A scientific campaign is set to closely observe the immense storm clouds generated by certain wildfires. Named INSPYRE, it mobilizes several aircraft, ground instruments, and satellites. Its goal is to understand how these phenomena propel smoke and particles into the upper layers of the atmosphere.
These formations are called pyrocumulonimbus, or pyroCb, or fire storms. They appear when the heat of a fire creates an updraft powerful enough to form a storm. The cloud can then produce lightning, alter local winds, and transport smoke well above the altitudes normally reached by a wildfire.
Illustration NASA
The 2026 campaign takes place from July 27 to September 11 in western North America. It notably involves a NASA ER-2 aircraft flying at high altitude and a Gulfstream V operated by the NSF and NCAR. Ground teams will complement the measurements with radars and lidars.
The two aircraft will not have exactly the same role. The ER-2 will observe the clouds from a distance with remote sensing instruments. The Gulfstream V will directly sample the air in the plumes when conditions permit. This combination aims to link the cloud's structure to its chemical composition.
The researchers want to determine which wildfires produce these storms and why some inject smoke into the stratosphere. This atmospheric layer begins above the zone where most weather develops. Particles that reach it can therefore remain suspended and travel long distances.
Pyrocumulonimbus also represent an immediate risk. Their lightning can ignite new fires, and their turbulence complicates the work of firefighting aircraft. High plumes can also disrupt air routes and degrade air quality far from the area affected by the flames.
INSPYRE will also study the effect of smoke on Earth's radiative budget. Some particles absorb or reflect part of the solar energy. Their influence depends on their altitude, size, and composition. The data should help better integrate these events into atmospheric and climate models.
A second campaign is planned for 2027 to expand the sample and study wildfires with different characteristics.