In mid-July 2026, extensive wildfires across Canada sent smoke plumes drifting through parts of the United States and Canada, causing significant air quality declines over the course of a week. NASA scientists used advanced modeling to trace the movement of brown carbon, a key pollutant from wildfire smoke, revealing its widespread impact on the atmosphere and public health.
- Brown carbon worsened air quality across U.S. and Canada.
- Smoke plumes tracked using NASA's GEOS model and satellite data.
- Cities like Detroit and Toronto experienced hazardous air quality levels.
What happened
In July 2026, increased wildfire activity in Canada produced massive smoke plumes that traveled across North America. Lightning-triggered fires rapidly expanded, especially in Ontario and northern Minnesota, releasing large amounts of brown carbon into the atmosphere. This organic aerosol gives wildfire smoke its distinctive yellow-brown coloration and is a significant component of fine particulate matter (PM2.5), known to harm respiratory and cardiovascular health.
NASA's Goddard Earth Observing System (GEOS) model, which incorporates satellite data and meteorological conditions, traced these smoke plumes from July 14 to 20. The smoke traveled over southern Ontario, the Upper Midwest, and Northeast U.S., worsening air quality for over a week and pushing pollution levels into unhealthy and hazardous categories in major cities such as Detroit, Toronto, Chicago, and New York.
Why it feels good
Tracking wildfire smoke accurately is a key advancement in understanding and responding to air quality events. NASA’s use of enhanced GEOS modeling that distinguishes brown carbon from other pollution sources enables clearer detection of wildfire impacts. This helps governments and communities prepare for smoke episodes and protect public health more effectively.
Moreover, the distinction between brown carbon from wildfires and black carbon from both fires and human activities improves scientific knowledge around air pollution sources. Such insights empower more targeted strategies to manage environmental and health risks associated with wildfire seasons, a growing concern with climate change.
What to enjoy or watch next
As wildfire seasons continue to intensify, following NASA Earth Observatory’s updates and animations offers remarkable views into how smoke travels and evolves in our atmosphere. These real-time visualizations deepen public awareness of wildfire effects beyond the immediate fire zone and encourage proactive air quality measures.
Looking forward, efforts in fire-prone regions include prescribed burns and improved monitoring to reduce the severity and unpredictability of wildfires. Staying informed about air quality forecasts and NASA's ongoing research can help communities across North America enjoy clearer skies and healthier days despite the natural challenges.