New El Niño phenomenon discovered

The El Niño phenomenon is a climate phenomenon in which the sea surface temperature of the Pacific Ocean near the equator becomes higher than normal, disrupting weather patterns and causing abnormal weather such as droughts and heavy rains around the world. A research team from the University of Reading in the UK has reported that a climate phenomenon very similar to the El Niño phenomenon has recently been discovered to be occurring in parts of New Zealand and Australia.

Southern Hemisphere Circumpolar Wavenumber‐4 Pattern Simulated in SINTEX‐F2 Coupled Model - Senapati - 2024 - Journal of Geophysical Research: Oceans - Wiley Online Library
https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2023JC020801

New El Nino discovered south of equator - University of Reading
https://www.reading.ac.uk/news/2024/Research-News/New-El-Nino-discovered-south-of-equator

Mysterious 'New El Niño' Was Just Discovered South of The Equator : ScienceAlert
https://www.sciencealert.com/mysterious-new-el-nio-was-just-discovered-south-of-the-equator

The new El Niño phenomenon involves four alternating warm and cool regions that circle the Southern Hemisphere, starting in a small area of ocean near New Zealand and Australia, but creating a wave-like pattern in the atmosphere that eventually spreads across the Southern Hemisphere with the help of strong westerly winds.

The new El Niño phenomenon is similar to the El Niño phenomenon in that 'fluctuations in sea surface temperature affect wide-area weather through the atmosphere,' but the difference is that the El Niño phenomenon occurs in the tropics at low latitudes, whereas this new El Niño phenomenon occurs in mid-latitudes. The research team has named this new El Niño phenomenon 'Southern Hemisphere Circumpolar Wavenumber-4 Pattern'.

The research team used an advanced climate model that simulates 300 years of climate conditions to track this Southern Hemisphere Circumpolar Wavenumber-4 Pattern. This model can comprehensively represent the Earth's climate system by combining elements of the atmosphere, ocean, and sea ice, and by analyzing the data simulated by this model, the research team reported that they were able to identify a repeating pattern of sea surface temperature fluctuations around the Southern Hemisphere.

The Southern Hemisphere Circumpolar Wavenumber-4 Pattern occurs in the Southern Hemisphere summer, that is, from December to February, but it is not yet clear what changes will occur over the course of several months. However, since the climate patterns of the entire Southern Hemisphere have already been observed, it is thought that the Southern Hemisphere Circumpolar Wavenumber-4 Pattern can help explain the climate patterns.

'This discovery is like finding a new weather-changing switch on Earth,' said Balaji Senapati, lead author of the paper. 'It shows that a relatively small area of ocean can have far-reaching effects on the planet's weather and climate patterns.'