Cyclone
In
meteorology, a cyclone is the rotation of a volume of air around an area of
low atmospheric pressure. This rotation is
clockwise in the southern hemisphere, and counter-clockwise in the northern hemisphere. Cyclones are responsible for a wide variety of different meteorological phenomena such as
tropical cyclones and
tornadoes. Because of this, most weather forecasters avoid using the term
cyclone without a qualifying term.
The terms
hurricane and
typhoon are regionally specific names for a strong tropical cyclonea non-frontal, synoptic-scale, warm-core low-pressure system with cyclonic surface wind circulation .
Encyclopedia
In
meteorology, a
cyclone is the rotation of a volume of air around an area of
low atmospheric pressure. This rotation is
clockwise in the southern hemisphere, and counter-clockwise in the northern hemisphere. Cyclones are responsible for a wide variety of different meteorological phenomena such as
tropical cyclones and
tornadoes. Because of this, most weather forecasters avoid using the term
cyclone without a qualifying term.
The terms
hurricane and
typhoon are regionally specific names for a strong tropical cyclone—a non-frontal, synoptic-scale, warm-core low-pressure system with cyclonic surface wind circulation .
Structure
The center of a cyclone is a low-pressure region,it is also called the eye. Near the center of the cyclone the pressure gradient force, from high- to low-pressure regions, and the Coriolis force must be in an approximate balance . The wind flow around a large cyclone is
counterclockwise in the northern hemisphere, and
clockwise in the southern hemisphere, due to the
Coriolis effect. Large anticyclonic storms are extremely rare on
Earth, though Jupiter's
Great Red Spot storm is anticyclonic.
On
satellite imagery, a polar low appears very similar to a hurricane, with an eye and convective bands wrapping around the center. Research aircraft data suggests that these "arctic hurricanes" may be warm-core systems. Lack of weather data makes forecasting of polar lows difficult. Most predictions in this area are more subjective than the prediction of
tropical cyclones.
Derivation of the term
The word "cyclone" appears to have been used first by Henry Piddington around 1840. The word is derived from the Greek word "kyklon" which means moving in a circle .
Cyclone as metaphor
The cyclone has been used for over 100 years as a metaphor for political upheaval. For example, according to
political interpretations of The Wizard of Oz, the cyclone takes Dorothy to a utopia , and kills the Wicked Witch of the East who had oppressed the little people . The storm cellar has also been used as a metaphor for seeking safety, as the 1894 cartoon shows. The caption reads, "In the cyclone cellar, waiting for fair weather."
See also
External links
- - Dr. Michael Pidwirny, University of British Columbia, Okanagan
- - The National Snow and Ice Data Center
- - The National Snow and Ice Data Center
- - StormWiki
- - Weather Online UK
