Rime: Difference between revisions
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<div class="definition"><div class="short_definition">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.</div><br/> <div class="paragraph">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<sup>-3</sup>. 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]]. <br/>''See also'' [[hard rime]], [[soft rime]].</div><br/> </div> | <div class="definition"><div class="short_definition">A white or milky and opaque granular deposit of [[ice]] formed by the rapid [[freezing]] of [[supercooled water|supercooled water]] drops as they impinge upon an exposed object.</div><br/> <div class="paragraph">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<sup>-3</sup>. 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|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]]. <br/>''See also'' [[hard rime]], [[soft rime]].</div><br/> </div> | ||
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Latest revision as of 16:47, 25 April 2012
rime
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.
See also hard rime, soft rime.
See also hard rime, soft rime.
