f Appraisal of the Electromagnetic Induction Effects on Geomagnetic Micropulsation Studies

Geomagnetic micropulsations as recorded by a network of magnetometers are a useful guide to investigate the complex magnetospheric processes in general and to understand the generation and propagation mechanisms of the ULF waves in particular .(Hughes, 1994). In these studies, parametrization of the wave polarization properties is inevitably the first step. The geomagnetic field variations as recorded at the Earth's surface are the vector sum of external (source) and internal current systems, the latter resulting from the electromagnetic induction in the electrically conductive layers of the Earth.