Abstract
Abstract. A major part of the plasma in the Earth's magnetotail is populated through transport of plasma from the solar wind via the magnetotail lobes. In this paper, we present a statistical study of plasma convection in the lobes for different directions of the interplanetary magnetic field and for different geomagnetic disturbance levels. The data set used in this study consists of roughly 340 000 one-minute vector measurements of the plasma convection from the Cluster Electron Drift Instrument (EDI) obtained during the period February 2001 to June 2007. The results show that both convection magnitude and direction are largely controlled by the interplanetary magnetic field (IMF). For a southward IMF, there is a strong convection towards the central plasma sheet with convection velocities around 10 km s−1. During periods of northward IMF, the lobe convection is almost stagnant. A By dominated IMF causes a rotation of the convection patterns in the tail with an oppositely directed dawn-dusk component of the convection for the northern and southern lobe. Our results also show that there is an overall persistent duskward component, which is most likely a result of conductivity gradients in the footpoints of the magnetic field lines in the ionosphere.
Highlights
The Earth’s magnetosphere is a dynamical system primarily controlled by the solar wind and the interplanetary magnetic field (IMF)
The recently opened magnetic field lines are dragged by the solar wind across the polar caps into the magnetotail lobes and eventually into the central plasma sheet of the magnetotail where the field lines eventually reconnect and return towards the Earth (Dungey, 1961)
In this paper we present a comprehensive survey of lobe convection as a function of IMF direction and magnitude as well as secondary effects reflected by various geomagnetic disturbance indicators
Summary
The Earth’s magnetosphere is a dynamical system primarily controlled by the solar wind and the interplanetary magnetic field (IMF). The recently opened magnetic field lines are dragged by the solar wind across the polar caps into the magnetotail lobes and eventually into the central plasma sheet of the magnetotail where the field lines eventually reconnect and return towards the Earth (Dungey, 1961). In the case of northward IMF, reconnection can take place between the IMF and already open polar cap field lines at high latitudes. Tailward of approximately 10 RE, the magnetic field lines in the northern (southern) central lobe are almost parallel (anti parallel) to the XGSE direction. In this paper we present a comprehensive survey of lobe convection as a function of IMF direction and magnitude as well as secondary effects reflected by various geomagnetic disturbance indicators.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
