Dissipation at the core-mantle boundary on a small-scale topography

Jean-Louis Le Mouël (1) , C Narteau (1) , M Greff-Lefftz (1) , M Holschneider (2)

1 IPGP - Institut de Physique du Globe de Paris
2 Institutes of Applied and Industrial Mathematics

The parameters of the nutations are now known with a good accuracy, and the theory accounts for most of their values. Dissipative friction at the core-mantle boundary (CMB) and at the inner core boundary is an important ingredient of the theory. Up to now, viscous coupling at a smooth interface and electromagnetic coupling have been considered. In some cases they appear hardly strong enough to account for the observations. We advocate here that the CMB has a small-scale roughness and estimate the dissipation resulting from the interaction of the fluid core motion with this topography. We conclude that it might be significant.

Domains: Earth Sciences

Jean-Louis Le Mouël, C Narteau, M Greff-Lefftz, M Holschneider. Dissipation at the core-mantle boundary on a small-scale topography. Journal of Geophysical Research, 2006, 111 (B4), pp.B04413. ⟨10.1029/2005JB003846⟩. ⟨insu-01267531⟩