Atmospheric icing occurs when waterdroplets in the air freeze on objects they come in contact with. This is very dangerous on aircraft, as the built up ice changes the aerodynamics of the flight surfaces, and can cause loss of lift, with a subsequent crash. Image File history File links Photographer:Richardfabi. ... Image File history File links Photographer:Richardfabi. ... Impact of a drop of water. ... Water dropping from a faucet A drop is a small volume of liquid, bounded completely or almost completely by free surfaces. ... Airbus A380 An aircraft is any machine capable of atmospheric flight. ... Lift consists of the sum of all the fluid dynamic forces on a body perpendicular to the direction of the external flow approaching that body. ...
Not all water freezes at 0° C or 32° F. This is called supercooled liquid water. These supercooled droplets are what cause icing problems on aircraft. Usually, icing is not a problem in clouds if the temperature in the cloud is -20°C or colder. This is because at temperatures below -20°C clouds rarely consist of supercooled water droplets, but rather ice particles. Supercooling is the process of chilling a liquid below its freezing point, without it becoming solid. ...
References
Advisory Circular 20-113: Pilot Precautions and Procedures to be taken in Preventing Aircraft Reciprocating Engine Induction System and Fuel System Icing Problems
Advisory Circular 20-117: Hazards Following Ground Deicing and Ground Operations in Conditions Conducive to Aircraft Icing
Advislabory Circular 20-147: Turbojet, Turboprop, and Turbofan Engine Induction System Icing and Ice Ingestion
Icing along the NSR is generally not a serious problem for large cargo ships, but along some routes (Murmansk-Igarka, Murmansk-Dudinka) icing may be very dangerous, especially during a long cruise at the end of autumn or in winter when air temperatures are below zero and there is no ice cover on the sea surface.
Fast icing in which speed of ice accumulation is 1.5 to 4 tons per hour, or 1 to 3 cm/hour occur with air temperatures of -3°C to -8°C and wind speed of 7 to 15 m/sec.
In September the slow icing occurrence rate is 20-40% in the coastal areas, and 50-70% in the central parts of the arctic seas.
On average, the Atlantic is the saltiest of the world's major oceans; the salinity of the surface waters in the open ocean ranges from 33 to 37 parts per thousand by mass and varies with latitude and season.
The Gulf Stream, for example, warms the atmosphere of the British Isles and northwestern Europe, and the cold water currents contribute to heavy fog off the coast of northeastern Canada (the Grand Banks area) and the northwestern coast of Africa.
The surface is usually covered with sea ice in the Labrador Sea, Denmark Strait, and Baltic Sea from October to June.
Feeds |
Contact