What type of fog is produced over land when radiation cooling reduces temperature to or below the dew point?

When radiation cooling takes place during the night or early morning, the surface air temperature can drop to or below the dew point. This cooling often occurs in clear skies with calm winds when the ground loses heat through radiation. As the air cools, moisture condenses into tiny water droplets, forming fog. This phenomenon is specifically referred to as radiation fog.

Radiation fog typically develops in low-lying areas such as valleys, where cold air can settle. It is most commonly observed during late fall and early spring when there is enough moisture in the air and temperatures are prone to dropping at night. This condition is relatively localized and tied directly to the cooling of the land surface.

Understanding the formation processes of different types of fog, including radiation fog, is essential for navigation and safety at sea, particularly for mariners who may encounter reduced visibility conditions.