How wildfires in Alberta lead to poor air quality in the Midwest

Residents of the central United States experienced poor air quality and smoke over the weekend. The potentially dangerous air has a far-off source: the wildfires raging in Canada.

The fires have ravaged western Canada, with more than 10,500 people evacuated from communities across Alberta.

The effects of the fires extend far beyond Canada, with poor air quality emerging in states as far away as Missouri and New York. Here's what you need to know about how the smoke may continue to affect parts of the US.

While all fires produce smoke, the bigger the fire, the more smoke it can produce. As this spring's Canadian wildfires burn bigger and hotter, the heat from the fire causes the smoke to travel farther up in the atmosphere, where it gets picked up by winds and weather patterns.

The higher in the atmosphere the smoke rises, the farther the smoke can spread. The winds in the upper levels of the atmosphere can spread smoke hundreds or even thousands of miles away, which can lead to hazy skies and poor air quality in cities far away from where the fires are occurring.

Wildfire smoke was measured to rise as high as 1 to 2 miles above the surface during the 2018 Camp Fire in California, according to NASA. As the smoke moves away from its heat source, the air will eventually cool and the smoke can sink, keeping it in the troposphere, the layer of the atmosphere closest to the surface of the Earth.

The troposphere is where the daily weather we typically experience occurs. High and low pressure systems can cause all sorts of weather from strong winds, to thunderstorms, hail and snow. The troposphere can extend 4 to 12 miles above the Earth's surface, according to the National Weather Service.