Jovian longitudinal asymmetry in Io-related and Europa-related auroral hot spots

Journal Article · Fri Jun 15 04:00:00 EDT 1979 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/157155· OSTI ID:6249237

Dessler, A J; Chamberlain, J W

Jupiter's internal magnetic field is markedly non-dipolar. We propose that Io- or Europa-generated auroral emissions (originating at the foot of either Io's or Europa's magnetic flux tube) are largely restricted to longitudes where Jupiter's ionospheric conductivity is enhanced. Trapped, energetic electrons that drift into Jupiter's atmosphere, in regions where the Jovian magnetic field is anomalously weak, produce the increased conductivity. The longitude range of enchanced auroral hot-spot emissions is thus restricted to an active sector that is determined from dekametric radio emission to lie in the northern hemisphere in the Jovian System III (1965) longitude range of 205/sup 0/ +- 30/sup 0/. Relatively weaker auroral hot spots should occur in the southern hemisphere along the mgnetic conjugate trace covering the longitude range of 215/sup 0/ +- 55/sup 0/. At other longitudes, the brightness of the hot spot should decrease by at least one order of magnitude. These results, with respect to both brightness and longitude, are in accord with the observations of Jovian auroral hot spots reported by Atreya et al. We show that the northern hemisphere foot of either Io's or Europa's magnetic flux tube was in the preferred longitude range (the active sector) at the time of each observation.

• Research Organization: Applied Physics Laboratory, Johns Hopkins University
• OSTI ID: 6249237
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 230:3; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640107* -- Astrophysics & Cosmology-- Planetary Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ATMOSPHERES
COLLISIONS
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELECTRON COLLISIONS
ELECTRONS
ELEMENTARY PARTICLES
FERMIONS
JUPITER PLANET
LEPTONS
LYMAN LINES
MAGNETIC FIELDS
MAGNETIC FLUX
NUCLEAR REACTIONS
PHYSICAL PROPERTIES
PLANETARY ATMOSPHERES
PLANETS