O. Gervasi et al. (Eds.): ICCSA 2009, Part I, LNCS 5592, pp. 107–117, 2009. © Springer-Verlag Berlin Heidelberg 2009 An Evaluation of the Performance of the CHIMERE Model over Spain Using Meteorology from MM5 and WRF Models Marta G. Vivanco 1 , Inmaculada Palomino 1 , Fernando Martín 1 , Magdalena Palacios 1 , Oriol Jorba 2 , Pedro Jiménez 2 , José María Baldasano 2 , and Oier Azula 3 1 Atmospheric Pollution Unit, Environmental Department, CIEMAT, Avda. Complutense 22, 28040 Madrid, Spain 2 Earth Science Department, Barcelona Supercomputing Center-Centro Nacional de Supercomputación (BSC-CNS), Barcelona, Spain 3 Departamento de Química Fisica, UPV, Paseo de la Universidad, 7, 01006 Vitoria-Gasteiz, Spain Abstract. The presence of high pollution levels in the atmosphere can produce damages to human health and ecosystems. Because of this reason, the prediction of air pollutant concentration is important to prevent any potential damage. Chemistry-transport models constitute a useful tool to quantify the presence of pollutants in the atmosphere. Input information, such as meteorology and emissions, has a strong influence on model results. Many research activities are focused on trying to reduce errors affecting input information. In this paper we have applied the CHIMERE photochemical model to simulate ozone, NO 2 and SO 2 in Spain for two sets of meteorological fields obtained with the MM5 and WRF meteorological models. An evaluation of the performance of the CHIMERE model for both meteorological data sets is presented. Very similar air pollutant concentrations were found for the three pollutants and for the two sets of meteorological information. Keywords: Photochemical modeling, air quality forecast, evaluation of model performance. 1 Introduction Predicting air pollutants levels has become an important goal in environmental management in order to prevent potential damage to human health or ecosystems. Air quality models are being extensively applied as a tool to obtain predicted pollutant concentrations in the troposphere. Large efforts trying to reduce discrepancies between model predictions and observations are being done by air quality modeling community. The evaluation of the performance of models has become a common and very important practice to assess the quality of model predictions. In Spain the use of air quality models has significantly increased over the last years ([1], [2], [3], [4], [5], [6]). A provisional forecast system in Spain was presented in [7], in the framework of the CALIOPE project financed by the Environment Ministry of Spain. Four institutions participate in this project: the Barcelona Supercomputing