Browse > Article
http://dx.doi.org/10.5140/JASS.2004.21.2.093

CHARACTERISTIC SOLAR WIND DYNAMICS ASSOCIATED WITH GEOSYNCHRONOUS RELATIVISTIC ELECTRON EVENTS  

Kim, Hee-Jeong (Department of Astronomy and Space Science, College of Natural Sciences and Institute for Basic Science Research, Chungbuk National University)
Lee, Dae-Young (Department of Astronomy and Space Science, College of Natural Sciences and Institute for Basic Science Research, Chungbuk National University)
Publication Information
Journal of Astronomy and Space Sciences / v.21, no.2, 2004 , pp. 93-100 More about this Journal
Abstract
We have investigated characteristic solar wind dynamics associated with relativistic electron events at geosynchronous orbit. Most of the events for April, 1999 through December, 2002 are found to be accompanied by a prolonged solar quiet period which is characterized as low solar wind density, weak interplanetary magnetic field (IMF), and fast alfvenic fluctuations in IMF $B_z$. In a typical relativistic event, electron fluxes begin to increase by orders of magnitude when solar wind parameters drop to low values (e.g., $n_{sw}∼5 cm^{-3}$ and |$B_{IMF}$∼5 nT) after sharp peaks. Then the elevated electron fluxes stay at the high level during the solar quiet period. This observation may suggest the following scenario for the occurrence of a geosynchronous relativistic event: (ⅰ) Quiet solar winds can yield a stable and more dipole-like magnetospheric configurations in which the geosynchronous orbit locates well inside the trapping boundary of the energetic electrons. (ⅱ) If a large population of MeV electrons are generated (by whatever acceleration process(es)) in the inner magnetosphere, they can be trapped and effectively accumulated to a high intensity. (ⅲ) The high electron flux can persist for a number of days in the geosynchronous region as long as the solar wind dynamics stays quiet. Therefore the scenario indicates that the occurrence of a relativistic event would be a result of a delicate balance between the effects of electron acceleration and loss. In addition, the sensitive dependence of a relativistic event on the solar wind conditions makes the prediction of solar wind variability as important as understanding of electron acceleration processes in the forecast of a relativistic event.
Keywords
solar winds; relativistic electron events; geosynchronous orbit;
Citations & Related Records
연도 인용수 순위
  • Reference
1 /
[ Baker, D. N. ] / IEEE Trans. Plas. Sci.   DOI   ScienceOn
2 /
[ Baker, D. N.;Kanekal, S.;Blake, J. B.;Klecker, B.;Rostoker, G. ] / Eos Trans. AGU.   DOI
3 /
[ Gussenhoven, M. S.;Mullen, E. G.;Brautigam, D. H.;Holeman, E.;Jordan, C. ] / IEEE Trans. Plas. Sci.   DOI   ScienceOn
4 /
[ Kepko, L.;Spence, H. E. ] / J. Geophys. Res.   DOI
5 /
[ Kim, H.-J.;Lee, D. Y. ] / JA&SS
6 /
[ Kim, H.-J.;Rostoker, G.;Kamide, Y. ] / J. Geophys. Res.
7 /
[ Li, X.;Temerin, M.;Baker, D. N.;Reeves, G. D.;Larson, D. ] / Geophys. Res. Lett.   DOI   ScienceOn
8 /
[ O'Brien, T. P.;McPherron, R. L.;Sornette, D.;Reeves, G. D.;Friedel, R. H. W.;Singer, H. J. ] / J. Geophys. Res.   DOI
9 in Quantitative Modeling of Magnetospheric Processes /
[ Paulikas, G. A;Blake, J. B.;W. P. Olson(ed.) ] / AGU Geophysical Monograph Series
10 /
[ Reeves, G. D. ] / Geophys. Res. Lett.   DOI   ScienceOn
11 /
[ Reeves, G. D. ] / Geophys. Res. Lett.   DOI   ScienceOn
12 /
[ Kim, H.-J.;Chan, A. A. ] / J. Geophys. Res.   DOI