Electromagnetic Fields Induced by the Wake of a Moving Slender Body in Two-Layer Ocean of Infinite Depth

An analytical approach to evaluate the electromagnetic fields induced by the surface wake of a submerged moving slender body in a two-layer ocean of infinite depth is presented. The slender body is equivalent to a pair of point sources, and the dominant characteristic mode of surface wake is extracted. Then the electric currents in the medium are calculated via the flowing wake cutting the geomagnetic field. Finally, the induced electromagnetic fields are obtained according to Maxwell equations with appropriate boundary conditions. Numerical results show that the magnetic anomaly near the sea surface is typically a few hundred pico-Tesla.