The skies have been white with smoke for significant periods of time on two separate occasions this summer. During much of June, the source of the smoke was large forest fires across central and northern Saskatchewan. More recently, the smoke has come from the Pacific Northwest.
Many questions have come into the weather office about what path this smoke has taken to reach our area. Initially, smoke rises because, caused by actual fire, smoky air is warmer than its surroundings. At some point in the atmosphere, the smoky air cools to the point at which it is the same temperature as the surrounding air, often between 6,000 and 18,000 feet above sea level. Wind at these altitudes is usually different from surface winds, which is why the smoke may persist even though the wind outside has often been blowing from the south in recent days.
Another question has been about what eventually happens to the smoke. Because it remains in the lower to middle levels of the atmosphere, it eventually is cleared out by rain. Eventually, every single particulate will be struck and carried to the ground by precipitation. Thus, the carbon will become part of the soil.
Meteorologist John Wheeler