SM23D-07
Investigations of the origin and evolution of inner magnetospheric temperature anisotropies, and implications for radiation belt dynamics
Tuesday, 15 December 2015: 15:10
2018 (Moscone West)
Scot Richard Elkington1, James Parker McCollough II2, Allison N Jaynes3, Thiago V Brito1, David Malaspina4, Maria Usanova5, Anthony Arthur Chan6, Michael James Wiltberger7 and Daniel N. Baker5, (1)Laboratory for Atmospheric and Space Physics, Boulder, CO, United States, (2)Kirtland Air Force Base, Kirtland AFB, NM, United States, (3)University of Colorado at Boulder, LASP, Boulder, CO, United States, (4)University of Colorado, Boulder, Laboratory for Atmospheric and Space Physics, Boulder, CO, United States, (5)University of Colorado at Boulder, Boulder, CO, United States, (6)Rice University, Houston, TX, United States, (7)National Center for Atmospheric Research, High Altitude Observatory, Boulder, CO, United States
Abstract:
Energetic electrons and ions with energies of 10s of keV form the so-called 'source populations' underlying the formation of magnetospheric chorus and EMIC waves, respectively. Temperature anisotropies among these populations, wherein the kinetic temperature perpendicular to the local magnetic field exceeds the parallel temperature, provide the source of free energy for either type of electromagnetic wave generation. In this work we use observations from the Van Allen Probes, combined with global MHD/particle simulations of the dynamic solar wind-magnetospheric interaction, to examine the distribution of temperature anisotropies in the inner magnetosphere, with an emphasis on understanding the relative roles of radial transport and drift orbit bifurcation in the evolving temperature profiles. We focus on recent storm events, including the October 2, 2013 and March 17, 2015 geomagnetic storms, which were characterized by significant radial transport and wave activity. Implications for the acceleration and loss of radiation belt particles as a result of this wave activity are discussed.
