Simulation of the geomagnetically induced currents in low-latitude power networks during geomagnetic storms

The issue of geomagnetically induced currents (GICs) on ground based conductive systems has been a global space weather concern nowadays. Successful prediction of GICs in these systems is the ultimate pursuit of GIC studies. While numerous efforts have been carried out in modeling the GICs at high-latitudes, in this study, we focus on simulating GICs at low-latitude power grids during geomagnetic storms. We use the Space Weather Modeling Framework (SWMF) to model the geomagnetic perturbations at a low-latitude substation during three storms and then calculate the geoelectric field and GICs locally. The simulation results indicate that although more false signals on the northward geoelectric field E_x are produced, the model reproduces the eastward component of geoelectric field E_y quite well for all three storms. In general, the simulations capture the active periods of GICs and some peaks of GICs during storm time. Furthermore, event-based analysis method is applied to evaluate the model performance. Results indicate that the numerical model is more applicable than the persistence model for the prediction of GICs at low-latitude power grids during storms.