Articles | Volume 18, issue 16
Atmos. Chem. Phys., 18, 12345–12361, 2018
Atmos. Chem. Phys., 18, 12345–12361, 2018

Research article 27 Aug 2018

Research article | 27 Aug 2018

Historical black carbon deposition in the Canadian High Arctic: a >250-year long ice-core record from Devon Island

Christian M. Zdanowicz1, Bernadette C. Proemse2, Ross Edwards3,4, Wang Feiteng5, Chad M. Hogan2, Christophe Kinnard6, and David Fisher7 Christian M. Zdanowicz et al.
  • 1Department of Earth Sciences, Uppsala University, Uppsala, 752 36, Sweden
  • 2School of Biological Sciences, University of Tasmania, Hobart, TAS 7001, Australia
  • 3Physics and Astronomy, Curtin University, Perth, WA 6102, Australia
  • 4Depart of Civil and Environmental Engineering, University of Wisconsin, Madison, WI 53706, USA
  • 5Cold and Arid Regions Environment and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou, China
  • 6Département des Sciences de l'Environnement, Université du Québec à Trois-Rivières, Trois-Rivières, G9A 5H7, QC, Canada
  • 7Department of Earth Sciences, University of Ottawa, 120 University, Ottawa, K1N 6N5, ON, Canada

Abstract. Black carbon aerosol (BC), which is emitted from natural and anthropogenic sources (e.g., wildfires, coal burning), can contribute to magnify climate warming at high latitudes by darkening snow- and ice-covered surfaces, and subsequently lowering their albedo. Therefore, modeling the atmospheric transport and deposition of BC to the Arctic is important, and historical archives of BC accumulation in polar ice can help to validate such modeling efforts. Here we present a > 250-year ice-core record of refractory BC (rBC) deposition on Devon ice cap, Canada, spanning the years from 1735 to 1992. This is the first such record ever developed from the Canadian Arctic. The estimated mean deposition flux of rBC on Devon ice cap for 1963–1990 is 0.2 mg m−2 a−1, which is at the low end of estimates from Greenland ice cores obtained using the same analytical method ( ∼ 0.1–4 mg m−2 a−1). The Devon ice cap rBC record also differs from the Greenland records in that it shows only a modest increase in rBC deposition during the 20th century. In the Greenland records a pronounced rise in rBC is observed from the 1880s to the 1910s, which is largely attributed to midlatitude coal burning emissions. The deposition of contaminants such as sulfate and lead increased on Devon ice cap in the 20th century but no concomitant rise in rBC is recorded in the ice. Part of the difference with Greenland could be due to local factors such as melt–freeze cycles on Devon ice cap that may limit the detection sensitivity of rBC analyses in melt-impacted core samples, and wind scouring of winter snow at the coring site. Air back-trajectory analyses also suggest that Devon ice cap receives BC from more distant North American and Eurasian sources than Greenland, and aerosol mixing and removal during long-range transport over the Arctic Ocean likely masks some of the specific BC source–receptor relationships. Findings from this study suggest that there could be a large variability in BC aerosol deposition across the Arctic region arising from different transport patterns. This variability needs to be accounted for when estimating the large-scale albedo lowering effect of BC deposition on Arctic snow/ice.

Short summary
Black carbon (BC) particles emitted by natural and anthropogenic sources (e.g., wildfires, coal burning) can amplify climate warming by increasing sunlight energy absorption on snow-covered surfaces. This paper presents a new ice-core record of historical (1810–1990) BC deposition in the Canadian Arctic. The Devon ice cap record differs from Greenland ice cores, implying large variations in BC deposition across the Arctic that must be accounted for to better quantity their future climate impact.
Final-revised paper