This text is taken from the Courrier de la Planète. Click here to subscribe.
Canada needs to replace thermometers in its weather stations due to unprecedented heat waves hitting the country. Current sensors are no longer able to accurately measure temperatures above 50°C.
The all-time heat record of 49.6°C, recorded in 2021 in Lytton, British Columbia, has been hard on residents, but also on the measurement systems of meteorologists. Approaching the 50°C threshold, the thermometers ceased to function properly.
“Temperature sensors can measure above 50°C, but the uncertainty increases after this threshold. The uncertainty is really getting bigger and we need precision, ”explains to Le Devoir the director general of Environment Canada, David Harper. The margin of error can thus approach 0.5°C in the event of extreme heat.
“We want to be sure that this fork shrinks, and that’s why we are evaluating [ce remplacement]. »
The coveted new thermometers should be able to maintain their accuracy at extreme temperatures exceeding 60°C.
This change of instruments will be done on a “case by case” basis, station by station, nuance Mr. Harper, but all the thermometers could be changed.
“There are places in Canada where obviously we will never reach 50°C, but for the sake of consistency in our network, we will look [cette option] says Mr. Harper.
Replacing these state-of-the-art instruments will be “very expensive,” he notes. The Meteorological Service of Canada has just under 600 weather stations on its territory, each with one to three heat sensors. Each of these thermometers (called a “thermistor” in scientific jargon) costs between $100 and $200, according to information from the Duty.
Adapting measuring instruments to climate change is a challenge for meteorologists. Environment Canada recently opened a new “division” within its department to re-evaluate all of the country’s weather station sensors.
The need will be felt, because the period 2023-2027 will almost certainly be the hottest ever recorded on Earth, the World Meteorological Organization warned a few weeks ago. It estimates a 66% chance that the average annual global surface temperature will exceed pre-industrial levels by 1.5°C for at least one of the next five years.