The "Heat Apocalypse" is sweeping Europe and the UK. [Europe's heatwave moves north... – Guardian]. In Gironde, an area equal to the extent of the whole of Paris has gone up in smoke. [En Gironde, la surface de Paris partie en fumée... – Libération]. The west of France hit by completely new temperatures. [Au pic de la canicule, l'ouest de la France... – Le Monde]. The fierce heat in Europe heads north. [Heatwave: Ferocious European heat heads north – BBC]. Because Europe is becoming an epicenter for heat waves. [Why Europe Is Becoming a Heat Wave Hot Spot – NYT]
- Europe’s heatwave moves north as UK braces for hottest day on record
Temperatures also forecast to rise in the Netherlands and Belgium as wildfires continue to rage in southern parts of the continent
Firefighters continued to battle blazes in southern Europe as searing temperatures moved north and Britain braced for what could be its hottest day on record.
Expectations are now high that on Tuesday the British record of 38.7C could be broken and 40C breached for the first time, with experts blaming climate change and predicting more frequent extreme weather to come.
Temperatures are also forecast to rise above 35C in the Netherlands while neighbouring Belgium is expected to hit 40C and over.
- In Gironde, the surface of Paris went up in smoke, more than 30,000 people were evacuated. (En Gironde, la surface de Paris partie en fumée, plus de 30 000 personnes évacuées)
Since July 12, two oversized fires have flared up in Gironde. The seaside resort of La Teste-de-Buch and six municipalities around Landiras were evacuated on Monday. The fight against flames reveals the inadequacy of the equipment.
Changing winds, temperatures that exceed 42 degrees in some places, atmosphere still just as dry: the elements gathered in Gironde to make July 18 the Black Monday in the history of fires in France. While several thousand hectares have already gone up in smoke in the last six days and on Sunday evening the government announced that it is implementing additional resources, the fires that flare up in the middle of the tourist season in the seaside resort of La Teste-de-Buch and the hinterland of the municipality of Landiras were not yet under control on Monday evening 18 July, bringing the number of evacuations to a level rarely reached in France.
- Let's remove the forest from planetary urbanization (Sortons la forêt de l’urbanisation planétaire)
The progression of fires in France reveals the excessive industrialization of wooded areas, whose biodiversity is sometimes lower than that of cities, warns political scientist Max Rousseau.
- Heat wave in France: 42°C in Nantes, 39.3°C in Brest... the west of France has experienced absolutely unprecedented temperatures (Canicule en France : 42 °C à Nantes, 39,3 °C à Brest… l’ouest de la France a connu des températures totalement inédites)
This Tuesday the heat will extend to the north and east, with peaks above 40°C. We are currently experiencing the third most intense heat wave observed since 1947, according to Météo-France. It should last at least another week.
An Atlantic façade that becomes crimson and the rest of the country scarlet red: the heat wave reached its peak throughout France on Monday 18 July. The entire territory had been subjected to surveillance of heat waves, with 15 departments in red and 69 in orange. The event reached a level completely unknown in the West, where all-time heat records were beaten. If these regions now cool, the country will continue to suffer a heat wave whose results are not yet seen. On Tuesday morning, Météo France revoked the red vigilance in France, but 73 departments remained under orange surveillance.
- Heatwave: Ferocious European heat heads north
The hottest temperatures have now moved to the north and east. Hundreds of people have had to leave their homes in the far north-west of Brittany, and fire has destroyed 1,330 hectares of vegetation.
The UK had one of its hottest days on record on Monday, with a high of 38.1C recorded in Suffolk, in eastern England. Forecasters say Tuesday could see temperatures top 40C, with extreme heat warnings covering central, northern and south-east England.
There were severe travel disruptions with trains cancelled and flights at London's Luton Airport suspended when part of the runway buckled under the searing heat.
- Why Europe Is Becoming a Heat Wave Hot Spot
Global warming plays a role, as it does in heat waves around the world, because temperatures are on average about 2 degrees Fahrenheit (1.1 degrees Celsius) higher than they were in the late 19th century, before emissions of carbon dioxide and other heat-trapping gases became widespread. So extreme heat takes off from a higher starting point.
But beyond that, there are other factors, some involving the circulation of the atmosphere and the ocean, that may make Europe a heat wave hot spot.
No two heat waves are precisely the same. The current scorching temperatures that reached into England and Wales on Monday were caused in part by a region of upper level low-pressure air that has been stalled off the coast of Portugal for days. It’s known as a “cutoff low” in the parlance of atmospheric scientists, because it was cut off from a river of westerly winds, the mid-latitude jet stream, that circles the planet at high altitudes.
Low-pressure zones tend to draw air toward them. In this case, the low-pressure zone has been steadily drawing air from North Africa toward it and into Europe. “It’s pumping hot air northward,” said Kai Kornhuber, a researcher at Lamont-Doherty Earth Observatory, part of Columbia University.
Dr. Kornhuber contributed to a study published this month that found that heat waves in Europe had increased in frequency and intensity over the past four decades, and linked the increase at least in part to changes in the jet stream. The researchers found that many European heat waves occurred when the jet stream had temporarily split in two, leaving an area of weak winds and high pressure air between the two branches that is conducive to the buildup of extreme heat.
Efi Rousi, a senior scientist at Potsdam Institute for Climate Research in Germany and the lead author of the study, said the current heat wave appeared to be linked to such a “double jet,” which she said has been in place over Europe for the past two weeks. This could have led to the creation of the cutoff low, Dr. Rousi said, as well as to an area of weak winds over Europe that allowed the heat to persist.
“It seems this is really favoring the buildup of this heat wave,” she said.
There may be other reasons Europe is seeing more, and more persistent, heat waves, although some of these are currently the subject of debate among scientists. Natural climate variability can make it difficult to tease out specific influences, Dr. Rousi said.
Dr. Kornhuber said warming in the Arctic, which is occurring much faster than other parts of the world, may play a role. As the Arctic warms at a faster rate, the temperature differential between it and the Equator decreases. This leads to a decrease in summertime winds, which has the effect of making weather systems linger for longer. “We do see an increase in persistence,” he said.
There are also indications that changes in one of the world’s major ocean currents, the Atlantic Meridional Overturning Circulation, may affect Europe’s climate. Dr. Rousi published a paper last year that showed, using computer simulations, that a weakening of the current as the world warmed would cause changes in atmospheric circulation leading to drier summers in Europe.
As in other parts of the world, a heat wave in Europe can make it more likely for others to occur in the same area, because a period of extreme heat dries out the soil.
When there is some moisture in the soil, some of the sun’s energy is used in evaporating the water, leading to a slight cooling effect. But when one heat wave wipes out almost all the soil moisture, there is little left to evaporate when the next wave of hot air arrives. So more of the sun’s energy bakes the surface, adding to the heat.
