“The girl It ended”, wrote the National Weather Service sharing the news announced by the US Oceanic and Atmospheric Administration (NOAA). The agency anticipated that “andn Argentina we are not going to see much variation yet in rainfall”, at least for the next few
The decline of the climatic phenomenon is important for Argentina, which has been suffering from La Niña for almost three years, which worsened the droughts in much of the country. However, experts fear the arrival of El Niño, which is usually accompanied by greater rainfall, for the second half of 2023.
“Despite the change in ocean temperature, the atmosphere is still maintained with a circulation according to that of La Niña”, they warned from the SMN. La Niña has been officially replaced by “ENSO-neutral conditions,” the NOAA Climate Prediction Center explained in its “La Niña Final Advisory” on Thursday morning.
But, what does enso neutral mean: This is the same as saying that neither La Niña nor El Niño are present. “ENSO neutral effectively means that the conditions in the tropical Pacific are closer to average, so there is not a great interruption in the atmospheric circulation that El Niño La Niña offers,” Michelle L’Heureux, a meteorologist for the Nexstar agency, told the agency. Climate Prediction Center,
“During February 2023, below-average sea surface temperatures weakened and currently only persist over the central Pacific Ocean,” NOAA specifies.
When do the rains come?
You will still have to be patient. “Just because the girl has come to an end doesn’t mean it’s suddenly going to start raining. This is because one of the ENSO components, the ocean, has already changed its phase, but the atmosphere is not as fast. In general, this gaseous mass finds it a little more difficult to react to changes in the temperature of the water, that is, it is not something immediate,” the meteorologist explained to PROFILE. Sergio Jalfin.
“Despite this announcement of the end of La Niña, the reality is that the atmosphere is still behaving as if this phenomenon were still present. In the central region of the country and the coast we have two precipitation maximums every year due to the natural weather, which are in the fall (March-May) and in the spring (September-November). It is likely that this autumn it rains a little more in relation to the last autumns, but rainfall will still be insufficient. The same they would probably be normalizing towards the spring of this year”, he anticipated.
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La Niña and its impact on the hottest summer in history
The extreme and infrequent heat that is sustained this March responds to various factors, including La Niña. “La Niña is directly associated with drought and therefore with the lack of rainfall. So if it doesn’t rain the days are clearer and due to the effect of solar radiation the temperature rises more. This is logical, since, since there are no clouds at this time of year, the days end up being hot”, Jalfin pointed out.
“In addition, since November 2022 there have been several heat wave events, the current one being the ninth heat wave that is underway. That is to say that this heat wave is also a consequence of all the previous ones that have already occurred during this summer, that is to say, it is the story that the atmosphere brings ”, he maintained.
“We are living the hottest summer in history. In addition to all these described conditions, in recent days, a very particular general configuration of the atmosphere in central and northern Argentina: very light winds at all levels of the atmosphereassociated with the predominance of high pressures, resulting in very stable conditions, preventing the arrival of frontal systems from Patagonia,” Jalfin explained to this medium.
“And all this circulation it remains stationary as a ‘block’, which means that the temperatures practically do not change. When these types of blocks appear, they generally last 8 to 10 days maximum. The impressive thing about that event is that this situation began in the last days of February, and It could be extended until March 18 or 19 at least. And this is what defines this event as extraordinary, because it can last between 20 and 25 days since it began, there is no precedent for something like this,” he stressed.
What are El Niño and La Niña?
According to the description provided on the National Meteorological Service (SMN) website, “El Niño/Southern Oscillation (ENSO) is a natural phenomenon characterized by fluctuating ocean temperatures in the central and eastern part of the equatorial Pacific, associated with changes in the atmosphere”. It modifies the climatic conditions of various parts of the world and in particular the South American region.
“El Niño and La Niña are the oceanic components, while the Southern Oscillation is the atmospheric component, and both give rise to the term El Niño/Southern Oscillation. This phenomenon comprises three phases: El Niño, La Niña and a neutral phase.
“Particularly during the spring and summer, the northeast of Argentina tends to register higher than normal rainfall during an El Niño phase. During the La Niña phase, the same area tends to record rainfall below normal”, they explain.
This phenomenon is declared “when sea temperatures in the tropical eastern Pacific increase/decrease 0.5°C above/below average for several consecutive months (5 quarters)”.
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