The dynamics of high-latitude jets within Earth’s core by computational fluid dynamics (CFD) simulation

The movement of Earth’s liquid core is responsible for generating our planetary magnetic field, yet we know very little about its structure and dynamics because direct observation is not possible.

Recent high-resolution satellite data have enabled the identification of a jet-stream at high-latitude within the core. This jet may play an important role in the global dynamics of the core (just as the jet-stream does in our atmosphere) and also may act to excite torsional waves, which travel within the core and are magnetically observable.

Most models of the core are spherical, and focus on the broad global dynamics. In this project, spanning both geophysics and applied mathematics, we will focus attention at high latitude on how jets and other structures form, and their expected signature within the magnetic field. The work will involve developing new theory and using numerical high-resolution computational fluid dynamics (CFD) supercomputer models of the core using both Nek 5000 software package that is based on spectral elements, and OpenFOAM that is based on finite volumes.
The student will learn the theory of fluids within the Earth’s core, but also how to use CFD packages to produce images (and animations).
Project objectives:
1. To model the dynamics within the electrically-conducting fluid of Earth’s core at high-latitude, investigating jet and other flow structures and how they evolve.
2. To investigate whether a jet can, through electromagnetic coupling, cause the solid inner core to rotate. To identify any waves caused by high-latitude jets.
3. To compare the magnetic signature of the jet and waves, to the observations from high-resolution satellite measurements of the Earth’s magnetic field.