Chapter 4 - Outer core dynamics

Abstract

We begin this chapter with a description of the physical environment of the outer core, focusing on its most distinctive attributes. We then characterize the outer core environment using dimensionless parameters defined in terms of the physical and chemical properties that govern its dynamics. Special emphasis is given to thermochemical buoyancy, the primary driver for outer core convection. Next, we describe the multiple types of laminar and wave-like flows in the outer core, and what their observations imply about the structure and state of the core. We then apply the results of laboratory and numerical experiments to infer the properties of rotating convection in the outer core. Finally, we show how numerical dynamo models are used to link outer core convection to the state of the core described in Chapter 2, the seismic structure of the core described in Chapters 1, 5, and 6, the dynamics of the inner core described in Chapter 7, and the evolution of the core and the geodynamo described in Chapters 3 and 8.