On the local nature of turbulence in Earth's outer core

摘要

Numerical simulations are described that strongly suggest that any large buoyant mass in the Earth's outer core will be rapidly broken up into plate-like structures elongated in the directions of the rotation axis and of the prevailing magnetic field, giving rise to the highly anisotropic motions foreseen by Braginsky and Meytlis (1990) which will then form the dominant characteristic of the local fluid flow. This result casts serious doubt on the hypothesis of Moffatt (1989) that core flow is driven by buoyant parcels or plumes periodically released from Earth's inner core.