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Colin Hardy

Liquidity and Funding Scenario Analysis, Treasury Risk Control
UBS, Switzerland
PhD project title
Building a realistic model of Earth's magnetic field using constrained dynamics
Dr Phil Livermore and Dr Jitse Niesen


I graduated from The University of Birmingham with a First Class MSci in Theoretical Physics and Applied Mathematics. During the course I studied many fluid dynamics modules including; continuum mechanics, viscous fluid mechanics and nonlinear waves. My final year project focused on an analytic approach to studying the behaviour of Non-Newtonian fluids, with the specific focus being 'Squeeze flow of a viscoelastic fluid'. During my first year here I carried out a team Msc project researching 'Downdraughts in convective storms', my focus on was how source duration effects the resulting flow behaviour in the downdraught.

Research Interests

I am interested in the fluid dynamics in the outer core of the Earth and the dynamo process responsible for generating the geomagnetic field. Determining the structure of the magnetic field within Earth's core and understanding the complex nonlinear geodynamo mechanism, remain some of the greatest outstanding problems in Earth science. This magnetic field is vitally important for protecting us from harmful radiation from cosmic rays and preventing the atmosphere from being destroyed by solar wind.

The deep Earth is an enigmatic place, with many intricate features, an example is at the top of Earth's core where a layer of stably stratified layer may prevail, I am investigating the role that this may play on the geomagnetic field. Full direct numerical dynamo simulations are a valuable tool for gaining insight into this, but this can amplified when synergised with a theoretical comprehension of the underlying physics. To this end I utilise reduced models for this complex system which facilitate analytic progress. From a mathematical standpoint, the outer core can be realistically modelled as a constrained dynamical system, so it is instructive to consider the Earth’s outer core as evolving under the control of a system of constraints, which stem from the dominance of the rotational forces inside the core and the presence of stratification.

Exploiting the combination of these constraints allows us to obtain a realistic model of the large-scale background structure of the internal geomagnetic field. I am involved in developing the methodology to investigate the dynamics of such magnetic fields to construct a model for the geomagnetic field evolution over the long geophysical timescales, we then compare these to geomagnetic observations and direct numerical dynamo simulations, to advance understanding.

Why I chose the CDT in Fluid Dynamics

Coming from a mainly theoretical background I was keen for the opportunity to experience the experimental and computational study of fluid dynamics and develop skills in these new areas before undertaking a PhD, the first year allowed me to develop these skills and apply them during my Msc project. Also I found the extended process of selecting a PhD project to be very useful. I believe the chance to carry out some background reading and have several meetings with the potential supervisors to discuss the project, allows a more informed decision to be made.


C. M. Hardy, P. W. Livermore, J. Niesen, J. Luo, K. Li, 2018. Determination of the instantaneous geostrophic flow within the three-dimensional magnetostrophic regime. Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, Volume 474, Issue 2218. DOI: 10.1098/rspa.2018.0412.

C. M. Hardy, J. Wong, 2019. Stably stratified layers within Earth’s core. Astronomy and Geophysics, 60(3), pp.3-30. DOI: 10.1093/astrogeo/atz148

C. M. Hardy, P. W. Livermore, J. Niesen, 2019. Constraints on the magnetic field within a stratified outer core. Geophysical Journal International, (submitted).