CR 50:51-68 (2011)  -  DOI: https://doi.org/10.3354/cr01036

ABSTRACT: We investigated the changes in exceedances of key atmospheric pollutants due to climate change in central and southeastern Europe. The RegCM3/CAMx and ­ALADIN-CLIMATE/CMAQ regional climate-chemistry modelling systems were used for high-resolution simulations (10 km). The simulations performed cover 3 decadal time slices (1991−2000, 2041−2050, 2091−2100). The future simulations were driven under the A1B IPCC scenario. Our model simulations yielded changes in ozone, particulate matter with a diameter <10 µm (PM₁₀) and sulphur ­dioxide (SO₂) resulting from climate change, without taking into consideration changes in anthropogenic emissions. We observed a shift in the average pollutant levels, and the frequency of occurrence of extreme pollution changed, especially in 2091–2100. Due to elevated air temperature, accumulated ozone exposure over the 40 ppbv (parts per billion by volume) threshold (AOT40) for crops and forests tended to increase by up to 20 to 30% in many areas of central Europe by the end of the century. Marked increases in the number of 8 h ozone threshold exceedances and ozone maxima were also observed. An increase in hourly and daily SO₂ exceedances was predicted. Finally, PM₁₀ exceedances were predicted to change due to different future climate. A small change (±1 d yr⁻¹) was calculated for an extensive area of central Europe, and exceedances decreased around the Benelux states and Romania. The modelled SO₂ and PM₁₀ changes can be partly attributed to different horizontal and vertical mixing as evidenced by changes in the ventilation co­efficient (defined as the product of horizontal wind speed at the surface and the planetary boundary layer height), and the majority of the SO₂ and PM₁₀ exceedances occurred during winter and autumn.

KEY WORDS: Future air quality · Climate change · Pollutant exceedances · Ozone · Particulate matter · Coupled climate-chemistry models