Rapidly rotating experiments as laboratory models of planetary cores

Experiments using sodium or water can explore rapidly rotating flows in order to better understand the Earth's outer core. Inertial modes and turbulent flows dominated by wave modes (such as MAC waves), are likely, but unobserved, components or flows in the outer core. Local measurements of rotating flows in a 60 cm rotating sodium experiment show Coriolis restored modes and the magnetic fields that they induce. We have also observed these waves in water experiments in a rapidly rotating three meter experiment. While those tests are being done in part to commission that system toward sodium experiments, measurements of the fluctuating pressure and shear stress show wave mode dominated turbulent flows even in the absence of magnetic fields. If the flows in planetary cores are dominated by large amplitude, fast time scale waves, those would have an important causative effect but still be invisible on the surface. Implications on simulations via the form of temporal and spatial spectra need to be understood if we hope to improve modeling toward geomagnetic forecasting. The support of NSF Earth Sciences is greatly acknowledged.