Clear ice
Encyclopedia
Clear ice refers to a solid precipitation
which forms when air temperature is between 0 °C (32 °F) and -3 °C (27 °F) and there are supercooled, relatively large drop
s of water
(from freezing fog
). A rapid accretion and a slow dissipation of latent heat of fusion favor the formation of a transparent ice coating, without air or other impurities.
A similar phenomenon occurs when freezing rain
or drizzle
hit a surface and is called glaze
.
Clear ice, when formed on the ground, is often called Black ice
, and can be extremely hazardous.
Clear ice is denser and more homogeneous than hard rime; like rime, however, clear ice accumulates on branches and overhead lines, where it is particularly dangerous due to its relative high density
.
Precipitation (meteorology)
In meteorology, precipitation In meteorology, precipitation In meteorology, precipitation (also known as one of the classes of hydrometeors, which are atmospheric water phenomena is any product of the condensation of atmospheric water vapor that falls under gravity. The main forms of precipitation...
which forms when air temperature is between 0 °C (32 °F) and -3 °C (27 °F) and there are supercooled, relatively large drop
Drop (liquid)
A drop or droplet is a small column of liquid, bounded completely or almost completely by free surfaces. A drop may form when liquid accumulates at the lower end of a tube or other surface boundary, producing a hanging drop called a pendant drop...
s of water
Water
Water is a chemical substance with the chemical formula H2O. A water molecule contains one oxygen and two hydrogen atoms connected by covalent bonds. Water is a liquid at ambient conditions, but it often co-exists on Earth with its solid state, ice, and gaseous state . Water also exists in a...
(from freezing fog
Fog
Fog is a collection of water droplets or ice crystals suspended in the air at or near the Earth's surface. While fog is a type of stratus cloud, the term "fog" is typically distinguished from the more generic term "cloud" in that fog is low-lying, and the moisture in the fog is often generated...
). A rapid accretion and a slow dissipation of latent heat of fusion favor the formation of a transparent ice coating, without air or other impurities.
A similar phenomenon occurs when freezing rain
Freezing rain
Freezing rain is the name given to rain that falls when surface temperatures are below freezing. The raindrops become supercooled while passing through a sub-freezing layer of air, many hundred feet , just above the surface, and then freeze upon impact with any object they encounter. The resulting...
or drizzle
Freezing drizzle
Freezing drizzle is drizzle that freezes on contact with the ground or an object at or near the surface. Its METAR code is FZDZ. When freezing drizzle accumulates on land it creates an icy layer of glaze...
hit a surface and is called glaze
Glaze ice
Glaze ice or simply glaze is a smooth, transparent and homogenous ice coating occurring when freezing rain or drizzle hits a surface. It is similar in appearance to clear ice, which forms from supercooled water droplets...
.
Clear ice, when formed on the ground, is often called Black ice
Black ice
Black ice, sometimes called glare ice or clear ice, refers to a thin coating of glazed ice on a surface.While not truly black, it is virtually transparent, allowing black asphalt/macadam roadways to be seen through it, hence the term "black ice"...
, and can be extremely hazardous.
Clear ice is denser and more homogeneous than hard rime; like rime, however, clear ice accumulates on branches and overhead lines, where it is particularly dangerous due to its relative high density
Density
The mass density or density of a material is defined as its mass per unit volume. The symbol most often used for density is ρ . In some cases , density is also defined as its weight per unit volume; although, this quantity is more properly called specific weight...
.
External links
- Weather Glossary, C. The Weather Channel