In an unexpected twist that links Canada’s record-breaking wildfires to strange atmospheric phenomena in the Arctic, Japanese researchers have discovered that smoke particles from the 2023 fires traveled thousands of miles to create ice clouds under unusually warm conditions.
The study, published in Atmospheric Research, reveals how organic carbon particles from the Canadian wildfires rode atmospheric rivers – long, narrow regions of intense moisture transport – to reach the Arctic Ocean, where they helped form ice clouds at temperatures far warmer than typically required.
Using a combination of drone technology and specialized sensors deployed from the Japanese research vessel Mirai in September 2023, scientists detected particle concentrations in the lower atmosphere that were a hundred times higher than normal levels over the Arctic Ocean.
“Our drone-based particle counter recorded particle counts two orders of magnitude higher than the voyage average,” explains Dr. Kazutoshi Sato from the National Institute of Polar Research, Japan, who led the study. “Using the CPS sonde, we detected ice clouds in the mid-troposphere under temperatures warmer than −15°C, near a stream of warm and moist air coming from mid-latitudes.”
Traditionally, ice clouds form at temperatures below -38°C. However, the research team observed ice formation at much warmer temperatures, suggesting that wildfire particles were acting as catalysts for ice crystal formation. This discovery has significant implications for understanding Arctic climate dynamics, as ice clouds and water clouds affect the Earth’s energy balance differently.
Professor Jun Inoue, a co-author of the study, emphasizes the significance of atmospheric rivers in this process: “The AR event is a very important event for moisture transport from mid-latitudes to the polar region, and this study also shows that aerosols can be transported by this system as well.”
Using sophisticated tracking methods, the researchers traced the path of these particles back to their source in Canada. The timing coincided with the country’s most severe wildfire season on record, which saw unprecedented levels of organic carbon released into the atmosphere.
The findings suggest a complex feedback loop: as climate change increases the likelihood of severe wildfires, the particles they release may alter cloud formation patterns in the Arctic, potentially affecting regional and global climate systems. The particles can act as ice-nucleating particles (INPs), which enable ice formation at temperatures where it wouldn’t normally occur.
This research comes at a crucial time, as scientists work to understand how human activities and natural disasters influence Arctic climate patterns. The Arctic region is warming at approximately twice the global average rate, making it particularly sensitive to environmental changes.
The study, conducted during an expedition to the Chukchi and Beaufort seas, combined real-time measurements with atmospheric modeling to create a comprehensive picture of how wildfire emissions interact with Arctic cloud systems. The research vessel Mirai served as a floating laboratory, allowing scientists to gather data in previously understudied regions of the Arctic Ocean.
This work, supported by the Japanese Ministry of Education, Culture, Sports, Science and Technology, represents a significant step forward in understanding the long-range impacts of wildfires on global climate systems. The findings will be published in the April 2025 edition of Atmospheric Research.
As wildfires become more frequent and intense due to climate change, understanding their far-reaching effects becomes increasingly crucial for climate modeling and prediction. This research not only illuminates an unexpected connection between wildfires and Arctic cloud formation but also highlights the need for continued monitoring of these complex atmospheric interactions.