What is an Advection Fog?

There are  different types of fog such as radiation fog, advection fog, valley fog, and freezing fog.  fog that is formed during the moving of air horizontally over a cool surface and is thus cooled below the Dew Point is called Advection Fog. It can occur over land or sea. In Britain, it is due to warm moist air, e.g., in a Warm Sector, moving over the land after a cold spell.