Why can wind speed help disperse fog?

Correct answer: It mixes saturated lower air and reduces droplet concentration

Correct answer: A. Fog depends on a layer of moist, nearly saturated air containing many tiny droplets near the ground. Wind can cause turbulence and mix this shallow layer with air above or nearby that is less saturated. The moisture and droplets are then spread out, and the droplet concentration may fall enough for the fog to become thinner or disappear. Wind does not remove all water vapour instantly, and its effect depends on the temperature, humidity, and strength of mixing. Option A is correct because it describes dilution and mixing of the foggy air. Option B is impossible; wind cannot switch off the Sun. Option C is not a real atmospheric process. Option D is wrong because wind does not always cool a surface below freezing; it may even mix warmer air downward. The key is not simply “wind equals cold,” but “mixing can break up the shallow saturated layer.” Memory cue: “Mixing thins the fog.”