Measurement of the Earth's magnetic and electric fields are used for a number of purposes, Navigation, Radio Propagation, Auroral studies, Meteor studies, error signals in seismometers, Earthquake 'prediction', etc, and there are a variety of Websites which give relevant information. There is a map of the stations.
Archive traces are available.
This has Magnetometry links including magnetic pulse FFT's, Sky Cameras and Radar. This is the most southerly station. It includes VLF radio, radar and there is a tutorial about the magnetosphere.