Contribution of Saharan dust in an integrated air quality system and its on-line assessment

[1] Nowadays none of the operational daily forecasts in Europe includes the influence of Saharan dust on a nonclimatic basis. In order to account for this, the BSC-CNS currently operates daily photochemical forecasts in the Iberian Peninsula with MM5-EMEP-CMAQ modelling system and Saharan dust forecasts over Southern Europe with Eta/ DREAM. The necessity of coupling both modelling systems is addressed by the study of a long summer episode combining regional re-circulations and Saharan dust covering from June 19 to July 12, 2006. As a first approach, the natural dust contribution from Eta/DREAM is added on-line to the anthropogenic output of CMAQ. The performance of the model has been quantitatively evaluated with discrete and categorical (skill scores) statistics by a fully operational on-line comparison of the first-layer simulations results of CMAQand CMAQ+DREAM and the values measured in two different stations located in the Mediterranean part of the domain. The results indicate a remarkable improvement in the discrete and skill-scores evaluation (accuracy, critical success index and probability of detection) of PM10 exceedances set in regulations when using CMAQ+DREAM compared to CMAQor DREAM-alone simulations. Citation: JiménezGuerrero, P., C. Pérez, O. Jorba, and J. M. Baldasano (2008), Contribution of Saharan dust in an integrated air quality system and its on-line assessment, Geophys. Res. Lett., 35, L03814, doi:10.1029/ 2007GL031580.