GPU-based three-dimensional calculation of lightning-generated electromagnetic fields

We present and validate a computational approach for the efficient calculation of lightning-produced electromagnetic fields and solution of pertinent problems in realistic environments. Given that various factors, such as ground-material inhomogeneities and irregular earth surface, may inhibit the utilization of simplified approaches, the finite-difference time-domain method is applied in its general three-dimensional formulation, so that important details are taken into consideration. As lightning problems usually call for a significant number of computations, the numerical approach is parallelized by exploiting the computing capabilities of contemporary graphics-processing-units. The proposed implementation results in serious shortening of the simulations' duration and facilitates the study of problems with uncertainties, thus contributing to the development of a useful tool for the study of lightning-related phenomena.