Which type of fog occurs when warm air moves over a cold surface, particularly in coastal areas?

Advection fog forms when warm, moist air moves over a cooler surface, causing the temperature of the air to drop and resulting in condensation. This phenomenon is especially common in coastal regions where warm air from the sea interacts with cooler land or water temperatures. The process involves the horizontal movement of air (advection) and is typically observed when ocean breezes carry warm air over relatively colder waters or land, leading to the formation of fog.

This type of fog is significant in coastal weather patterns because it can limit visibility and impact navigation, making it important for those operating unmanned aircraft systems to understand the conditions that lead to its development.

Radiation fog typically forms overnight as the ground loses heat, cooling the air directly above it, while ice fog occurs in extremely cold conditions where water vapor sublimates directly into ice crystals. Steam fog occurs when cold air moves over warm water, causing water vapor to evaporate and rise in visible steam-like fog. Hence, the other types do not accurately describe the scenario where warm air moves over a cold surface typically seen in coastal areas.