Saturday, December 7

Why It’s Alarming That Deep-Sea Currents are Beginning to Slow

Down in the coldest recesses of the inmost oceans, Earth’s circulatory system is pumping the brakes. Left untreated, it threatens to stop a procedure that manages the world’s energy balance and supports our environment.

“Earth’s environment is basically managed by our ocean and by the ocean’s reversing flow,” states Matthew England, an oceanographer at Australia’s University of New South Wales. In March, he and a group released the most comprehensive international design of Antarctic water masses and other deep-sea currents to date in the journal Nature. They discovered that, compared to its circulation in the 1990s, this important oceanic conveyor belt might slow by about 40 percent before 2050.

Where are the Ocean Currents?

Deep water flow begins at the polar extremes. In the southern Antarctic seas, freezing seawater relinquishes its salt, triggering the water around it to grow heavy. Cold as ice and far saltier than a can of sardines, it plunges to more than 13,000 feet and starts slipping northward into the world’s sunken ocean basins.

As years pass, this extra-salty Antarctic Bottom Water (AABW) sneaks towards the subtropics. There, waves and vortexes pull it to the surface area, making space up leading by pressing warmer water to greater,

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