup>0</sup>N, 38<sup>0</sup>W, 3216 m asl). Numerous publications dating back to the 1970s document the history of Arctic air pollution and especially ~ 250 publications on “Arctic Haze” in dedicated issues of G.R.L (1984), 3 volumes of Jr. Atmos. Chem. (1989) and 3 volumes of Atmos. Environ.(1985, 1989 and 1993).
Air Pollution in the Arctic: Climate, Environment and Societies