Examples of particulate
pollution episodes

The map on the right display the isolines of PM10 peak concentrations (in µg/m3) calculated by the CHIMERE model for the 1st of February 2006. In this case, the strong concentrations of PM10 observed on the Paris area have a local origin - as it is showed by the observations, as well as the composition of the particles simulated by the model.

Strong atmospheric stability which prevails during anticyclonic situations limits the dispersion of the atmospheric pollutants and supports their accumulation near large emission centers (cities, industries).

On the right-hand side, the maps display the isoconcentrations of PM10 (in µg/m3) calculated by the CHIMERE model during a wintertime episode of particulate pollution. This episode last from March 26 to March 31, 2004 (maps refer to the 30th of March 2004, 0 a.m.). They highlight the largely continental origin of this episode of particulate pollution: the areas concerned extend on a  broad band, from East Germany to Cotentin. All the North of France is touched.

Such winter episodes of particulate pollution are often associated to anticyclonic systems localised on Scandinavia or the North Sea. The conditions of strong atmospheric stability as well as the light flow of the North-East which prevails over Europe in these situations limit the dispersion of the atmospheric pollutants and support their transport from areas of strong emissions (cities, industries) towards places remote from large emission centers.