An El Niño currently appears possible after three wet La Niña years, which could reduce rainfall, increase temperatures, and result in nightmare wildfire conditions.
There is a huge blob of warm water between 100 and 200 meters deep in the Pacific Ocean, stretching almost 12,000 kilometers along the equator.
If enough of that water rises to the surface, it may trigger an El Niño event, which could increase global temperatures and increase the likelihood of heatwaves, droughts, and bushfires in Australia.
Prof. Axel Timmermann, the head of the IBS Center for Climate Physics at Pusan National University in South Korea, likens it to a loaded rifle. The atmosphere hasn’t fired the trigger yet, but the magazine is full.
What is El Niño, and will it certainly occur?
Due to the size of the Pacific Ocean, El Nioñs’ effects can be felt all over the world, resulting in delayed or unsuccessful monsoons on the Indian subcontinent as well as floods and landslides in Central America.
The cooler cousin of El Niño, La Niña, which causes lower-than-normal ocean temperatures in the central Pacific, has just finished three years in Australia. This influenced Australia’s temperatures in a cooling way, but it also contributed to catastrophic rainfall and flooding.
The El Niño-Southern Oscillation, or Enso, is the name given to this cycle between El Niño and La Niña. It also contains a neutral phase, which is where we are right now.
The central equatorial Pacific’s temperatures will have climbed to at least 0.8C above average by August, according to climate models from weather agencies around the world analyzed by the Bureau of Meteorology, entering El Niño zone.
In its most recent prognosis, the US National Oceanic and Atmospheric Administration stated that there was a 62% possibility of an El Niño forming by July.
However, climate experts emphasize that during the autumn in the southern hemisphere, they have less faith in their models. For instance, a strong El Niño that was forecasted for 2014 never materialized.
According to Timmermann, many powerful wind bursts from the west to the east are required to start an El Niño, but so far, that hasn’t happened.
He asserts that the models cannot forecast winds, despite the fact that there is broad consensus among them that an El Niño is expected to develop later this year. This is one of the factors lowering forecast confidence at this time of year.
In order for an El Niño to occur, the atmosphere must react with those warm ocean waters, according to Dr. Andrea Taschetto, an Enso expert at the University of New South Wales.
We must keep in mind that this system is connected, she says. “Both the water and the atmosphere must react. The winds are very significant.
Another clear indication that an El Niño is developing is a weakening of the trade winds, which typically blow from east to west and allow warmer, deeper water to ascend to the surface.
Forecasters will wait until May or June to be truly confident.
Does El Niño always mean hot and dry for Australia?
If an El Niño develops, Australia may benefit from knowing where it is.
According to Taschetto, El Niños with warm surface water in the central Pacific are more likely to be linked to a lack of rainfall in Australia than El Niños with warmer water farther east.
According to Taschetto, the 1997–1998 and 2015–16 strong El Niños were more eastwardly centered and had less of an impact on Australia’s rainfall.
El Niño occurrences in the eastern Pacific do not have a significant impact on Australia, but they do elsewhere, particularly in South and North America. Australia often experiences more effects from central Pacific El Niños.
El Niños in the central Pacific are thought to weaken the updrafts that aid in the formation of clouds and rain over Australia’s east coast.
Taschetto claims that it is still too early to pinpoint the exact location of any El Niño.
Regardless of where in the Pacific they occurred, a research conducted last month by CSIRO scientists examined all El Niño episodes since 1950 and concluded that, on average, they quadrupled the likelihood of a dry spring for eastern Australia. However, there were some exceptions.
While the huge eastern two-thirds of the continent were hit, Brisbane and Sydney, along the crowded eastern shore, were less affected.
How powerful could this El Niño be?
Forecasts from some national weather organizations, including Australia’s, increase the likelihood of an intense El Niño,
in which Pacific temperatures are around 2C above average.
The US National Oceanic and Atmospheric Administration’s Dr. Mike McPhaden stated this week that there is a very wide range in the expected El Niños’ magnitude, ranging from “blockbuster” to “wimp.”
According to Noaa’s assessment from this week, there is a 40% possibility that a strong El Niño with ocean temperatures above 1.5C would be active by the end of the year.
However, Timmermann and others have cautioned that it is still too early to put too much stock in their predictions.
The size of an El Niño “is not necessarily related to the size of the impacts,” according to Dr. Jaci Brown, research director of CSIRO’s climate intelligence program.
“Each El Niño is unique. However, it is currently telling us which direction to lean rather than which way to jump, as they say in agriculture.
What dangers exist?
Marine researchers have noted that El Niños increase the likelihood of severe coral bleaching along the Great Barrier Reef in addition to reducing rainfall and raising temperatures.
Climate scientists and bushfire specialists in Australia have expressed great concern that the excessive development of grass and vegetation could result in nightmare blaze conditions next summer after three rainy La Niña years.
According to Brown, the horrific and unheard-of black summer bushfires in 2019 and 2020 should not be forgotten.
“With this record-breaking [vegetation] increase, we are now prepared for bushfires. We could be in for one of the worst bushfire seasons ever, in my opinion.
According to Taschetto and Brown, there is still much to learn about the dynamics of Enso. This field of study is ongoing.
But according to research, El Niños and La Niñas will likely get more extreme as the climate warms, according to Brown.