Polar Vortex, Global Warming, and Cold Weather

• Polar vortexes exist at a high altitude.  They are most well-defined in the stratosphere, higher up than the portion of the atmosphere in which most of what is typically thought of as weather is (troposphere).  Their circulations extend down to lower altitudes (the atmosphere is a continuum) but are more irregular and chaotic in the troposphere.  As observations and understanding of higher altitudes have evolved, the American Meteorological Society Glossary definition has evolved, originally referring to the middle and upper troposphere (which is where I originally learned it was), and then the middle troposphere to the stratosphere, and the now the scientific literature mostly refers to the stratospheric polar vortex.  NASA Goddard refers to it extending from the tropopause (boundary between troposphere and stratosphere) all the way up to the mesosphere, which begins approximately 50 kilometers (~31 miles) above the Earth's surface, and indeed the current chart above of the *1* millibar height shows the polar vortex very pronounced at almost that altitude!    [Update: The AMS has again changed the definition.  There's what seems to be an a typo at that link: "not merely a stratospheric phenomenon" must mean "not merely a tropospheric phenomenon," since it's referring directly to the original Glossary entry that cited only the troposphere. They still refer to two "centers" when they're really axes or lobes, and only in the long-term means, which can be misleading, as they're not necessarily there at any given time (and much of the time are not).  And it says the vortex is strongest during the winter in the upper troposphere and stratosphere, whereas what started all the "endless media mangling" was the L in on the chart below at 500 mb in the mid troposphere.  And about that troposphere ... interestingly there are apparently many more uses of "circumpolar vortex" in the literature in regard to that level than just "polar vortex" ... which makes sense, since while a subtle semantic difference, the definition of circum- seems to apply well to the tropospheric manifestation, given that there it's largely a band of westerlies circulating around, but removed from, the pole, and relatively irregular and chaotic, stretching (figuratively and literally) the term "vortex," whereas the stratospheric polar vortex is more truly polar and more truly a vortex.]