Satellite Roles in Radio Emission from Jupiter.

Abstract

view Abstract Citations (1) References Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Satellite Roles in Radio Emission from Jupiter. Witting, J. Abstract Jupiter I is known to influence quite strongly the probability of decameter wavelength radio emission from Jupiter. It is shown that the direct scattering of electrons of 40 keV by the satellite produces particle lifetimes of the order of months, probably much longer than lifetimes required by the intensity of the bursts. It is also shown, however, that Alfv6n waves which propagate along magnetic fields without radial attenuation can be generated by the moving satellite. This might provide a mechanism for triggering plasma instabilities leading to decameter bursts. Radio emission from Jupiter at decimeter wavelengths implies a radiation belt of relativistic electrons near the orbit of Jupiter V. It is shown that Jupiter V scatters relativistic electrons out of the belt in less than 2 yr, either by direct impact or reflection from large-amplitude Alfve'n waves generated by the moving satellite. This lifetime is small compared to the lifetime of highly relativistic electrons against radio emlsslon. This implies either that electron densities are larger than those given by Chang and Davis (1962) or that the magnetic field near Jupiter V is greater than 1 G. If large-amplitude Alfve'n waves are present, they provide a means of accelerating electrons through Fermi acceleration, such that electron energies follow a power law spectrum having exponent of the order of - 1, which is consistent with decimeter observations. Publication: The Astronomical Journal Pub Date: February 1966 DOI: 10.1086/110093 Bibcode: 1966AJ.....71R.187W full text sources ADS |