Remember meForgot password?
    Log in with Twitter

article imageBiggest fire-fueled thunderstorm event on record occurred in B.C.

By Karen Graham     Apr 25, 2018 in Science
Vienna - Large wildfires can fuel "dirty" thunderstorms that fill the stratosphere with as much smoke as a volcanic eruption. We know this because of a study on the biggest fire-fueled thunderstorm event on record that occurred in British Columbia last year.
The year 2017 set a record for the number of wildfires around the globe, and their full impact on the atmosphere remains uncertain. We do know that wildfires can sometimes fuel "dirty" thunderstorms, known as pyrocumulonimbus or pyroCb, for short.
However, thanks to research by climate scientists at the U.S. Naval Research Laboratory (NRL), the world is gaining more insight into what drives these massive and escalating events.
NRL meteorologist Dr. David Peterson explained his findings from his recent research, “Wildfire-Driven Thunderstorms Cause a Volcano-Like Stratospheric Injection of Smoke,” at the annual meeting of the European Geosciences Union in Vienna, Austria, which was held from April 8 to 13.
A pyrocumulonimbus cloud towers over thick smoke from fires burning near Canberra  Australia  in 200...
A pyrocumulonimbus cloud towers over thick smoke from fires burning near Canberra, Australia, in 2003. The cloud's strong winds caused the fires to explode into the Australian city.
NASA/New South Wales Rural Fire Service
Dr. Peterson explained that like regular thunderstorms, pyroCbs are very tall and produce lightning, but pyroCbs are also filled with smoke. "You end up with this very dirty thunderstorm. Essentially, this is a giant chimney taking smoke from the surface to high altitudes, at least to aircraft-cruising altitudes."
The impact of volcanic eruptions on the climate system has been recognized for several decades, but pyroCb research is relatively new, originating at NRL in the early 2000s, according to Peterson. While such major volcanic events are sporadic, Peterson said, pyroCb events occur every year, however, scientists have not studied these storms enough to understand their full impact on our climate.
On August 2  2017  the Visible Infrared Imaging Radiometer Suite (VIIRS) on the Suomi NPP satellite ...
On August 2, 2017, the Visible Infrared Imaging Radiometer Suite (VIIRS) on the Suomi NPP satellite captured this image of smoke from wildfires in the western United States and Canada. Actively burning areas, detected by VIIRS thermal bands, are outlined in red.
NASA Earth Observatory
The largest fire-fueled thunderstorm event on record
On August 22, 2017, Digital Journal reported that the wildfire season in British Columbia broke the one million hectares (2.5 million acres) mark on Monday, August 21, with firefighters battling a wildfire of historical size after 19 separate fires merged, creating one massive blaze.
But what makes B.C.'s 2017 fire season so interesting and the center of the NRL study was an event that occurred on the night of August 12, 2017. A combination of the intense heat from the fires burning in a remote region of the province, combined with the right atmospheric conditions, generated a series of four thunderstorms in a 5-hour period.
The intensity of the stratospheric injection from the pyroCb event "produced a high-altitude smoke layer that encircled the Northern Hemisphere over several months,” Peterson said. “This event provides the best opportunity to date for highlighting pyroCb activity as an important consideration in the climate system.”
A pyrocumulonimbus storm combines smoke and fire with the features of a violent thunderstorm. Pollut...
A pyrocumulonimbus storm combines smoke and fire with the features of a violent thunderstorm. Pollutants from these storms are funneled into the stratosphere.
NASA/Naval Research Lab/Mike Fromm
Using satellite data, Peterson's team observed the signal from this smoke in the lower stratosphere — the second layer of Earth's atmosphere, above the troposphere. "This was the mother of all pyroCbs," Peterson said. "Normally, when you see something like this, you think volcanic eruptions — that's what normally puts a lot of material into the stratosphere — but it's all coming from these wildfire-driven thunderstorms."
As a comparison, the 2008 eruption of Mount Kasatochi, an island volcano in Alaska, sent about 0.7 to 0.9 teragrams (nearly 1.0 million tons) of aerosols — tiny, suspended particles — into the stratosphere, Peterson said. Because of the sulfates and ash the volcano injected into the atmosphere, for months afterward, people around the Northern Hemisphere documented unusually colored sunsets
The British Columbia pyroCb event sent about 0.1 to 0.3 teragrams (about 200,000 tons) of aerosols into the stratosphere, comparable to a moderate volcanic eruption event - but this one event injected more aerosols into the atmosphere than all the fires during the entire 2013 fire season in North America, Peterson said.
More about firefueled thunderstorms, pyrocumulonimbus storms, pryoCb, Volcanic eruption, britisk columbia 2017
Latest News
Top News