Open AccessWhistler mode illumination of the plasmaspheric resonant cavity via in situ injection of ELF/VLF waves
Author(s) -
Kulkarni P.,
Inan U. S.,
Bell T. F.
Publication year - 2006
Publication title -
journal of geophysical research: space physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2006ja011654
Subject(s) - plasmasphere , whistler , physics , magnetosphere , earth's magnetic field , van allen radiation belt , field line , geophysics , resonance (particle physics) , geomagnetic latitude , magnetic dip , radiation , ray tracing (physics) , equator , magnetic field , latitude , optics , computational physics , atomic physics , astronomy , quantum mechanics
Numerical ray tracing indicates that the in situ injection of whistler mode waves of 1 kHz to 4 kHz can be used to illuminate the inner radiation belts and slot region. These results were derived by using the Stanford VLF Ray Tracing Program to simulate sources placed at a total of six points in the inner magnetosphere: L = 1.5, L = 2.0, and L = 2.5 at two geomagnetic latitudes, the equator and a latitude of 20° along each field line. The results demonstrate that an in situ source, by varying the frequency of the injected waves, can illuminate L shells both higher and lower than the source site, with wave frequencies below (above) the local lower hybrid resonance, f LHR , moving to higher (lower) L shells. Accounting for the limitations that would be imposed by a practical antenna immersed in the magnetospheric medium restricts the radiating wave frequency, f , to 0.9 f LHR ≤ F < ( f LHR + 1 kHz), and the wave normal angle at injection to no farther than 3° from the resonance cone. Even after accounting for these restrictions, it requires only three in situ sources placed at the above locations to illuminate 1.4 ≃ L ≃ 2.7, which comprises the bulk of the inner radiation belt.