File:Fire Cloud over Northern Russia.jpg

English: This is a true-colour view of far northern Russia on August 1, 2010. This image provides rare evidence that fire clouds can pull smoke into the stratosphere. The circular cloud surrounded by hazy, gray-white smoke is a pyrocumulonimbus, a powerful thunderstorm that forms over large fires. Weather models and other satellite data reveal that it formed over fires in western Russia on July 30, then drifted northward.

Fires heat the air, pushing it high into the atmosphere where it can cool and form clouds with ice crystals. The crystals conduct electricity, forming a strong, dangerous thunderstorm. Pyrocumulonimbus clouds can produce strong winds and tornadoes that can further fuel the fire’s growth.

In the past decade, it has become clear that pyrocumulonimbus clouds also act like chimneys, pulling smoke into the stratosphere. Once in the stratosphere and above the weather, smoky aerosols can linger for a long time and spread around the globe. These aerosols can warm the stratosphere and cool the air below by absorbing energy from the Sun.

However, this image shows one of the few pyrocumulonimbus clouds that have ever been documented, so it isn’t clear how often fires put aerosols in the stratosphere and how large an impact they have on weather and climate.