Weatherwatch: more El Niño events expected in future

David Hambling

New research in Nature Geoscience looks at coral records to show how the pattern of El Niño events has altered over the last four centuries.

El Niño, considered one of the most important climatic phenomena globally, involves a warming of the Pacific Ocean’s surface. The Spanish term for “The Boy”, referring to the infant Jesus, as El Niño’s effect may be most evident around Christmas. There are two types of El Niño, those in the eastern Pacific, close to South America, and those further out in the central Pacific.

As expected, the report found El Niño events have become more frequent. It also showed a change in the type.

“We used to have roughly the same number of central and eastern Pacific events,” says the lead researcher, Mandy Freund, of the University of Melbourne. “Most recently, we only have one eastern Pacific event and nine central Pacific events.”

Both types of events mean reduced rainfall in Asia and Australia, but the eastern Pacific version brings heavy rainfall and flooding in the Americas, while central Pacific events produce dry conditions. El Niño events also affect other weather phenomena around the globe, including cyclones and colder British winters.

The research will enable scientists to create better models to predict the effects of future El Niño events.