OTTAWA (dpa-AFX) - Wild land fire activity in Canada ramped up in July, a time of year when lightning ignitions typically increase, according to a seasonal outlook published by several North American fire agencies. The blazes sent smoke plumes pouring across the U.S. and Canada, affecting air quality in both countries, the report says.
Brown carbon, emitted by wild land fires and tracked over the span of a week earlier this month, worsened air quality in parts of North America.
Data from a version of NASA's Goddard Earth Observing System model tracked brown carbon, the organic aerosols emitted by fires that give smoke plumes their characteristic yellow, orange, and brown tint. Brown carbon is a major component of a fire's PM2.5 emissions, a type of air pollution that can aggravate cardiovascular and respiratory conditions. The report says the plume drifted across North American skies from July 14 through July 20.
GEOS assimilated inputs from satellites, aircraft, and ground-based observing systems. In addition to satellite observations of aerosols and fires, the model also incorporates meteorological data such as air temperature, moisture, and winds to project the plume's behavior.
On July 14, at the start of the animation, numerous fires had already cropped up, including more than 180 in Ontario and several in northern Minnesota. Winds carried the smoke southeast, and by July 15, skies turned hazy and air quality declined from southern Ontario in Canada to the Upper Midwest and Northeast in the U.S. On July 16 and 17 air quality in many areas continued to plummet, including in Detroit, where it stayed in the hazardous range for several consecutive days. Toronto, Chicago, New York City, and Washington, D.C., saw air quality ranging from unhealthy to hazardous.
On July 19 and 20, smoke continued to affect air quality downwind, including in the Great Lakes region, according to the National Weather Service. Storms began clearing it away in parts of the East, where air quality improved to good or moderate. Meanwhile, fires in the Pacific Northwest began degrading air quality there.
North American Seasonal Fire Assessment and Outlook was issued for North America for July, August and September. Predictive Services and CPC outlooks indicate that warm and dry conditions are likely to continue in the northwestern U.S., with above normal temperatures likely along much of the East Coast. Drier than normal conditions are also expected in the Upper Midwest.
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