Charged particle periodicity in the Saturnian magnetosphere

Journal Article · Wed Sep 01 04:00:00 EDT 1982 · Geophys. Res. Lett.; (United States)

DOI:https://doi.org/10.1029/GL009i009p01073· OSTI ID:6598611

Carbary, J F; Krimigis, S M

The low energy charged particles (LECP) experiments on the Voyager 1 and 2 spacecraft performed measurements of electrons (approx.22 keV to approx.20 MeV) and ions (approx.28 keV to approx.150 MeV) during the Saturn encounters in 1980 and 1981. Count rate ratios of two of the low energy electron (22 to 35 keV and 183 to 500 keV) and ion (43 to 80 keV and 137 to 215 keV) channels exhibit an approximation 10 hour periodicity in the outer Saturnian magnetosphere beyond the orbit of Titan. Electron ratios vary from approx.50 to approx.300; ion ratios vary from approx.3 to approx.20. Similar but less pronounced periodicities are observed for higher and lower energy electron and ion spectral indices. Three complete cycles were observed during the Voyager 2 outbound portion of the encounter from which were determined an electron ratio period of 10/sup h/21/sup m/ +- 48/sup m/ and an ion ratio period of 9/sup h/49/sup m/ +- 59/sup m/. Using Saturn Kilometric Radiation (SKR) and Saturn Electrostatic Discharge (SED) periods, extrapolation backward from Voyager 2 to Voyager 1 suggests that the periodicities are Saturnian rather than Jovian in nature, and that they persist in phase for time intervals at least as long as 287 days. Ratio minima, or spectral hardenings, occur in the same hemisphere as do auroral brightenings, SKR activity, and spoke enhanement. We interpret the observations as prima facie evidence of an asymmetry in the Saturian magnetic field and the root cause of the observed SKR periodicity.

• Research Organization: Applied Physics Laboratory, The Johns Hopkins University, Laurel, Maryland 20707
• OSTI ID: 6598611
• Journal Information: Geophys. Res. Lett.; (United States), Journal Name: Geophys. Res. Lett.; (United States) Vol. 9:9; ISSN GPRLA
• Country of Publication: United States
• Language: English

Related Subjects

640107* -- Astrophysics & Cosmology-- Planetary Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ATMOSPHERES
CHARGED PARTICLES
ELECTROMAGNETIC RADIATION
LONG WAVE RADIATION
PLANETARY ATMOSPHERES
PLANETARY MAGNETOSPHERES
PLANETS
RADIATIONS
RADIOWAVE RADIATION
SATURN PLANET
SPACE VEHICLES
VARIATIONS
VEHICLES
VOYAGER SPACE PROBES