Under what conditions does clear icing form?

Clear icing occurs primarily when supercooled water droplets come into contact with a surface that is below freezing. The most conducive conditions for this phenomenon are indeed observed in the temperature range of -10°C to 2°C. When supercooled droplets strike an object in this temperature range, they do not freeze instantaneously, allowing for a thin layer of clear ice to form as the droplets spread out and freeze gradually. This type of icing is particularly hazardous because it can create a slick surface on aircraft wings or roads without readily visible signs of ice formation.

The other temperature ranges and conditions described in the remaining choices generally result in different icing types or are less likely to yield clear icing. For instance, colder temperatures without supercooled droplets lead to more rime icing, which has a rough texture, while direct contact with water at temperatures above freezing tends not to lead to icing at all due to the water remaining in a liquid state. The specific conditions required for clear icing—especially the presence of supercooled droplets—are crucial for its formation.