Precession driven dynamos

Precession is a change in the orientation of the rotation axis of a rotating body. The earth goes through one full precessional period over a duration of approximately 26000 years due to the luni-solar tidal torque acting on the Earth's equatorial bulge.

Enlarged view: Precession of the Earth.
Precession of the Earth.

From an energetic point of view, precession is a possible driving mechanism for the generation of Earth’s magnetic field, the so-called geodynamo. We investigate precession driven dynamos in a full sphere via direct numerical simulations. A highly parallelized spectral code is used to solve the Navier-Stokes equation and magnetic field diffusion equation.

Precession driven dynamo (laminar regime).
Precession driven dynamo (laminar regime).
Precession driven dynamo (unstable regime).
Precession driven dynamo (unstable regime). Isosurfaces of magnetic field strength (left) and velocity magnitude (right).

Isosurfaces of magnetic field strength rendered by the color scale of the velocity magnitude. Left: insulating boundary condition. Right: conducting boundary condition.

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