标题：Towards quantitative assessment of the hazard from space weather. Global 3-D modellings of the electric field induced by a realistic geomagnetic storm
摘要：In order to estimate the hazard to technological systems due to geomagnetically induced currents (GIC), it is crucial to understand the response of the geoelectric field to a geomagnetic disturbance and to provide quantitative estimates of this field.Most previous studies on GIC and the geoelectric field generated during a geomagnetic storm assume a 1-D conductivity structure of Earth.This assumption however is invalid in coastal regions, where the lateral conductivity contrast is large.In this paper, we investigate the global spatio-temporal pattern of the surface geoelectric field induced by a typical major geomagnetic storm in a conductivity model of Earth with realistic laterally-heterogeneous oceans and continents.Exploiting this model makes the problem fully 3-D.Data from worldwide distributed magnetic observatories are used to construct a realistic model of the magnetospheric source.The results of our numerical studies show large amplification of the geoelectric field in many coastal regions.Peak amplitudes obtained with 3-D modelling exceed the amplitudes obtained in a 1-D model by at least a factor 2, even if the latter makes use of the local vertical conductivity structure.Lithosphere resistivity is a critical parameter, which governs both amplitude and penetration width of the anomalous electric field inland. Key words Geomagnetic storms GIC geoelectric field 3-D modelling.
关键词：Geomagnetic storms ;GIC ;geoelectric field ;3-D modelling
