Finite-Element Formulation of Electromagnetic Induction with Coupled Potentials
Electric and magnetic potentials in the Coulomb gauge provide a convenient formulation for finite-element modeling of electromagnetic (EM) induction in heterogeneous conductivity structure. The formulation uses standard linear finite elements defined on tetrahedra. The finite-element equations are solved by a sparse, ILU decomposition that ignores fill-in to achieve maximum storage efficiency. The formulation can handle models of interest to oil and gas exploration, mining, and environmental studies. It is applied here in spherical geometry to model EM induction in the upper mantle due to a magnetospheric ring current.