Generation mechanism of a dipole field by a magnetohydrodynamic dynamo

摘要: Computer simulation of a magnetohydrodynamic dynamo in rotating spherical shell is performed. A strong magnetic field generated by thermal convection motion an electrically conducting fluid. The has well-organized structure. expanded the harmonics ${\mathrm{Y}}_{\mathrm{\ensuremath{\ell}}}^{\mathrm{m}}$. leading moment dipole (\ensuremath{\ell}=1,m=0) which 1.3 times larger than second moment, octapole (\ensuremath{\ell}=3,m=0). These two moments occupy more half total power field. Structure and generation mechanism are examined detail. It found that well-known \ensuremath{\alpha}-\ensuremath{\omega} scenario gives good explanation whole cycle.