A condition that exists during the winter time in the Antarctic, in which the air moves in a ringing, circular motion, allowing little air to come in or out. This is one of the factors resulting in the low stratospheric temperature during the polar night, which are a prerequisite for the ozone hole. When the vortex dissipates during ozone-deprived air can spread over other parts of the globe, leading to excess UV radiation.
A semi-isolated area of cyclonic circulation formed each winter in the polar stratosphere. The southern polar vortex is stronger than the northern one. The vortex increases ozone depletion by trapping very cold air containing aerosols on which ozone- depleting reactions can take place.
A low depression system caused by strong westerly winds that remains stationary over the south pole.
wind region around the North or South pole. The southern vortex is a well formed circular to oblong mass of extremely cold, stagnant air, held in place by the ocean surrounding the Antarctic land mass and a strong westerly circulation pattern produced by the coriolis effect. The northern vortex is not as distinct because the Arctic is a frozen ocean surrounded by rugged land masses, which cause the circulating winds to encounter a variety of temperatures.
A distinct column of cold air contained over the poles (esp. South) by meterological effects. Develops during the polar winter when the polar regions are in polar night (sunlight does not reach the poles). Wind speeds around the vortex may reach 100 metres per second. The vortex establishes itself in the middle to lower stratosphere. It's important because it isolates the very cold air within it.
Field measurements in and theoretical studies of the Antarctic stratosphere have demonstrated that processes that occur in the wintertime engender chemical transformations that lead to the formation of the springtime ozone hole over the Antarctic continent.
A circumpolar wind circulation which isolates the Antarctic continent during the cold Southern Hemisphere winter, heightening ozone depletion.
In the stratosphere, a strong belt of winds that encircles the South Pole at mean latitudes of approximately 60°S to 70°S. A weaker and considerably more variable belt of stratospheric winds also encircles the North Pole at high latitudes during the colder months of the year.
High pressure system located in the upper atmosphere at the polar regions. In this system, air in the upper troposphere moves into the vortex center and then descends to the Earth's surface to create the polar highs.
large-scale cyclonic circulation in the middle and upper troposphere centered generally in the polar regions; it is often called circumpolar vortex.
The polar vortex is a persistent, large-scale cyclone located near the Earth's poles, in the middle and upper troposphere and the stratosphere. It surrounds the polar highs and is part of the polar front The vortex is most powerful in the hemisphere's winter, when the temperature gradient is steepest, and diminishes or can disappear in the summer. The Antarctic polar vortex is more pronounced and persistent than the Arctic one; this is because the distribution of land masses at high latitudes in the northern hemisphere gives rise to Rossby waves which contribute to the breakdown of the vortex, whereas in the southern hemisphere the vortex remains more undisturbed.