Cognizant Citizen: North American Heat Dome

SInce the last week, British Columbia and the Pacific Northwest have been experiencing unprecedented summer temperatures. Around 250 km from Vancouver, the village of Lytton recorded Canada’s highest-ever mercury reading of 49.5⁰C on Sunday, June 27, 2021. The obliterating heatwave has caused the sudden deaths of over five hundred people along the west coast of North America.

Around 13 million people are sweltering in the “heat dome” trapped region. People in houses without air conditioning have been transferred to emergency shelters to protect themselves from the intense heat. The scorching temperatures have also caused damage to infrastructure and property, including buckling roads, melting electric wires, and deforming aluminium sheet structures.


What is a Heat Dome?

Heat Dome” is a phenomenon of trapping atmospheric heat on land due to high pressure. High-pressure air moves towards low pressure such that hot air rushes from land to the coast. Prevailing winds from the Pacific Ocean present at an altitude of 1.3km from sea level, transport hot winds westwards. Consequently, jet streams at the height of around 8km that travel (at a speed of 442km/h) eastwards entraps the hot air and forces it down to the land, thus forming a heatwave and eventually a heat dome. 

Formation of a Heat Dome

Another significant factor involving the formation of a heat dome is the time of the year. The summer solstice was on June 21, the amount of sunlight reaching the surface was the highest. Further, the angle of the sun’s rays on the region was at its maximum of 45⁰, thus collecting hot air at its most significant potential. The skies are also cloudless during this time, hence, directing all the sun’s rays onto Earth without hindrance.


The Severity of the Heat Dome

Heatwaves are common in the northwest Pacific region; they frequently occur every few years. But a heat dome? The previous heat dome ever recorded was in 1937 in the Saskatchewan Province, logging a temperature of 45⁰C. 

Temperatures in Pacific Northwest and British Columbia

However, Mount Rainier, one of Washington’s most giant glaciers, has begun to melt for the first time in a hundred years. 

On average, the death toll is 165 deaths over five days due to heatwaves. From June 27 to June 30, 2021, British Columbia registered “sudden and unexpected” 486 deaths, most of whom were middle-aged or old-aged, found dead at homes without air conditioning. Oregon alone reported 79 deaths, and more than 200 people were treated for heat-related illnesses. Washington confirmed at least a dozen deaths.

Three people swimming in rivers and lakes in Washington died too. Some farmers have been out at night picking out cherries from their farms to save their crops from dying. Campers at Mount Hood, a potentially active stratovolcano in Oregon, were evacuated with a fear of flooding the snowmelt, accelerating volcanic eruptions.

Not just humans, 90 terns in Seattle died due to excessive heat, most of whom were young birds and couldn’t fly yet were stuck on the ground letting asphalt burn them.

Several roads have buckled due to excessive heat, including Interstate 5 (near Seattle), a major north-south route of the Interstate Highway System, State Road Florida 544 in Whatcom County.

Wildfire in Lytton

Lytton has seen over 87 wildfires, leading to the rampant burning of 78 square kilometres of land. The fire set about a hundred homes ablaze resulting in two deaths. Almost everyone in the village was instantly evacuated. 


Coping with the Heat

Dubai would be cooler than what we see now,” David Phillips, a senior climatologist for Environment Canada, stated. 

Schools and Covid-19 vaccination centres have been forced to shut down in and around the province. Officials have installed water fountains and misting stations around street corners.

Residents at a cooling centre in Portland, Oregon

Air conditioners and fans sold out dramatically. Those without cooling systems at home found comfort in the air conditioning system of their cars. Cities also opened up emergency cooling shelters for residents.

The state has resumed rolling out electricity blackouts limiting outages to one hour of power to a customer per day. 

All citizens were requested to remain indoors and stay hydrated at all times. The city also sent police personnel back home, and the public was asked to call 911 only in case of emergencies.

The heat dome is likely to persist for a week before high-pressure winds decrease.


Impact of Climate Change

There are ongoing debates to confirm the heat dome as evidence of global warming. The occurrence of a heat dome 87 years ago before the significance of climate change implies the heat dome is a natural heat disaster. At the same time, experts suggest that as global warming continues globally, the frequency of such heat domes is likely to increase in the near future. 

Pacific Northwest isn’t the only region experiencing extreme heat temperatures; areas far north in Russia and the Arctic are also facing the same. Daniel Swain, another climatologist, says that even half a degree of global warming can “substantially increase the odds for extreme heat events in the Pacific region and more generally.”


Sources: BBC News, CBC News, The Independent, Times of India, National Ocean Service, King 5, The Washington Post, The Weather Channel, National Geographic

Written by Vaishnavi Karkare for MTTN

Edited by Cynthia Maria Dsouza for MTTN

Featured Image by Vanshika Chanani for MTTN

Image Sources (in order): BBC News, Koin 6 News, Global News, Bloomberg


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