ACP Atmospheric Chemistry and Physics ACP 1680-7324 Copernicus GmbH Göttingen, Germany 10.5194/acp-5-623-2005 Evaluation of detailed aromatic mechanisms (MCMv3 and MCMv3.1) against environmental chamber data Bloss C. 1 Wagner V. 1 Bonzanini A. 1 Jenkin M. E. 2 Wirtz K. 3 Martin-Reviejo M. 3 Pilling M. J. 1 School of Chemistry, University of Leeds, Leeds LS2 9JT, UK Imperial College London, Silwood Park, Ascot, Berkshire SL5 7PY, UK Centro de Estudios Ambientales del Mediterraneo, C. Charles R. Darwin 14, 46980 Paterna, Spain 01 03 2005 5 3 623 639 This is an open-access article ditributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. This article is available from http://www.atmos-chem-phys.net/5/623/2005/acp-5-623-2005.html The full text article is available as a PDF file from http://www.atmos-chem-phys.net/5/623/2005/acp-5-623-2005.pdf

A high quality dataset on the photo-oxidation of benzene, toluene, <i>p</i>-xylene and 1,3,5-trimethylbenzene has been obtained from experiments in the European Photoreactor (EUPHORE), a large outdoor environmental reaction chamber. The experiments were designed to test sensitive features of detailed aromatic mechanisms, and the dataset has been used to evaluate the performance of the Master Chemical Mechanism Version 3 (MCMv3). An updated version (MCMv3.1) was constructed based on recent experimental data, and details of its development are described in a companion paper. The MCMv3.1 aromatic mechanisms have also been evaluated using the EUPHORE dataset. Significant deficiencies have been identified in the mechanisms, in particular: 1) an over-estimation of the ozone concentration, 2) an under-estimation of the NO oxidation rate, 3) an under-estimation of OH. The use of MCMv3.1 improves the model-measurement agreement in some areas but significant discrepancies remain.