MOSCOW, July 22, Tatyana Pichugina. An extreme heat belt has formed in the Northern Hemisphere. Heat domes covered the southern states of the United States and northern China, and Europe received a heatstroke from the Sahara. Thousands of temperature records have been broken on land and in the oceans. People are dying. understood the reasons.
Started in the South, responded in the North
The wildfire season in Canada seemed to develop according to the standard scenario, but after six weeks the elements got out of control . Hundreds of outbreaks spontaneously broke out across the country. The authorities announced a mass evacuation of the population.
At the end of June, it became clear that the fires were intensifying. According to a government report, there are about five hundred fires in the forests, half of which are uncontrolled. Ten million hectares of land were scorched (usually 2.5 million on average). The situation was recognized as unprecedented in the history of observations.
In late spring, the first signs of an impending El Niño, the warm phase of the Southern Oscillation, the largest climate event on the planet, were recorded off the coast of Peru. El Niño occurs once every few years and leads to abnormal warming of the Pacific Ocean between Australia and South America, which ultimately affects global weather. The warm phase lasts from two to four years and is replaced by a cool one — La Niña.
The US National Oceanic and Atmospheric Administration reported El Niño on June 8. According to the simulations, it will peak in 2024 and it looks like it will be very strong.
Heat Competition
This summer broke several global weather records at once. June and July have been the warmest months since at least 1979. And on July 3, when the average temperature on the planet reached 17 degrees, it was anomalous in the entire history of observations.
The heating of the World Ocean also exceeds the average values by 0.8 degrees. It is believed that the matter is in the excess energy accumulated in the cool phase, which lasted for three and a half years — La Niña. Warm water is now rising to the surface.
Authorities monitoring sea ice in Antarctica, where it is winter, are marking a record low extent.
At the same time, anomalous heat waves are being reported from different parts of the Northern Hemisphere. The southern regions of the USA, Europe, and northern China are especially affected.
In the US states of Florida and California, the heat anomaly continues for an unprecedented 39 days. 2,300 local temperature records have been broken there, according to the media. Millions of people suffer from the heat. Hospitals are overcrowded — like in the COVID-19 pandemic.
In the densely populated metropolis of Phoenix, the capital of Arizona, the temperature does not drop below 43 degrees for 19 days. That's a lot even for a desert climate. The last time a long heat wave covered the region in 1974, but the current one has surpassed everything. In Phoenix, 12 people died directly from the heat. In total, there are 55 deaths in the country associated with a thermal anomaly.
In the Mediterranean countries of Europe — at least 38 degrees, sometimes over 40. In Sicily — 46.3. Forest fires break out. Spontaneous power outages all over Italy.
The heat wave forced the authorities to issue the highest risk warnings, in Greece closed the Acropolis for several days. The fears are not in vain. Nature emphasizes that heat is very bad for health. Scientists counted over 70,000 excess deaths in the summer of 2003, during a heatwave. In the summer of 2022, there were about 61 thousand.
China is also suffering. The heat came in the north of the country at the end of May, two weeks ahead of schedule. Four heat waves followed at once. In Beijing in June, according to the National Climate Center, the temperature exceeded 41 degrees, breaking the record. And on July 17, in the urban district of Turpan, Xinjiang province, in the west, 52.2 was recorded — the maximum since 2015.
What El- Nino
Scientists explain abnormal heat by failures in the general zonal circulation of the atmosphere. The high altitude jet stream in the Northern Hemisphere is blocked and too much heat has accumulated. The result is extreme heat in some places, severe flooding in others, like in Japan, and in some places even below normal temperatures (for example, in New York).
A high-altitude jet stream flows around the British Isles from the south, Malcolm Mistry, assistant professor of climatology at the London School of Hygiene and Tropical Medicine, explains in an interview with the Science Media Center. As a result, at higher latitudes — cool Arctic air and a low pressure area, lower, on the contrary, — a high pressure area into which hot air is drawn from Africa. Atlantic, and the trade winds, which bring mineral dust from North Africa, cooling the ocean. This time the machine failed. Carsten Heustein of the German Climate Center adds another factor: Regulations on aerosol emissions from ships came into force in 2020, which may have temporarily accelerated warming in the North Atlantic.
El Niño has yet to be dealt with. So far, scientists are leaning towards blaming a combination of factors.
Mistry believes that what is now observed in the southern United States and eastern China can be called heat domes. These are air masses trapped in an area of high pressure. In summer it is already so hot here, but due to the long immobility of the air and the heat coming from the earth's surface, a temperature excess has formed. In addition, clouds do not penetrate under such a dome.
Many are wondering if this is due to climate change. Heusstein believes that, at least in terms of records, the answer is yes. Mistry is more cautious: «From the trend of recent years, such blocking atmospheric anomalies will become more frequent, but observations are needed to confirm this. Such phenomena are studied using climate simulations.» more frequent and stronger heat waves. There is no consensus about the high-altitude jet stream, «comments Professor Liz Stephens from the University of Reading. «Heat waves are silent, unnoticed killers. We do not notice how they affect health until death statistics come in a few months later,» the expert adds.
How long record heat waves and domes will last will become clear in the coming weeks . It is predicted that in the US the anomaly will continue into August. As for the long-term forecast, scientists remind: El Niño is only gaining momentum. What is his strength and what to expect from him, we will find out in the winter.