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2 June 2023
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Nova Scotia battles its largest fire in history, Canada
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Canadian fire fighters are fighting the biggest wildfire in the history of the Atlantic province. The catastrophic spring wildfire season with massive and powerful fires are burning out of control in all corners of the country and thousands more people displaced on Friday. "This is a scary time for a lot of people from coast to coast to coast," said Prime Minister Justin Trudeau, alluding to the vastness of a nation on fire stretching from the Pacific to the Atlantic to the Arctic oceans. The fire on the southern tip of the province has burned over 17 000 hectares, with flame lengths reaching nearly 100m. And another fire near Halifax has forced the evacuation of thousands of residents. Smoke has drifted south, triggering air quality warnings in the US. Nova Scotia officials said the fire’s burning in Shelburne County and about 50 homes have been destroyed.
Almost 1 000 fire fighters from Australia, New Zealand, South Africa and the United States also arrived or were en route to bolster fire fighting efforts. And Ottawa was deploying the military in Nova Scotia and Quebec to help out, officials said.
Canada’s federal government had already provided airlifts, aerial surveillance, crew comfort trailers and food at the emergency shelters, said Sean Fraser, a cabinet minister and parliament member from Nova Scotia.
Dave Rockwood with the Nova Scotia Department of Natural Resources said that the fire’s very fast-moving. He said about 5 000 people were evacuated, according to reports from the Royal Canadian Mounted Police (RCMP). A smaller fire near Halifax earlier burned about 200 homes and evacuated over 16 000 people.
About 200 homes, as well as a wooden bridge and a historic private Halifax club founded in 1908, have been destroyed and nearly 20 000 residents have been displaced by wildfires in Nova Scotia. A few were allowed to return home on Friday after more than a week away. Nova Scotia Premier Tim Houston lamented the "many, many lives turned upside down" by fires, noting a number of people "responding to the fires are evacuees themselves and it's absolutely heart-breaking."
But he also expressed solace: "Though all this despair, zero deaths, zero missing persons, zero serious injuries."
“We’re in a crisis in the province and we want and we need and we will take all the support we can get,” Premier Houston said on Wednesday. “Unprecedented resources are being used because these fires are unprecedented.” Additional resources have been shipped in from Ontario and a dozen water bombers from neighbouring regions and the Coast Guard have been engaged. Houston said he has also asked for military assistance.
Prime Minister Trudeau called the wildfires “heart-breaking” and promised unlimited support.
On Wednesday, Nova Scotia officials increased the fine for breaking the province-wide burn ban, a restriction on outdoor fires, to $25 000 CAD (almost $19 000 USD). Officials said rain is not forecasted for the region until Friday and they remain unsure on when residents can return to their homes.
Canada has been hit repeatedly by extreme weather in recent years, the intensity and frequency of which have increased due to global warming. Officials hoped rain and cooler temperatures in forecasts for the weekend following a record-breaking heat wave will bring relief.
In Nova Scotia, the relative humidity is predicted to drop below 20 per cent over the next few days, while the temperature is projected to be 20 to 25 degrees Celsius. The crossover is “an indicator of extreme fire behaviour”, accelerated movement or expansion.
The term is a guideline for fire managers, says Chelene Hanes, a wildland fire research scientist for the Canadian Forest Service, alerting them to potential changes to how fires may start and move.
A wildfire’s behaviour depends on three major factors, said Hanes: weather, topography and things to burn, fuel. When the weather is dry and hot, “That’s where you get these small ignitions and when that stuff is really dry, it can sustain that flaming, so it helps to move that fire along.”
When the wind begins to push a fire, feeding it new, dry fuel as it goes along, a fire can rapidly grow to the point where battling it head-on becomes unsafe for fire fighters and they have to get out of the way and resort to picking away at its flanks.
And when a fire gets really big, it can create its own weather.
Even on a smaller scale, large fires can make their own wind by convection, the draught you feel standing by a wood stove or a fireplace, multiplied by a million. That fire draught can increase wind’s speed, helping a fire grow even faster by giving it more oxygen, said Mike Flannigan, professor of wildland fire at Thompson Rivers University in Kamloops, BC.
When a fire gets to a certain size and intensity like those in Fort McMurray in 2016 and elsewhere in Alberta this year, it can create what’s called a fire-generated thunderstorm, also known as pyroCb for pyrocumulonimbus. From Flannigan’s observations, the Shelburne County fire is of a size to develop its own pyroCb, given the right conditions.
“In the fire and the combustion process, there’s heat, but there’s also moisture being released. It’s almost like you’re going through the water cycle, air rises, cools, condenses, forms clouds, and that eventually develops into a thunderstorm.”
Sometimes, that storm creates rain and hail which may contribute to putting the fire out. But it can also create lightning, starting new fires. “That’s what happened at Fort McMurray. There were about four fires that started from one of these fire generated thunderstorms,” said Flannigan. “The Sparks Lake fire in BC in 2021 started approximately 40 new fires. And because these fire-generated thunderstorms can be quite large, some of them were 20, 30 kilometres away.”
Those pyroCbs have always been around, said Flannigan, he wrote about one in 1986 in Ontario but they seem to be getting more frequent. Though fire propagation through pyroCbs is the most dramatic example of wildfires creating their own weather on a regional scale, it’s not the largest, he added.
Really intense fires put a lot of smoke into the atmosphere and a pyroCb can push some of that smoke into the stratosphere, 10km up. There it can block solar radiation which can cause significant cooling over a large area.
