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Polarity reversals in dependence on the Prandtl number and density stratification

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Abstract

Dependence of polarity reversals on the Prandtl number and density stratification using the MAG dynamo code was investigated. The magnetic field is dipole-dominated in the stable polarity state and during the reversals it is multipolar. Quadrupole and octupole components of magnetic fields are stronger at the Prandtl number equal to 0.2 than at the Prandtl number equal to 1. Polarity reversals occur at higher values of the Rayleigh number, while at its lower values the magnetic field does not undergo reversals. The situation is the same with the magnetic Prandtl number: polarity reversals occur at higher values of the magnetic Prandtl number, while at its lower values the magnetic field does not undergo reversals (neither if the magnetic field becomes weak in the polar regions nor if it is strong). During the 1000 simulated time units two reversals occur in the case of uniform stratification and at both investigated values of the Prandtl number, while in the case of non-uniform stratification and at both investigated values of the Prandtl number only one reversal occurs.

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  1. Institute of Geophysics, Acad. Sci. Czech Republic, Boční II/1401, 141 31, Praha 4, Czech Republic

    Ján Šimkanin

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  1. Ján Šimkanin
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Correspondence to Ján Šimkanin.

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Šimkanin, J. Polarity reversals in dependence on the Prandtl number and density stratification. Stud Geophys Geod 59, 137–158 (2015). https://doi.org/10.1007/s11200-014-0724-6

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  • DOI: https://doi.org/10.1007/s11200-014-0724-6

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