Definition

Noun: - A type of fog, occurring in very cold conditions, that consists of numerous tiny ice crystals suspended in the air. It is a dense, frozen fog that reduces visibility and typically forms when the air temperature is well below freezing.

Usage

• Ice fog is a meteorological phenomenon distinct from regular water-droplet fog.
• It is commonly associated with Arctic or Antarctic climates and severe winter conditions in temperate regions.
• The term is used to describe the specific condition where the fog particles are frozen.

Examples

• The pilot delayed the flight due to the thick ice fog covering the runway.
• In the Alaskan interior, ice fog often forms when the temperature drops below -30°C.
• Driving through the ice fog was hazardous because the ice crystals coated the windshield.

Advanced Usage

• "Ice fog" is sometimes referred to as "freezing fog" when it leads to rime ice deposition on surfaces, though "freezing fog" can also refer to supercooled water droplet fog that freezes on contact.
• In scientific contexts, it is categorized as a type of "pogonip" (a term of Shoshone origin used in the western United States).

Variants and Related Words

• Pogonip (n): A regional term, primarily used in the mountainous western United States, for a dense winter fog containing ice crystals.
• Freezing fog (n): A closely related term; fog where the water droplets are supercooled and freeze upon contact with surfaces, or fog composed of ice crystals.
• Rime (n): The white ice that forms when ice fog or freezing fog deposits ice crystals on objects, especially on the windward side.

Synonyms

• Frozen fog
• Diamond dust (This typically refers to a similar but less dense precipitation of ice crystals falling from a clear sky, not a fog that reduces visibility.)

Notes

• Ice fog is not a phrasal verb or an idiom. It is a compound noun with a specific technical meaning in meteorology.
• It differs from "frost" or "hoarfrost," which are ice deposits that form directly on surfaces from water vapor, not a suspension of particles in the air that reduces visibility.

Noun

1. a dense winter fog containing ice particles