Journal article
A Global Map of Average Electron Densities in the Magnetosphere of Saturn
Journal of geophysical research. Space physics, Vol.130(10), e2025JA034007
10/04/2025
DOI: 10.1029/2025JA034007
Abstract
Measurements from the Cassini Radio and Plasma Wave Science (RPWS) experiment obtained during the entire orbital phase of the Cassini mission around Saturn (13.2 years) are processed into a meridional map of plasma densities, comprising the innermost region of the ring ionosphere, the Enceladus plasma torus, and the outer magnetosphere, up to a dipole L-shell of 30. We combine data from RPWS wave observations, such as whistler-mode waves and upper hybrid electrostatic emissions, and from the RPWS Langmuir probe when operated in the proxy mode, providing an estimate for the spacecraft potential. In the region between dipole L-shells of 2.4 and 30, observed electron densities are described by an analytic model that fits two functions, one for the water group ions and one for the protons, to observed densities across latitude on each magnetic field line. The derived electron density profiles are then augmented by a model for the cold core electron temperature as a function of L-shell to obtain a meridional map of the electrostatic potential of the ambipolar electric field. The potential is extrapolated to the inner region of the rings, i.e., to below L=2.4 , to solve for the distribution of electron density in the ring ionosphere. A solution is based on a diffusive equilibrium model for the electrons and two ion species, and on observations from Cassini along the Saturn Orbit Insertion trajectory. A combination of analytic and diffusive equilibrium results finally yields an average global picture for the distribution of electron density in Saturn's magnetosphere.
Details
- Title: Subtitle
- A Global Map of Average Electron Densities in the Magnetosphere of Saturn
- Creators
- Ulrich Taubenschuss - Czech Academy of Sciences, Institute of Atmospheric PhysicsOndrej Santolik - Czech Academy of Sciences, Institute of Atmospheric PhysicsDavid Pisa - Czech Academy of Sciences, Institute of Atmospheric PhysicsMasafumi Imai - Czech Academy of Sciences, Institute of Atmospheric PhysicsGeorg Fischer - University of GrazSiyuan Wu - University of SouthamptonMichiko W. Morooka - Swedish Institute of Space PhysicsWilliam S. Kurth - University of Iowa
- Resource Type
- Journal article
- Publication Details
- Journal of geophysical research. Space physics, Vol.130(10), e2025JA034007
- DOI
- 10.1029/2025JA034007
- ISSN
- 2169-9380
- eISSN
- 2169-9402
- Publisher
- Amer Geophysical Union
- Number of pages
- 24
- Grant note
- Czech MEYS Interexcellence II programme
- Language
- English
- Date published
- 10/04/2025
- Academic Unit
- Physics and Astronomy
- Record Identifier
- 9985014896002771
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