1. Early Season 2023 Wildfires Generated Record‐Breaking Surface Ozone Anomalies Across the U.S. Upper Midwest.
- Author
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Cooper, Owen R., Chang, Kai‐Lan, Bates, Kelvin, Brown, Steven S., Chace, Wyndom S., Coggon, Matthew M., Gorchov Negron, Alan M., Middlebrook, Ann M., Peischl, Jeff, Piasecki, Alison, Schafer, Nell, Stockwell, Chelsea E., Wang, Siyuan, Warneke, Carsten, Zuraski, Kristen, Miyazaki, Kazuyuki, Payne, Vivienne H., Pennington, Elyse A., Worden, John R., and Bowman, Kevin W.
- Subjects
SMOKE plumes ,SURFACE of the earth ,AIR pollution ,PARTICULATE matter ,GREENHOUSE gases ,TRACE gases - Abstract
During summer 2023 Canada experienced its most intense wildfire season on record. Smoke plumes from these fires advected across the United States (U.S.) Upper Midwest, producing regional scale surface enhancements of PM2.5 and ozone, as recorded by the U.S. surface monitoring network. These events are notable because they occurred early in the fire season (May 15‐June 30), and they produced the highest regional‐scale surface ozone levels ever recorded across the northern tier of the U.S. during early (May–June) or late (July‐August) summer. Specifically, the Upper Midwest 50th ozone percentile was greater than in any other year since 1995, when the ozone monitoring network had sufficient coverage to assess regional‐scale ozone levels; the 90th percentile was the highest since 2002. Satellite and aircraft measurements demonstrate the availability of ozone precursors and ozone production within the smoke plumes. Plain Language Summary: Ozone is a trace gas in the atmosphere that acts as an important greenhouse gas, and high concentrations near Earth's surface are a form of air pollution, detrimental to human health and vegetation productivity. Ozone is formed by sunlight reacting with precursor gases, such as those emitted by fossil fuel combustion. Wildfires are also an important source of ozone precursor gases. During summer 2023 Canada experienced its most intense wildfire season on record. Smoke from these fires impacted the U.S. Upper Midwest during May–June 2023, leading to regional scale surface enhancements of fine particulate matter and ozone. These unusual early season fires produced the highest regional‐scale surface ozone levels ever recorded across the northern U.S. Mid‐latitude wildfires have increased as the planet warms, and their frequency is expected to increase further with continued climate change. This analysis suggests that extreme ozone pollution episodes associated with wildfires could also increase in the future. Key Points: During summer 2023 Canada experienced its most intense wildfire season on recordSmoke from these fires impacted the United States (U.S.) Upper Midwest during May–June, leading to regional scale surface enhancements of PM2.5 and ozoneThese unusual early season fires produced the highest regional‐scale surface ozone levels ever recorded across the northern United States [ABSTRACT FROM AUTHOR]
- Published
- 2024
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