An Approach to Model Earth Conductivity Structures with Lateral Changes for Calculating Induced Currents and Geoelectric Fields during Geomagnetic Disturbances

Figure 3

Sketch of the computational model used for 3D FEM implementation. All the conductivity values and layer thicknesses are the same with those in Figure 1. For comparison with 2D FEM results, the model size along -axis is chosen small (= 30 km) along which the conductivity structure and geoelectromagnetic fields are constant. As a consequence, all field quantities remain unchanged in this orientation. For real 3D conductivity structures, the model scale should be large enough due to the fact that the electromagnetic fields are three-dimensional.