Heat Dome and Heat Wave

Why in News?

• Recently, Several countries in Europe recorded their hottest January weather ever in 2023 with temperatures 10 to 20 degrees Celsius above average.

Highlights

• These included Poland, Denmark, the Czech Republic, the Netherlands, Belarus, Lithuania and Latvia.
• Experts said that the continent is experiencing an extremely warm spell because of the formation of a heat dome over the region.
• In 2021, a heat dome formed over western Canada and the US, causing deadly heat waves.
• Another heat dome settled over the US in September 2022 and raised temperatures to a new high.
• A heat dome occurs when an area of high-pressure traps warm air over a region, just like a lid on a pot, for an extended period of time.
• The longer that air remains trapped, the more the sun works to heat the air, producing warmer conditions with every passing day.
• Heat domes generally stay for a few days but sometimes they can extend up to weeks, which might cause deadly heat waves.
• The heat dome’s formation is related to the behaviour of the jet stream.
• Jet streams are relatively narrow bands of strong wind in the upper levels of the atmosphere
• The jet stream is believed to have a wave-like pattern that keeps moving from north to south and then north again.
• When these waves get bigger and elongated, they move slowly and sometimes can become stationary.
• This is when a high-pressure system gets stuck and leads to the occurrence of a heat dome.