On the Usage of Diffusion-Free Parameterizations of Convective Heat Transfer

Abstract:

The Earth’s magnetic field is generated in the outer core by thermochemical rotating convection. Many present-day models of the dynamo describe core conditions by extrapolating empirical scaling laws that relate diffusion-free nondimensional parameters [e.g., 1]. To test the efficacy of such diffusion-free parameterizations, here we perform a theoretical analysis of empirical dynamo scaling laws using synthetic heat transfer datasets. We show that the seemingly robust collapse of heat transfer data using diffusion-free parameters is actually an a priori consequence of the way these parameters are constructed.

References

[1] Christensen, U.R., Aubert, J., 2006. Geophys. J. Int. 166, 97–114.