What characterizes rime icing and its temperature range?

Rime icing is characterized by its formation at temperatures typically found within the range of -10 to -20 degrees Celsius. This type of ice presents as a milky or frosty layer that forms on surfaces when supercooled water droplets freeze upon contact. The conditions required for rime icing often coincide with cloud conditions and high humidity, where these supercooled droplets are prevalent.

The temperatures in this range are critical because they allow the water droplets to remain in a liquid state despite being below freezing, which is essential for rime icing to occur. When these droplets collide with structures, such as trees or aircraft, they rapidly freeze, forming the characteristic milky appearance of rime icing. This is notably different from other icing types, which may occur at different temperatures or display different appearances.

The other options mischaracterize rime icing. Clear ice typically forms between 0 to -10 degrees Celsius and is often associated with freezing rain. Soft ice formation above 0 degrees Celsius does not correlate with rime icing, as rime specifically occurs at sub-zero temperatures. Thin ice layers forming below -20 degrees Celsius are also inconsistent with the attributes of rime icing, which is distinctly observed within the -10 to -20 degrees range.