@article {2988,
	title = {Elliptical instability of the Earth{\textquoteright}s fluid core},
	journal = {Physics of the Earth and Planetary Interiors},
	volume = {103},
	year = {1997},
	pages = {365 - 374},
	abstract = {The elliptical instability of a rotating fluid contained in a thick spherical \&nbsp;shell has been excited in our laboratory by a tide-like perturbation of the \&nbsp;flexible inner boundary. For an inviscid fluid, the growth rate of the \&nbsp; instability is approximately proportional to the perturbation amplitude \&nbsp; and the rotation rate. Development of the instability appears to be limited \&nbsp;by the spherical outer surface and the relatively small perturbation \&nbsp;applied over the inner surface. If the corresponding instability were \&nbsp;excited in the Earth{\textquoteright}s fluid core by tidal forces, in the absence of \&nbsp;dissipation the e-folding time for growth would be on the order of several \&nbsp;thousand years. Although this time scale is similar to current estimates \&nbsp;for the time needed for the geomagnetic field to undergo a reversal, the \&nbsp;instability would grow at a rate equal to the difference between the ideal \&nbsp;growth rate and the overall decay rate. The rates of viscous and \&nbsp;electromagnetic damping are determined by material properties of the \&nbsp;core fluid that are not well known. If elliptical instability plays a central role in geomagnetic reversals, upper limits on the viscosity and \&nbsp;conductivity of the fluid core might be inferred.},
	author = {Keith Aldridge and Behnam Seyed-Mahmoud and Gary Henderson and William van Wijngaarden}
}
