1Paul Scherrer Institut, Laboratory of Atmospheric Chemistry, 5232 Villigen PSI, Switzerland
2Institute of Environmental Assessment and Water Research (IDAEA), CSIC, 08034 Barcelona, Spain
3Dept. of Chemistry and Biochemistry, University of Bern, 3012 Berne, Switzerland
4Oeschger Centre for Climate Change Research, University of Bern, 3012 Berne, Switzerland
5Dept. of Chemistry and Biochemistry, University of Colorado, Boulder, CO, USA
6Cooperative Institute for Research in Environmental Sciences (CIRES), USA
7Dept. of Atmospheric and Oceanic Science, University of Colorado, Boulder, CO, USA
8Laboratory of Ion Beam Physics, ETH Hönggerberg, 8093 Zurich, Switzerland
9Air Chemistry Group of the Hungarian Academy of Sciences, University of Pannonia, 8201 Veszprém, Hungary
10Institute for Atmospheric Sciences and Climate (ISAC), CNR, Bologna, Italy
11Finnish Meteorological Institute, Air Quality Research, 00101 Helsinki, Finland
12Unitat d'Ecologia Global CREAF-CEAB-CSIC, Centre de Recerca Ecològica i Aplicacions Forestals (CREAF), Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain
13Institute of Ion Physics and Applied Physics, Innsbruck University, 6020 Innsbruck, Austria
14Norwegian Institute for Air Research (NILU), 2027 Kjeller, Norway
*now at: Dept. of Nuclear Physics, University of Lund, 221 00 Lund, Sweden
**now at: Atmospheric Chemistry Division, National Center for Atmospheric Research, Boulder, CO 80301, USA
Received: 26 Jul 2011 – Discussion started: 19 Aug 2011
Abstract. We present results from the international field campaign DAURE (Determination of the sources of atmospheric Aerosols in Urban and Rural Environments in the Western Mediterranean), with the objective of apportioning the sources of fine carbonaceous aerosols. Submicron fine particulate matter (PM1) samples were collected during February–March 2009 and July 2009 at an urban background site in Barcelona (BCN) and at a forested regional background site in Montseny (MSY). We present radiocarbon (14C) analysis for elemental and organic carbon (EC and OC) and source apportionment for these data. We combine the results with those from component analysis of aerosol mass spectrometer (AMS) measurements, and compare to levoglucosan-based estimates of biomass burning OC, source apportionment of filter data with inorganic composition + EC + OC, submicron bulk potassium (K) concentrations, and gaseous acetonitrile concentrations.
Revised: 28 Oct 2011 – Accepted: 16 Nov 2011 – Published: 06 Dec 2011
At BCN, 87 % and 91 % of the EC on average, in winter and summer, respectively, had a fossil origin, whereas at MSY these fractions were 66 % and 79 %. The contribution of fossil sources to organic carbon (OC) at BCN was 40 % and 48 %, in winter and summer, respectively, and 31 % and 25 % at MSY. The combination of results obtained using the 14C technique, AMS data, and the correlations between fossil OC and fossil EC imply that the fossil OC at Barcelona is ∼47 % primary whereas at MSY the fossil OC is mainly secondary (∼85 %). Day-to-day variation in total carbonaceous aerosol loading and the relative contributions of different sources predominantly depended on the meteorological transport conditions. The estimated biogenic secondary OC at MSY only increased by ∼40 % compared to the order-of-magnitude increase observed for biogenic volatile organic compounds (VOCs) between winter and summer, which highlights the uncertainties in the estimation of that component. Biomass burning contributions estimated using the 14C technique ranged from similar to slightly higher than when estimated using other techniques, and the different estimations were highly or moderately correlated. Differences can be explained by the contribution of secondary organic matter (not included in the primary biomass burning source estimates), and/or by an overestimation of the biomass burning OC contribution by the 14C technique if the estimated biomass burning EC/OC ratio used for the calculations is too high for this region. Acetonitrile concentrations correlate well with the biomass burning EC determined by 14C. K is a noisy tracer for biomass burning.
Minguillón, M. C., Perron, N., Querol, X., Szidat, S., Fahrni, S. M., Alastuey, A., Jimenez, J. L., Mohr, C., Ortega, A. M., Day, D. A., Lanz, V. A., Wacker, L., Reche, C., Cusack, M., Amato, F., Kiss, G., Hoffer, A., Decesari, S., Moretti, F., Hillamo, R., Teinilä, K., Seco, R., Peñuelas, J., Metzger, A., Schallhart, S., Müller, M., Hansel, A., Burkhart, J. F., Baltensperger, U., and Prévôt, A. S. H.: Fossil versus contemporary sources of fine elemental and organic carbonaceous particulate matter during the DAURE campaign in Northeast Spain, Atmos. Chem. Phys., 11, 12067-12084, doi:10.5194/acp-11-12067-2011, 2011.