HR: 17:00h
AN: SM14B-05    [Abstracts]
TI: The origin of plasmaspheric hiss
AU: * Bortnik, J
EM: jbortnik@gmail.com
AF: University of California, Los Angeles, 405 Hilgard Ave., Los Angeles, CA 90095, United States
AU: Thorne, R M
EM: rmt@atmos.ucla.edu
AF: University of California, Los Angeles, 405 Hilgard Ave., Los Angeles, CA 90095, United States
AU: Meredith, N P
EM: nmer@bas.ac.uk
AF: British Antarctic Survey, National Environment Research Council, Madingly Road, Cambridge, CB3 OET, United Kingdom
AB: Plasmaspheric hiss is an electromagnetic emission found ubiquitously within the plasmasphere, and other high density regions such as plasmaspheric drainage plumes. It has been known for some time that hiss is an important scattering (loss) mechanism for the high energy electrons that populate the Van Allen (radiation) belts, and lead to the radiation-belts" well-known two-zone structure. However, the origin of plasmaspheric hiss has been a hotly debated topic since its discovery, over four decades ago. The two leading theories are: (1) the evolution of lightning-generated, magnetospherically reflected whistler waves into the incoherent hiss band, and (2) the in-situ growth of wave energy due to cyclotron interactions with energetic particles. Both theories suffer from significant deficits and cannot explain all of the observed features of hiss. In the present work, we present a new theory: the evolution of ELF/VLF chorus waves into the hiss spectrum, and show on the basis of extensive ray tracing that chorus is able to leak into the plasmasphere, and reproduce the observed hiss bandwidth, day/night asymmetry, and wave normal angle distribution. The modeling work is compared against current and previous satellite observations.
DE: 2753 Numerical modeling
DE: 2772 Plasma waves and instabilities (2471)
DE: 2774 Radiation belts
DE: 6964 Radio wave propagation
DE: 6984 Waves in plasma (7867)
SC: SPA-Magnetospheric Physics [SM]
MN: 2007 Fall Meeting