polar front


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Related to polar front: Polar high, Polar easterlies

polar front,

zone of transition between polar and tropical air massesair mass,
large body of air within the earth's atmosphere in which temperature and humidity, although varying at different heights, remain similar throughout the body at any one height.
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. Its average position during the winter is at about 30° lat. and during the summer at about 60° lat. In the N Atlantic Ocean, for example, the polar front can often be traced as a continuous line extending over thousands of miles, usually toward the northeast from a point just off the coast of the United States at about 30°N. Most cyclonescyclone,
atmospheric pressure distribution in which there is a low central pressure relative to the surrounding pressure. The resulting pressure gradient, combined with the Coriolis effect, causes air to circulate about the core of lowest pressure in a counterclockwise direction
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 outside the tropics develop along the polar front from waves caused by the juxtaposition of cold air moving toward the equator and hot air moving toward the poles; the earth's rotation gives this air its cyclonic twist. See frontfront,
in meteorology, zone of transition between adjacent air masses. If a cold air mass is advancing to replace a warmer one, their mutual boundary is termed a cold front; if the reverse, then the boundary is termed a warm front, whereas a stationary front indicates that no
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.

Polar Front

 

an atmospheric front arising at the boundary between an air mass originating outside the tropical latitudes and one originating within the tropical latitudes, that is, between polar, or cooler, air and tropical air. The polar front in each hemisphere usually consists of several separate branches, each of which is associated with a series of cyclones that develop along it.

polar front

[′pō·lər ′frənt]
(meteorology)
The semipermanent, semicontinuous front separating air masses of tropical and polar origin; this is the major front in terms of air mass contrast and susceptibility to cyclonic disturbance.

polar front

polar front
Typical polar front depression in the Southern Hemisphere.
A semipermanent and semicontinuous front separating air masses of tropical and polar origin.
References in periodicals archive ?
Abbreviations: ACC, Antarctic Circumpolar Current; APF, Antarctic Polar Front; BIC, Bayesian information criterion; RAD, restriction-site-associated DNA; SNP, single-nucleotide polymorphism.
For example, she refers to the cold circumpolar vortex as the "polar calotte" or cap, cold air pressing southward as a "spreading cold tongue," nascent waves on the polar front as spiral-formed "breakers," and the three vertical cells of the general circulation as "running like cogged wheels." Following Bergeron, she called the cyclone stage, when the cold front just overtakes the warm sector, a "seclusia" and the final stage, when the warm front is completely overtaken by the cold, an "occlusia." Summertime showery weather was referred to as "amoeba" cyclones.
In the opinion of meteorologist Lou McNally, Beck's understanding and use of the Bergen school wave-cyclone model and the procedures for identifying the polar front on a synoptic surface map placed her "at the cutting-edge of forecast theory and application." Although she was confronted by vast regions with sparse data and stations with poor observations, the discrete steps Beck learned in Bergen for identifying fronts helped her overcome these lacunae, producing a viable analysis.
The battle zone across the UK is called the polar front. During autumn this moves southwards as the sun moves into the southern hemisphere.
In the opposite direction, ridges extend to 60[degrees]S pushing warm air into the Polar Front zone so exciting vortex development with equally deep low pressure cores often going as low as 940hPa.
Similar weather conditions will continue to prevail on Thursday during the day, while in the evening, the country will be affected by a very cold polar front accompanied by a depression centered over northwestern Syria.
The Jordan Meteorological Department has said temperatures will dip below the freezing point tonight and in evenings over the next couple of days as the polar front and depression will continue to affect the Kingdom with more rainfall and snowfall forecast in highlands.
25 (Petra) The polar front Monday is expected to deepen and snowfall will blanket areas 700m and higher above sea level with cold westerly to northwesterly gusty winds.
On Monday, the polar front will deepen and snowfall will spread to areas 700 meters high while hail and thunderstorms are forecast in other parts of the Kingdom.
Amman, Jan.24 (Petra) The polar front centered over Syria is forecast to deepen on Sunday, causing temperatures to dip well below their annual average and bringing heavy rain accompanied with thunder and lightening and snow across the Kingdom.
The impact of the polar front will deepen on Friday when a sharp drop in mercury levels is expected.
* the link between sea level rise south of the polar fronts, deep subsurface warming and large-scale wind shifts.