“It can last for weeks and months up there before it settles out,” Flannigan said. “The Australian fire in 2019-2020 injected as much material in the stratosphere as a moderate sized volcano which can cause regional cooling for months.”
Earlier this month, researchers held those fires to blame for the strong La Niña occurrences from 2020-2022, which affected weather patterns across the globe.
Sources: Wildfire Today, BBC News, Aljazeera, Associated Press, The Star
Almost 1 000 fire fighters from Australia, New Zealand, South Africa and the United States also arrived or were en route to bolster fire fighting efforts. And Ottawa was deploying the military in Nova Scotia and Quebec to help out, officials said.
Canada’s federal government had already provided airlifts, aerial surveillance, crew comfort trailers and food at the emergency shelters, said Sean Fraser, a cabinet minister and parliament member from Nova Scotia.
Dave Rockwood with the Nova Scotia Department of Natural Resources said that the fire’s very fast-moving. He said about 5 000 people were evacuated, according to reports from the Royal Canadian Mounted Police (RCMP). A smaller fire near Halifax earlier burned about 200 homes and evacuated over 16 000 people.
About 200 homes, as well as a wooden bridge and a historic private Halifax club founded in 1908, have been destroyed and nearly 20 000 residents have been displaced by wildfires in Nova Scotia. A few were allowed to return home on Friday after more than a week away. Nova Scotia Premier Tim Houston lamented the "many, many lives turned upside down" by fires, noting a number of people "responding to the fires are evacuees themselves and it's absolutely heart-breaking."
But he also expressed solace: "Though all this despair, zero deaths, zero missing persons, zero serious injuries."
“We’re in a crisis in the province and we want and we need and we will take all the support we can get,” Premier Houston said on Wednesday. “Unprecedented resources are being used because these fires are unprecedented.” Additional resources have been shipped in from Ontario and a dozen water bombers from neighbouring regions and the Coast Guard have been engaged. Houston said he has also asked for military assistance.
Prime Minister Trudeau called the wildfires “heart-breaking” and promised unlimited support.
On Wednesday, Nova Scotia officials increased the fine for breaking the province-wide burn ban, a restriction on outdoor fires, to $25 000 CAD (almost $19 000 USD). Officials said rain is not forecasted for the region until Friday and they remain unsure on when residents can return to their homes.
Canada has been hit repeatedly by extreme weather in recent years, the intensity and frequency of which have increased due to global warming. Officials hoped rain and cooler temperatures in forecasts for the weekend following a record-breaking heat wave will bring relief.
In Nova Scotia, the relative humidity is predicted to drop below 20 per cent over the next few days, while the temperature is projected to be 20 to 25 degrees Celsius. The crossover is “an indicator of extreme fire behaviour”, accelerated movement or expansion.
The term is a guideline for fire managers, says Chelene Hanes, a wildland fire research scientist for the Canadian Forest Service, alerting them to potential changes to how fires may start and move.
A wildfire’s behaviour depends on three major factors, said Hanes: weather, topography and things to burn, fuel. When the weather is dry and hot, “That’s where you get these small ignitions and when that stuff is really dry, it can sustain that flaming, so it helps to move that fire along.”
When the wind begins to push a fire, feeding it new, dry fuel as it goes along, a fire can rapidly grow to the point where battling it head-on becomes unsafe for fire fighters and they have to get out of the way and resort to picking away at its flanks.
And when a fire gets really big, it can create its own weather.
Even on a smaller scale, large fires can make their own wind by convection, the draught you feel standing by a wood stove or a fireplace, multiplied by a million. That fire draught can increase wind’s speed, helping a fire grow even faster by giving it more oxygen, said Mike Flannigan, professor of wildland fire at Thompson Rivers University in Kamloops, BC.
When a fire gets to a certain size and intensity like those in Fort McMurray in 2016 and elsewhere in Alberta this year, it can create what’s called a fire-generated thunderstorm, also known as pyroCb for pyrocumulonimbus. From Flannigan’s observations, the Shelburne County fire is of a size to develop its own pyroCb, given the right conditions.
“In the fire and the combustion process, there’s heat, but there’s also moisture being released. It’s almost like you’re going through the water cycle, air rises, cools, condenses, forms clouds, and that eventually develops into a thunderstorm.”
Sometimes, that storm creates rain and hail which may contribute to putting the fire out. But it can also create lightning, starting new fires. “That’s what happened at Fort McMurray. There were about four fires that started from one of these fire generated thunderstorms,” said Flannigan. “The Sparks Lake fire in BC in 2021 started approximately 40 new fires. And because these fire-generated thunderstorms can be quite large, some of them were 20, 30 kilometres away.”
Those pyroCbs have always been around, said Flannigan, he wrote about one in 1986 in Ontario but they seem to be getting more frequent. Though fire propagation through pyroCbs is the most dramatic example of wildfires creating their own weather on a regional scale, it’s not the largest, he added.
Really intense fires put a lot of smoke into the atmosphere and a pyroCb can push some of that smoke into the stratosphere, 10km up. There it can block solar radiation which can cause significant cooling over a large area.
“It can last for weeks and months up there before it settles out,” Flannigan said. “The Australian fire in 2019-2020 injected as much material in the stratosphere as a moderate sized volcano which can cause regional cooling for months.”
Earlier this month, researchers held those fires to blame for the strong La Niña occurrences from 2020-2022, which affected weather patterns across the globe.
Sources: Wildfire Today, BBC News, Aljazeera, Associated Press, The Star
