What the FAQ: What is a heat dome? Why hundreds are dying as Canada experiences record temperatures

Canada and several parts of the North-Western United States are reeling from an unprecedented rise in temperatures. Over a hundred people have died in Canada due to this record-breaking heatwave. According to Canada's chief coroner Lisa Lapointe, there has been a 195 per cent increase in the number of fatalities in the last five days. Experts believe that this is a result of a heat dome that has formed over that part of North America. Let's find out what this heat dome is all about.

What is a heat dome?
US Department of Commerce's National Oceanic and Atmospheric Administration (NOAA) says that a heat dome is formed when the earth's atmosphere traps hot air from the ocean and doesn't allow it to escape, much like a dome. The phenomenon occurs when there is a drastic change in ocean temperatures and that gives way to a process called convection. This gives rise to an excess amount of warm air, which is further heated by the ocean's surface and rises above. Due to the presence of winds, the air moves east, while the northern jet stream traps the hot air inland, where it sinks and forms deadly heatwaves.

What is happening in the US and Canada?
On June 29, Canada recorded its highest temperature ever at 49.5 degrees Celsius. This is the third day in a row when records have been shattered. On the contrary, several parts of the US, like Portland in Oregon, recorded unusual temperatures in summer. According to weather reports there, the temperature dropped from 46 degrees Celsius to 17 degrees Celsius overnight in Portland.

What's the impact?
Besides the unprecedented increase in the number of deaths, such a rise in temperature can severely damage crops and vegetation and increase the demand for electricity. It can also lead to wildfires in the forests and even lead to droughts.

Why is this happening?
According to weather scientists, this is a direct result of climate change. They predict that more severe heatwaves will be common in the upcoming decades. The impact of climate change and this heatwave was felt even in cities in the Arctic Circle, which also broke records this week in terms of temperature rise.