Physics Department Seminar University of Alaska Fairbanks

J O U R N A L    C L U B


Electron dynamics in kinetic scale field line resonances

Peter Damiano,
Geophysical Institute, UAF



Field line resonances (FLRs), or standing shear Alfvén waves along the Earth’s closed magnetic field lines, are an important mechanism for coupling the magnetosphere and ionosphere leading to the formation of some auroral arcs. They have been noted in observations for decades, both in the auroral zone and inner magnetosphere. Historically, most research effort has focused on the study of these waves at large perpendicular scales. However, recent Van Allen Probes observations have illustrated examples of these waves with perpendicular scale lengths on the order of the equatorial ion gyroradius that are prevalent in the inner magnetosphere particularly during storm time conditions. In this limit, they are termed kinetic scale field line resonances (KFLRs) and the kinetic scale physics alters the way the electrons interact with the waves. In this talk, I present a brief overview of KFLRs and then summarize recent simulation results of the electron distributions within these waves, the features of which agree well with observations of both the Cluster and Van Allen Probes satellites. The simulation results also illustrate how the kinetic scale physics affect the longer term evolution of these standing modes.


Friday, 12 April 2019

Globe Room, Elvey Building