Context

• Canada and parts of United States are experiencing extreme temperatures, due to which hundreds of people have died.
• The weather is due to heat dome, a climate phenomenon behind sudden rise in temperatures.
• The abnormal heat wave caused the temperature in the country to rise to 49.5 degrees Celsius, an all-time record.

What is a heat dome?

• A heat dome occurs when the atmosphere traps hot ocean air like a lid or cap.
• The phenomenon begins when there is a strong change (or gradient) in ocean temperatures.
• In the process known as convection, the gradient causes more warm air, heated by the ocean surface, to rise over the ocean surface.
• As prevailing winds move the hot air east, the northern shifts of the jet stream trap the air and move it toward land, where it sinks, resulting in heat waves.

How long does a heat dome last?

• A heat dome typically lasts a week.

Effects of heat domes

• Temperatures rise to unbearably high, leading to sudden fatalities.
• The trapping of heat can also damage crops, dry out vegetation and result in droughts.
• The heat domes can also act as fuel to wildfires, which destroy a lot of land area in the US every year.

Climate change and heat domes

• Weather scientists have been highlighting the effects of rising temperature (climate change) on more extreme heat waves.
• Average US temperatures have increased since the late 19th century – Experts
• The western Pacific Ocean’s temperatures have increased in the past few decades and are relatively more than the temperature in the eastern Pacific.
• This strong change in ocean temperature from the west to the east is the reason for the heat dome.
• In decades to come, the climate scientists expect more days of severe heat wave.

https://indianexpress.com/article/explained/what-is-the-heat-dome-causing-record-high-temperatures-in-parts-of-north-america-7384994/

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