What atmospheric condition typically creates radiation fog?

Radiation fog typically forms under conditions of nighttime cooling. This phenomenon occurs when the ground loses heat through radiation, which in turn cools the air directly above it. When the air temperature drops to its dew point, moisture in the air condenses into tiny water droplets, resulting in fog. This process is most common in clear nights where the heat can escape, making it conducive for the formation of this type of fog.

Other atmospheric conditions presented in the choices do not directly lead to radiation fog. For instance, warm air moving over cold water can produce advection fog, whereas moist air rising rapidly is more associated with the formation of cumulus clouds or other types of fog under different atmospheric conditions. Strong wind currents typically work against the establishment of the calm conditions necessary for radiation fog, as they can prevent the cooling of air close to the surface. Thus, the correct scenario of nighttime cooling is key to understanding radiation fog formation.