In this manuscript we improved previous analyses on the threat posed by Geomagnetically Induced Currents (GICs) to the Spanish 400 kV grid by resorting to different strategies to progress in:
1) The knowledge of the geomagnetic field variations at each node of the grid.
We have investigated the effect of their spatial changes by interpolating the field from the records of several close observatories with different techniques.
2) The Earth's geoelectrical structures beneath the power grid.
We have identified the importance of estimating the MT impedance tensor when predicting GIC, especially where the effect of lateral heterogeneities is important
3) The topology and the relative resistances of the grid elements.
We performed a sensitivity analysis to assess the reliability of both the information about the network topology and resistances, and the assumptions made when all the details or the network status are not available
In our case, the most essential issue to improve the coincidence between model predictions and actual observations came from the use of realistic geoelectric information involving local MT measurements.
Manuscript available upon request
Torta, J. M., A. Marcuello, J. Campanyà, S. Marsal, P. Queralt, and J. Ledo (2017), Improving the modeling of geomagnetically induced currents in Spain, Space Weather, 15, doi:10.1002/2017SW001628.