| Term: | Rime |
| Definition: |
A white or milky and opaque granular deposit of ice formed by the rapid freezing of super-cooled water drops as they impinge upon an exposed object; it is denser and harder than hoarfrost, but lighter, softer, and less transparent than glaze. NSIDCCryosphere
A solid surface deposit formed by the rapid freezing of supercooled water, distinguished from glaze by being less dense. See also hoar. IHPGlacierMassBalance Deposit of ice generally formed by the freezing of supercooled fog or cloud droplets on objects the surface temperature of which is below or slightly above 0 degrees C. WMOMeteoterm Deposit of ice composed of grains more or less separated by trapped air. WMOHydrology A white or milky and opaque granular deposit of ice formed by the rapid freezing of supercooled water drops as they impinge upon an exposed object. It is denser and harder than hoarfrost, but lighter, softer, and less transparent than glaze. Rime is composed essentially of discrete ice granules and has densities as low as 0.2-0.3 g cm-3. Glaze is generally continuous but with some air pockets and has much higher densities. Factors that favor rime formation are small drop size, slow accretion, a high degree of supercooling, and rapid dissipation of latent heat of fusion. The opposite effects favor glaze formation. Both rime and glaze occur when supercooled water drops strike an object at a temperature below freezing. Such formation on terrestrial objects constitutes an ice storm; on aircraft, it is called aircraft icing (where rime is known as rime ice). Either rime or glaze may form on snow crystals, droxtals, or other ice particles in the atmosphere. When such a deposit is wholly or chiefly of rime, snow pellets result; when most or all of the deposit is glaze, ordinary hail or ice pellets result. The alternating clear and opaque layers of some hailstones represent glaze and rime, deposited under varying conditions around the growing hailstone. AMSglossary Deposit of ice crystals that occurs when fog or super cooled water droplets comes in contact with an object with a temperature below freezing (0 Celsius). This deposit develops outward on the windward side of the object. PhysicalGeography A deposit of ice composed of grains more or less separated by trapped air, sometimes adorned with crystalline branches, produced by the rapid freezing of supercooled and very small water droplets. SPRI GCW |