MAGNETO-CORIOLIS WAVES

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 European Space Agency’s Swarm satellite mission has detected a completely new type of magnetic wave that generates across the outermost part of Earth’s outer core every seven years. 

According to, Nicolas Gillet, from the University Université Grenoble Alpes and lead author of the paper,  “Geophysicists already theorised  the existence of such waves, but they were thought to take place over much longer time scales than our research has shown.  

Measurements of the magnetic field from instruments based on the surface of Earth suggested that there was some kind of wave action, but we needed the global coverage offered by measurements from space to reveal what is actually going on.

The waves called as "Magneto-Coriolis" waves because they move along the Earth’s axis of rotation, as per the Coriolis effect moving from East to West in tall columns that can travel up to 930 miles (1,500 kilometers) per year. 

Earlier German Champ mission and Danish Ørsted mission,worked  on this  issue . Earth’s magnetic field is like a huge cover, protecting us from the  cosmic radiation and charged particles carried by powerful solar storms. 

This research is significant in Understanding exactly how and where our magnetic field is generated, why it fluctuates constantly, how it interacts with solar wind and, indeed, why it is currently weakening could be important.Most of the field is generated by the mass of superheated, swirling liquid iron that makes up Earth’s outer core 1,800 miles under our feet.

It acts like a spinning conductor, which generates electrical currents and the continuously changing electromagnetic field. ESA’s Swarm mission, comprises of three identical satellites, measures these magnetic signals that generates from Earth’s core, and other signals that come from the crust, oceans, ionosphere and magnetosphere. To probe these waves in details ,it is essential to measure  our magnetic field from space . Mineral physics had provided information about content and properties of the core.  Seismology has provided elaborate study of the core but they could not explain the motion of the liquid outer core which is generating such mysterious waves. 

But with the help of the Swarm mission, scientists have revealed many secret.

The waves called as "Magneto-Coriolis" waves because they move along the Earth’s axis of rotation, as per the Coriolis effect moving from East to West in tall columns that can travel up to 930 miles (1,500 kilometers) per year . The motion and magnetic field changes associated with these waves are strongest near the equatorial region of the core.

According to Dr Gillet , “Magnetic waves are likely to be triggered by disturbances deep within the Earth's fluid core, possibly related to buoyancy plumes.

“Each wave is specified by its period and typical length-scale, and the period depends on characteristics of the forces at play. For magneto-Coriolis waves, the period is indicative of the intensity of the magnetic field within the core.





 

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