Polar cyclone

It has been suggested that this article be merged with Polar vortex. (Discuss)

Polar cyclones (also known as Arctic Cyclones) are large areas of low pressure. They should not be confused with polar lows since people happen to use the same term for polar cyclones. Polar cyclones are usually 1,000 to 2,000 kilometers wide in which the air is moving in a spiral counterclockwise fashion in the northern hemisphere. The reason for the rotation is the same as tropical cyclones, the Coriolis effect. They also exist in places such as Greenland, the Eurasian Arctic area, and northern Canada, with about 15 cyclones per winter. Polar cyclones can form in any time of the year, although summer polar cyclones are usually weaker than the ones that form in the winter.^[1] Also, they are not closely studied and are rarely destructive since they happen in areas with little or no population.

One center is near Baffin Island and the other over northeast Siberia.^[2] In the southern hemisphere, it is usually near the edge of the Ross ice shelf near 160 west longitude.^[3]

The Antarctic vortex of the Southern Hemisphere is a single low-pressure zone that is found near the edge of the Ross ice shelf, near 160 west longitude. When the polar vortex is strong, the mid-latitude Westerlies (winds at the surface level between 30° and 60° latitude from the west) increase in strength and are persistent. When the polar vortex is weak, high-pressure zones of the mid-latitudes may push poleward, moving the polar vortex, jet stream, and polar front equatorward. The jet stream is seen to "buckle" and deviate south. This rapidly brings cold dry air into contact with the warm, moist air of the mid-latitudes, resulting in a rapid and dramatic change of weather known as a "cold snap".^[4]

Ozone depletion occurs within the polar vortices – particularly over the Southern Hemisphere – reaching a maximum depletion in the spring.

1. ↑ Halldór Björnsson. Global circulation. Archived 2011-08-07 at the Wayback Machine Veðurstofa Íslands. Retrieved on 2008-06-15.
2. ↑ Glossary of Meteorology (June 2000). Polar vortex. Archived 2011-01-09 at the Wayback Machine American Meteorological Society. Retrieved on 15 June 2008.
3. ↑ Rui-Rong Chen, Don L. Boyer, and Lijun Tao (December 1993). "Laboratory Simulation of Atmospheric Motions in the Vicinity of Antarctica". Journal of the Atmospheric Sciences. 50 (24). American Meteorological Society: 4058–4079. Bibcode:1993JAtS...50.4058C. doi:10.1175/1520-0469(1993)050<4058:LSOAMI>2.0.CO;2. Retrieved 2008-06-15.{{cite journal}}: CS1 maint: multiple names: authors list (link)^{[permanent dead link]}
4. ↑ "Stratospheric Polar Vortex Influences Winter Cold, Researchers Say" (Press release). American Association for the Advancement of Science. 2001-12-03. Archived from the original on 2019-06-24. Retrieved 2015-05-23.