Smoke from the Canadian wildfires is once again drifting into our region, raising new concerns about air quality in Erie. A haze blankets the skies, impacting visibility and prompting public health warnings as air pollution levels rise.

The smoke, carried by strong upper-level winds, contains a mix of pollutants including ground-level ozone and fine particulate matter, known as PM2.5. To better understand the science behind these conditions, Steven Brown, The Program Lead for Tropospheric Chemistry at the National Oceanic and Atmospheric Administration (NOAA) explains wildfire smoke and its effects on the atmosphere.

"There's actually quite a lot of smoke being transported out across the North Atlantic and possibly all the way to Europe," Brown said.

Brown explained how smoke transforms in the atmosphere as it travels. "After the smoke is in the air, it cooks in the sunlight and creates a whole lot of ozone quickly, and then the ozone is transported with that smoke when it comes to a place like Erie, Pennsylvania."

This chemical reaction intensifies pollution levels in areas far from the fires themselves, putting vulnerable populations at risk. "You can see smoke flames really clearly when you see a while further in the distance. What you can see is that PM2.5 between 50 and 100 is what they call moderate. 150 is unhealthy for sensitive groups, and when you get to about 150 it's very serious. And I think I've seen a lot of moderate to unhealthy groups."

According to the Department of Environmental Protection in Northwest Pennsylvania, moderate levels of Particulate Matter 2.5 are expected through Thursday across all areas of the state, with skies continuing to appear quite hazy due to smoke at higher elevations of the atmosphere.