Determination of a few geomagnetic field characteristics from data of low-orbiting satellites.

An examination of Intercosmos-17 data acquired in late 1977 and early 1978 is used to compare the distribution of large-scale field-aligned currents with the location of sharp gradients of high-energy precipitating particles and model distributions of a number of geomagnetic-field parameters at high latitudes. It is demonstrated how data on auroral increases of solar-cosmic-ray electrons can be used to determine the boundary between closed and open magnetic field lines. Observations of the morning-evening asymmetry of the geomagnetic field and of regions of reduced field strength at night are analyzed.