Low-energy solar electrons and ions observed at Ulysses February-April, 1991: The inner heliosphere as a particle reservoir

• Published in: Geophysical research letters Vol. 19; no. 12; pp. 1243 - 1246
• Main Authors: Roelof, E. C., Gold, R. E., Simnett, G. M., Tappin, S. J., Armstrong, T. P., Lanzerotti, L. J.
• Format: Journal Article
• Language: English
• Published: Legacy CDMS Blackwell Publishing Ltd 19.06.1992; American Geophysical Union
• Subjects: Astronomy; Decay; Earth, ocean, space; Exact sciences and technology; Flares; Heliosphere; Interplanetary space; Joints; Low energy; Reservoirs; Solar activity; Solar electrons; Solar Physics; Solar system; Low energy; Heliosphere; Solar activity; Space probe observation; Ions; Electrons; Solar flare
• ISSN: 0094-8276; 1944-8007
• DOI: 10.1029/92GL01312

Ulysses observations at 2.5 AU of 38-315 keV electrons and 61-4752 keV ions during February-April 1991 suggest in several ways that, during periods of sustained high solar activity, the inner heliosphere serves as a 'reservoir' for low-energy solar particles. Particle increases were not associated one-to-one with large X-ray flares because of their poor magnetic connection, yet intensities in March-April remained well above their February levels. The rise phase of the particle event associated with the great flare of 2245UT March 22 lasted most of two days, while throughout the one-week decay phase, the lowest-energy ion fluxes were nearly equal at Ulysses and earth (IMP-8).