He is analyzing the many hours of data to investigate such phenomena as the precipitation of electrons of 20-500 keV energy in the region where the earth's magnetic field connects with the interplanetary medium, and the relationship of these phenomena to the electromagnetic held and plasma parameters of the region. In these studies he is also using the University of Houston data, satellite data obtained by severaf other institutions, and the data obtained by Dr Rosenberg at the South Pole. Data of this kind often display variations on the time scale of seconds to milliseconds, which are related to natural and man-made electromagnetic waves in the whistler mode. In another study, data from an x-ray astronomy satellite are being used to measure atmospheric density in the altitude range of 80 to 150 km as deduced from the extinction of a galactic source as it rises or sets.
Total density is obtained without the use of adjustable parameters.
Agreement with models and with data that cover a narrower range of constituents and altitude is satisfactory. Rosenberg, J.C. Siren, D.L. Matthews, K. Marthinsen, J.A. Holtet, A. Egeland, D.L. Carpenter and R.A. Helliwelf, J. Geophys.