Crres observations of the composition of the ring-current ion populations
The Magnetospheric Ion Composition Spectrometer onboard the CRRES spacecraft provided mass and charge state composition data for positive ions in the energy-per-charge range 10-425 keV/e. The CRRES data is compared to the AMPTE/CCE observations during both geomagnetically quiet and active periods. The CRRES average radial profiles of H+, He+, and He++ during quiet intervals are remarkably similar to those measured by CCE. The excess of ions measured by CRRES at L <4 compared to standard ion transport models tends to support the necessity of additional ion radial diffusion by ionospheric electric-field variations. A summary is also given of the measured storm-time variations of the major ion populations during the large storm of March 1991. The results are compared to previous observations by the AMPTE/CCE spacecraft during a large storm. The CRRES data confirm that the rapid initial recovery of the Dst magnetic index is due to a momentary change of the relative ion composition of the ring current to an oxygen-dominated state. A preliminary test of the Dessler-Parker-Sckopke relation between the ion energy and the global magnetic perturbation shows that the observed particle fluxes during the March 1991 storm could account for only 30-50% of the variation of the Dst magnetic index.
- Research Organization:
- Aerospace Corp., El Segundo, CA (United States). Technology Operations
- OSTI ID:
- 147378
- Report Number(s):
- AD-A-296327/0/XAB; TR-95(5940)-3; CNN: Contract F04701-93-C-0094; TRN: 53240372
- Resource Relation:
- Other Information: PBD: 15 Feb 1995
- Country of Publication:
- United States
- Language:
- English
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