The 24 March 1991 CRRES Event

On 24 March 1991 a strong interplanetary shock reached Earth and caused a very large geomagnetic storm. The shock produced large energetic particle fluxes in interplanetary space.

Data from the CRRES satellite also showed increases by factors of ~100-1000 in trapped proton fluxes above ~15 MeV in the region 1.8 < L < 2.5. These increased fluxes effectively constituted a "second belt" of trapped protons, which filled the so-called "slot region", between the well-known inner and outer Van Allen belts. There was apparently relatively little change in the trapped proton fluxes at L < 1.8. [See Gussenhoven et al. 1996 for further details.]

Some devices in the CRRES/MEP also showed increases in SEU rates both during the event and in the following week. [See Campbell et al. 1994 for further details.]

Older datasets suggest that similar events have been seen but perhaps not recognized in the past [Mullen et al. 1991]. Designers should therefore examine the possible impact such an event might have on systems which are intended to operate in the "slot region".

The CRRESPRO program [Meffert & Gussenhoven 1994], developed by the USAF Phillips Laboratory, provides a numerical description of the enhanced trapped proton fluxes seen during the 24 March 1991 event. For further information on the CRRESPRO program, contact Dr. M.S. Gussenhoven at Phillips Laboratory.

For further information on the 24 March 1991 event and its effects, see Blake et al. 1992a; 1992b and Shea et al. 1992.

References:

1. Blake et al. 1992a: J.B. Blake, W.A. Kolasinski, R.W. Fillius, and E.G. Mullen, "Injection of Electrons and Protons with Energies of Tens of MeV into L < 3 on March 24, 1991", Geophysical Research Letters 19, pp. 821-824, 1992.
2. Blake et al. 1992b: J.B. Blake, M.S. Gussenhoven, E.G. Mullen, and R.W. Fillius, "Identification of an Unexpected Space Radiation Hazard", IEEE Transactions on Nuclear Science 39, pp. 1761-1764, 1992.
3. Campbell et al. 1994: A.B. Campbell, P. McDonald, R. Gonyea, and M. Reeves, "Results from the CRRES MEP Experiment", IEEE Transactions on Nuclear Science 41, no. 3, pp. 432-437, June 1994.
4. Gussenhoven et al. 1996: M.S. Gussenhoven, E.G. Mullen, and D.H. Brautigam, "Improved Understanding of the Earth's Radiation Belts from the CRRES Satellite", IEEE Transactions on Nuclear Science 43, no. 2, pp. 353-368, April 1996.
5. Meffert & Gussenhoven 1994: J.D. Meffert and M.S. Gussenhoven, "CRRESPRO Documentation", PL-TR-94-2218, Phillips Laboratory, AFMC, Hanscomb AFB, MA , 1992.
6. Mullen et al. 1991: E.G. Mullen, M.S. Gussenhoven, K. Ray, and M. Violet, "A Double-Peaked Inner Radiation Belt: Cause and Effect As Seen on CRRES", IEEE Transactions on Nuclear Science 38, no. 6, pp. 1713-1717, December 1991.
7. Shea et al. 1992: M.A. Shea, D.F. Smart, J.H. Allen, and D.C. Wilkinson, "Spacecraft Problems in Association with Episodes of Intense Solar Activity and Related Terrestrial Phenomena During March 1991", IEEE Transactions on Nuclear Science 39, no. 6, pp. 1754-1760, December 1992.