In recent summers, wildfire smoke has been inescapable across Wisconsin, drifting south from Canada and leading to long stretches of poor air quality. In recent summers, wildfire smoke has been inescapable across Wisconsin, drifting south from Canada and leading to long stretches of poor air quality. Whether that smoke clears or lingers is often influenced in part by the atmospheric boundary layer — the lowest part of the atmosphere, where airborne particles mix and move. Under these conditions, pollutants, including smoke, can become trapped near the surface, increasing exposure and health risks. During the day, as the ground warms, the boundary layer rises and can reach heights of 2,000 meters, enhancing vertical mixing and the dispersion of pollutants.