Swarm tracks elusive ocean magnetism
European Space Agency
However, the field generated by tides is tiny – and extremely difficult to measure, but ESA’s Swarm mission has done just this in remarkable detail. Swarm has been used to measure the magnetic signals of tides from the ocean surface to the seabed, which offers a global picture of how the ocean flows at all depths. The magnetic tidal signal measured by Swarm is important for ocean and climate modelling, and is used to determine the electrical properties of the Earth’s lithosphere and upper mantle. Swarm is ESA’s first constellation of Earth observation satellites. As well as shedding this new light on magnetic tides, Swarm has also yielded a new map of the magnetic field generated by Earth’s crust.