Investigation of space weather hazards near ocean-continental boundary using FDTD

The geomagnetic disturbances caused during the solar storms create large-scale geo-magnetically induced currents (GICs) in long conductors at the Earth's surface. The GIC might cause hazard to the electrical transmission lines located at the vicinity of ocean. The unique physics behind this phenomena lies at the sharp contrast in the electrical conductivity between ocean and continent. Though analytical methods were used previously to study electromagnetic fields at ocean-continent boundaries, those were only limited for highly simplified geometries and sinusoidal sources. We are generating Maxwell's equations finite-difference time-domain (FDTD) models of disturbed ionospheric currents in the vicinity of ocean-continent boundaries to solve for more realistic electromagnetic field behavior. Advantages of FDTD include the ability to model arbitrary source time waveforms as well as highly complex coastal geometries. Using  3-D FDTD Models, we are running FDTD simulations for different topographical structure with varying coastal geometries. We are presenting on certain geological factors enhancing the horizontal electric field at the coast and discuss on the potential hazardous distance inland of the shore.