State of the magnetotail: Magnetotail currents and tail stress index

E.I. Tanskanen and J.A. Slavin
NASA Goddard SFC, Greenbelt, MD, USA


Two Cluster tail passes are examined: 20-21 August, 2002 and 25-26 August, 2002. During both passes magnetosphere was strongly driven by solar wind and interplanetary magnetic field (IMF). IMF Bz was southward over 20 hours during the first Cluster tail pass and about 8 hours during the second pass. State of the magnetospheric convection is analyzed based on tail static pressure. All four Cluster s/c are used to compute tail current components, which are further used to analyze the stress level of the entire magnetotail.