SAChE Atmospheric Dispersion Practice Test 2025 – Complete Exam Prep

Stability class G indicates neutral atmospheric stability, which occurs in conditions that are neither stable nor unstable. This class typically encompasses scenarios where the mixing of the air is effective but does not favor dispersion or concentration of emissions.

Class F, in contrast, describes a very stable atmospheric condition, generally associated with temperature inversions, where air near the surface is cooler than the air above. This stability can trap pollutants near the ground, inhibiting their dispersion.

The distinction is thus clear: stability class G represents conditions that allow for better mixing of pollutants than class F, which is characterized by significant suppression of vertical movement. Therefore, class G is not more stable than class F; rather, it represents a state that is less stable in terms of pollutant dispersion potential.