CRRES ONR-307 Experiment Data Analysis

A number of scientific results have been obtained from analysis of the CRRES ONR-307 energetic particle and ion data, concentrating on three key areas of investigation: particle precipitation and wave particle interactions, radiation belt and ring current modeling, and dynamic event studies. Utilizing the ONR-307 particle data together with plasma wave data from other instrumentation on CRRES, we have studied, for the first time from the same spacecraft in the outer belt region, the simultaneous nature of waves and precipitating electrons near the equator, both for trapped particles and narrow particle dropouts. These studies showed that there is a general correlation between wave intensities and electron fluxes. Investigation of the ion composition data during the large magnetic storm of March 1991 revealed detailed structure of the ring current, allowed mapping of the structure for the first time, and showed dynamic transport of hydrogen, helium, and oxygen ions to lower L-shells. The low energy ion mass spectrometers observed new phenomena near the equator where pitch-angle distributions are asymmetric for long periods of time during geomagnetic storms. These distributions were caused by parallel electric fields that appear to be induced by increasing Birkeland currents and by decreasing tail currents. Prepared in cooperation with Taylor Univ., Upland, IN, National Science Foundation, Arlington, VA, and New Hampshire Univ., Durham, NH.