Waves in Saturn's rings probed by radio occultation

Thesis/Dissertation · Sun Jan 01 04:00:00 EST 1989

OSTI ID:6862978

Rosen, P A

Thirty wave features, observed in 3.6 and 13 cm-wavelength optical depth profiles of Saturn's rings obtained by Voyager 1 radio occultation, are analyzed individually and comparatively. Many are the signature of spiral density waves and bending waves excited by gravitational resonances with Saturn's satellites. A new technique for locating waveform extrema, which fits a sinusoid to each half cycle of wave data, quantifies the wavelength variation across a feature. Fitting dispersion models to the derived wavelengths provides new estimates of ambient surface mass density {sigma} in each wave region. For fourteen weak density waves in Ring A, modelling of the waveform near resonance with linear density wave theory gives independent estimates of {sigma}, as well as reliable estimates of resonance location. Measurements of wave amplitude damping give an upper bound for ring thickness 2H, where H is the ring scale height. In the wave regions studied, Rings A, B, and C have 30 {approx lt} {sigma} {approx lt} 70, {sigma} {approx gt} 65, and {sigma} {approximately} 1 g/cm{sup 2}, respectively. Mass loading estimates from waveform modelling are 20 to 40% larger than dispersion-derived values, suggesting accumulation of mass in the wave regions. The average offset of derived wave location from theoretical resonance is about 1 km. Model waveforms of overlapping waves excited by the satellites Janus and Epimethenus agree well with observed morphologies in the linear region near resonance. In Ring C, dispersion analysis indicates that the most prominent wave feature, previously unidentified, is a one-armed spiral wave.

• Research Organization: Stanford Univ., CA (USA)
• OSTI ID: 6862978
• Country of Publication: United States
• Language: English

Related Subjects

640107* -- Astrophysics & Cosmology-- Planetary Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
DAMPING
DENSITY
ECLIPSE
ELECTROMAGNETIC RADIATION
MASS
MATHEMATICAL MODELS
MORPHOLOGY
PHYSICAL PROPERTIES
PLANETS
RADIATIONS
RADIOWAVE RADIATION
RINGS
SATELLITES
SATURN PLANET
SPACE VEHICLES
VEHICLES
VOYAGER SPACE PROBES
WAVE PROPAGATION