On an unusual day in Canada, cold air haunts. Stranger still, we can hear the voices of people 5 km away from our location.
From January 17 to February 5, 1947 in Yukon, Canada, cold air reigned. On February 3, the temperature was lowest, reaching -64°C. Launching Science Alert, people's breath at that time turned into white powder in the air and made a clattering sound.
The skin can also be frozen and the threat of hypothermia in sight. But apart from that, there have also been changes in sound transmission.
This change was felt by the residents of Snag, Yukon, the area with the coldest temperatures. Weather forecaster Gordon Toole said visibility was very limited, but he said he could hear dogs barking 6 km away.
In fact, the sound of cracking in the White River 1.6 km away sounded like gunshots.
What is causing this strange sound effect? It turns out that temperature does affect the sound. As well as moving more slowly in cold weather, sound also travels farther and can be heard if a person is above the ground.
When the air near the ground is cold and the air above is warm, sound is refracted by the warm air towards the surface. Sound then bounces between the ground and warm air, traveling farther than sound in warmer temperatures.
"The inversion of temperature causes sound waves to bend back toward the ground rather than outward," climatologist David Phillips told the National Post.
"People at the airport can clearly hear the dogs barking in the city and the townspeople speak as if they are close by, not like 5 kilometers away," he continued.
It can be concluded that the strange day in Canada was influenced by low temperatures. Sound conduction in cold temperatures can be farther than when the air temperature is warm.