Overshielding event of 28-29 July 2000

J. Goldstein, R.W. Spiro, B.R. Sandel, R.A. Wolf, S.-Y. Su, P.H. Rei 


On 29 July 2000, IMAGE EUV observed a shoulder-like bulge on the 
afternoon sector plasmapause. Goldstein et al. [2002] showed that 
plasmaspheric shoulders may be caused by a pre-dawn concentration 
of eastward overshielding electric (E) field triggered by a decrease 
in magnetospheric convection.  A simulation by the Magnetospheric 
Specification Model (MSM) captures the formation of the shoulder, 
reproducing its approximate size and location. ROCSAT-1 ion drift 
meter data are consistent with the strength, time development and 
local-time variation ofthe MSM eastward penetration E-field (and 
associated radial flows) during the shoulder formation on 28 July.  

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Geophysical Research Letters, in press