Wave activity above the ionosphere of Titan

Predictions for the Cassini mission

Zoltán Dóbé, K. Szegö

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

In this paper we present a study of the beam-driven wave generation mechanisms in linear approximation which are viable in the flowside plasma mantle of Saturn's moon, Titan. The flowside plasma mantle is defined, by analogy with the dayside plasma mantle of the planet Venus and Mars, as being the interaction region between the "cold7" ionospheric plasma and "hot" streaming plasma of magnetospheric or solar wind origin, with both types of plasma being present in comparable densities. Since no in situ plasma and field measurements are currently available in Titan's flowside mantle, we performed our model calculations in a broad plasma parameter space encompassing the plasma characteristics determined by Voyager 1 in Titan's wake. Two types of beam instability modes were found to be dominant: a fluid-like (nonresonant) modified two-stream instability (MTSI) and the kinetic (beam resonant) ion-ion acoustic instability (IIAI). The two instability modes are characterized by distinct frequency ranges (an order or below the lower hybrid frequency for the MTSI and a few times the lower hybrid frequency for the IIAI) and are found to be dominant in well-separated spatial regions determined by the presence/absence of cold ionospheric electrons. Giving a global rather than a specific description of the instability types expected to be the most important growing modes within Titan's flowside mantle, we intend to make predictions concerning the wave characteristics of the dominant wave modes measurable by the plasma wave instrument on board the Cassini spacecraft.

Original languageEnglish
Article numberA03224
JournalJournal of Geophysical Research: Space Physics
Volume110
Issue numberA3
DOIs
Publication statusPublished - 2005

Fingerprint

Cassini mission
Titan
Ionosphere
ionospheres
ionosphere
ions
Plasmas
plasma
prediction
predictions
Earth mantle
acoustics
mantle
Ions
acoustic instability
ion
ionospherics
electrons
Acoustics
Mars (planet)

ASJC Scopus subject areas

  • Geophysics
  • Space and Planetary Science

Cite this

Wave activity above the ionosphere of Titan : Predictions for the Cassini mission. / Dóbé, Zoltán; Szegö, K.

In: Journal of Geophysical Research: Space Physics, Vol. 110, No. A3, A03224, 2005.

Research output: Contribution to journalArticle

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