Global MHD eigenmodes of the outer magnetosphere

Abstract

The global scale time-dependent behavior of the magnetosphere is naturally described in terms of MHD waves. As these waves propagate they transport energy throughout the system, couple different regions together and form part of the magnetospheric current circuit. Theory and observations of ULF waves have a tradition of developing together and provide much insight and understanding of the magnetosphere. A historical review is given by Hughes [1994]. The origins of theory date back to Dungey's [1954; 1967] consideration of MHD waves in a cold axisymmetric magnetic field. In this case only the fast and Alfvén modes exist, and were shown to decouple when the

Dependence of ground-based Pc5 ULF wave power on F10.7 solar radio flux and solar cycle phase

“…Ultra low frequency (ULF) waves in the Pc5 wave band (150-600 s period) are thought to play a pivotal role in energising the magnetospheric cavity in a variety of ways (see e.g., the review by Wright and Mann, 2006). These waves can play an important role in a number of magnetospheric processes including, but not limited to, energy transport across the magnetopause (e.g., Mann et al, 2002Mann et al, , 1999Miura, 1987;Rae et al, 2005;Southwood, 1974), ohmic energy dissipation in the ionosphere (e.g., Rae et al, 2008), the energisation and transport of relativistic electrons (e.g., Degeling et al, 2007;Elkington et al, 1999Elkington et al, , 2003Hudson et al, 2001;Mann et al, 2004;Mathie and Mann, 2000), the formation of auroral arcs (Samson et al, 1996), the modulation of electron precipitation (Rae et al, 2007), and the dynamics of the ring current (e.g., Mann, 2001, 2008).…”

Coupled Alfvén and Kink Oscillations in Coronal Loops

“…The context of these studies was the Earth's magnetotail, part of the Earth's magnetosphere which has a rich history of MHD wave coupling studies (see, e.g., the review by Wright & Mann 2006).…”

Simulations of Alfvén waves in the geomagnetic tail and their auroral signatures

“…The study of decoupled fast modes in more realistic tail equilibria has continued to receive attention [e.g., Hopcraft and Smith , 1986; Edwin et al , 1986]. Subsequently the coupling of fast and Alfvén waves in the magnetotail has been of interest [see Liu et al , 1995; Allan and Wright , 1998, 2000; Wright et al , 1999] and has been reviewed by Wright and Mann [2007].…”