Detection of Jovian whistler mode chorus; implications for the Io torus aurora

Journal Article · Tue Jan 01 04:00:00 EST 1980 · Geophys. Res. Lett.; (United States)

DOI:https://doi.org/10.1029/GL007i001p00045· OSTI ID:5391650

Coroniti, F V; Scarf, F L; Kennel, C F; Kurth, W S; Gurnett, D A

Near the Io torus outer boundary (Lapprox. =8), the Voyager 1 plasma wave instrument detected high frequency (f) waves near one-half the electron cyclotron frequency f/sub c/. High resolution waveform measurements demonstrate that these fapprox. =F/sub c//2 signals are banded whistler mode chrous at f< or approx. =f/sub c//2 and half-cyclotron frequency emissions with f slightly above f/sub c//2. The high resolution spectral information, and the theory of whistler mode waves, permit us to estimate the density (approx.2.5 cm/sup -3/), energy (few keV), and omnidirectional energy flux (10/sup 2/ ergs/cm/sup 2/-sec) of the electrons resonant with the chorus. Chorus precipitates about 6 ergs/cm/sup 2/-sec of few keV electron energy to the Jovian ionosphere at L=8. Electrostatic emission, probably electron cyclotron half-harmonic modes, have also been detected near the magnetic equator in the Io torus region. At L=8, the multimode pitch-angle diffusion associated with the detected waves should produce a precipitation flux about a factor two below the 50 ergs/cm/sup 2/-sec required to generate the observed auroral emission; however, the flux could well be larger deeper within the torus.

• Research Organization: Space Sciences Department, TRW Defense and Space Systems Group, Redondo Beach, California 90278
• OSTI ID: 5391650
• Journal Information: Geophys. Res. Lett.; (United States), Journal Name: Geophys. Res. Lett.; (United States) Vol. 7:1; ISSN GPRLA
• Country of Publication: United States
• Language: English

Related Subjects

640107* -- Astrophysics &amp; Cosmology-- Planetary Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ATMOSPHERES
AURORAE
CHARGED-PARTICLE PRECIPITATION
DIFFUSION
ELECTROMAGNETIC RADIATION
ELECTRON DENSITY
ELECTRON PRECIPITATION
INCLINATION
JUPITER PLANET
NOISE
PLANETARY ATMOSPHERES
PLANETARY IONOSPHERES
PLANETARY MAGNETOSPHERES
PLANETS
PLASMA WAVES
RADIATIONS
RADIO NOISE
RADIOWAVE RADIATION
SATELLITES
WAVELENGTHS
WHISTLERS