The United States National Oceanic and Atmospheric Administration (NOAA), the agency responsible for monitoring climate and oceans, is expected to officially announce the end of the phenomenon after 14 consecutive weeks.
The La Niña phenomenon is nearing an end after almost five months of colder-than-average surface waters in the equatorial strip of the Pacific Ocean, according to an assessment by MetSul Meteorologia. The phenomenon occurs when surface waters in the central and eastern equatorial Pacific cool, causing changes in winds, atmospheric pressure and precipitation patterns.
The expectation is that the United States National Oceanic and Atmospheric Administration (NOAA), the agency responsible for monitoring the climate and oceans, will officially announce the end of the phenomenon after 14 consecutive weeks. Despite this, the Pacific still presents remnants of conditions associated with La Niña.
The sea surface temperature reached -0.8°C between the 12th and 19th of November and returned to that level in January, characterizing an episode considered weak and short-lived. On Wednesday, 27th, according to data from NOAA, the anomaly in the Central-Eastern Equatorial Pacific is at -0.3°C, a value that falls within the neutrality range, which goes from -0.5°C to +0.5°C. The last record at this level was on October 8, also at -0.3°C.
According to MetSul, the recent period of neutrality would still not be enough, in itself, to declare the definitive end of La Niña. However, the presence of warmer waters below the ocean’s surface raises doubts about the possibility of a new cooling process resuming.
The identified period of neutrality may precede El Niño. The climate phenomena La Niña and El Niño are natural oscillations in the interaction between the ocean and the atmosphere. Generally speaking, La Niña occurs when the equatorial Pacific cools, while El Niño is characterized by the warming of these waters. Both tend to change the rainfall and temperature regime in different regions of the planet, including South America.
Columbia University, in New York, points to a 5% probability of La Niña between March and May, 88% of neutrality and 7% of El Niño.
*With information from Estadão Conteúdo
