Pyrocumulonimbus clouds: fire-created storm systems

Blog Post created by faithberry Employee on Sep 10, 2015

Did you know that large wildfires can create their own weather patterns?  New data from a recent NASA

Picture of a pyrocumulonimbus storm from the US Naval Research Lab by Mike Fromm
Picture from US Naval Research Lab by Mike Fromm

research project studied clouds formed by large wildfires called pyrocumulonimbus and how they can affect the spread of wildfire as well as their ability to funnel pollutants into the stratosphere. 

According to the University Corporation for Atmospheric Research, “Cumulonimbus clouds are thunderstorm clouds that form if cumulus congestus clouds continue to grow vertically. Their dark bases may be no more than 300 m (1000 ft) above the Earth's surface. Their tops may extend upward to over 12,000 m (39,000 ft). Tremendous amounts of energy are released by the condensation of water vapor within a cumulonimbus. Lightning, thunder, and even violent tornadoes are associated with the cumulonimbus.

Pyrocumulonimbus clouds, according to the NASA website, are "an explosive storm cloud actually created by the smoke and heat from fire, and which can ravage tens of thousands of acres.  And in the process, 'pyroCb' storms funnel their smoke like a chimney into Earth’s stratosphere, with lingering ill effects.”  According to NASA research scientist Dr. Glen K Yue from the Langley Research Center, “An individual PyroCB can inject particles into the lower stratosphere as high as 10 miles.”  Data for this research was collected from a SAGE II instrument on the Earth Radiation Budget satellite that orbited the earth from 1984 to 2005.

Pyrocumulonimbus cloud near Canberra, Australia NASA website credit; New South Wales Rural Fire Service

Dr. Yue co-authored the paper "The Untold Story of Pyrocumulonimbus," in the Bulletin of the American Meteorological Society. The paper documents the devastating effects of pyrocumulonimbus storms, including a major wildfire near Canberra, Australia in 2003, when the cloud’s strong winds caused the fire to spread rapidly into the nearby city. It also documents these effects in the 2002 Hayman Fire in Colorado, where the winds generated by that storm caused the fire to rapidly consume 138,000 acres. 

Research on these fire driven weather patterns may help wildland firefighters make better decisions as they deploy resources to fight these large wildfires in the future.