Polar cell
From Glossary of Meteorology
polar cell
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 equatorward 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.