What is a heat dome? Canada's extreme weather explained as heatwave shatters records

Canada is reeling under a severe heatwave, which has smashed temperature records and caused an unprecedented 195 per cent rise in sudden fatalities within the past five days. According to BBC, police in the Vancouver area have responded to more than 130 sudden deaths since Friday. The country also broke its temperature record for a third straight day on Tuesday, with Lytton, British Columbia, recording 49.6C. 

As per reports, the US northwest has also seen record highs and a number of fatalities. US President Joe Biden has said that the heatwave was tied to climate change. BBC reported that the heat over western parts of Canada and the US has been caused by a dome of static-high pressure hot air stretching from California to the Arctic territories. 

What is a heat dome?

According to the National Oceanic and Atmospheric Administration (NOAA) of US department of commerce, 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. NOAA said that in the process known as convection, the gradient causes more warm air, heated by the ocean surface, to rise over the ocean surface. It further added that 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 heatwaves. 

As the scientists have said that a heat dome typically lasts a week, officials have warned that the number of heat-related fatalities is likely to rise. In Vancouver alone, heat is reportedly believed to have been contributing factor in the unexpected deaths of 65 people since Friday. BBC reported that dozens of officers have been redeployed in the city, while the increased volume of emergency calls have created a backlog and depleted police resources. 

“Vancouver has never experienced heat like this, and sadly dozens of people are dying because of it,” Sgt. Steve Addison said in a news release. “Our officers are stretched thin, but we’re still doing everything we can to keep people safe”. 

Environment Canada said the weather system shattered 103 heat records across British Columbia, Alberta, Yukon and Northwest Territories on Monday. Those records include a new Canadian high temperature of 118 degrees (47.9 Celsius) set in Lytton, British Columbia, smashing the previous record of 116 degrees (46.6 Celsius) set in the same village a day earlier. Apart from Canada, cities as far north as the Arctic Circle broke heat records this week. 

Effects of heat dome

Officials have said that those living without an air conditioner can see the temperatures of their homes rising to unbearably high, leading to sudden fatalities. The trapping of heat can damage crops, dry out vegetation and result in droughts, according to experts. The sweltering heatwave will also lead to rise in energy demand, especially electricity, leading to pushing up rates. The heat domes can also act as fuel to wildfires, which destroys a lot of land area in the US every year.

(Image: AP)