NASA Researchers Chase 'Pyrocumulonimbus' Storm Clouds Over Utah

• NASA's INSPYRE mission team is conducting aerial atmospheric research to study pyrocumulonimbus (pyroCb) clouds, which are extreme weather systems triggered by wildfires.
• PyroCb events from the Widemouth 2 fire in Utah demonstrated how intense heat can inject smoke and aerosols into the stratosphere, potentially impacting the ozone layer and Earth's energy budget.
• Scientists estimate that wildfires contribute up to 25% of the black carbon and organic aerosols found in the lower stratosphere.

Characteristics of Pyrocumulonimbus Clouds

• These are towering, smoke-infused storm clouds capable of producing lightning, hail, and heavy rain.
• They are identified by cloud-top brightness temperatures falling below -40°C, signaling that they have penetrated the upper troposphere or the stratosphere.
• Once particles reach the stratosphere, they can linger for months or years, circling the globe and affecting global climate.

The INSPYRE Mission

• The team uses NASA's ER-2 aircraft, the NSF/NCAR GV, and ground-based sensors to sample smoke plumes shortly after they form.
• On August 3, 2026, the GV aircraft sampled smoke at approximately 12 kilometers (8 miles) altitude, collecting data that is rarely incorporated into standard forecast models.
• A primary goal of the mission is to reduce uncertainty for fire forecasters who must manage the complex behavior of these fire-induced storms.

Unanswered Questions

• Approximately 70 pyroCb events are detected annually globally, with at least 13 identified in the continental United States so far in 2026.
• Researchers still lack answers regarding which vegetation types are most conducive to pyroCb formation, why lightning production varies between fires, and how to improve the accuracy of event forecasting.