What is El Nino? Has the extreme El Niño become more often?

El Niño is a climate phenomenon that takes place over the equatorial Pacific. When there is a warming of the sea surface temperature in the eastern and central equatorial Pacific Ocean, it is known as El Niño. When the opposite cooling phase takes place, it is known as La Niña.

While El Niño causes warmer temperatures over the equatorial Pacific, these are known to suppress monsoon rainfall. When La Niña happens, it has been found to be helpful in bringing good rainfall.

El Niño is one phase of an alternating cycle known as El Niño Southern Oscillation (ENSO). ENSO can result in extreme weather events in many regions of the world, and therefore has very important implications for seasonal climate predictions, including the monsoon in India.

Has Extreme El Nino become more often?

A new study published in the journal Proceedings of the National Academy of Science by the researchers from the University of Hawaii at Manoa International Pacific Research Center (IPRC) makes the following observations:

• Because of climate change, extreme El Niño events are likely to become more frequent.
• Factors such as increased surface temperatures in the western Pacific warm pool and easterly winds in the central Pacific along with continued global warming may lead to a continued increase in frequency in extreme El Niño events.

These frequent extreme El Niño trends due to anthropogenic forcing will induce profound socioeconomic consequences.