Dor several days, the Belgian sky has been disturbed by persistent fog without it raining. According to meteorologist Philippe Mievis, interviewed by our colleagues from Sudinfothis astonishing disturbance is caused by “an inversion phenomenon” which acts like a “real lid”. “It doesn’t rain because we are protected by a powerful anticyclone and this humidity is trapped in the lower layers of the atmosphere,” he explains.
We speak of an “inversion phenomenon”, when the air temperature increases with altitude instead of decreasing. “That’s why yesterday afternoon it was very mild in the Hautes Fagnes with a beautiful blue sky.” He explains: “This phenomenon often traps cold air, and therefore polluted air, close to the ground, which can have consequences on air quality and the health of residents in certain regions. »
A “stable layer” thus traps polluted air close to the ground. “This phenomenon is often accentuated in valleys or basins, where air circulation is limited. Pollutants from automobile traffic, industry or heating accumulate. Which can lead to persistent smog and poor air quality, especially in winter. »
Belgium
