Scientists have discovered a climate phenomenon similar to El Niño, starting off the coast of New Zealand, which could cause temperature changes across the Southern Hemisphere.
El Niño and La Niña, temperature variations in the Eastern Pacific, impact the entire globe, causing droughts and floods in various regions. Researchers have recently found a similar phenomenon with widespread effects in the Southern Hemisphere, originating from a small area in the Pacific, off the coast of New Zealand, IFL Science reported on July 24.
Conditions in a relatively small ocean area can significantly affect global climate and weather patterns. (Photo: Shane Bartie)
Specifically, the researchers simulated climate conditions over a 300-year period during pre-industrial times and observed a continuously repeating sea surface temperature pattern. The new study, published in the journal Geophysical Research: Oceans, was conducted by a team of experts at the Indian Institute of Technology Kharagpur and the Japan Agency for Marine-Earth Science and Technology.
The research team named the new phenomenon “Wave Model 4 Southern Hemispheric Pattern”, or W4. “This discovery is akin to finding a new ‘switch’ for Earth’s climate. It indicates that a relatively small ocean region can have far-reaching effects on global climate and weather patterns,” said a member of the research team, an expert at the Indian Institute of Technology Kharagpur.
W4 begins off the coast of New Zealand when an area of unusually warm or cool water forms during the Southern Hemisphere summer. This creates an atmospheric ripple, producing alternating regions of contrasting temperatures around similarly latitudinal ocean areas. When fully developed, the wave pattern consists of 4 warm regions and 4 cool regions.
W4 tends to dissipate by late autumn (Southern Hemisphere), meaning its duration is usually shorter than that of El Niño and La Niña. Many weather phenomena are associated with either El Niño or La Niña. However, W4 can occur with either or during neutral years.
Most people do not pay much attention to sea surface temperatures, unless they affect conditions on land, as is the case with El Niño and La Niña. In the new study, the scientists noted that the impact of W4 on rainfall over land needs further investigation.
El Niño and La Niña can have severe consequences in vulnerable regions. In bad years, droughts and floods can claim hundreds of thousands of lives. Food supplies are also frequently disrupted, but the growing knowledge and predictive capabilities regarding El Niño and La Niña have significantly mitigated damages as farmers adjust their practices.
Senapati believes the same applies to W4. “Understanding this new weather system could significantly improve weather forecasts and climate predictions, particularly in the Southern Hemisphere. It also has the potential to help decode previously unresolved climate changes and enhance the ability to predict extreme climate and weather events,” he stated.
