Fires in the United States: how the gigantic smoke reached Europe

Huge fires ravage the western United States.

The first outbreaks developed during the second half of August in California and Colorado.

Since early September, they have extended to Oregon and Washington State.

According to data from the Copernicus Atmosphere Monitoring Service (CAMS), these forest fires are very intense, significantly more intense than the average recorded between 2003 (start of data coverage) and 2019 on the areas concerned.

The exceptional magnitude of their radiative power reflects their devastating effect.

These blazes are accompanied by a gigantic release of smoke and pollutants, causing the quantities of carbon released into the atmosphere to explode.

These releases reached 21.7 million tonnes in California and 7.3 million tonnes in Oregon.

Global carbon emissions in the western United States have exceeded 30 million tonnes.

Values ​​much higher than those recorded so far.

These fumes do not stay put.

They are the plaything of the vagaries of the weather, the wind, the atmospheric conditions ... On August 25, for example, they reached New York and Washington DC.

On September 9, a jet stream carried them at very high altitude to the United Kingdom.

On September 15, they blanketed much of the United States, extending west over the Pacific Ocean, where they interacted with Tropical Storm Karina.

The next day, a thick plume was observed in the east, over Iceland.

Their traces can be seen more than 8000 kilometers from their origins ...

The fires, producing intense heat, push the smoke to dizzying altitudes.

On September 7, a particle-laden pyrocumulonimbus cloud formed over a height of 15 kilometers, emerging from the troposphere to penetrate at the base of the stratosphere, at a much higher level than that taken by airliners.

The effects of smoke on the ground, especially on health, are known: irritation of the eyes, respiratory system, worsening of chronic heart or lung diseases ... The air quality of Los Angeles, San Francisco, Portland and Seattle matters currently among the worst in the world.

The effects of smoke at altitude are less well understood, although in some respects they may be similar to those of clouds caused by volcanic eruptions.

Producing a solar darkening, these fumes would have an impact on the temperature on the ground, the photosynthesis of plants and the behavior of animals.

According to scientific consensus, the unprecedented scale of these fires is one of the consequences of climate change, linked to worsening periods of drought and to the warming of the ocean surface.

Phenomena which, by increasing, should further exacerbate forest fires in the future.

Last year alone, Australia, Brazil, Argentina and Siberia had already experienced record fires.