Fast flow during current sheet thinning 

R. Nakamura, W. Baumjohann, A. Runov, M. Volwerk, T.L. Zhang, B. Klecker, 
Y. Bogdanova, A. Roux, A. Balogh, H. Reme, J.A. Sauvaud, and H.U. Frey



In this paper we report Cluster observation of a fast flow event in the plasma
sheet associated with a small auroral substorm intensification at 1838 UT on
August 12, 2001. Cluster, located in the plasma sheet, experienced significant
thinning of the current sheet associated with a high-speed Earthward flow of 900
km/s. By using the four spacecraft magnetic field data and a Harris-type current
sheet model, it was estimated that the thickness of the current sheet changes
from about 1 RE before the flow observation down to 400 km, i.e., close to the
ion inertia length. In the vicinity of this thin current sheet there were also
signatures of enhanced current density off the center of the neutral sheet,
consistent with recent Geotail results. 

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Geophysical Research Letters, 29(23), 2140, doi:10.1029/2002GL016200, 2002