Local anthropogenic impact on particulate elemental carbon concentrations at Summit, Greenland G. S. W. Hagler1, M. H. Bergin1,2, E. A. Smith1, M. Town3, and J. E. Dibb4 1School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA 2School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA 3Department of Atmospheric Sciences, University of Washington, Box 351640, Seattle, WA 98195-1640, USA 4Climate Change Research Center, Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, NH 03824, USA
Abstract. Summit, Greenland is a remote Arctic research station
allowing for field measurements at the highest point of the Greenland Ice
Sheet. Due to the current reliance on diesel generators for electricity at
Summit, unavoidable local emissions are a potential contamination threat to
the measurement of combustion-related species in the air and snow. The
effect of fossil-fuel combustion on particulate elemental carbon (EC) is
assessed by a combination of ambient measurements (~1 km from the main
camp), a series of snow pits, and Gaussian
plume modeling. Ambient measurements indicate that the air directly downwind
of the research station generators experiences particulate absorption
coefficient (closely related to EC) values that are up to a factor of 200
higher than the summer 2006 non-camp-impacted ambient average. Local
anthropogenic influence on snow EC content is also evident. The average EC
concentration in 1-m snow pits in the "clean air" sector of Summit
Camp are a factor of 1.8–2.4 higher than in snow pits located 10 km and
20 km to the north ("downwind") and south ("upwind") of the research site.
Gaussian plume modeling performed using meteorological data from years
2003–2006 suggests a strong angular dependence of anthropogenic impact, with
highest risk to the northwest of Summit Camp and lowest to the southeast.
Along a transect to the southeast (5 degree angle bin), the modeled
frequency of significant camp contribution to atmospheric EC (i.e. camp-produced EC>summer 2006 average EC) at a distance of 0.5 km, 10 km,
and 20 km is 1%, 0.2%, and 0.05%, respectively. According to both
the snow pit and model results, a distance exceeding 10 km towards the
southeast is expected to minimize risk of contamination. These results also
suggest that other remote Arctic monitoring stations powered by local fuel
combustion may need to account for local air and snow contamination in field
sampling design and data interpretation.
Citation: Hagler, G. S. W., Bergin, M. H., Smith, E. A., Town, M., and Dibb, J. E.: Local anthropogenic impact on particulate elemental carbon concentrations at Summit, Greenland, Atmos. Chem. Phys., 8, 2485-2491, doi:10.5194/acp-8-2485-2008, 2008.