The US Weather Service has announced that the La Niña event has ended. But according to Martín Jacques, a geophysicist at the University of Concepcion, the impact is unpredictable for Chile at this point.
The National Oceanic and Atmospheric Administration (NOAA) announced on March 9, La Niña phenomenon On Earth, after analyzing data received from the Climate Prediction Center (NWSPCC).
La Niña events are characterized by lower sea temperatures in the central and eastern equatorial Pacific. It occurs every two to seven years, alternating between reverse episodes and neutral moments. These temperature changes can cause major climate changes around the world.
In the words of Dr. Martín Jacques of the Department of Geophysics, University of Concepción, “La Niña is a ‘cold period’ of a phenomenon called the El Niño Southern Oscillation (ENSO), which modulates climate conditions globally, particularly in Chile’s climate from year to year. variability of”.
The current episode began in September 2020 and could partially mitigate global warming, but 2021 and 2022 were both the hottest years on record since 2015, according to the World Meteorological Organization. (WMO) warned in a quarterly update.
As explained by climatologist Emily Becker on the website of NOAAthis ‘cold period’ ended after being present on the equatorial Pacific and South American coasts for 3 years, 1.5 of which was uninterrupted, and that pattern is expected to diminish in the coming weeks.
Geophysicists describe a potential step towards El Niño. But now is a very troublesome time for models. The latter is due to the ‘predictability barrier’ of the northern spring, which marks the point at which numerous El Niño-related climate events complicate predictions.
Impact in Chile
The past three years have seen the effects of La Niña on Chile’s climate. But in summers with signs of La Niña, the Altiplano and southern regions of Chile tend to record more rainfall, and the Central Valley tends to record higher maximum temperatures,” Jacques said. I will explain in detail.
“These are all part of recent meteorological observations. La Niña and El Niño events alternate every few years and are essentially opposite in character. events were listed as “Triple Girl” Well, it started in September 2020.
Now that it’s over, the cycle is held in neutral. “This means that the climate forcing associated with this phenomenon is weakening, which means that sea surface temperature anomalies are expected to moderate and the strength of the Southeast Pacific High to weaken. In other words, climate regulation. The factor is briefly “off” until it activates again (probably in a warm El Niño period).
“This is good news in the sense that elements of prolonged drought are fading in south-central Chile. However, we have to consider that there are other factors that determine weather conditions and work on other timescales,” the expert warned. “For example, beyond ENSO (annual scale), he now observes decadal forcings (since 2010), which are mainly responsible for the ‘megasechia’ in central Chile.”
Furthermore, he says there are factors that act on a weekly basis, and that all these factors “overlap” to produce climate and atmospheric conditions.
“El Niño is associated with favorable conditions for winter precipitation in central and southern Chile and warmer temperatures generally along the Chilean coast. There are centers that make predictions for ,” the climate scientist points out.
For example, “The International Climate Institute and society predict that neutral conditions will persist into the fall, followed by an El Niño event in the winter. However, some experts say El Niño could delay its arrival.” I point out that there is.
“It should be noted that we are now at a time when predicting future ENSO conditions has proven more complex. This is called the ‘predictability barrier.’ So, if El Niño takes hold in winter or spring, we can expect somewhat better precipitation conditions in central and southern Chile,” he explains.
Regarding the massive drought affecting the country, Jack indicates that there is still “uncertainty” about its future. , which is an inherently tropical phenomenon that operates on the scale of weeks. For now, as a result of this last indication, The Chilean Meteorological Service predicts above-average rainfall from Nuble to the south in March. Rains have fallen further south this month, but the front system has not reached Neuble and Bio-Bio much. ”
Impact on global warming
Earlier, in early March, the United Nations Meteorological Office warned that after a very long La Niña event that exacerbated drought and precipitation, a warm El Niño event could return, threatening to break global temperature records. Did.
“Despite the fact that the past eight years have been the warmest on record, the cooling caused by the long La Niña has temporarily capped global temperature rise,” said WMO Director-General Peteri Taalas. rice field.
But UN agencies warn that while La Niña is ending, a reverse warming event called El Niño is likely to occur.
“If we enter the El Niño stage now, it is likely that global temperatures will rise again,” he added.
“Tracking the variability between the two phases will help us prepare for potential shocks such as floods, droughts and extreme heat,” he told Agence France-Presse.
Although El Niño and La Niña are natural phenomena, they “occur in the context of climate change caused by human activities that increase global temperatures, affect seasonal rainfall patterns, and cause more extreme temperatures,” according to the WMO. emphasizes.