Articles | Volume 12, issue 18
Atmos. Chem. Phys., 12, 8499–8527, 2012

Special issue: EMEP – an integrated system of models and observations...

Atmos. Chem. Phys., 12, 8499–8527, 2012

Research article 21 Sep 2012

Research article | 21 Sep 2012

Modelling of organic aerosols over Europe (2002–2007) using a volatility basis set (VBS) framework: application of different assumptions regarding the formation of secondary organic aerosol

R. Bergström1,2, H. A. C. Denier van der Gon3, A. S. H. Prévôt4, K. E. Yttri5, and D. Simpson6,7 R. Bergström et al.
  • 1Department of Chemistry and Molecular Biology, University of Gothenburg, 41296 Gothenburg, Sweden
  • 2Swedish Meteorological and Hydrological Institute, 60176 Norrköping, Sweden
  • 3TNO Netherlands Organisation for Applied Scientific Research, Utrecht, The Netherlands
  • 4Laboratory of Atmospheric Chemistry, Paul Scherrer Institut, Villigen, Switzerland
  • 5Norwegian Institute for Air Research, Kjeller, Norway
  • 6EMEP MSC-W, Norwegian Meteorological Institute, Oslo, Norway
  • 7Dept. Earth & Space Sciences, Chalmers Univ. Technology, Gothenburg, Sweden

Abstract. A new organic aerosol module has been implemented into the EMEP chemical transport model. Four different volatility basis set (VBS) schemes have been tested in long-term simulations for Europe, covering the six years 2002–2007. Different assumptions regarding partitioning of primary organic aerosol and aging of primary semi-volatile and intermediate volatility organic carbon (S/IVOC) species and secondary organic aerosol (SOA) have been explored. Model results are compared to filter measurements, aerosol mass spectrometry (AMS) data and source apportionment studies, as well as to other model studies. The present study indicates that many different sources contribute significantly to organic aerosol in Europe. Biogenic and anthropogenic SOA, residential wood combustion and vegetation fire emissions may all contribute more than 10% each over substantial parts of Europe. This study shows smaller contributions from biogenic SOA to organic aerosol in Europe than earlier work, but relatively greater anthropogenic SOA. Simple VBS based organic aerosol models can give reasonably good results for summer conditions but more observational studies are needed to constrain the VBS parameterisations and to help improve emission inventories. The volatility distribution of primary emissions is one important issue for further work. Emissions of volatile organic compounds from biogenic sources are also highly uncertain and need further validation. We can not reproduce winter levels of organic aerosol in Europe, and there are many indications that the present emission inventories substantially underestimate emissions from residential wood combustion in large parts of Europe.

Final-revised paper