A 3-D Global Earth-Ionosphere FDTD Model Including an Anisotropic Magnetized Plasma Ionosphere

A 3-D global Earth-ionosphere finite-difference time-domain (FDTD) model is introduced that includes for the first time an anisotropic magnetized cold plasma ionosphere. All previous global FDTD Earth-ionosphere models to date have employed an isotropic conductivity profile. To generate the new model, a previously validated and published 3-D Cartesian magnetized cold plasma algorithm is adapted to the global latitude-longitude FDTD mesh that involves trapezoidal cells, merging of cells in the Polar regions, and triangular cells at the Poles. The global geomagnetic field, ionospheric particle densities and collision frequencies, as well as the Earth's topographic and bathymetric data are all mapped onto the global space grid. After a local high-resolution validation that demonstrates correct calculations of electromagnetic propagation in magnetized plasma, another numerical study is performed to validate the model on a global scale. This new model opens doors to a wide variety of advanced modeling for higher frequency and higher altitude electromagnetic phenomena and represents a paradigm shift from the commonly used ray-tracing codes. It also provides the opportunity to couple FDTD Earth-ionosphere models to other geophysical models, such as the Naval Research Lab's SAMI3, to yield a multiphysics simulator.