Estimating the magnetic energy inside traveling compression regions

Abstract

Abstract. We investigate a series of six TCRs (traveling compression regions), appearing in the course of a small substorm on 19 September 2001. Except for two of these TCRs, all Cluster spacecraft were located in the lobe and detected the typical signatures of TCRs, i.e., compressions in |B| and bipolar B z variations. We use these perturbations in B z for calculations on the magnetic energy inside the TCR and compare the amount of magnetic field energy with the kinetic energy inside the underlying plasma bulge. According to results obtained from theory, the amount of magnetic energy inside TCRs is about two times higher than the kinetic plasma energy inside the accompanied plasma bulge. We verify this theoretical result by first investigations of the magnetic field energy inside TCRs. The calculations lead to a magnetic energy in the order of 10 10 Joule per R E for each of the TCRs.

On the azimuthal size of flux ropes near lunar orbit

“…2003b; Kiehas et al, 2009aKiehas et al, , 2012. In a statistical study of TCRs observed with Cluster, Slavin et al [2005] found that in 76% of the observed events, TCRs occurred in series within a maximum interval of 15 min with the majority of these events being paired TCRs.…”

“…Statistically, the relation of flux ropes and TCRs is shown in Slavin et al [], where Geotail observations of flux ropes are compared with TCR observations of Cluster. Event studies with Cluster and Acceleration, Reconnection, Turbulence and Electrodynamics of the Moon's Interaction with the Sun (ARTEMIS) show the direct relation between TCRs and flux ropes, when the flux rope and the associated TCR are simultaneously observed by spatially separated spacecraft [e.g., Slavin et al , ; Kiehas et al , , ]. In a statistical study of TCRs observed with Cluster, Slavin et al [] found that in 76% of the observed events, TCRs occurred in series within a maximum interval of 15 min with the majority of these events being paired TCRs.…”