There are still two months of summer left. Temperatures are rising across Europe at or near triple digits. According to scientists, this year’s continued high heat is in accordance with a trend. They claim that heat waves in Europe are becoming more frequent and intense faster than in practically any other region of the world, including the Western United States.
Temperatures are on average around 2 degrees Fahrenheit (1.1 degrees Celsius) higher than they were in the late 19th century, when emissions of carbon dioxide and other heat-trapping gases became common, global warming causes heat waves all over the world. This results in intense heat beginning at a higher altitude. However, there are additional causes that could turn Europe into a hot zone for heat waves, some of which involve the circulation of the atmosphere and water.
A region of upper level low-pressure air that has been stationary off the coast of Portugal for days is partly responsible for the present scorching temperatures that reached England and Wales on Monday. In the parlance of atmospheric scientists, it is referred to as a “cutoff low” because it was isolated from the mid-latitude jet stream, a river of westerly winds that encircle the planet at great altitudes.
Air tends to go toward areas of low pressure. The low-pressure area in this situation has been progressively luring air from North Africa toward it and into Europe. It is pumping hot air northward.
A study this month found that heat waves in Europe had increased in frequency and intensity over the previous 40 years. Kai Kornhuber, a researcher at Columbia University’s Lamont-Doherty Earth Observatory, linked the increase to changes in the mid-latitude jet stream, which circles the planet at great altitudes.
The researchers discovered that many of Europe’s heat waves occurred when the jet stream divided briefly into two branches, creating a region of low winds and high pressure air that is ideal for the development of extremely hot temperatures.
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 appears to be related to such a “double jet,” which she claimed has been over Europe for the previous two weeks. According to Dr. Rousi, this may have resulted in the formation of the cutoff low and a region of feeble winds across Europe that allowed the heat to continue.
It appears that this is significantly promoting the development of this heat wave, she said.
There may be additional causes for Europe’s increasing and severe heat waves. According to Dr. Rousi, the variability of the natural climate can make it challenging to isolate specific factors.
According to Dr. Kornhuber, the Arctic’s warming, which is occurring much more quickly than in other parts of the world, could be a concern. The difference in temperature between the Equator and the Arctic reduces as the Arctic heats more quickly. This results in a reduction in summer winds, which has the effect of extending weather systems. “We do observe a rise in persistence,” he added.
Additionally, there are hints that the Atlantic Meridional Overturning Circulation, one of the world’s largest ocean currents, may have an impact on Europe’s temperature. In a paper he released last year, Dr. Rousi used computer simulations to demonstrate how a weakening of the current as the planet warmed would alter air circulation, resulting in drier summers in Europe.
Temperatures are on average around 2 degrees Fahrenheit (1.1 degrees Celsius) higher than they were in the late 19th century, when emissions of carbon dioxide and other heat-trapping gases became common, global warming causes heat waves all over the world. This results in intense heat beginning at a higher altitude. However, there are additional causes that could turn Europe into a hot zone for heat waves, some of which involve the circulation of the atmosphere and water.
A region of upper level low-pressure air that has been stationary off the coast of Portugal for days is partly responsible for the present scorching temperatures that reached England and Wales on Monday. In the parlance of atmospheric scientists, it is referred to as a “cutoff low” because it was isolated from the mid-latitude jet stream, a river of westerly winds that encircle the planet at great altitudes.
Air tends to go toward areas of low pressure. The low-pressure area in this situation has been progressively luring air from North Africa toward it and into Europe. It is pumping hot air northward.
A study this month found that heat waves in Europe had increased in frequency and intensity over the previous 40 years. Kai Kornhuber, a researcher at Columbia University’s Lamont-Doherty Earth Observatory, linked the increase to changes in the mid-latitude jet stream, which circles the planet at great altitudes.
The researchers discovered that many of Europe’s heat waves occurred when the jet stream divided briefly into two branches, creating a region of low winds and high pressure air that is ideal for the development of extremely hot temperatures.
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 appears to be related to such a “double jet,” which she claimed has been over Europe for the previous two weeks. According to Dr. Rousi, this may have resulted in the formation of the cutoff low and a region of feeble winds across Europe that allowed the heat to continue.
It appears that this is significantly promoting the development of this heat wave, she said.
There may be additional causes for Europe’s increasing and severe heat waves. According to Dr. Rousi, the variability of the natural climate can make it challenging to isolate specific factors.
According to Dr. Kornhuber, the Arctic’s warming, which is occurring much more quickly than in other parts of the world, could be a concern. The difference in temperature between the Equator and the Arctic reduces as the Arctic heats more quickly. This results in a reduction in summer winds, which has the effect of extending weather systems. “We do observe a rise in persistence,” he added.
Additionally, there are hints that the Atlantic Meridional Overturning Circulation, one of the world’s largest ocean currents, may have an impact on Europe’s temperature. In a paper he released last year, Dr. Rousi used computer simulations to demonstrate how a weakening of the current as the planet warmed would alter air circulation, resulting in drier summers in Europe.
