La Niña

The positive phase of the ENSO climate phenomenon. Before receiving this name it began to be called "El Viejo" and the "anti-El Niño," as it presents precisely the opposite conditions to El Niño. In this case, pressure decreases on the western side of the tropical band of the Pacific basin and increases on the eastern side. As a consequence, the trade winds intensify, causing the upwelling of deep cold waters and the progressive cooling of the surface waters of the equatorial Pacific. The temperature anomalies reached are smaller - and of opposite sign - than those occurring during El Niño episodes. The phenomenon does not have a fixed duration, ranging from 9 months in the shortest episodes to almost 3 years. Its onset usually occurs in the middle of the year, reaching its maximum intensity toward the end, with those first six months of life being when it manifests with the greatest intensity. Like El Niño, its impacts translate into different alterations in meteorological and oceanic patterns not only in the intertropical band of the Pacific Ocean, but in other, more distant areas of the planet.