Monitoring atmospheric composition & climate
Smog over Belgium


smog_vms_small.jpgToday, 24 January 2013, Belgian authorities implemented a smog alarm leading to an immediate reduction of the speed limit to 90 km/h in certain areas. The smog alarm resulted from high concentrations of atmospheric particulates (PM10) that have a direct impact on human health. Especially people with already existing respiratory diseases, such as asthma, are affected.


MACC-II routinely provides daily forecasts of PM10 concentrations as well as other air quality indicators, and the forecast for today shows indeed elevated PM10 concentrations in an area centred above Belgium and the south of The Netherlands. MACC-II uses an ensemble of 7 European air quality models to provide the best estimate of forecasted concentrations as well as an indication of the inherent model uncertainty. The mean European forecast of daily mean PM10 concentrations for today clearly shows the area affected by the increased concentrations and the development of the plume due to stable atmospheric conditions catching anthropogenic emissions due to road traffic and residential heating. Future forecasts for the Euroepan domain can be found on the MACC-II web site.


A magnification of the affected area using one of the individual models shows even more detail. While situations like these are not uncommon in winter, PM10 concentrations over Belgium, the North of France and the Paris area are clearly exceeding the European regulatory limit value for the daily mean: 50 μg/m3. These critical levels are expected to remain in the area for tomorrow, although slightly displaced to the south.

A 4-day forecast for Brussels based on the model ensemble shows the mean as well as the range of the individual models. These plots, which are currently available for all European capitals on the MACC-II web site, provide an alternative presentation of the air quality forecast and its uncertainty.