The magnetic signatures of field-alighed and ionospheric currents can be u used to trical current systems which couple the ionosphere to the outer regions of the earth's magnetosphere. It is now recognized that the currents flowing in the evening sector are an important clue to the understanding of processes leading to explosive substorm instabilities and episodes of intense ionospheric disruption. In this reporet we have used a combination of ground-based magnetometer data and Isis 2 satellite data in the form of energetic particles, auroral luminosity, and electromagnetic and/or electrostatic noise measurements to provide a comprehensive picture of processes which are taking place on field lines penetrating the auroral oval in the evening and midnight sectors. We shall show that noise measurements in the frequency range 100