Sunset in Gran Canaria, Spain, April 26
Borja Suarez/Reuters
A fierce, unseasonable heatwave hit southern Spain, Portugal and Morocco this week, with temperatures approaching 40°C (104°F) in some areas. The heat wave is putting additional climatic stress on southern Europe, which is already suffering from severe drought, which threatens to push up food prices. Here’s what we know about why record heat waves are happening, and how it might be linked to climate change.
Which country broke the record?
On April 27, according to Spain’s Meteorological Agency, Cordoba airport in southern Spain recorded the hottest temperature for April, reaching 38.8°C (101.8°F). This broke his previous record of 37.4°C (99.3°F) set in April 2011 in Murcia.
On the same day, Portugal recorded the highest April temperature of 36.9°C (98.4°F) in Mora, in the country’s center, and a record 41.3°C (106°F) in Marrakech, Morocco. .
According to the Met Office, these temperatures are 10-15°C above the seasonal average.
why did this happen?
Heatwaves are caused by large volumes of very hot air moving from North Africa to Southern Europe and slow-moving high-pressure systems that limit rainfall, keep skies clear, and allow heat to accumulate. I am doing
The ongoing drought in these countries may also be a contributing factor. Wet soil has a cooling effect when the water it contains evaporates. If the soil is dry, little solar energy is used for evaporation and transpiration, and more solar radiation accumulates as the surface warms.
Erich Fischer of ETH Zurich, Switzerland, says dry soils can increase the intensity of heat waves by 2-3°C. “A drought is basically an amplification of a heat wave,” he says. But he notes that it’s unusual to see this effect so early in the year. “Usually at this time of year, even in Southern Europe, the soil is still moist,” he says.
What are the impacts of climate change?
Fisher said the current heatwave is becoming more severe due to the background rate of warming from climate change. But the sheer volume of record-breaking heat events seen in recent years should set off alarm. In fact, southern Europe and northern Africa aren’t the only ones currently experiencing extreme heat. Southeast Asia has also been hit by extreme heat in recent weeks, with the highest temperature recorded by monitoring stations in Thailand, Laos, Myanmar and Vietnam earlier this month, he said, at 45°C (113°F). “Records should be very rare these days,” Fisher says. “But they are happening everywhere.”
Some new evidence suggests that low North Atlantic sea surface temperatures may influence the occurrence of extreme heat in Europe by influencing the movement of jet streams and ocean currents. I have.
Does this mean it will be hot in the summer too?
The current heat wave gives meteorologists little indication of what will happen in the northern hemisphere summer. However, continued drought could make Europe and North Africa more susceptible to extreme heat if a high pressure system develops later this year. “It’s too early to say what these spring temperature extremes will mean for summer values,” said Paul Hutchion of the Japan Meteorological Agency’s Global Guidance Unit in a blog post earlier this week. The ground means further heatwave conditions could lead to even higher temperatures later in the year.”
Why is it still cold in the UK and Northern Europe?
Much of northern and eastern Europe, including the UK, has seen below average temperatures this week, in contrast to the sweltering temperatures in southern Europe.
Waves of jet streams are bringing warm air to southwestern Europe, while cold air is being drawn from the Arctic to the UK and northern Europe. However, forecasters expect the cold snap to end within the next few days, with temperatures approaching average across most of the UK by next week.
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