A climate phenomenon known as La Niña has begun to develop in the equatorial region of the Pacific Ocean. This was announced by the National Oceanic and Atmospheric Administration (NOAA) of the United States.
According to experts, La Niña has brought some surprises this year. Climatologists believe that this weather phenomenon is likely to be shorter and weaker than usual.
La Niña regularly occurs in the southern part of the Pacific Ocean when stable easterly winds push warm water away from the coasts of Peru and Chile towards Indonesia and Australia. As a result, cold water from the depths rises to the surface, leading to a cooling in the region.
Meteorologists informed the Associated Press (AP) that northern regions of South America may experience more precipitation than usual due to La Niña. La Niña also contributes to an increase in hurricane activity in the Atlantic Ocean.
However, experts believe that the current La Niña has developed later than expected and has not gained strength before winter arrives. Scientists think that La Niña will last until April and will not be recorded in the official observation history if it ends by March.
Difference Between El Niño and La Niña
El Niño and La Niña are two opposing climate phenomena in the Pacific Ocean that influence weather patterns worldwide. Trade winds in the Pacific typically blow from east to west, pushing warm surface waters towards the western part of the ocean.
El Niño occurs when these winds weaken or change direction, causing waters in the eastern Pacific—along the coasts of North and South America—to become warmer than usual.
During La Niña, the easterly trade winds strengthen, and warm waters are pushed further west towards the coasts of Australia and Southeast Asia. This results in the "upwelling" of cold water from the ocean depths, causing sea surface temperatures to be cooler on average, especially in North and South America.
Episodes occur every two to seven years and usually last from nine to twelve months.
Both El Niño and La Niña can affect weather conditions globally. Although each episode is different, La Niña is associated with wetter-than-normal weather in certain parts of the world, such as northern Australia, southeastern Africa, and northern Brazil. Additionally, some regions may experience an increased risk of flooding, and the hurricane season may become more intense.
Unusual Situation
The Earth has experienced three consecutive La Niña phenomena from 2020 to 2023. "We have had three consecutive winters with La Niña conditions, which is unusual because the only other time this happened was from 1973 to 1976," said Michelle L'Heureux, a climatologist at NOAA.
"La Niña typically lasts longer and occurs more frequently than El Niño," the specialist notes.
Ben Cook, a climatologist at NASA's Goddard Space Flight Center, warned that the frequency of La Niña events could create additional stress for regions that have recently struggled with drought, such as East Africa.