The European Space Agency (ESA) has announced the discovery of an additional magnetic field around the Earth, detailing that this previously unknown phenomenon is caused by ocean currents.
Specifically, ESA was able to distinguish the magnetic contribution due to ocean tides from other factors such as the molten iron from the outer core of the planet and the magnetized rocks in the earth's crust, a task previously considered extremely difficult to carry out due to the fact that the magnetic effect of the tides is much lower.
The discovery was made with the help of three satellites from the ESA Swarm mission, which for four years orbited an average of 400 kilometers above the earth's surface collecting magnetic signals. The results showed that the second field, detected at that altitude, turned out to be 20,000 times weaker than the global magnetic field.
"We have used Swarm to measure the magnetic signals of the tides from the surface of the ocean to the seabed," Nils Olsen, head of geomagnetism at the Technical University of Denmark, said in a statement, adding that the finding will help to understand More accurate oceanic behavior.
"This gives us a truly global picture of how the ocean flows in all depths, and this is new," he said of the discovery, which will also serve to generate better models to describe global warming.