0440702 - GFÚ 2016 RIV CZ eng J - Journal Article
Šimkanin, Ján
Polarity reversals in dependence on the Prandtl number and density stratification.
Studia geophysica et geodaetica. Roč. 59, č. 1 (2015), s. 137-158. ISSN 0039-3169. E-ISSN 1573-1626
R&D Projects: GA MŠMT(CZ) LG13042
Institutional support: RVO:67985530
Keywords : polarity reversals * Prandtl number * non-uniform density stratification * hydromagnetic dynamo
Subject RIV: DE - Earth Magnetism, Geodesy, Geography
Impact factor: 0.818, year: 2015

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.
Permanent Link: http://hdl.handle.net/11104/0243829