There are many indications that the climate phenomenon El Niño will occur in the tropical Pacific Ocean by July, writes the German public-law media ARD. In order to make more accurate forecasts, climatologists monitor a certain part of the ocean near the equator. And if large amounts of warm water accumulate there under the surface, this is considered a strong sign that El Niño is coming, explains the German public media.
When will the next El Niño occur?
The situation is exactly like this now, climate researcher Emily Becker tells ARD. "The probability of creating conditions for El Niño between May and July is 82 percent, and for winter - even 96 percent."
Computer models are getting better and better, says Karlsruhe meteorology professor Andreas Fink. "They all indicate that this event is coming." Accordingly, it is considered very likely that El Niño will occur soon.
What El Niño actually is
El Niño is the most significant natural climate phenomenon on Earth, writes ARD. Its name comes from Peruvian fishermen. As early as the 19th century, they observed how the sea water along the coast warmed up unusually strongly and fishing fell. Since this happened around Christmas, they called the phenomenon El Niño (from Spanish for the boy or the infant).
The other phase, in which the water is rather cold, is called La Niña - the girl. The two phases alternate periodically.
How frequent is El Niño?
El Niño occurs every two to seven years and reverses "normal" weather conditions, the German public media notes. The trade winds in the equatorial region usually direct warm surface waters from South America to the West. The direction depends on the Earth's rotation and the so-called Coriolis force - a complex inertial force.
The warm seawater leads to rainy periods in Southeast Asia, Oceania and Australia. And off the coast of South America, cold waters from the bottom rise to the surface - it remains colder and drier there.
How exactly does El Niño manifest itself
When El Niño appears, the balance of the water cycle is disrupted, as the trade winds weaken or stop altogether. The accumulated warm water returns to the coast of South America, and this can lead to heavy rains and floods there, along with the withdrawal of fish to colder waters. On the opposite side of the Pacific Ocean, the risk of heat, drought and forest fires increases.
If El Niño is particularly strong, it can even have repercussions as far as India or South Africa, writes ARD. The German public media explains that the strength of the phenomenon depends on the water temperature. When it comes to a "normal" El Niño, it is one degree above average. But it can also rise by two degrees or more in more intense events - as happened in 1982, 1997 and 2015.
Current values have meanwhile "almost reached the record from 1997", says Carsten Hausstein of the Leipzig Institute of Meteorology.
Super or Mega El Niño?
El Niño traditionally reaches its peak at Christmas. Most models predict a rise of two degrees for this season, which could lead to a new Super El Niño this year, Hausstein believes.
Climatologist Andreas Fink, for his part, would prefer to avoid terms like Super or Mega El Niño. "We scientists prefer to talk about "strong" or "very strong" El Niño." These are the categories used in the UN Climate Change Office's forecasts. Emily Becker believes that the probability of a strong El Niño is around 60 percent.
Which countries are most affected?
El Niño has its greatest impact in and around the tropical Pacific Ocean. Countries like Ecuador and Peru need to prepare now, says meteorologist Andreas Fink. However, this preparation is also a question of resources, and it is not known for sure what exactly will happen.
Forecasts in this regard are difficult. In El Niño, the atmosphere, i.e. the air, plays a decisive role in addition to the sea, and things are much more complex there. Climatologist Hausstein emphasizes to ARD: "While developments in the ocean can already be predicted relatively well, it is still too early to make reliable predictions for the atmosphere."
As for the question of whether El Niño would have any effect on the weather in Europe, there is no consensus among scientists, Fink points out. But El Niño would definitely lead to an increase in the global average temperature, since the Pacific Ocean would be able to absorb less heat from the atmosphere. And it could turn out that 2026 or 2027 will be the hottest year since measurements began.
Author: Florian Falzeder