Definition - What does Ice Fog mean?
Ice Fog is a form of fog which consists of fog crystals dangling in the air. It is present only in the cold areas as the water droplets that dangle in the air can remain in liquid form till -40 degree Celsius. It is required to be distinguished from diamond dust which is the precipitation of the inadequate ice crystals that fall from the clear sky. It must also be distinguished from the freezing fog, commonly known as pogonip.
Petropedia explains Ice Fog
Ice Fog is very common in the northern and interior Alaska as temperatures in the area frequently drop below -40 degrees in winter months. It is formed only under specific conditions – humidity is required to be near 100 percent as the air temperature drops below 0 degrees Celsius which allows ice crystals to be formed in the air. Ice crystals then settle down onto the surface. Ice fog was also called white death by the early settlers as it was believed that the ice crystals get inside their lungs and cause death.