Rough Ice
Rime or (older name) rime is a solid precipitate , which especially at high wind speeds and air temperature of typically from -2 to -10 ° C from undercooled fog forms water droplets on surfaces, typically against the wind direction . The resulting ice layer of gray-white-grained particles has a sponge-like appearance and is compared to solid clear ice loose right.
Rough ice is characterized by the fact that it has no crystalline structures and that it includes a large number of air bubbles in its structure. Due to the partial melting and re-freezing of the particles, they stick together to different degrees, depending on the prevailing temperature conditions. Rough ice can therefore achieve a certain level of firmness, but quickly loses it at a few degrees Celsius and can then easily become a danger for passers-by due to falling pieces of ice.
Rough ice, like clear ice, preferably accumulates on branches and overhead lines , where it can lead to damage , especially as an area , due to the not insignificant additional weight load . Both phenomena are to be distinguished from frozen dew , frost and hoar frost .
Rough ice in aviation
Compared to clear ice, rough ice is less dangerous for safe flight operations, but should not be underestimated either. It is recognizable - in contrast to clear ice, which "grows" backwards on the wings - by its fine structure (as described above) that grows against the direction of the flow.
Web links
supporting documents
- ↑ Fog deposits. German weather service, weather dictionary. Retrieved December 11, 2019 .
- ↑ Rime, Rough Ice, Raufrost - What Now? December 6, 2014, accessed December 24, 2016 .