Multiple choice

Which type of icing occurs when the temperature of the air is below the frost point of ambient air?

  1. Rime ice

  2. Hoar frost

  3. Glaze ice

  4. None of these

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Hoar frost forms when air temperature is below the frost point, causing water vapor to deposit directly as ice crystals on surfaces without passing through a liquid phase. This differs from rime and glaze ice which involve supercooled liquid water freezing on contact.