From Factories to Flurries, Industrial Particles Are Spurring Downstream Snowfall

Let it snow, but there’s a catch.

Imagine the common phenomenon of lake-effect snow, where proximity to a body of water amplifies localized snowfall. Now, replace the lake with an industrial factory. A recent paper published in Science sheds light on how aerosols—tiny particles in the air—released by industrial activities can sometimes trigger downstream snowfall events. 

The study, led by scientists from the University of Tartu in Estonia and supported by Matthew Christensen, an Earth scientist at Pacific Northwest National Laboratory (PNNL), provides some of the first direct evidence for this link. 

Christensen, an expert in remote sensing and cloud microphysics, has been working with lead author Velle Toll since 2016. The pair collaborated on studies examining volcanic emissions, identifying key uncertainties in how aerosols influence the water budget of clouds, which plays a significant role in the radiative impacts driving climate change. Their previous research laid some of the important groundwork for this latest study. 

“Velle and I wrote several papers together on emissions and impacts from a variety of sources, including oil refineries, smelters, coal-fired power plants, cities, wildfires, and ships, using satellite data and modeling,” Christensen explains. “That contributed to my development of a framework to study cloud systems, specifically tracking cloud evolution with satellite imagery over their entire lifecycle.”

This framework was valuable in linking industrial aerosol emissions to snowfall events, with satellite-based remote sensing data playing a key role in their findings. The results revealed that aerosol emissions from industries like metallurgy, mineral processing, and coal- and oil-fired power plants were associated with “glaciation events”—moments when snow occurred because of ice formation around aerosols. 

For his role in the study, Christensen applied models he’d used for tracking wind flow from specific locations. This is what helped the team provide additional evidence that the localized snowfall events were linked to the industrial hot spots analyzed in the study.

This research relates to findings from earlier this year looking at aerosol impacts on clouds. Scientists at PNNL discovered that a reduction in sulfur emissions from the shipping industry has contributed to warming over the Northern Hemisphere. Each study emphasizes the importance of understanding the effects of industrial activity on Earth’s climate, albeit on different scales.

The snowfall accumulations found in this study were relatively modest, accumulating up to 0.5 inches (15 mm). Though the snowfall from industrial aerosols may not pique the interest of winter enthusiasts, this research highlights the importance of an improved understanding of how industrial pollution influences weather patterns and climate systems.

“This work highlights a very localized phenomenon, so its broader implications for regional or global climate change are still unclear,” Christensen notes. “Future work using high-resolution simulations could provide deeper insights into the specific processes driving these glaciation events.”

In fact, PNNL already uses high-resolution simulations to examine the dynamics and microphysics of liquid and ice-phase boundary layer clouds (those closest to Earth’s surface) as part of the Integrated Cloud, Land-Surface, and Aerosol System Study (ICLASS). Advancing process-level understanding and improving their representation in Earth system models remain key priorities of their research.