Answer:
When cold air passes over warm surface, it condenses and take a form of fog (smoke like appearance). Fog is classified under various categories. Its called radiation fog.
Step-by-step explanation:
Condensation means transformation of watervapour into liquid. Some forms of condensation are fog, dew, mist etc.
Land surface and water bodies receive insolation at a same time in a same quantity. But during the radiation process land surface cool down much faster than water bodies.
During winter, length of night time is maximum which provides earth surface maximum time to radiate its energy. When it cool down and warm air passes over it, air molecules condenses and creates fog. that is called radiation fog.