A weak meridional circulation in the high-latitude troposphere characterized by ascending motion in the subpolar latitudes (50-70), descending motion over the pole, poleward motion aloft, and equatorw
ard motion near the surface. As a residual of many transient weather systems, the polar cell is barely detectable in means with respect to time of latitude-height cross sections.
Direct, weak, meridional circulation approximately between the pole and 60˚ latitude. There is a sinking motion near the poles, weak easterlies at low levels, a rising motion near latitude 60˚ and a p
oleward flow aloft.
Three-dimensional atmospheric circulation cell located at roughly 60 to 90 North and South of the equator. Vertical air flow in the Polar cell consists of rising air at the polar font and descending a
ir at the polar vortex.
The rather shallow, irregular, and diffuse easterly winds located poleward of the subpolar low pressure belt. In the mean in the Northern Hemisphere, these easterlies exist to an appreciable extent on
ly north of the Aleutian low and the Icelandic low.
1. According to the polar-front theory, the semipermanent, semicontinuous front separating air masses of tropical and polar origin. This is the major front in terms of air mass contrast and susceptibi
lity to cyclonic disturbance. Compare arctic front. 2. In oceanography, see Antarctic Polar Front, Arctic Polar Front.
Weather front located typically in the mid-latitudes that separates arctic and polar air masses from tropical air masses. Along the polar front we get the development of the mid-latitude cyclone. Abov
e the polar front exists the polar jet stream.