Edmonton is caught in a stagnant weather pattern. Get ready for more poor air quality

Worst periods are early morning and rush hour, with some improvement by midday

Image | Pollution edmonton

Caption: Downtown Edmonton buildings shrouded in fog Wednesday morning. Environment and Climate Change Canada's Air Quality Health index was at an eight Wednesday morning, indicating high health risk. (David Bajer/CBC)

The Prairies Climate Change Project is a joint initiative between CBC Edmonton and CBC Saskatchewan that focuses on weather and our changing climate. Meteorologist Christy Climenhaga brings her expert voice to the conversation to help explain weather phenomena and climate change and how they impact everyday life.

Fog and poor air quality have moved into much of Alberta, with the worst air qualities being reported around the capital region.
The Air Quality Health Index has ranged from six to eight in Edmonton, putting our pollutant levels in the moderate to high risk category for the past few days.
So where is it coming from and when will it end?

Nothing is moving

Extended air quality advisories in the winter like we are seeing now, are usually a product of … nothing. Literally, nothing moving in our atmosphere.
"We're in a pretty stagnant weather pattern and the current atmospheric conditions are conducive to trapping pollutants near the surface," said Jesse Wagar, a meteorologist with Environment and Climate Change Canada.
The current weather pattern has our jet streams, those fast moving bands of air in the upper atmosphere that guide our weather systems, moving further to the north and south of Alberta.
That means the province is caught in the middle.
"There's not a lot of dynamics that are going on to initiate surface level weather patterns that are more dynamic in nature," Wagar said.
Our atmosphere is also set up in an inversion, where colder air is at the surface and warmer air is at higher levels. When we get into these setups, the cool air is trapped, capped by the warmer air above.
"It starts to trap those pollutants through the surface and if that continues over you know a number of days and it allows it to build up and then it gets worse."

Image | Pollution Edmonton January 2023

Caption: High levels of pollutants are expected throughout the week. (Jamie McCannel/CBC)

At this time of the year, when people are heating homes and buildings and using cars more frequently, more pollutants are being released with nowhere to go.
"Things that are happening in the winter often lead to more pollutants being released into the atmosphere," Wagar said.

Varying degrees of risk

With these prolonged periods of poor air quality, some will feel the effects more than others.
Those with asthma or other lung or cardiovascular disease, the elderly, children, and those who work or spend extended periods of time outside are more at risk than the general population when it comes to air quality.
"Older adults tend to have pre-existing conditions which increases their risk," said Shelby Yamamoto, an associate professor in the School of Public Health at the University of Alberta.
"And children are also developing and they have systems that aren't quite yet mature and so air pollution can also affect them more heavily then for example the general population."
People suffering from air pollution can see increased coughing, throat irritation, headaches or shortness of breath that can worsen as the days drag on.
"If people are exposed to poor air quality over a much more extended period of time, we start to worry about the linkage that this has to things like chronic conditions," Yamamoto said.
She said we can see chronic issues, such as cardiovascular conditions and respiratory conditions, become worse or even see new conditions develop.

Air pollution and climate change

Air pollution and climate change are closely linked.
"Some of the pollutants that we are concerned about for climate change and also in terms of air quality are the same," said Yamamoto.
One example is methane, a greenhouse gas which interacts with sunlight and other gases to form ozone. Yamamoto said there is concern for methane's impact on health.
As we continue to see our climate changing, links to longer allergy seasons and increased wildfire smoke deteriorating air quality are well known, she said.

Image | Smoky Edmonton August 2018

Caption: The view across the North Saskatchewan River in August of 2018 as smoke blanketed Alberta from wildfires in British Columbia. (Terry Reith/CBC)

Heat events and urban heat islands are also being investigated.
"Is this having an impact in terms of your air quality?" Yamamoto said. "Because the thing is, you often get heat events sort of co-occurring with poor air quality."
But as we take steps to combat climate change, she said there is a spillover when it comes to pollutants.
"When we introduce mitigation measures or adaptation measures that address one, it often has an impact in terms of the other, a beneficial impact."

When will this end?

It looks like most of this week will include elevated pollutant levels, but we will see changes throughout the day, according to Wagar.
"Early morning hours and rush hour — those are usually the worst periods of time for poor quality," she said.
"We do see a bit of an improvement in the midday and into the early afternoon. But then again, once the afternoon rush hour starts and the air starts to settle, it gets worse again."

Image | Pollution city hall

Caption: Pollutant levels are elevated overnight, in the morning and during rush hour. (David Bajer/CBC)

According to Wagar, the end will come when we finally see a big shake-up in our weather patterns.
"We really need a strong enough weather system to move through and flush it out, but we're not seeing that," she said.
She said Alberta could see something come through into the weekend or next week but warns that another pattern like this is possible.
"There's always the possibility that those weather patterns will, you know, even out and stagnate again and then we'll sort of see another round of things like this," she said.
"It's not unusual to see these episodes with these periods of poorer quality, particularly in the winter."

Our planet is changing. So is our journalism. This story is part of a CBC News initiative entitled "Our Changing Planet" to show and explain the effects of climate change. Keep up with the latest news on our Climate and Environment page(external link).

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