Over the past week, western Canada and the United States have been experiencing a wave of heat waves, causing record high temperatures (49.6C Tuesday Litton, BC) and multiple wildfires – especially over 7,000 hectares already under “lava” fire between Oregon and California.

They are formed from air that causes fire or volcanic eruptions

These fires appear as “fire-breathing” clouds or pyrocumulonimbus (also known as cumulonimbus flammagenitus), which is observed by various meteorologists. But what exactly is this?

As a reminder, the cumulonimbus, the “classic” cloud we know, is formed when hot air filled with water vapor rises into the atmosphere and cools to altitude. Pyrocomulus clouds appear under a similar phenomenon, but from air emitted from an intense heat source such as a fire or volcanic eruption. Initially, these clouds were not dangerous.

“If the fire is particularly large or intense or if the atmosphere above is unstable” a pyrocamulus can be a pyrocomulonimbus. As described I Rachel Badlan, researcher on atmospheric dynamics at the University of New South Wales (Australia).

The original “Hurricanes of Fire”

The peculiarity of these pyrocomulonimbus is that they produce their own climate, and not only rain (which is very good). “The impact of ice particles located on the very cold upper reaches of these clouds causes electric charges to accumulate, releasing giant lightning bolts. Quoted by Science and the future.

Pyrocomulonimbus thunderstorms and therefore lightning on the ground that causes a fire to start, and / or the violent winds of a dry wind that spreads over twenty kilometers, adoring the flames of an existing fire … they thus create real “hurricanes of fire”. The mixture of smoke and ice created by these clouds gives them their color, which is whiter than the smoke from the fire.

This is not going to improve with global warming

This “fire breathing” cloud phenomenon is impossible to control, and the fire itself is difficult to predict. However, scientists believe that global warming, especially high temperatures and dry winds, favored the formation of this pyrocomulonimbus.

In addition, it can have adverse effects on the weather, especially by scattering pollutants over tens of thousands of kilometers. “Pyrocomulonimbus clouds are like large chimneys that carry large amounts of smoke into the lower stratosphere,” he explains. On the NASA website David Peterson, FIREX-AQ (The Impact of Fire on the Regional to Global Environment Experiment – Air Quality)