Physics Journal of the Indonesian Physical Society
SYMMETRY PROPERTIES BREAKING OF THE CORE'S FLUID FLOW IN THE MAGNETOSTROPHIC APPROXIMATION
T. Prastowo1 and S. Bijaksana2
1Physics Department, Universitas Negeri Surabaya, Kampus Ketintang, Surabaya 60231, Indonesia
2Physics Department, Institut Teknologi Bandung, Jalan Ganesa 10, Bandung 40132, Indonesia
The secular variation of Earth's magnetic field can be produced by geodynamo processes at the Earth's liquid outer core. To get deeper understanding the dynamical behavior of the fluid flow near core-mantle boundary (CMB) it has been simultaneously solved magnetic induction equation, Navier-Stokes equation and continuity equation. There is an inherent non-uniqueness in the radial component of the magnetic induction equation, and hence additional constraints are required to obtain a unique solution. Based on the frozen-flux hypothesis proposed by Roberts and Scotts, we introduce a new approximation, namely a magnetostrophic assumption, for investigating the fluid flow at the core surface. We analytically find that this constraint indicates symmetry properties breaking of the flow because of a strong-imposed magnetic field near the CMB.