Large vortices formed in the oceans are mathematically equivalent to black holes, argue researchers in Switzerland and the USA. Hitherto unseen, these formations seem to transfer water over long distances and might affect the global climate.
The existence of these giant vortices, which can reach a diameter of 150 km, was known from previous observations. Their role in ocean circulation was difficult to study, as the limits of these rotating water formations were almost impossible to identify.
In a new study published in the Journal of Fluid Mechanics, a Swiss-American team presents a new mathematical technique that allows the detection and monitoring of such vortices from satellite images.
To the surprise of the researchers, the giant vortices are closed formations that from the mathematical point of view behave like black holes.
Black holes are objects so massive that anything, even light, cannot escape if approached over a specific distance. As it turns out, these giant whirlpools are also keeping all the ‘trapped’ water within them, i.e. they are closed formations of trapped water, such as black holes are closed formations of trapped mass.
In the case of black holes, there is a threshold beyond which there is no return, which is called the ‘event horizon’ (because no event can be seen beyond this limit). A ray of light that is passing through this limit follows a spiral orbit and then gets lost forever in the cosmic monster.
However, just outside the event horizon, there is another threshold called the ‘photon sphere’. A ray of light approaching this imaginary sphere does not fall into the hole, but instead it becomes curved and gets trapped in orbit around the black hole forever.
Researchers at the Federal Institute of Technology in Zurich, Swizzerland, discovered a similar photon sphere in giant ocean vortices, within which the water molecules are constantly moving in closed circles. And, just as it happens in a black hole, what is inside the vortex cannot escape in calm waters.
The closed boundaries of vortices are what allows their identification and tracking from satellite images, said the researchers.
They also point out that, since the vortices are closed and stable water formations, they effectively act as vehicles of water transportation over long distances.
At the same time, researchers at the University of Miami managed to recognize black hole-type vortices in the Agulhas Rings, a series of ocean vortices that appear in the southern tip of Africa and migrate to the Southern Ocean.
These findings were confirmed by independent researchers, also at the University of Miami, who used the new technique to discover a black hole-type vortex in the Gulf of Mexico.
The scientific team suspects that other liquid formations outside the oceans may be also the mathematical equivalent of black holes. For example, such a case may be the Great Red Spot, a giant stable vortex on Jupiter.