Articles | Volume 12, issue 1
Atmos. Chem. Phys., 12, 125–138, 2012
Atmos. Chem. Phys., 12, 125–138, 2012

Research article 02 Jan 2012

Research article | 02 Jan 2012

Chemical characterisation of atmospheric aerosols during a 2007 summer field campaign at Brasschaat, Belgium: sources and source processes of biogenic secondary organic aerosol

Y. Gómez-González1, W. Wang2, R. Vermeylen1, X. Chi2,*, J. Neirynck3, I. A. Janssens4, W. Maenhaut2, and M. Claeys1 Y. Gómez-González et al.
  • 1Department of Pharmaceutical Sciences, University of Antwerp (Campus Drie Eiken), Antwerp, Belgium
  • 2Department of Analytical Chemistry, Institute for Nuclear Sciences, Ghent University, Gent, Belgium
  • 3Research Institute for Nature and Forest (INBO), Geraardsbergen, Belgium
  • 4Department of Biology, University of Antwerp (Campus Drie Eiken), Antwerp, Belgium
  • *present address: Biogeochemistry Department, Max Planck Institute for Chemistry, Mainz, Germany

Abstract. Measurements of organic marker compounds and inorganic species were performed on PM2.5 aerosols from a Belgian forest site that is severely impacted by urban pollution ("De Inslag", Brasschaat, Belgium) during a 2007 summer period within the framework of the "Formation mechanisms, marker compounds, and source apportionment for biogenic atmospheric aerosols (BIOSOL)" project. The measured organic species included (i) low-molecular weight (MW) dicarboxylic acids (LMW DCAs), (ii) methanesulfonate (MSA), (iii) terpenoic acids originating from the oxidation of α-pinene, β-pinene, d-limonene and Δ3-carene, and (iv) organosulfates related to secondary organic aerosol from the oxidation of isoprene and α-pinene. The organic tracers explained, on average, 5.3 % of the organic carbon (OC), of which 0.7 % was due to MSA, 3.4 % to LMW DCAs, 0.6 % to organosulfates, and 0.6 % to terpenoic acids. The highest atmospheric concentrations of most species were observed during the first five days of the campaign, which were characterised by maximum day-time temperatures >22 °C. Most of the terpenoic acids and the organosulfates peaked during day-time, consistent with their local photochemical origin. High concentrations of 3-methyl-1,2,3-butanetricarboxylic acid (MBTCA) and low concentrations of cis-pinonic acid were noted during the first five days of the campaign, indicative of an aged biogenic aerosol. Several correlations between organic species were very high (r>0.85), high (0.7<r<0.85), or substantial (0.5<r<0.7), suggesting that they are generated through similar formation pathways. Substantial correlations with temperature were found for OC, water-soluble OC, MBTCA, and several other organic species. MBTCA and terebic acid were highly correlated with the temperature (r>0.7) and showed an Arrhenius-type relationship, consistent with their formation through OH radical chemistry.

Final-revised paper