While it’s still hotly debated among scientists whether climate change causes a shift from the traditional form of El Niño to one known as El Niño Modoki, scientists now say that El Niño Modoki affects long-term changes in currents in the North Pacific Ocean. The study was published online in the journal Nature Geoscience.
El Niño is a periodic warming in the eastern tropical Pacific that occurs along the coast of South America. Recently, scientists have noticed that El Niño warming is stronger in the Central Pacific rather than the Eastern Pacific, a phenomenon known as El Niño Modoki (Modoki is a Japanese term for “similar, but different”).
Last year, the journal Nature published a paper that found climate change is behind this shift from El Niño to El Niño Modoki. While the findings of that paper are still being debated, this latest paper in Nature Geoscience presents evidence that El Niño Modoki drives a climate pattern known as the North Pacific Gyre Oscillation.
His research found that El Niño Modoki is responsible for changes in the oscillation, said Emanuele Di Lorenzo, associate professor in the School of Earth and Atmospheric Sciences at the Georgia Institute of Technology. The reason this is important is because the oscillation has significant effects on fish stocks and ocean nutrient distributions in the Pacific, especially along the west coast of the United States, he said.
The North Pacific Gyre Oscillation, named two years ago by Di Lorenzo and colleagues in a paper in Geophysical Research Letters, explained for the first time long-term changes in ocean circulation of the North Pacific, which scientists now link to an increasing number of dramatic transitions in coastal marine ecosystems.
The ecosystems of the Pacific may very well become more sensitive to the oscillation in the future, said Di Lorenzo. His data show that this oscillation is definitively linked to El Niño Modoki, so as Modoki becomes more frequent in the central tropical Pacific, the oscillation will also intensify, he said.
By the Georgia Institute of Technology news service