The impact of sea breeze under different synoptic patterns on air pollution within Athens basin

► Atmospheric circulation is classified into thirteen patterns and two types of sea breeze are identified. ► Higher air pollution concentrations during sea breeze days compared to Etesian days. ► Higher O3 concentrations for the pure sea breeze and for the modified, under offshore background flow. ► At the urban center high NOx and low O3 concentrations, sea breeze transport leads to high O3 levels at north of the basin. ► Air pollution accumulates when sea breeze persists for more than one day.