Furthermore, while the tropospheric vortex exists all year, the stratospheric polar vortex exists only from fall to spring.īoth the tropospheric and stratospheric polar vortices are basic features of the earth’s climatology. The latitude at which the zonal wind reaches its hemispheric maximum can be considered as marking the approximate edge of a polar vortex, and there is a clear vertical discontinuity in this latitude around 100 hPa, It is also clear that the vortex in the troposphere is much larger than the vortex in the stratosphere, and that the two are not directly connected. The existence distinct tropospheric and stratospheric vortices can be easily seen in plots of the climatological zonal-mean zonal winds shown below.
Although Earth’s polar vortices are sometimes described as extending from the middle troposphere to the upper stratosphere, there are distinct tropospheric and stratospheric vortices, as illustrated schematically below. There are polar vortices in Earth’s atmosphere as well the atmospheres of other planetary bodies. In the atmospheric science literature, the term “polar vortex” is most commonly used as an abbreviation for “circumpolar vortex”, and refers to a planetary-scale flow that encircles the pole in middle or high latitudes. The key points from this essay are below, and here are some FAQ. Adam Sobel, Lorenzo Polvani, and I have written an essay to Bulletin of the American Meteorological Society clarifying what is meant by polar vortices in the atmospheric science literature and the connections with extreme weather events at the earth’s surface. However, there is some confusion regarding what polar vortices are and how they are related to various weather events. The term “polar vortex” has become part of the everyday vocabulary after the widespread media coverage of the extreme cold events over the USA during the early winter of 2014.