Conference proceeding
The Location of the High-Density Boundary in Saturn’s Inner Magnetosphere (extended abstract)
Planetary Radio Emissions VII: Proceedings of the 7th International Workshop on Planetary, Solar and Heliospheric Radio Emissions held at Graz, Austria, September 15–17, 2010, pp.129-132
2011
DOI: 10.1553/pre7s129
Abstract
Electron density measurements from the Cassini RPWS Langmuir Probe instrument have identified a sharply-defined region of low plasma densities in Saturn’s magnetosphere outside a dipole L-shell of ~15. Gradients in the density profiles define a boundary identified as the plasmapause [Gurnett et al., 2010] that separates the region of higher plasma density from the region of very low plasma density. During seven consecutive high-latitude passes in the northern hemisphere from September through December 2006, Cassini followed a series of trajectories that skimmed along high-latitude magnetic field lines for several days. The orientation of these trajectories made it possible for the RPWS to detect modulations in the high-latitude auroral hiss emissions at a 10.6 hour rotational modulation rate [Gurnett et al., 2009] and for the RPWS Langmuir Probe instrument to detect modulations in the electron density profiles that were anti-correlated with the hiss emissions [Gurnett et al., 2010]. The strong and periodic modulations in the density profiles indicate that Cassini is passing in and out of a plasma region of higher densities. One example during this seven-orbit time interval is shown in Figure 1. The periodic modulations in the density profile are shown in the bottom panel and are clearly anti-correlated with the periodic occurrence of intense auroral hiss emissions shown in the upper panel. The highest densities in this high-latitude region are 0.1 cm-3, two orders of magnitude greater than the lowest densities in this part of Saturn’s magnetosphere but well below the densities seen inside Saturn’s plasma disk [Morooka et al., 2009;Persoon et al., 2009].
Details
- Title: Subtitle
- The Location of the High-Density Boundary in Saturn’s Inner Magnetosphere (extended abstract)
- Creators
- A M Persoon - University of IowaD A Gurnett - University of Iowa, Physics and AstronomyJ S Leisner - University of LeicesterM. Morooka - Swedish Institute of Space PhysicsJ-E Wahlund - Swedish Institute of Space PhysicsJ. B. Groene - University of IowaW S Kurth - University of Iowa, Physics and AstronomyG B Hospodarsky - University of Iowa, Physics and Astronomy
- Resource Type
- Conference proceeding
- Publication Details
- Planetary Radio Emissions VII: Proceedings of the 7th International Workshop on Planetary, Solar and Heliospheric Radio Emissions held at Graz, Austria, September 15–17, 2010, pp.129-132
- DOI
- 10.1553/pre7s129
- Language
- English
- Date published
- 2011
- Academic Unit
- Physics and Astronomy
- Record Identifier
- 9984454745102771
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