The Hall current system revealed as a statistical significant pattern during fast flows K. Snekvik1, R. Nakamura2, N. Østgaard1, S. Haaland1,3, and A. Retinò2 1Department of Physics and Technology, University of Bergen, Bergen, Norway 2Space Research Institute, Austrian Academy of Sciences, Graz, Austria 3Max-Planck-Institut für Extraterrestrische Physik, Garching, Germany
Abstract. We have examined the dawn-dusk component of the magnetic
field, BY, in the night side current sheet during fast flows in
the neutral sheet.
237 h of Cluster data from the plasma sheet between 2 August 2002
and 2 October 2002 have been analysed.
The spatial pattern of BY as a function of the distance from the
centre of the current sheet has been estimated by using a Harris current sheet
We have used the average slopes of these patterns
to estimate earthward and tailward currents.
For earthward fast flows there is a tailward current in the inner central plasma sheet
and an earthward current in the outer central plasma sheet on average. For tailward fast flows the
currents are oppositely directed.
These observations are interpreted as signatures of Hall currents in the reconnection
region or as field aligned currents which are connected with these currents. Although
fast flows often are associated with a dawn-dusk current wedge, we believe that
we have managed to filter out such currents from our statistical patterns.
Citation: Snekvik, K., Nakamura, R., Østgaard, N., Haaland, S., and Retinò, A.: The Hall current system revealed as a statistical significant pattern during fast flows, Ann. Geophys., 26, 3429-3437, doi:10.5194/angeo-26-3429-2008, 2008.