Presentation and analysis of geomagnetic storm signals at high data rates

There is substantial interest in the coupling of geomagnetic field fluctuations created by magnetic storms and substorms tot eh electric power system. Since the coupling is dependent on the detailed time behavior of the magnetic field, the deep earth conductivity and the power system geometry, the problem is complex. We have recently completed the first phase of a measurement and analysis program where three components of the magnetic field and the current on two long wires in roughly North/South and East/West directions are sampled simultaneously at a rate of one sample every two seconds. The results indicate that important magnetic and electric field fluctuations may be missed with longer sampling times.