Climate change and emissions impacts on atmospheric PAH transport to the Arctic

Environ Sci Technol. 2014;48(1):429-37. doi: 10.1021/es403098w. Epub 2013 Dec 9.

Abstract

We investigate effects of 2000-2050 emissions and climate changes on the atmospheric transport of three polycyclic aromatic hydrocarbons (PAHs): phenanthrene (PHE), pyrene (PYR), and benzo[a]pyrene (BaP). We use the GEOS-Chem model coupled to meteorology from a general circulation model and focus on impacts to northern hemisphere midlatitudes and the Arctic. We project declines in anthropogenic emissions (up to 20%) and concentrations (up to 37%), with particle-bound PAHs declining more, and greater declines in midlatitudes versus the Arctic. Climate change causes relatively minor increases in midlatitude concentrations for the more volatile PHE and PYR (up to 4%) and decreases (3%) for particle-bound BaP. In the Arctic, all PAHs decline slightly under future climate (up to 2%). Overall, we observe a small 2050 "climate penalty" for volatile PAHs and "climate benefit" for particle-bound PAHs. The degree of penalty or benefit depends on competition between deposition and surface-to-air fluxes of previously deposited PAHs. Particles and temperature have greater impacts on future transport than oxidants, with particle changes alone accounting for 15% of BaP decline under 2050 emissions. Higher temperatures drive increasing surface-to-air fluxes that cause PHE and PYR climate penalties. Simulations suggest ratios of more-to-less volatile species can be used to diagnose signals of climate versus emissions and that these signals are best observed in the Arctic.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Air Pollutants / analysis*
  • Arctic Regions
  • Benzo(a)pyrene / analysis*
  • Climate Change*
  • Environmental Monitoring
  • Extraction and Processing Industry
  • Models, Theoretical
  • Petroleum
  • Phenanthrenes / analysis*
  • Pyrenes / analysis*
  • Ships

Substances

  • Air Pollutants
  • Petroleum
  • Phenanthrenes
  • Pyrenes
  • Benzo(a)pyrene
  • phenanthrene
  • pyrene