Dynamics of air pollution in the northwestern Mediterranean Basin (Catalonia) in summer using high-resolution air-quality modeling

The high levels of photochemical pollutants in summer (especially ozone, O3) over the northwestern Mediterranean Basin (NWMB) and, specifically Catalonia, influence both ecosystems and human health. The cloud-free conditions and high solar radiation intensity promote the photochemical build-up of O3 and other pollutants (Lelieveld et al., 2002), and measurements have shown high O3 concentrations in this Mediterranean region (e.g. Ziomas et al., 1998; Millán et al., 2000; Dueñas et al., 2002). According to Ribas and Peñuelas (2004), the European Union’s thresholds for human and plant protection are exceeded in the NWMB on 54 and 297 days per year, respectively. Atmospheric CONTRIBUTIONS to SCIENCE, 3 (2): 167–180 (2006) Institut d’Estudis Catalans, Barcelona