Atmospheric Moisture Practice Test 2025 - Free Atmospheric Moisture Practice Questions and Study Guide

The phenomenon described occurs specifically when supercooled water droplets collide with surfaces and instantly freeze upon contact, creating a distinct icy accumulation. This process results in what is known as rime, which tends to form on objects such as trees, power lines, and buildings, giving them a frosted appearance.

Rime typically appears in conditions where supercooled liquid water is present, often in foggy or cloudy environments, and it can build up more significantly in windy conditions where droplets are forced against these surfaces.

In contrast, hoar frost forms under different conditions, usually appearing on clear, cold nights when water vapor sublimates directly into ice without passing through a liquid phase. Graupel refers to soft, pellet-like snow that develops from supercooled droplets that freeze onto snowflakes, while snow itself is composed of ice crystals that have formed in the atmosphere and fallen to the ground. Understanding these distinctions helps clarify why the correct term for the frost-like ice accumulation that arises from supercooled droplets freezing is indeed rime.