Towards evidences of a threshold system as the source for magnetic storms detected on Earth’s surface

In this work we present evidences that point to a threshold system as the source for magnetic storms detected on the Earth. We based our analysis on series of data acquired during many years in the network of magnetic observatories of the National Observatory (Brazil). In particular we focused our attention on October 2000 month of the Vassouras Observatory, which have been active since 1915. The data was appropriately processed using classical Fourier formalisms. The analysis of statistical distribution of amplitudes, periods of calm and storms was implemented on the difference resulting from the processed and unprocessed data.