Prediction and Modelling of the Earth's magnetic field variations

• Applicant: Dr. Ingo Wardinski
• Subject Area: Geophysics
• Term: from 2010 to 2018
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 169824480

We propose to study to what extend the temporal variability of the Earth’s core magnetic field can be forecasted using all available observations of the geomagnetic field. In the first approach, the temporal variability of the Gauss coefficients are reconstructed by stochastic differential equation using methods from time series analysis and system theory. The integration of this mathematical model provides a prediction of the geomagnetic field variability. The second approach combines a method to reconstruct the time-varying magnetic field at the core surface which incorporate physical constraints (kinematic magnetic field modelling) and techniques of data assimilation. Kinematic magnetic field modelling is characterized by simultaneous modelling of core field and core surface flow where the radial diffusion-less induction equation is applied as constraint. This method has been proven to obtain backward projection spatially high resolved core field models in time over decades. In order to obtain predictions of the future Earth’s magnetic field variability, this method is combined with data assimilation. However, it is expected to misrepresent millennial field variation, where diffusive processes are becoming more important causing the frozen flux assumption to fail. To characterize the effect of diffusive processes results of recent geodynamo models are analysed and their implications for flow inverse problems quantified.

• DFG Programme: Priority Programmes
• Subproject of: SPP 1488: Planetary Magnetism (PlanetMag)
• Participating Person: Dr. Johannes Wicht