A fiery heat wave during the last week of June in western Canada left very few marks, including fragile glaciers that are already melting at a rapid rate, experts say.
Dozens of temperature records were broken during the period, including a Canadian record of 49.6 C in Lytton, BC, the day before the fire destroyed most of the community.
Brian Menounos, Canada research professor in glacier change at the University of Northern British Columbia, said that even at elevations of 3,000 meters, it was about six degrees above average.
“Warmer than anything we’ve seen, so it was clearly a warm event, quite warm.”
He and other scientists are working to quantify the melting of glaciers caused by the heat wave, Menounos said.
Most of the glaciers in the mountains of Alberta and British Columbia “have not been in good shape” and are expected to disappear by the end of the century due to greenhouse gas emissions and human-caused climate change, he said. .
Jeffrey Kavanaugh, an associate professor at the University of Alberta’s faculty of science, estimated that ice melt during the so-called June heat dome on the Wapta Icefield was three times normal over the past twelve years. The Wapta Icefield is the source of the glacier and the Bow River.
He looked at the data from June 25 to July 4 and compared it to temperatures for the same interval over the previous 12 years.
The temperature only dropped below zero once in that time; all other nights it stayed as high as 7.5 C.
“Because the increased melting during the heat dome event melted the snow cover in many places and exposed the ice from the glaciers, this changed the rate of melting for the remainder of the summer,” Kavanaugh said.
“So the melting will increase compared to a normal summer. Even if the temperatures are normal, we will see more melting the rest of the summer than we would have otherwise. It is an impact that will continue at least until the snow falls and comes back again. to cover the glaciers. ”
The #WesternCanada heat wave accelerates the rate of melting of glaciers, experts say. #HeatWave #GlacialMelt #HeatDome
Menounos said the heat coincided with the summer solstice, when the northern hemisphere gets “maximum energy” from the sun.
“It was really kind of a one-two punch.”
Smoke from the hundreds of fires burning in the province is an additional problem, with soot increasing melting and a layer of smoke that reduces sunlight but also traps heat to increase the melting of glaciers, he said.
“It is a complicated research topic that many people are beginning to study and try to understand better,” Menounos added.
This rate of glacier melt is generally seen in late July and August, he said.
Glaciers will see a “longer melt season” if temperatures remain above normal, he noted.
“Glaciologists are concerned whenever conditions arise that are going to sustain melting for, you know, a considerable amount of time.”
This Canadian Press report was first published on July 14, 2021.