1Joint Center for Environmental Technology UMBC, Baltimore, MD, USA
2Laboratory for Atmospheres, NASA Goddard Space Flight Center, Greenbelt, MD, USA
3NASA Langley Research Center, Hampton, VA, USA
4Universities Space Research Association, GESTAR, Columbia, MD, USA
5Department of Chemistry, University of California, Irvine, CA, USA
6Global Modeling and Assimilation Office, NASA Goddard Space Flight Center, Greenbelt, MD, USA
7Science Systems and Applications Inc, Lanham, MD, USA
8Department of Meteorology, Florida State University, Tallahassee, FL, USA
9School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA, USA
10Department of Earth and Planetary Science, University of Tokyo, Tokyo, Japan
11School of Computer, Mathematical and Natural Sciences, Morgan State University, Baltimore, MD, USA
12Institut für Ionenphysik, University of Innsbruck, Innsbruck, Austria
Received: 10 Feb 2012 – Discussion started: 05 Apr 2012
Abstract. We use the NASA GEOS-5 transport model with tagged tracers to investigate the contributions of different regional sources of CO and black carbon (BC) to their concentrations in the Western Arctic (i.e., 50–90° N and 190–320° E) in spring and summer 2008. The model is evaluated by comparing the results with airborne measurements of CO and BC from the NASA Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) field campaigns to demonstrate the strengths and limitations of our simulations. We also examine the reliability of tagged CO tracers in characterizing air mass origins using the measured fossil fuel tracer of dichloromethane and the biomass burning tracer of acetonitrile. Our tagged CO simulations suggest that most of the enhanced CO concentrations (above background level from CH4 production) observed during April originate from Asian anthropogenic emissions. Boreal biomass burning emissions and Asian anthropogenic emissions are of similar importance in July domain wise, although the biomass burning CO fraction is much larger in the area of the ARCTAS field experiments. The fraction of CO from Asian anthropogenic emissions is larger in spring than in summer. European sources make up no more than 10% of CO levels in the campaign domain during either period. Comparisons of CO concentrations along the flight tracks with regional averages from GEOS-5 show that the along-track measurements are representative of the concentrations within the large domain of the Western Arctic in April but not in July.
Revised: 27 Mar 2013 – Accepted: 16 Apr 2013 – Published: 07 May 2013
Bian, H., Colarco, P. R., Chin, M., Chen, G., Rodriguez, J. M., Liang, Q., Blake, D., Chu, D. A., da Silva, A., Darmenov, A. S., Diskin, G., Fuelberg, H. E., Huey, G., Kondo, Y., Nielsen, J. E., Pan, X., and Wisthaler, A.: Source attributions of pollution to the Western Arctic during the NASA ARCTAS field campaign, Atmos. Chem. Phys., 13, 4707-4721, doi:10.5194/acp-13-4707-2013, 2013.