An international team of researchers has identified another El Niño—a variation in winds and currents in the tropical Pacific Oceans that influences weather across the planet. The Southern Hemisphere Circumpolar Wavenumber-4 Pattern, dubbed the “New El Niño,” is emerging to the south of the southwestern subtropical Pacific. “This discovery is like finding a new switch in Earth’s climate,” meteorologist Balaji Senapati of the University of Reading, UK, told ScienceAlert. Early in the Southern Hemisphere’s summer (between December and February), in a relatively small area of ocean near Australia and New Zealand, annual fluctuations in sea surface temperature occur that are linked to a specific pattern known as wavenumber-4 (W4), which causes changes in atmospheric temperatures in the subtropics and mid-latitudes. Winds then carry these temperature changes through the atmosphere, and according to studies, can carry warm or cool air around the globe in a climate pattern distinct from the known El Niño and its sister phenomenon, La Niña, which occur in the equatorial Pacific. The discovery helps explain the intense droughts seen in the Southern Hemisphere in recent years (Journal of Geophysical Research: Oceans, July 6; LiveScience, July 25).
RepublishMeteorology
Another El Niño, south of the equator
Wind and current changes in the Pacific influence climate across the planet
