Model spectra for the electric and magnetic fields induced by oceanic internal waves are obtained by combining Green function solutions to the two electromagnetic modal equations with the Garrett-Munk kinematic description of the internal wave field. The poloidal magnetic mode is dominant at frequencies above 3f, where f is the local Coriolis frequency, and self and mutual induction are not important over this range. The toroidal magnetic mode is increasingly important at frequencies below 3f and is sensitive to the conductivity structure below the seafloor for near-inertial frequencies. The moored electric field is shown to be largely a measure of the local velocity field at high frequencies. The vertical electric field is sensitive to the horizontal velocity field, while the horizontal electric field primarily reflects the vertical velocity field an is quite small at the sea-earth and sea-air interfaces. The magnetic field is a measure of the spatially averaged velocity field and is dominated by the poloidal magnetic mode. Electromagnetic boundary effects reduce the horizontal magnetic spectrum by decades at the seafloor and sea surface. At the seafloor and sea surface, internal wave-induced magnetic fields are within an order of magnitude of their externally induced counterparts, while in the ocean's interior, internal waves are probably the largest source of magnetic signals in the period range one day to one hour. The internal wave-induced electric field is not measurable except in the vertical component. |