Thanks to a team of scientists, led by Kevin Speer at Florida State University, Tallahassee, who’s working with John Marshall, an oceanography professor at the Massachusetts Institute of Technology, another piece of the puzzle as to how water in the oceans circulates has been found.
The recent impact of Tropical Storm Isaac, likely to be upgraded to a hurricane today, brought Florida and Louisiana residents face-to-face, once again, with the realities of Mother Nature. The storm killed at least two dozen people in Haiti, caused schools and universities to close throughout Florida, and delayed the Republican National Convention in Tampa.
Ocean currents—and how those currents of warm and cold water interact with the atmosphere—are of course driving Isaac and any storm like it. So, Speer and his team are trying to gain a better understanding of how the rebalancing of heat energy, through those currents, works on our planet.
Before their latest paper, published in Nature Geoscience, the understanding of how the oceans circulate around the world had one big missing piece: You see, we know that when the sun heats up regions in the tropics more than the poles, it causes the ocean water near the poles to become colder. This cold water sinks. On the other hand, water in the tropics heats up, and this water tends to rise, to float on top of the ocean there, thus pushing more cold water down.
Now, with cold water being pushed down at the poles and cold water being pushed down near the equator, where does it all come up again? That was the question that needed answering, the riddle that needed solving in order to understand ocean currents on a global scale.
Speer, Marshall, and their teams now believe this colder water comes back up to the surface not in the warmer oceans, as had been previously thought, but in the Southern Ocean, which surrounds Antarctica.
“We’re not saying that nothing comes up in the rest of the World Ocean, just that the main thrust is in the Southern Ocean,” Speer said. “To a large extent it’s driven by the wind.”
And when he says “wind,” he’s not talking about a summer breeze or even a winter blast. Sailors have some names for winds in the Southern Ocean, including “Furious Fifties,” referring to 50-knot wind speeds.
Time to check those textbooks in terms of Earth science. You just might have to cross out a few details in light of this new research.