Steam fog typically forms when which type of air interacts with warm water?

Steam fog occurs when cold air interacts with warmer water, leading to a specific phenomenon where the warmer water vapor creates fog. Essentially, when the cold, dry air moves over the warmer water, the heat from the water causes the air immediately above it to warm. This air then can hold more moisture, and as moisture levels increase, the water vapor begins to condense into tiny droplets, which form fog.

In this case, the interaction of cold air serves to cool the moisture in the air directly above the warm water, facilitating condensation and resulting in the visible steam fog. Thus, the correct choice directly reflects the essential conditions under which steam fog develops.