Thunderstorms are weather disturbances characterized by concentrations of thunder, lightning and fierce winds.
When they accumulate in clusters, these storms are often accompanied by violent cloud bursts and flooding, which can devastate the areas affected.
Denmark is no stranger to this phenomenon. In 2011, large parts of Copenhagen were submerged by deluges that lead to roughly 6 billion kroner in damages reported to insurance companies.
In a new study, researchers from the University of Copenhagen shed light on one particular mechanism that has the potential to spawn powerful thunderstorms and cloud bursts:
“We conclude that the atmosphere’s ability to generate large thunderstorms is influenced, among other things, by the difference between the temperature of the earth’s surface during the night versus during the day. If the difference is great, we see more thunderstorms, and subsequently, more cloud bursts,” explains Jan Olaf Härter, an associate professor at the University of Copenhagen’s
Weather and wildfires share a close relationship. Certain weather conditions are known to ignite wildfires: High temperatures and low humidity dry out the landscape, lightning strikes can spark a flame, and fast-moving winds spread flames across nearby desiccated land.
But wildfires also spawn their own weather systems, including pyrocumulonimbus clouds—which NASA has called the “fire-breathing dragon of clouds” for the thunderbolts they hurl at Earth, fueling further blazes and sometimes even fire tornadoes.
Fire weather has contributed to the scale of several historic conflagrations, including the 2009 Black Saturday bushfires that burned more than a million acres across Australia, and the wildfires across the West Coast of the United States in 2020. Here’s what causes firestorms—and why they’re becoming more common in a warming world.
How firestorms get started
Firestorms form through a convective process, in which heat rises through the air. When a column of moist air over a