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The efficiency of “viscous interaction” between the solar wind and the magnetosphere during intense northward IMF events
Author(s) -
Tsurutani Bruce T.,
Gonzalez W. D.
Publication year - 1995
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 - 10.1029/95gl00205
Subject(s) - magnetosphere , solar wind , physics , coronal mass ejection , interplanetary spaceflight , interplanetary magnetic field , geophysics , atmospheric sciences , magnetohydrodynamics , astrophysics , magnetic field , computational physics , quantum mechanics
We examined 11 cases when the interplanetary magnetic field (IMF) was intensely northward (> 10 nT) for long durations of time (> 3 hours), to quantitatively determine an upper limit on the efficiency of solar wind energy injection into the magnetosphere. We have specifically selected these large B N events to minimize the effects of magnetic reconnection. Many of these cases occurred during intervals of high‐speed streams associated with coronal mass ejections when viscous interaction effects might be at a maximum. It is found that the typical efficiency of solar wind energy injection into the magnetosphere is 1.0 × 10 −3 to 4.0 × 10 −3 , 100 to 30 times less efficient than during periods of intense southward IMFs. Other energy sinks not included in these numbers are discussed. Estimates of their magnitudes are provided.