Analysis of the Atmospheric Electric Circuit using the Finite Element Method

This study concerns the electrical properties of the Earth´s lower atmosphere. A theoretical description of the terrestrial global circuit is presented. An electrostatic model based on the finite element technique is used to investigate the following parameters of the Earth-ionosphere cavity: (i) energy storage in different regions; (ii) variation with height of the electric field and space charge. The modeled domain is bound by two concentric conductive spheres to represent the Earth´s surface and the lower ionosphere; a set of intermediate concentric conductive spheres is employed to discretize the inner space. The sources of energy are defined by specifying the electric potential of all conductive spheres; these potentials are obtained from the vertical electric field profile proposed by Gish. The axisymmetric problem provides three-dimensional information about the various parameters. Numerical calculations of the different parameters are compared to analytical predictions of the Gish model and show a very good correlation.