Hydromagnetic dynamos in rotating spherical fluid shells in dependence on the Prandtl number, density stratification and electromagnetic boundary conditions

0440703 - GFÚ 2015 RIV SK eng J - Článek v odborném periodiku
Šoltis, T. - Šimkanin, Ján
Hydromagnetic dynamos in rotating spherical fluid shells in dependence on the Prandtl number, density stratification and electromagnetic boundary conditions.
Contributions to Geophysics & Geodesy. Roč. 44, č. 4 (2014), s. 293-312. ISSN 1335-2806
Institucionální podpora: RVO:67985530
Klíčová slova: hydromagnetic dynamo * non-uniform stratification * Prandtl number * penetrative convection * electromagnetic boundary conditions
Kód oboru RIV: DE - Zemský magnetismus, geodézie, geografie

We present an investigation of dynamo in a simultaneous dependence on the non-uniform stratification, electrical conductivity of the inner core and the Prandtl number. Computations are performed using the MAG dynamo code. In all the investigated cases, the generated magnetic fields are dipolar. Our results show that the dynamos, especially magnetic field structures, are independent in our investigated cases on the electrical conductivity of the inner core. This is in agreement with results obtained in previous analyses. The influence of non-uniform stratification is for our parameters weak, which is understandable because most of the shell is unstably stratified, and the stably stratified region is only a thin layer near the CMB. The teleconvection is not observed in our study. However, the influence of the Prandtl number is strong. The generated magnetic fields do not become weak in the polar regions because the magnetic field inside the tangent cylinder is always regenerated due to the weak magnetic diffusion.
Trvalý link: http://hdl.handle.net/11104/0243805