STARE measures the two dimensional spatial electron drift distribution in the E region, with a temporal resolution of 20 s and with the added assumption of a Hall conductance, the total Hall current distribution. By using Biot-Savart's law, the Hall currents can be integrated to give an estimate of the ground magnetometer response and when compared with the observed magnetometer response this yields the assumed Hall conductance. Data from 18 geomagnetically disturbed days were analysed and the calculated conductances show seasonal and diurnal behavior similar to empirical conductance models. Daytime conductances agree well with solar insolation conductance estimates and night time conductances while more variable, are in reasonable agreement with absorption measured by a narrow beam meter. Spatial conductance gradients allow the Pedersen current to contribute to the source free currents resulting in an anticlockwise rotation of the observed horizontal ground magnetometer response relative to the response expected solely from the Hall current. Equivalently, the Hall current contributes to the ionospheric closure current. By using this information, solar insolation is identified as a significant factor for the closure current. |