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It’s a long-documented pattern that typically goes unnoticed by those of us living in lower latitudes except for when, every once in a while, the air pressure and winds shift. When the vortex is strong, it’s a clearly defined single vortex, and the Arctic air is well contained within the vortex because of the rotations high velocity. It ALWAYS exists near the poles, but weakens in summer. Strong fluctuations from cold to hot are often. A polar vortex strengthens in the winter and weakens in the summer because its strength depends on the temperature difference between the mid-latitudes and the poles. The polar vortex is a large area of low pressure and cold air surrounding both of the Earths poles. It is present in winter, and is not a new phenomenon, scientists have known about it. The vortex size increases with height and wind speeds are largest around the edge of the vortex. The polar vortex is a large area of low pressure and cold air around the Earth’s North Pole. Last winter had a strong and stable polar vortex like a robust doughnut, holding cold air in the Arctic regions. The polar vortex is a circulation of winds high up in the stratosphere, up to 30 miles (50 km) above the earth. This figure shows the 3-D structure of the Arctic vortex (colored by temperature) from the tropopause to the middle mesosphere and planetary waves propagating up from the troposphere (black regions). See example below of the Arctic vortex in the Modern Era Retrospective-analysis for Research and Applications (MERRA) data on 1 December 1981. When this occurs, significant changes in middle atmosphere chemistry and dynamics are observed and these changes are linked to tropospheric weather patterns. These disruptions result in the vortex being displaced off the pole and in some cases even split into two separate cyclones. Extreme disruptions to the vortex are referred as sudden stratospheric warming events (see Sudden Stratospheric Warmings section). Remember the polar vortexThat weather pattern that sent temperatures plummeting across much of North America last winter, causing the Niagara Falls to partly freeze.

The CGER has provided maps of the polar vortex. The vortex is occasionally disrupted by the upward propagation of planetary waves from the troposphere and the amplitude of these waves is larger in the Northern Hemisphere (NH) than in the Southern Hemisphere (SH). The polar vortex nuisance factor is usually more pronounced in winter than in summer, which figures because winter is when there are icy roads. The STRAS utilizes meteorological data for intensive observation projects and analysis of monitoring data. It will combine its strength with a negative wind. It is maintained radiatively by cold temperatures at the pole due to a lack of ozone heating during polar night. A new stratospheric Polar Vortex is emerging over the North Pole, powering up for Winter 2021/2022. The vortex is present in both hemispheres during the winter and decays during the spring season. So far, our understanding of these changes has been developed using point measurements, measurements along localised aircraft flight tracks, through the use of temperature observations, and, primarily, computer models and assimilative analyses.The polar vortex is a large circumpolar cyclone in the middle atmosphere that forms in the fall due to decreased solar insolation at polar latitudes. It works by emitting short, powerful pulses of ultraviolet light from a laser and measures the Doppler shift from the very small amount of light that is scattered back to the instrument from molecules and particles to deliver profiles of the horizontal speed of the world’s winds mostly in the east-west direction in the lowermost 26 km of the atmosphere.Īlthough Aeolus only measures wind in the lower part of the atmosphere, the lower part of the current stratospheric polar vortex jet leaves a signature in the satellite’s data.Ĭorwin Wright, Royal Society research fellow at the University of Bath in the UK, said, “Changes in the wind structure in a sudden stratospheric warming event have never been observed directly at a global scale before. This happens fairly regularly and is often associated with outbreaks of cold temperatures in the United States. During winter, the polar vortex at the North Pole expands, sending cold air southward. Fortunately, scientists now have ESA’s Aeolus satellite at hand to help understand more about why and how the polar vortex is pushed off balance.Īeolus is the first satellite in orbit to profile directly Earth’s winds from space. This particular polar vortex breakdown has been a whopper. The polar vortex is a low pressure areaa wide expanse of swirling cold airthat is parked in polar regions.