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Titel |
A study of solar and interplanetary parameters of CMEs causing major geomagnetic storms during SC 23 |
VerfasserIn |
C. Oprea, M. Mierla, D. Beşliu-Ionescu, O. Stere, G. Mariş Muntean |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
0992-7689
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Digitales Dokument |
URL |
Erschienen |
In: Annales Geophysicae ; 31, no. 8 ; Nr. 31, no. 8 (2013-08-01), S.1285-1295 |
Datensatznummer |
250019072
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Publikation (Nr.) |
copernicus.org/angeo-31-1285-2013.pdf |
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Zusammenfassung |
In this paper we analyse 25 Earth-directed and strongly geoeffective
interplanetary coronal mass ejections (ICMEs) which occurred during solar
cycle 23, using data provided by instruments on SOHO (Solar and Heliospheric Observatory), ACE (Advanced Composition Explorer) and
geomagnetic stations. We also examine the in situ parameters, the energy
transfer into magnetosphere, and the geomagnetic indexes. We compare observed
travel times with those calculated by observed speeds projected into the
plane of the sky and de-projected by a simple model. The best fit was found
with the projected speeds. No correlation was found between the importance of
a flare and the geomagnetic Dst (disturbance storm time) index. By comparing the in situ parameters
with the Dst index we find a strong connection between some of these
parameters (such as Bz, Bs · V and the energy transfer into the
magnetosphere) with the strength of the geomagnetic storm. No correlation was
found with proton density and plasma temperature. A superposed epoch analysis
revealed a strong dependence of the Dst index on the southward component of
interplanetary magnetic field, Bz, and to the Akasofu coupling function, which
evaluates the energy transfer between the ICME and the magnetosphere. The
analysis also showed that the geomagnetic field at higher latitudes is
disturbed before the field around the Earth's equator. |
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