The radiation fog is formed when the land surface cools after the sunset in the conditions of the clear sky. Thus the cooling ground cools the air above it and as a result of this the conduction causes the air temperature to fall and hence it reaches the dew point and forms a fog.
Because the Earth rotates on its axis, circulating air is deflected toward the right in the Northern Hemisphere and toward the left in the Southern Hemisphere. This deflection is called the Coriolis effect.
