Application of the Eit to Studies of Ground Effects of Space Weather.

摘要

An application of the electromagnetic exact image theory (EIT) for the calculation of electric and magnetic fields at the Earth's surface produced by an ionospheric current is presented. The complete EIT requires significant amount of computations, which can be reduced by using the 'accurate' low-frequency approximation proposed here. Some examples are shown, with exact reference data obtained by fast Hankel transform. Limitations of the method are discussed. The approximation is related to the well-known Walt's complex image method (CIM), but can be applied to currents with nonzero divergence, too.