Local anthropogenic impact on particulate elemental carbon concentrations at Summit, Greenland
- ISSN: 1680-7316
- DOI: 10.5194/acp-8-2485-2008
Summit, Greenland is a remote Arctic research station allowing for field\nmeasurements at the highest point of the Greenland Ice Sheet. Due to the\ncurrent reliance on diesel generators for electricity at Summit,\nunavoidable local emissions are a potential contamination threat to the\nmeasurement of combustion-related species in the air and snow. The\neffect of fossil-fuel combustion on particulate elemental carbon (EC) is\nassessed by a combination of ambient measurements (similar to 1 km from\nthe main camp), a series of snow pits, and Gaussian plume modeling.\nAmbient measurements indicate that the air directly downwind of the\nresearch station generators experiences particulate absorption\ncoefficient (closely related to EC) values that are up to a factor of\n200 higher than the summer 2006 non-camp-impacted ambient average. Local\nanthropogenic influence on snow EC content is also evident. The average\nEC concentration in 1-m snow pits in the `clean air' sector of Summit\nCamp are a factor of 1.8-2.4 higher than in snow pits located 10 km and\n20 km to the north ('downwind') and south ('upwind') of the research\nsite. Gaussian plume modeling performed using meteorological data from\nyears 2003-2006 suggests a strong angular dependence of anthropogenic\nimpact, with highest risk to the northwest of Summit Camp and lowest to\nthe southeast. Along a transect to the southeast (5 degree angle bin),\nthe modeled frequency of significant camp contribution to atmospheric EC\n(i.e. camp-produced EC>summer 2006 average EC) at a distance of 0.5 km,\n10 km, and 20 km is 1%, 0.2%, and 0.05%, respectively. According to\nboth the snow pit and model results, a distance exceeding 10 km towards\nthe southeast is expected to minimize risk of contamination. These\nresults also suggest that other remote Arctic monitoring stations\npowered by local fuel combustion may need to account for local air and\nsnow contamination in field sampling design and data interpretation.