Swarm reveals Earth’s changing magnetism

The first set of high-resolution results from European Space Agency’s (ESA) three-satellite Swarm constellation reveals the most recent changes in the magnetic field that protects our planet, ScienceDaily reports. 

Launched in November 2013, Swarm is providing unprecedented insights into the complex workings of Earth's magnetic field, which safeguards us from the bombarding cosmic radiation and charged particles.

Measurements made over the past six months confirm the general trend of the field's weakening, with the most dramatic declines over the Western Hemisphere.

But in other areas, such as the southern Indian Ocean, the magnetic field has strengthened since January.

The latest measurements also confirm the movement of magnetic North towards Siberia.

These changes are based on the magnetic signals stemming from Earth's core. Over the coming months, scientists will analyse the data to unravel the magnetic contributions from other sources, namely the mantle, crust, oceans, ionosphere and magnetosphere.

This will provide new insight into many natural processes, from those occurring deep inside our planet to space weather triggered by solar activity. In turn, this information will yield a better understanding of why the magnetic field is weakening.