Three Branches of Dynamo Action

Abstract

In addition to the weak-dipolar state and to the fluctuating-multipolar state, widely discussed in the literature, a third regime has been identified in Dormy (2016). It corresponds to a strong-dipolar branch which appears to approach, in a numerically affordable regime, the magnetostrophic limit relevant to the dynamics of the Earth's core. We discuss the transitions between these states and point to the relevance of this strong-dipolar state to Geodynamo modelling.

21 pages, 12 figures Accepted Manuscript Fluid Dynamics Research (online 2 June 2017)

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Cited by in corpus (11)

• Dynamo theories
• Magnetar formation through a convective dynamo in protoneutron stars
• The Turbulent Dynamo
• Force balance in numerical geodynamo simulations: a systematic study
• Relating force balances and flow length scales in geodynamo simulations
• Magnetic effects on fields morphologies and reversals in geodynamo simulations
• Numerical simulations of the Tayler-Spruit dynamo in proto-magnetars
• Transition from multipolar to dipolar dynamos in stratified systems
• Solenoidal force balances in numerical dynamos
• Spatial And Temporal Changes Of The Geomagnetic Field: Insights From Forward And Inverse Core Field Models
• Dynamo saturation down to vanishing viscosity: strong-field and inertial scaling regimes