Magnetics Business & Technology - September/October 2019 - 18

RESEARCH & DEVELOPMENT

European Space Agency Swarm Mission Pinpoints New Magnetic North and Geomagnetic
Jerks
dian Arctic towards Siberia. One of the practical consequences
of this is that the World Magnetic Model must be updated periodically with the pole's current location. The model is vital for many
navigation systems used by ships, Google maps and smartphones, for example.
ESA's Swarm mission is not only being used to keep track of
magnetic north, but scientists are using its data to measure and
untangle the different magnetic fields that stem from Earth's
core, mantle, crust, oceans, ionosphere and magnetosphere.
Our magnetic field exists because of an ocean of superheated,
swirling liquid iron that makes up the outer core. Like a spinning
conductor in a bicycle dynamo, this moving iron creates electrical currents, which in turn generate our continuously changing
magnetic field.
Tracking changes in the magnetic field can, therefore, tell
researchers how the iron in the core moves. Phil Livermore,
associate professor of geophysics at the University of Leeds in
the UK, said, "Several theories have been
proposed to explain this behavior but, since
they rely upon changes in the small-scale
magnetic field, they cannot explain the
recent trajectory of the pole."
The European Space Agency's Swarm Mission, a trio of satellites launched six years ago to advance understanding of Earth's
magnetic shield, has recently yielded new explanations on two
of its most intriguing phenomena - the constant shifting of the
magnetic North Pole and earth's magnetic jerks. Both have
implications for many modern electronic devices such as smart
phones and navigation equipment which can be affected by the
magnetic shield.

"Using data collected over two decades
by satellites, including ESA's Swarm trio,
Dr. Phil Livermore
we can see that the position of the north
magnetic pole is determined largely by a
balance, or tug-of-war, between two large
lobes of negative magnetic flux at the boundary between Earth's
core and mantle under Canada and Siberia."

Earth's magnetic jerks

Giant tug of war

Simulation of Earth's magnetic field
Simulation of shifting magnetic North Pole

The constant shifting of the magnetic North Pole has been one
of the magnetic shields most puzzling mysteries. Unlike our geographic North Pole, which is in a fixed location, magnetic north
wanders. This has been known since it was first measured in
1831, and subsequently mapped drifting slowly from the Cana-

18

Magnetics Business & Technology *

In 1978, scientists discovered the presence of geomagnetic
jerks, or random rapid shifts in our protective magnetic field.
However, these jerks have been poorly understood phenomenon, and difficult to forecast. Forecasts are important because
the magnetic field protects us from solar storms, which have the
potential to disrupt power supplies, communication links and

September/October 2019

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Magnetics Business & Technology - September/October 2019

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