MEASUREMENTS OF NOX AND AEROSOL-PARTICLES AT THE NY-ALESUND ZEPPELIN MOUNTAIN STATION ON SVALBARD - INFLUENCE OF REGIONAL AND LOCAL POLLUTION SOURCES

The accumulation of anthropogenic pollution in the Arctic during winte r and spring can be studied from only relatively few sites. In 1989 a new research station was put into operation on Zeppelin mountain, Sval bard (78 degrees 55'N, 11 degrees 53'E, 474 m above sea level). The lo cation near the top of the mountain was chosen to minimize impacts fro m the nearby village of Ny-Alesund. Meteorological data, mixing ratios of NOx, and concentrations of aerosol particles measured from Februar y to May 1994 are used to identify different types of influences on th e station. During periods of low atmospheric stability and wind speeds , relatively high NOx mixing ratios and variability together with a hi gh number concentration of nucleation mode particles can be used to id entify local pollution. During 6.4% of the time of our campaign the ai r was contaminated by local pollution sources, with the majority of ev ents occurring later in the campaign. Based on isentropic back-traject ories four major source regions for air arriving at the station are id entified. These are Western Europe, Russia, the Arctic and North Atlan tic regions. Elevated levels of pollution were seen when air arrived f rom either Western Europe or Russia. Western European flow showed, on average, the highest NOx mixing ratios, while Russian flow showed the highest mass loading of aerosols. Background air during flow from the Arctic or North Atlantic regions showed a median scattering coefficien t of 3.8 x 10(-6) and 1.3 x 10(-6) m(-1),respectively, and CN concentr ations of 180 and 270 cm(-3), respectively. Median ozone and NOx mixin g ratios during these periods were 37 ppbv and about 20 pptv, respecti vely.