Journal cover Journal topic
Atmospheric Chemistry and Physics An interactive open-access journal of the European Geosciences Union
Atmos. Chem. Phys., 16, 10313-10332, 2016
© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.
Research article
16 Aug 2016
Evaluation of European air quality modelled by CAMx including the volatility basis set scheme
Giancarlo Ciarelli1, Sebnem Aksoyoglu1, Monica Crippa1,a, Jose-Luis Jimenez2,3, Eriko Nemitz4, Karine Sellegri5, Mikko Äijälä6, Samara Carbone7,b, Claudia Mohr8, Colin O'Dowd9, Laurent Poulain10, Urs Baltensperger1, and André S. H. Prévôt1 1Paul Scherrer Institute, Laboratory of Atmospheric Chemistry, 5232 Villigen PSI, Switzerland
2Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO 80309, USA
3Department of Chemistry and Biochemistry, University of Colorado, Boulder, CO 80309, USA
4Centre for Ecology and Hydrology, Bush Estate, Penicuik, Midlothian, EH26 0QB, UK
5Laboratoire de Météorologie Physique CNRS UMR6016, Observatoire de Physique du Globe de Clermont-Ferrand, Université Blaise Pascal, 63171 Aubière, France
6University of Helsinki, Department of Physics, Helsinki, Finland
7Atmospheric Composition Research, Finnish Meteorological Institute, P.O. Box 503, 00101 Helsinki, Finland
8Karlsruhe Institute of Technology, Institute of Meteorology and Climate Research, Germany
9School of Physics and Centre for Climate & Air Pollution Studies, Ryan Institute, National University of Ireland Galway, University Road, Galway, Ireland
10Leibniz-Institute for Tropospheric Research (TROPOS), Permoserstr. 15, 04318 Leipzig, Germany
anow at: European Commission, Joint Research Centre (JRC), Institute for Environment and Sustainability (IES), Via Fermi, 2749, 21027 Ispra, Italy
bnow at: Institute of Physics, University of São Paulo, Rua do Matão Travessa R, 187, 05508-090 São Paulo, S.P., Brazil
Abstract. Four periods of EMEP (European Monitoring and Evaluation Programme) intensive measurement campaigns (June 2006, January 2007, September–October 2008 and February–March 2009) were modelled using the regional air quality model CAMx with VBS (volatility basis set) approach for the first time in Europe within the framework of the EURODELTA-III model intercomparison exercise. More detailed analysis and sensitivity tests were performed for the period of February–March 2009 and June 2006 to investigate the uncertainties in emissions as well as to improve the modelling of organic aerosol (OA). Model performance for selected gas phase species and PM2.5 was evaluated using the European air quality database AirBase. Sulfur dioxide (SO2) and ozone (O3) were found to be overestimated for all the four periods, with O3 having the largest mean bias during June 2006 and January–February 2007 periods (8.9 pbb and 12.3 ppb mean biases respectively). In contrast, nitrogen dioxide (NO2) and carbon monoxide (CO) were found to be underestimated for all the four periods. CAMx reproduced both total concentrations and monthly variations of PM2.5 for all the four periods with average biases ranging from −2.1 to 1.0 µg m−3. Comparisons with AMS (aerosol mass spectrometer) measurements at different sites in Europe during February–March 2009 showed that in general the model overpredicts the inorganic aerosol fraction and underpredicts the organic one, such that the good agreement for PM2.5 is partly due to compensation of errors. The effect of the choice of VBS scheme on OA was investigated as well. Two sensitivity tests with volatility distributions based on previous chamber and ambient measurements data were performed. For February–March 2009 the chamber case reduced the total OA concentrations by about 42 % on average. In contrast, a test based on ambient measurement data increased OA concentrations by about 42 % for the same period bringing model and observations into better agreement. Comparison with the AMS data at the rural Swiss site Payerne in June 2006 shows no significant improvement in modelled OA concentration. Further sensitivity tests with increased biogenic and anthropogenic emissions suggest that OA in Payerne was affected by changes in emissions from residential heating during the February–March 2009 whereas it was more sensitive to biogenic precursors in June 2006.

Citation: Ciarelli, G., Aksoyoglu, S., Crippa, M., Jimenez, J.-L., Nemitz, E., Sellegri, K., Äijälä, M., Carbone, S., Mohr, C., O'Dowd, C., Poulain, L., Baltensperger, U., and Prévôt, A. S. H.: Evaluation of European air quality modelled by CAMx including the volatility basis set scheme, Atmos. Chem. Phys., 16, 10313-10332,, 2016.
Publications Copernicus
Short summary
Recent studies based on aerosol mass spectrometer measurements revealed that the organic fraction dominates the non-refractory PM1 composition. However its representation in chemical transport models is still very challenging due to uncertainties in emission sources and formation pathways. In this study, a novel organic aerosol scheme was tested in the regional air quality model CAMx and results were compared with ambient measurements at 11 different sites in Europe.
Recent studies based on aerosol mass spectrometer measurements revealed that the organic...