Dual periodicity of the Jovian Magnetosphere

Journal Article · Wed Jun 01 00:00:00 EDT 1988 · Journal of Geophysical Research; (United States)

DOI:https://doi.org/10.1029/JA093iA06p05487· OSTI ID:5223522

Sandel, B R ^[1]; Dessler, A J ^[2]

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1. Univ. of Arizona, Tucson (USA)
2. Rice Univ., Houston, TX (USA)

Jupiter's magnetic field, like that of the Sun, and perhaps Saturn, exhibits a clear, persistent dual periodicity, the two Jovian periods differing by almost exactly 3%. The authors offer a provisional definition of a new Jovian longitude system (which is called system 4) to organize magnetospheric data that are not stationary in system 3. They show that available, independent data sets, covering a time interval of 4 years, which either drift in system 3 or show no particular organization in system 3, fit mutually consistent patterns in system 4. All of the data sets covering several rotations of the planet that are presently available to them, including Voyager observations of ultraviolet and narrow-band kilometric emissions and ground-based optical observations, are organized in either system 3, system 4, or both. Using these data, they derive provisional values for a transformation between systems 3 and 4: {lambda} {sub 4} = {lambda} {sub 3} + 338 {minus} 25.486(t {minus} 2443874.5) where t is the Julian day and fractional day of the observation. There are pronounced 14.1-day variations in a number of Jovian Magnetospheric phenomena. One possible interpretation of the system 4 modulation is that it is a sideband resulting from the 14.1-day amplitude modulation of system 3 phenomena. Alternately, the 14.1-day period could be explained if it is assumed that the existence of an active sector that is fixed in system 4 but drifts approximately 25.5/d relative to the active sector in system 3. When the system 3 and system 4 activity maxima are aligned, magnetospheric activity, such as radio emissions and torus asymmetries, is enhanced, and when the activity maxima are anti-aligned, magnetospheric activity is subdued.

• OSTI ID: 5223522
• Journal Information: Journal of Geophysical Research; (United States), Journal Name: Journal of Geophysical Research; (United States) Vol. 93:A6; ISSN 0148-0227; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

640107* -- Astrophysics & Cosmology-- Planetary Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ASYMMETRY
ATMOSPHERES
COORDINATES
ELECTROMAGNETIC RADIATION
JUPITER PLANET
MAGNETIC FIELDS
MOTION
PLANETARY ATMOSPHERES
PLANETARY MAGNETOSPHERES
PLANETS
RADIATIONS
RADIOWAVE RADIATION
ROTATION
SPACE VEHICLES
VARIATIONS
VEHICLES
VOYAGER SPACE PROBES