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The Solar Connection of Enhanced Heavy Ion Charge States in the Interplanetary Medium: Implications for the Flux-Rope Structure of CMEsWe investigated a set of 54 interplanetary coronal mass ejection (ICME) events whose solar sources are very close to the disk center (within +/- 15deg from the central meridian). The ICMEs consisted of 23 magnetic-cloud (MC) events and 31 non-MC events. Our analyses suggest that the MC and non-MC ICMEs have more or less the same eruption characteristics at the Sun in terms of soft X-ray flares and CMEs. Both types have significant enhancements in ion charge states, although the non-MC structures have slightly lower levels of enhancement. The overall duration of charge-state enhancement is also considerably smaller than that in MCs as derived from solar wind plasma and magnetic signatures. We find very good correlation between the Fe and O charge-state measurements and the flare properties such as soft X-ray flare intensity and flare temperature for both MCs and non-MCs. These observations suggest that both MC and non-MC ICMEs are likely to have a flux-rope structure and the unfavorable observational geometry may be responsible for the appearance of non-MC structures at 1 AU. We do not find any evidence for an active region expansion resulting in ICMEs lacking a flux-rope structure because the mechanism of producing high charge states and the flux-rope structure at the Sun is the same for MC and non-MC events.
Document ID
20150020481
Acquisition Source
Goddard Space Flight Center
Document Type
Reprint (Version printed in journal)
Authors
Gopalswamy, N.
(NASA Goddard Space Flight Center Greenbelt, MD United States)
Makela, P.
(Catholic Univ. of America Washington, DC, United States)
Akiyama, S.
(Catholic Univ. of America Washington, DC, United States)
Xie, H.
(Catholic Univ. of America Washington, DC, United States)
Yashiro, S.
(Catholic Univ. of America Washington, DC, United States)
Reinard, A. A.
(National Oceanic and Atmospheric Administration Boulder, CO, United States)
Date Acquired
November 3, 2015
Publication Date
January 9, 2013
Publication Information
Publication: Solar Physics
Publisher: Springer
Volume: 284
Issue: 1
Subject Category
Solar Physics
Report/Patent Number
GSFC-E-DAA-TN26688
Funding Number(s)
CONTRACT_GRANT: NNG11PL10A
Distribution Limits
Public
Copyright
Other
Keywords
flux rope
flares
coronal mass ejections

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