The Interpretation of Motionally Induced Electric Fields in Oceans of Complex Geometry
WASHINGTON UNIV SEATTLE APPLIED PHYSICS LAB
Pagination or Media Count:
Sea water moving through the earths magnetic field induces electric currents in the ocean, and in general their distribution depends on the 3D structure of the ocean and its surroundings. Although velocity is traditionally calculated from measurements of the electric field with a one-dimensional relationship in the vertical, higher dimension processes are expected near steep topography or in energetic and variable flows. The observational capabilities of recently developed electric field instruments highlight the need for a qualitative and quantitative assessment of higher dimensional processes. The first part of this dissertation analyzes electric field solutions for 2D effects caused by horizontal gradients of either velocity or topography. Magnetostatic solutions are calculated for simple geometries that are described by a few non-dimensional spatial scales. The second part analyzes measurements collected across the Gulf Stream where it separates from the continental margin, where the oceanic flow is fast and meandering, topography is steep, and sediment is thick. Geophysical data are compiled to estimate the sediment electrical properties.
- Electricity and Magnetism