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Solar wind flow angle and geoeffectiveness of corotating interaction regions: First results
Author(s) -
Rout Diptiranjan,
Chakrabarty D.,
Janardhan P.,
Sekar R.,
Maniya Vrunda,
Pandey Kuldeep
Publication year - 2017
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2017gl073038
Subject(s) - solar wind , interplanetary magnetic field , electrojet , geomagnetic storm , interplanetary spaceflight , physics , geophysics , magnetopause , coronal mass ejection , earth's magnetic field , geology , atmospheric sciences , magnetic field , quantum mechanics
A total of 43 Corotating Interaction Region (CIR)‐induced geomagnetic storms during the unusually deep solar minimum of solar cycle 23 (2006–2010) were identified using a superposed epoch analysis technique. Of these 43 events, detailed cross‐spectrum analyses, between the variations in the Z component of the interplanetary magnetic field (IMF B z ) and the equatorial electrojet (EEJ) strength, were performed for 22 events when the daytime EEJ strengths from Jicamarca were available. The analyses revealed that the ∼30 and ∼60 min periodic components in IMF B z were causally related to the EEJ strength subject to the average solar wind flow being radial to within 6° at L1 during the interval for which EEJ strengths were considered. This investigation elicits the important role of average solar wind azimuthal flow angle in determining the geoeffectiveness of CIR events.