2D Modeling of Geomagnetic Induction near Coastal Regions

Accurate calculation of the electric and magnetic fields induced in the Earth by time-varying ionospheric currents is an important step in computing the strength of geomagmatically induced currents (GICs) and in accurately inferring the strength and location of the source currents from ground-based magnetometers. The complexity of the Earth's conductivity adds to the difficulty of the problem, particularly near coastal regions where the conductivity of salt water is several orders of magnitude larger than that of the surrounding land mass. We demonstrate the use of a numerical technique known as the method of auxiliary sources (MAS) to calculate the induced electric and magnetic fields, resulting from a uniform source, near a 2D modeled coast. Dependence of the resulting fields on frequency, conductivity, and geometry are shown.