Electric Fields Induced by Turbulence in the Seabed Boundary Layer.

Abstract : The objective of this research was to describe and understand the electrical fluctuations that occur in a turbulent bottom boundary layer in shallow water. In the environment voltage fluctuations are produced not only by induction from large scale sources such as geomagnetic disturbances in the upper atmosphere, but also by small scale local processes including inducting from turbulent eddies and sea surface waves, and streaming potentials developed in seafloor sediments. In working towards this objective we have installed an array of electric and pressure detectors in the Strait of Juan de Fuca where a strong field stream generates a well defined bottom boundary layer, and wave action in a winter is expected to modify the layer. Theoretical studies were made to model the electric field based on models for vorticity fluctuations of water velocity in a turbulent boundary layer.