El Niño sets in.
One of the most powerful episodes of the phenomenon ever recorded will lead to a rise in temperatures in spring according to the World Meteorological Organization (ONM).
More precisely, "there is approximately a 60% chance that El Niño will persist between March and May" we can read in the institution's press release this Tuesday, March 5.
The warm side of the meteorological phenomenon called El Niño Southern Oscillation (ENSO), it is characterized by a positive temperature anomaly, i.e. a warming of the Pacific.
It causes a change in the circulation of the atmosphere, winds, temperatures and precipitation in remote areas.
All in a context of increasing greenhouse gas emissions.
However, it reached its peak between December 2023 and January 2024.
Why the late repercussions?
“We must understand that El Niño is a phenomenon governed by the oceans and not the atmosphere,” explains Davide Faranda, director of climatology research at the CNRS.
The difference ?
The volatility of the air causes visible effects in just a few days on temperatures while the ocean, governed by the inertia of water, affects the land after several months.
Hence this gap between the phenomenon and its effects.
Also read: What is El Niño, this meteorological phenomenon which promises temperature records?
Above all, El Niño returns cyclically every 4 to 5 years.
“Not always in the same way,” recalls the climatologist.
Although the phenomenon takes its name from the Christmas period, its peak has no calendar date.
“The peak can also occur in summer or early fall.”
It doesn't follow a perfect pattern.
Ditto, its cold counterpart, La Niña which tends to lower the temperature of the oceans, should develop later in the year, indicates the ONM.
In addition, there is “80% chance that climatic conditions will remain neutral between April and June,” continues the institution.
Regions under the influence of the Pacific
Not all territories are affected in the same way.
The tropical phenomenon, located in the Pacific Ocean, directly influences South America and Southwest Asia.
The fires that affected Chile, the heat waves in Brazil and the forest fires in Australia bear witness to this.
Other regions are affected such as Mexico and the United States where California receives more precipitation than normal.
Europe remains spared.
“There is no established link between El Niño and the European climate,” says Davide Faranda.
However, the Atlantic is also experiencing a wave of warming.
The latter influences the climate of the old continent.
The waters, currently very warm, can lead to more intense precipitation via the phenomenon of “atmospheric rivers”.
“They transport humidity and heat from the ocean to land and are likely to produce precipitation above the seasonal average,” explains the scientist.
The phenomenon was observed in France in the fall, leading to flooding in the north of France.