Penetration electric field and the formation of plasmaspheric shoulders and notches

J. Goldstein (1), R.W. Shapiro (1), R.A. Wolf (1), P.H. Reiff (1), J.W. Freeman (1), 
B.R. Sandel (2), W.T. Forrester (2), D.L. Gallagher (3), R.L. Lambour (4)

Sudden changes in solar wind (SW) and IMF allow outer mag-netospheric
E-fields to penetrate past the inner magnetosphere.s
shielding layer. The intensity of this .penetration E-field. is con-centrated
in MLT: .active regions. (AR) are found in the pre-dawn
(PD) and pre-noon (PN) local times. A comparison study
showing good agreement between simulations and IMAGE EUV
data, establishes the connection between penetration and .shoul-ders.
and .notches. that form in the PDAR, where penetration-induced
plasma motion is most pronounced. Detailed analysis
of EUV-observed plasmapause motion also shows both a pro-nounced
PDAR concentration and a strong correlation with rapidly-changing
SW/IMF.

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Presented at the 27th General Assembly of International Union of Radio 
Science (URSI), Maastricht, The Netherlands, August 17-24, 2002.