Arctic sea smoke near Qingdao, China on January 7, 2021 when cold surge hit northern China. A result of frigid air passing over relatively warm water, the phenomenon is rare, even in the Arctic. Credit: Shaoqing Wang
Key Points:
- Recent climate estimates indicate a rare third La Niña event could occur next year.
- It would be the first third-year La Niña since the 1998 to 2001.
- El Niño–Southern Oscillation has many socioeconomic impacts, including food security, agricultural production, human health, water resources and more.
El Niño–Southern Oscillation (ENSO) is an irregular periodic variation in winds and sea surface temperatures over the tropical eastern Pacific Ocean that affects the climate of much of the tropics and subtropics.
Typically, ENSO peaks during boreal winter and disappears in spring with somewhat periodic oscillations of 2 to 7 years. ENCSO rarely maintains for long in either its cold phase (La Niña) or warm phase (El Niño). However, since the turn of the current century, researchers have recorded three instances of so-called “double dip” La Niña events—2007 to 2009; 2010 to 2012 and 2020 to 2022.
Now, based on updated data from several organizations issued in April 2022, scientists are predicting something even rarer than a double dip—a third-year La Niña lasting through 2023.
“This would be the first third-year La Niña since the 1998 to 2001 event, which was the only such event observed since 1980,” said Xianghui Fang from Fudan University in China.
Investigating the status of the atmosphere–ocean system over the tropical Pacific in March 2022, Fang and his collaborator, Fei Zheng, found that the equatorial central to eastern Pacific was still maintaining colder conditions than normal, and the southeasterly winds over the equatorial Pacific were appreciable.
They analyzed the possible contributions of four physical factors related to the thermocline—the boundary between warmer ocean water at the surface and cooler water below—and surface winds in this potential third-year La Niña. They found that the atmospheric variables in Spring 2022 indicate the easterly and southerly winds will reach their largest amplitude since 1980, which supports the emergence of a third-year La Niña.
While there is much uncertainly in climatic effect, the researchers urge others to stay alert.
“We should be aware of the risk of intense cold surges in Eurasia, which could also produce more cold extremes either in eastern or northeastern China,” Fang warns.
ENSO has many socioeconomic impacts, including food security, agricultural production, human health, water resources and more.
Information provided by Chinese Academy of Sciences.