SOLAR, INTERPLANETARY, AND GEOMAGNETIC PHENOMENA IN MARCH 1991 AND THEIR ASSOCIATION WITH SPACECRAFT AND TERRESTRIAL PROBLEMS

The solar activity that occurred on 22 and 23 March 1991 resulted in m ajor interplanetary and geomagnetic disturbances. In spite of measurem ents in the earth's magnetosphere, near Venus, and by the Ulysses spac ecraft (at 2.48 AU) it is not possible to identify unambiguously the s ource of each perturbation. The intense solar particles caused single event upsets in spacecraft semiconductors. A very powerful shock resul ted in large geomagnetic disturbances and contributed to the generatio n of a third radiation belt, as measured by the CRRES spacecraft. In a ddition major oscillations in the cosmic ray intensity reflecting an u nusual structure in the interplanetary medium have not yet been explai ned.