Fig. 3
From: Physics-based secular variation candidate models for the IGRF
Deterministic chaos for the coupled Earth dynamo model of Aubert et al. (2013). 100 dynamo models are integrated forward in time, starting from close initial conditions. Each initial condition is defined by the same, well-equilibrated dynamo state whose axial dipole is slightly perturbed by a normal perturbation of relative amplitude \(10^{-8}\). a bulk magnetic energy versus time, normalized by its value at \(t=0\), for the 100 members of the ensemble. b latitude of geomagnetic North at Earth’s surface, for the 100 members of the ensemble. c 3D scatter \(S_{3D}\) versus time. \(\tau _e\) is the e-folding time. d scatter of simulated magnetic fields \(S_a\) at Earth’s surface. Ensemble integration and on-the-fly diagnostics obtained using the parody_pdaf implementation (Fournier et al. 2013). See text for details