Dynamo energetics and the structure of the outer core

Abstract

The development of a realistic model of the geomagnetic dynamo can be enhanced by parameterizing more accurately the fluid motions in the outer core which are driven by compositional buoyancy. It is argued that the bulk of the outer core may be weakly stably stratified, with convective plumes of compositionally buoyant material rising from the inner core boundary through a relatively quiescent outer core to the core-mantle boundary. The dynamo action of these isolated convective plumes may be more easily modeled than that of general outer-core convection.

Key Words:

• Dynamo
• convection
• Earth's outer core