Recently, the arctic region has been rapidly warming. This has been linked to extreme cold weather in the US. These are a result of the expansion of the Polar Vortex.
What is Polar Vortex?
- It is a mass of cold, low-pressure air that consistently hovers over the Arctic region.
- It is denoted by the word “vortex” because it spins counter-clockwise, just like a hurricane does.
What are the Reasons for expansion of Polar Vortex?
- Usually, the polar vortex remains strong and compact like the mass of frigid air that stays at the North Pole.
- But sometimes it weakens and expands to influence the jet stream.
- Once the jet stream is impacted, the cold polar air finds its way toward the midlatitude regions.
- Researchers found that the expansion of the polar vortex has been occurring more frequently due to the rapidly warming Arctic.
Duration and Strength of a Polar Vortex
The duration and strength of a Polar Vortex are as follows:
- A Polar low-pressure area is at its highest during the winter and its lowest during the summer.
- In the event of a volcanic eruption, a polar vortex will be further strengthened and it can stay that way for up to two years after the initial eruption
- There will be a single vortex when the Arctic low-pressure is elongated in shape with two cyclone centres.
- The Antarctic polar low-pressure is far more persistent than the Arctic variant.
- Climate phenomena related to the La Nina will significantly strengthen a polar low-pressure.
- The Arctic polar vortex breaks up between mid-March to mid-May. This event marks the end of winter and the beginning of spring. Farming activities, ecosystems, and other weather cycles are impacted by this event
- An early breakup of the polar low-pressure leads to one warming period that lasts from late February to mid-March. A late breakup period will lead to two warming periods, one in January and one in March.
Polar Vortex and Global Warming
Many a time, the polar low pressure is associated with global warming. It is believed that many global warming issues are caused due to polar Vortex.
- The worldwide temperature has increased by approx. 0.8°C since the 1880s.
- The Arctic has heated and melted at more than double the rate due to the polar low pressure.
- The North Pole, North America, and other similar regions have very little temperature difference from the Arctic region.
- The jet stream’s energy moves upward, disturbing the Polar Vortex and initiating it to split.
Impacts of Polar low-pressure area on Earth’s atmosphere
- Abrupt stratospheric warming due to the polar Vortex can lead to the warm Arctic region in the stratosphere as well as the troposphere.
- It favours cold air and causes more harsh winter weather in the Northern Hemisphere and mid-latitudes comprising the Eastern United States.
Read more: Zero Shadow Day