Dissipation Range Dynamics: Kinetic Alfven Waves and the Importance of Electron Beta
Robert J. Leamon, Norman F. Ness, Charles W. Smith and Hung K. Wong
Journal of Geophysical Research, submitted (1998)
In a previous paper we argued that the damping of obliquely propagating Kinetic Alfven waves, chiefly by resonant mechanisms, was a likely explanation for the formation of the dissipation range for interplanetary magnetic field fluctuations. This suggestion was based largely upon observations of the dissipation range at 1 AU as recorded by the Wind spacecraft. We pursue this suggestion here with both a general examination of the damping of obliquely propagating Kinetic Alfven waves and an additional examination of the observations. We explore the damping rates of Kinetic Alfven waves under a wide range of interplanetary conditions using numerical solutions of the linearized Maxwell-Vlasov equations and demonstrate that these waves display the nearly isotropic dissipation properties inferred from the previous paper. Using these solutions, we present a simple model to predict the onset of the dissipation range and compare these predictions to the observations. In the process we demonstrate that electron Landau damping plays a significant role in the damping of IMF fluctuations which leads to significant heating of the thermal electrons.
Return to Charles W. Smith's Publication Page
Return to Charles W. Smith Home Page