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
Received: 03 Jan 2012 – Discussion started: 20 Feb 2012
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.
Revised: 20 Aug 2012 – Accepted: 06 Sep 2012 – Published: 21 Sep 2012
Bergström, R., Denier van der Gon, H. A. C., Prévôt, A. S. H., Yttri, K. E., and Simpson, D.: 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, Atmos. Chem. Phys., 12, 8499-8527, doi:10.5194/acp-12-8499-2012, 2012.