A cloud of fire over Washington.
NASA Earth Observatory
- If it stays too hot for a long time, a forest fire can occur, which in turn can lead to so-called fire clouds.
- Satellite images show how a cloud of fire formed in the Canadian city of Lyot after a temperature of 50 °C and a forest fire.
- Fire clouds are so destructive because instead of rain they usually cause thunderstorms or lightning, which further fuels the fire.
This is a vicious circle: if it is too hot in an area for some time, a forest fire can occur, which in turn gives rise to so-called fire clouds (pyrocumulonimbus) to be able to lead. It is a type of cloud that results from fire storms and brings with them massive storms, thunderstorms and in rare cases tornadoes.
This is what happened in the Canadian city of Lyot, south of Vancouver. A record temperature of 50 degrees has been recorded here in the last few days. On Wednesday, the Forest Fire Service reported two fires in the province. Then on Thursday another devastating forest fire broke out – destroying 90 percent of the village. A satellite image tweeted by meteorologist Dakota Smith, an employee of the Cooperative Institute for Atmospheric Research in Colorado, shows how clouds of fire formed over Lyott on Wednesday evening, just before a major wildfire.
When you look at clouds above the smoke of a wildfire, you usually think of clouds as thunder. Instead, it is pyrocumulonimbus. By the way, fire is another name for clouds.cumulonimbus flagenitus“, which means something like “produced by flames”.
Thus come the clouds of fire
Thunderstorms usually occur when lots of warm, moist air rises from the ground to the sky. If it enters the lowest part of the atmosphere, the air cools and sinks back toward Earth. There it heats up again and rises again. Experts call this cycle convection – it causes thunderstorms to form clouds.
However, if warm air rises not from the ground, but over a smoky fire, then instead of thunder, the fire clouds described above are generated. They appear anvil shaped and can produce rain like other clouds. Often, however, they do not produce the drops needed immediately, but rather powerful bursts of air, known as “downbursts”.
These push dry air back to the ground, which means the embers and smoke of the fire are carried over long distances. First of all, the flames that provoke the storm are also vented. Pyrocumulonimbus storms can also generate powerful lightning bolts that start new fires. The largest cloud of its kind was observed over California in September 2020 – an area that would have fit three times over the city of Seattle.
An image of a pyrocumulonimbus cloud over wildfires in California in 2020.
Thalia Dockery
In the worst case, the convection wind in the pyrocumulonimbus cloud bank forms a swirling, circular column and the storm turns into a “whirlwind of fire.” This happened in 2003 near Canberra, Australia, when a fire broke out around the city for two weeks.
It may also happen that not only one firearm is formed, but several at the same time. For example, in the spring of 2009, huge bushfires engulfed an area of about 4,500 square kilometers in southeast Australia. Three separate pyrocumulonimbus storms have occurred – some of which have reached heights of about 14,500 m.
Hurricanes sometimes attack the stratosphere
As temperatures rise and the air becomes drier, forest fires are becoming more common. As these increase in frequency and severity, so do more firearms. A total of 17 such hurricanes occurred in Canada, the United States and Mexico in 2002, with 25 in western North America alone two decades later, environmental magazine Yale360 reports.
These storms can also be so high that they enter the stratosphere and the smoke coming out of the ground reaches there. It can be stored there for months or even years. A 2018 study showed that a large pyrocumulonimbus cloud can send as many smoke particles into the stratosphere as a medium-sized volcanic eruption.
This text has been translated from English. you can find the original Here.
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