Smoke from Canadian wildfires has crossed the Atlantic Ocean and reached southwestern Europe.
An image from NASA's Terra satellite taken Monday morning shows the plume drifting over northern Portugal and Spain.
Beyond the scope of the image, the agency said it also extended northward over other European countries.
The satellite used its Moderate Resolution Imaging Spectroradiometer to capture the image.
The black carbon particles, also known as soot, traveled more than 2,000 miles.
Black carbon density data shared by NASA comes from its Goddard Earth Observing System forward processing model. The model assimilates data from satellite, aircraft and ground-based observing systems, as well as incorporates meteorological data – like air temperature, moisture and winds – to project the plume’s behavior.
The hazy skies have also been observed by a network of ground sensors called the Aerosols Robotic Network.
The network, known as AERONET, contains more than 500 sun photometer instruments that measure global aerosol optical depth.
The sensors in Spain and France saw depth measurements greater than 0.5. Typically, that measurement in these areas is close to 0.1, with a perfectly clear sky with a measurement of less than 0.05.
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That said, air quality in parts of Europe impacted by the smoke remained mostly fair.
The reason for that is that most of the smoke was higher in the atmosphere and is less likely to impact human health.
Comparatively, 120 million residents in the U.S. were under air quality alerts on Wednesday.
Some of the poorest Air Quality Index readings were in Northeast Ohio, where several communities reported an AQI value above 300, according to FOX Weather.
On Thursday, officials in New York warned that air quality levels could reach poor values – although the FOX Forecast Center said the invasion of smoke would not be as extensive as when the Big Apple set records earlier in the month.
Nearly every province in Canada has fires burning, and the Canadian government says a record 30,000 square miles have burned.
The Associated Press contributed to this report.
