SAChE Atmospheric Dispersion Practice Test 2026 - Free Atmospheric Dispersion Practice Questions and Study Guide

Maximum pollutant dispersion is most likely to occur on a windy day. Wind plays a crucial role in mixing the atmosphere and dispersing pollutants. When the winds are strong, they can effectively transport and dilute the pollutants over a larger area, reducing their concentration at any given point. Wind energy enhances vertical and horizontal mixing, which helps in spreading out the pollutants quickly.

In contrast, scenarios like temperature inversions typically lead to stagnant air conditions, trapping pollutants close to the ground and preventing them from dispersing effectively. Similarly, calm nights lack the necessary wind to mix and disperse emissions, leading to localized buildup of pollutants. While heavy rain can wash out pollutants from the atmosphere, its effect on dispersion is limited when compared to the robust mixing action provided by wind. Thus, windy conditions are the most favorable for ensuring pollutants are dispersed widely across the environment.