{Simulated] Geomagnetic jerks finally reproduced and explained

Phys.org ^ | April 22, 2019

[BenLurkin]

The Earth's magnetic field experiences unpredictable, rapid, and intense anomalies that are known as geomagnetic jerks.

Initially described in 1978, geomagnetic jerks are unpredictable events that abruptly accelerate the evolution of the Earth's magnetic field, and skew predictions of its behaviour on a multi-year scale.

The Earth's magnetic field is produced by the circulation of matter within its metallic core, via the energy released when this core cools. Researchers know of two types of movements that cause two types of variations in the magnetic field: those resulting from slow convection movement, which can be measured on the scale of a century, and those resulting from "rapid" hydromagnetic waves, which can be detected on the scale of a few years. They suspected that the latter played a role in the jerks, but the interaction of these waves with slow convection, along with their mechanism of propagation and amplification, had yet to be revealed.

Julien Aubert from l'Institut de physique du globe de Paris (CNRS/IPGP/IGN/Université de Paris) developed, with a colleague from the Technical University of Denmark (DTU), a computer simulation very close to the physical conditions of the Earth's core. The simulation required the equivalent of 4 million hours of calculation, and was carried out thanks to the supercomputers of GENCI.

Researchers were subsequently able to reproduce the succession of events leading to geomagnetic jerks, which arise in the simulation from hydromagnetic waves emitted in the inner core.

[marktwain]

You mean like the Global Warming Models?

Yes, precisely.

Models are not reality.

Some models can be very good at predicting reality, like Newton's laws applied to the orbits of planets.

Most models are very bad at prediction.

[ExGeeEye]

[Redcitizen]

IOW, Earth ain’t firing on all 8 cylinders, thus the jerks.