Variabilité spatio-temporelle de la concentration atmosphérique des particules à Berlin

Spatial and temporal variability of atmospheric particle concentration in Berlin

Institut de Géographie, Université Humboldt de Berlin, Unter den Linden 6, 10099 Berlin, Allemagne

^* Email: wilfried.endlicher@geo.hu-berlin.de

Résumé

A Berlin, les niveaux de la concentration des particules augmentent de nouveau depuis l’an 2000 à cause de l’accroissement du trafic. Les progrès importants dus aux catalyseurs sont réduits par l’augmentation de la circulation routière. Une différenciation temporelle et spatiale de la pollution atmosphérique a été observée. Les types de temps jouent un rôle important dans la variabilité temporelle de la pollution par particules. La fraction plus grosse PM₁₀ a une plus grande variabilité spatiale que les particules plus fines PM_2.5. Les valeurs limites de la directive européenne ne sont pas respectées dans des secteurs avec une circulation routière importante.

Abstract

Despite of a significant improvement in urban air quality during the last decade, traffic related emissions like particulate matter and nitrogen dioxide are still a problem in urban areas. Reduced vehicle emissions due to exhaust emission catalysts are compensated by increasing traffic. In Berlin a marked spatial and a high temporal variability of particulate matter is observed. Weather types play an important role for the temporal variability of the pollution by particulate matter. Particulate matter background concentrations are already at a high level in particular in case of prevailing weather types from east to south. But it is evident that within the agglomeration highest levels are observed at traffic related sites. A distinctive spatial variability was rather observed for PM₁₀ than for PM_2.5. Traffic related sites show higher soot portions in general. At traffic hot spots it is obviously a problem to comply with the European air quality limit value for daily ambient PM₁₀ levels valid since 2005. Therefore a low emission zone was introduced in Berlin in the beginning of 2008. But further measures reducing individual motor-driven traffic in general are rather required. The observed annual mean values for PM₁₀ indicate that the compliance with the annual mean limit value of 40 μg/m³ should not be a certain problem. This is not also supposed for the future annual mean limit value of 25 μg/m³ for PM_2.5 valid from 2015.