Climate Change is Pushing Giant Ocean Currents Poleward
The world’s major wind-driven ocean currents are moving toward the poles at a rate of about a mile every two years, potentially depriving important coastal fishing waters of important nutrients and raising the risk of sea level rise, extreme storms and heatwaves for some adjacent land areas.
The shift was identified in a new study by researchers with the Alfred Wegener Institute at the Helmholtz Centre for Polar and Marine Research (AWI) in Bremerhaven, Germany, and published Feb. 25 in the journal Geophysical Research Letters.
The poleward shift is bad news for the East Coast of the U.S., because it makes sea level rise even worse, the researchers said. At about 40 degrees latitude north and south, where the effects of the shifting currents are most evident, sea level rise is already 8 to 12 inches more than in other regions.
On the West Coast, salmon are being pushed out of traditional fishing waters. In densely populated coastal Asia, the changes could unleash more intense rainstorms, and the shift also makes heat waves more likely in subtropical areas.
Eight major wind-driven ocean currents, known as gyres, circulate around vast areas of ocean: three in the Atlantic, three in the Pacific, and one each in the Indian and Antarctic Oceans. The rotating currents shape the weather and ocean ecosystems in coastal regions, where parts of the currents have regional names, like the Gulf Stream along the East Coast of the U.S.