In summer, levels of ozone (O3) in the atmosphere frequently
rise. In Galicia, due to human emissions and high levels of vegetation, summer
episodes of high concentrations of ozone affecting air quality have also been
recorded. An atmosphere modelling system applied to the northwest of the
Iberian Peninsula by researchers at the University of Aveiro (Portugal) and the
University of Santiago de Compostela (Spain) has detected ozone transfer from
northern Portugal to Galicia.