Articles | Volume 17, issue 17
Atmos. Chem. Phys., 17, 10879–10892, 2017
Atmos. Chem. Phys., 17, 10879–10892, 2017

Research article 14 Sep 2017

Research article | 14 Sep 2017

Contributions of transported Prudhoe Bay oil field emissions to the aerosol population in Utqiaġvik, Alaska

Matthew J. Gunsch1, Rachel M. Kirpes1, Katheryn R. Kolesar1, Tate E. Barrett2, Swarup China3, Rebecca J. Sheesley2,4, Alexander Laskin3,a, Alfred Wiedensohler5, Thomas Tuch5, and Kerri A. Pratt1,6 Matthew J. Gunsch et al.
  • 1Department of Chemistry, University of Michigan, Ann Arbor, MI, USA
  • 2The Institute of Ecological, Earth, and Environmental Sciences, Baylor University, Waco, TX, USA
  • 3Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA, USA
  • 4Department of Environmental Science, Baylor University, Waco, TX, USA
  • 5Leibniz Institute for Tropospheric Research, Leipzig, Germany
  • 6Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI, USA
  • acurrently at: Department of Chemistry, Purdue University, West Lafayette, IN, USA

Abstract. Loss of sea ice is opening the Arctic to increasing development involving oil and gas extraction and shipping. Given the significant impacts of absorbing aerosol and secondary aerosol precursors emitted within the rapidly warming Arctic region, it is necessary to characterize local anthropogenic aerosol sources and compare to natural conditions. From August to September 2015 in Utqiaġvik (Barrow), AK, the chemical composition of individual atmospheric particles was measured by computer-controlled scanning electron microscopy with energy-dispersive X-ray spectroscopy (0.13–4 µm projected area diameter) and real-time single-particle mass spectrometry (0.2–1.5 µm vacuum aerodynamic diameter). During periods influenced by the Arctic Ocean (70 % of the study), our results show that fresh sea spray aerosol contributed  ∼ 20 %, by number, of particles between 0.13 and 0.4 µm, 40–70 % between 0.4 and 1 µm, and 80–100 % between 1 and 4 µm particles. In contrast, for periods influenced by emissions from Prudhoe Bay (10 % of the study), the third largest oil field in North America, there was a strong influence from submicron (0.13–1 µm) combustion-derived particles (20–50 % organic carbon, by number; 5–10 % soot by number). While sea spray aerosol still comprised a large fraction of particles (90 % by number from 1 to 4 µm) detected under Prudhoe Bay influence, these particles were internally mixed with sulfate and nitrate indicative of aging processes during transport. In addition, the overall mode of the particle size number distribution shifted from 76 nm during Arctic Ocean influence to 27 nm during Prudhoe Bay influence, with particle concentrations increasing from 130 to 920 cm−3 due to transported particle emissions from the oil fields. The increased contributions of carbonaceous combustion products and partially aged sea spray aerosol should be considered in future Arctic atmospheric composition and climate simulations.

Short summary
Arctic sea ice loss is leading to increasing petroleum extraction and shipping. It is necessary to identify emissions from these activities for improved Arctic air quality and climate assessment. Atmospheric particles were measured from August to September 2015 in Utqiaġvik, AK. For periods influenced by Prudhoe Bay, significant influence associated with combustion emissions was observed, compared to fresh sea spray influence during Arctic Ocean periods.
Final-revised paper