On a late July afternoon in 2026, a NASA ER-2 research aircraft lifted off from Great Falls, Montana, climbed to an altitude of 21 kilometers (13 miles), and pointed its nose toward wildfire smoke boiling off the Oregon landscape. The plane carried no passengers, no oxygen masks, no cockpit windows. What it carried was a payload of atmospheric instruments designed to do something that has almost never been done before: fly deliberately and directly into a pyrocumulonimbus fire cloud.
The mission is called INSPYRE: the INjected Smoke and PYRocumulonimbus Experiment, and it represents a fundamental shift in how atmospheric science approaches these monstrous, fire-breathing thunderstorms. After decades of treating pyroCb encounters as accidents of timing and geography, researchers are finally going hunting.
One Data Point
The problem with pyrocumulonimbus is not that scientists do not know they matter. It is that they have essentially no direct data on how they work. In the entire history of atmospheric science, a single sample of fresh smoke has been collected from the stratosphere above an active pyroCb. One. Every other measurement has come from opportunistic sniff tests: aircraft that happened to be nearby while flying for entirely different purposes, catching the exhaust of a firestorm by coincidence rather than design.
This scarcity is remarkable because pyroCbs are some of the most energetic phenomena on the planet. When a wildfire grows intense enough, it creates its own weather system. The heat generates a towering thundercloud that can punch through the tropopause: the boundary between the lower and upper atmosphere, and inject smoke, ash, and trace gases directly into the stratosphere at altitudes of 10 to 50 kilometers (6 to 31 miles). Once there, the material does not rain out. It spreads across the globe, lingering for months to years, eroding the ozone layer, dimming sunlight, and altering atmospheric chemistry at planetary scale.
A 2023 study in Science Advances led by Feiqin Li and colleagues demonstrated that pyroCb smoke plumes modify the upper atmosphere’s radiation budget in ways climate models do not capture. The 2019-2020 Australian bushfire season produced pyroCb events that injected as much smoke into the stratosphere as a moderate volcanic eruption, with effects on stratospheric temperatures and circulation that persisted for more than a year. Research by Abatzoglou and Williams in PNAS showed that anthropogenic climate change lengthens fire seasons and increases extreme fire weather across the western United States, creating more conditions under which pyroCbs can form.
Yet for all their power, pyroCbs remain absent from operational weather and climate forecast models. This is not an oversight. It is a data problem. Without measurements of what goes into a pyroCb, how it organizes, and what controls whether it penetrates the stratosphere, modelers have nothing to parameterize.
The Forecast Gap
David Peterson, the Naval Research Laboratory meteorologist who leads INSPYRE, has identified what might be called a blind spot at the intersection of fire science and atmospheric science. Operational weather models do not account for smoke injection from pyroCbs at all. When smoke from a major firestorm enters the upper atmosphere, those models lose their ability to predict temperature, wind, and precipitation patterns in the affected region. The Navy has a direct interest in closing this gap because smoke plumes at flight altitudes create hazards for military aviation and degrade the performance of satellite-based navigation and communication systems.
The core questions INSPYRE is designed to answer are deceptively simple. Which fires produce pyroCbs, and why? Two wildfires burning in the same landscape under apparently similar conditions may behave completely differently: one stays on the ground, the other builds its own thunderhead. What is the tipping point? Second, what determines whether a given pyroCb injects smoke into the stratosphere? Many fire clouds billow upward but collapse before they breach the tropopause. The ones that make it are rare, and the difference between failure and stratospheric injection may come down to specific details of cloud microphysics that no one has measured in real time. Third, once that smoke is in the stratosphere, how does it modify the composition and radiation budget of the upper atmosphere? The Li et al. results suggest the effects are large and poorly constrained, but without direct in-plume measurements the magnitude of the impact remains uncertain.
Two Planes, One Storm
To answer these questions, INSPYRE deploys two complementary aircraft. The ER-2, a civilian derivative of the U-2 spy plane, operates at the very edge of the stratosphere. Flying above 21 kilometers (13 miles), it can overfly a developing pyroCb from above, sampling the outflow plume as it spreads into the stratosphere. Below, the NSF/NCAR Gulfstream V cuts directly through the cloud at lower altitudes, measuring aerosol composition, gas concentrations, and cloud properties inside the firestorm itself.
The two-tier approach is deliberate. The ER-2 sees what enters the stratosphere; the Gulfstream V sees what is happening inside the storm. Together, they give researchers the vertical profile of a pyroCb from its base to its anvil, something that has never been achieved.
On the ground, a team led by the University of Nevada, Reno operates mobile radar and lidar systems deployed near active fires. These instruments track plume evolution from below, measuring updraft velocity, cloud top height, and aerosol backscatter: data that anchors the airborne measurements to surface conditions. More than 150 researchers from NASA, the Naval Research Laboratory, the National Center for Atmospheric Research, and universities around the country are participating in the campaign.
The 2026 field phase runs through September 10, based out of Colorado with forward operating locations in Montana. An additional round of fieldwork is planned for 2027, allowing the team to sample fires across multiple seasons and geographic regions. The first flight, on July 29, targeted fires burning in Oregon, where conditions were favorable for pyroCb development.
Storms That Feed Themselves
Part of what makes pyroCbs scientifically fascinating is that they are not passive products of a wildfire. They become active participants. A mature pyroCb generates its own lightning, which can ignite new fires miles ahead of the main flame front. It produces powerful updrafts that pull in more oxygen and accelerate the burn below. It can spawn fire whirls: tornado-like vortices of flame and ash that move erratically and defy prediction. The fire and the storm become a single coupled system, each feeding the other in ways that current models cannot simulate.
This feedback loop has implications that extend far beyond the immediate fire zone. The Australian fires of 2019-2020 produced a pyroCb that sent a plume of smoke into the stratosphere that circled the globe and persisted for more than a year. Satellite measurements showed that the plume depleted ozone in the midlatitude stratosphere by several percent, comparable to the effect of a small volcanic eruption. If pyroCbs are becoming more frequent: and many scientists suspect they are, as warming climates dry out landscapes and extend fire seasons, then their cumulative effect on stratospheric chemistry could rival or exceed that of all but the largest volcanic events.
A Deliberate Science
The shift from opportunistic sampling to deliberate campaign science is the story of INSPYRE. The mission was conceived not because someone stumbled on a pyroCb with the right instrument package at the right time, but because researchers identified the data gap and built a program specifically to fill it. The aircraft were selected not for their availability but for their suitability. The instrument payloads were designed from scratch to handle the extreme conditions inside a fire cloud: heat, vibration, ash loading, and electrical activity that would damage or destroy most off-the-shelf atmospheric sensors.
The 2026 campaign is the opening chapter. The results will not come quickly. Data from the ER-2 and Gulfstream V flights will take months to calibrate and analyze. But the goal is clear: replace that single data point with a statistically meaningful sample set, and give modelers the information they need to finally put pyroCbs into the forecast.
For the Navy, for the aviation industry, for climate scientists trying to understand how the stratosphere is changing, and for anyone living in a landscape where fire seasons are getting longer and more extreme, the work cannot come soon enough. The smoke from the next big firestorm is already going to rise. INSPYRE is designed to make sure that this time, science will be there to meet it.