The smoke from the gigantic fires that have ravaged Canadian forests since the beginning of the year reached the French territory on Tuesday. But, for the time being, no deterioration in air quality is to be reported.
After covering the sky of Montreal or New York with a thick orange veil, the smoke from the gigantic Canadian fires reached France. These huge plumes, from the 7.4 million hectares burned, crossed the Atlantic Ocean to halo part of France on Tuesday, June 27. “Currently, three quarters of the country are affected”, explains on franceinfo Joris Vallon, forecaster at Météo France. The particles reached the country from the West overnight from Monday to Tuesday. They will shift towards the East on Thursday, before being swept out of the borders on Friday.
To follow the movement of this plume on both sides of the Atlantic Ocean, thehe Copernicus Atmosphere Monitoring Service (Cams) provides data and five-day forecasts by measuring aerosol optical depth (AOD). This indicator measures the degree of transparency of the atmosphere, and therefore the concentration of aerosols. The higher it is, the greater the presence of particles.
The smoke coming from Canada is mainly composed of carbon monoxide, a molecule with “atmospheric lifetime of about one month”, explains to AFP Mark Parrington, scientist at Cams. Its longevity makes it a “very good smoke transport tracer”.
Located at more than 3,000 meters above sea level, the smoke should “dilute quite easily in the atmosphere”, adds forecaster Joris Vallon. Especially since disruptions are planned for Thursday on French territory, which should “disappear” the fumes. However, it is possible to see them with the naked eye, as shown for example by these photos taken at Chevaigne (Ille-et-Vilaine) and Lelex Crozet (Jura), posted on Twitter. Now the sky seems “hazy, with a milky appearance”, explains the forecaster. But “there is no particular color”unlike dust from the Sahara. “You can have a white layer in the sky, without a precise outline”.
No impact on air quality yet
Eye irritation, asthma attacks… Exposure to these fine particles has a harmful effect on health. “They accumulate over the long term in our organs, in particular in the heart, where they contribute to increasing the risk of stroke, and again in the brain, where they increase the risk of developing Alzheimer’s and Parkinson’s disease” , explain to Point Charlotte Lepitre, project manager for Atmo France, the federation of associations responsible for monitoring air quality. In the long term, fine particles can promote the appearance of cardiovascular diseases or cancers, according to her.
Still, after having crossed thousands of kilometers to reach the Old Continent, the fumes are less concentrated in fine particles than at the start of their journey, in Canada, according to Cams. Data “thus show high values of aerosol concentration across the Atlantic, but mainly at very high altitudes”, explains Mark Parrington to AFP.
According to him, “it is therefore unlikely to have an impact on air quality in Europe”. In Paris and Ile-de-France, no significant impact is expected on air quality either. “But we cannot exclude deposit, that is to say fallout” if the atmospheric currents change in the coming days and the upper strata mix with the lower strata, explains to AFP Pierre Pernot, engineer at Airparif. Even if we are far from the images of New York trapped in smoke, scientists therefore remain attentive to the evolution of the altitude of this cloud.