Explained: Heat dome and how it caused intense heatwaves in US, Canada
- In Canada, known for harsh winters, a town called Lytton broke the country's temperature record three times this week
- British Columbia, Canada's westernmost province has recorded 486 deaths in five days
- The sweltering heatwave across the two countries is due to a phenomenon called heatwave
Western Canada and the northwest United States are experiencing a record-smashing heatwave. British Columbia, Canada's westernmost province has recorded 486 sudden deaths in just five days, the BC Coroners Service said Wednesday, reported Reuters. The US state of Oregon has reported 63 deaths linked to the heatwave, since Friday.
In Canada, known for its harsh winters, a town called Lytton in British Columbia smashed the country's all-time hottest temperature record three times this week. On Tuesday, it recorded the highest-ever temperature of 49.6°C. The previous high was 45°C recorded in Saskatchewan in 1937. Meanwhile, Chelan County in the US state of Washington witnessed temperatures soaring to as high as 48°C on Tuesday.A
Also read: Moscow records hottest June day in 120 years
So, what is behind the heatwave in Canada and the US?
The sweltering heatwave across the two countries is due to a phenomenon called 'heat dome'.
What is a heat dome?
As the name suggests, a heat dome is a high-pressure area that positions around an area like a lid over a pot.
When does a heat dome form?
As per the US National Oceanic and Atmospheric Administration (NOAA), a heat dome generally forms in a La Nina year, such as 2021.
How does a heat dome form?
When the water in the eastern Pacific is cool and that in the western pacific is warm, the temperature difference leads to the movement of dense, tropical, western air eastward.
However, the air gets trapped in a jet stream, which is an air current that spins in the anti-clockwise direction. Due to this, it moves to the west coast of the US and Canada. As the wind moves towards the land, it sinks, leading to heat waves.
How long does the heat dome last?
As per the NOAA, the phenomenon lasts for about a week.
What are the effects of heat dome?
The heatwave resulting from a heat dome can have an adverse impact on the health, especially of those living without an air conditioner. Many people have died in the US and Canada and several of those deaths have been linked to hyperthermia.
Vegetation also cannot survive such a condition, crops get destroyed and the phenomenon can also lead to droughts.
The intense heatwave can also fuel forest fire that destroys large swathes of land in the US every year.