Paper#: 43
Poster #:
Session Name: Workshop 5C: Tail Processes
Room: West Ballroom
Day: Thursday
Time: 5:15-5:40 p.m.
Abstract Title: The Role of Waves in Magnetotail Dynamics
PresentSurname: Cattell, C.
All Authors: C. Cattell
Abstract : The role of waves in the dynamics of the magnetotail has long been a topic of interest in magnetospheric physics. Although early observations of waves led to the suggestion that lower hybrid waves provided the dissipation needed for reconnection to occur, questions were raised about the amplitude of the waves and the suppression of the instability at high beta. ISEE and Geotail observations provided evidence that the waves were often large enough to enable reconnection and that large amplitude waves could occur within the current sheet. More recently, simulation studies have indicated that the Hall effect and the resulting whistler dispersion decouple the particles and that wave dissipation is not needed. However, an observational answer to the question of which small-scale structures and/or waves break the frozen in condition, decoupling of the motions of ions and electrons, during substorm reconnection is still unresolved. We will briefly review previous studies of waves in the magnetotail and their association with substorms and magnetotail dynamics. The recent launch of Cluster and the precession of the Polar apogee into the equatorial plane have provided the opportunity to examine the importance of waves with more sophisticated instruments. We will discuss results of several new event studies utilizing Polar and Cluster data to re-examine the importance of waves and nonlinear structures, such as electron holes, in substorms and magnetotail dynamics.