- Polar front
In
meteorology , the polar front is the boundary between the polar cell and theFerrel cell in each hemisphere. At this boundary a sharp gradient in temperature occurs between these two air masses, each at very different temperatures.The polar front arises as a result of cold polar air meeting warm tropical air. It is a stationary front as the air masses are not moving against each other. Off the coast of eastern North America, especially in winter, there is a sharp temperature gradient between the snow-covered land and the warm offshore currents.
The polar front theory says that mid-latitude cyclones form on boundaries between warm and cold air. In winter, the polar front shift towards the Equator, whereas high pressure systems can dominate more in the summer.
External links
* [http://www.geog.ucsb.edu/~joel/g110_w06/lecture_notes/midlat_surface/agburt10_02.jpgGraphic: Polar front - precipitation produced in zones of uplift]
* [http://www.geog.ucsb.edu/~joel/g110_w06/lecture_notes/midlat_surface/midlat_surface.html Polar Front Theory of Midlatitude Cyclone Development]
Wikimedia Foundation. 2010.