Podrobnosti záznamu

    Magnetic fields generated by hydromagnetic dynamos at the low Prandtl number in dependence on the Ekman and magnetic Prandtl numbers
    Hejda, Pavel
    Šimkanin, Ján
Typ dokumentu
    článek v odborném periodiku
Zdrojový dokument - seriál
    Physics of the Earth and Planetary Interiors
    Roč. 217, April
    s. 22-30
    Projekt: IAA300120704, GA AV ČR3cav_un_auth*0228938
    Rozsah: 9 s. : P
Předmětová kategorie
    hydromagnetic dynamo
    inertial forces
    magnetic Prandtl number
    Prandtl number
Klíčové slovo
Abstrakt (anglicky)
   This article investigates the dependence of hydromagnetic dynamos on the magnetic Prandtl number at low Prandtl number. In all the investigated cases, the generated magnetic fields are dipolar and neither transition to hemispherical dynamos nor weaker magnetic fields (which are less dipole dominated) were observed, although the inertia becomes important. The magnetic field becomes weak in the polar regions (is ''convected out of polar regions'') only for low Prandtl numbers, when the inertia becomes important. It is a basic condition. However, whether the magnetic field gets weak in the polar regions (is ''convected out of polar regions'') or not depends also on the magnetic Prandtl number. The magnetic Prandtl number has to exceed a minimum value in order to sustain dynamo action.
   If the magnetic diffusion is small (large magnetic Prandtl numbers) then this phenomenon does not exist but if it is large (small magnetic Prandtl numbers) it exists because the strong magnetic diffusion significantly weakens the magnetic field inside the tangent cylinder.
    AV ČR Brno, Geofyzikální ústav
Kód přispěvatele
    AV ČR, GFÚ
Zdrojový formát
Datum importu
    23. 10. 2014