Journal article
Electron densities in Jupiter's outer magnetosphere determined from Voyager 1 and 2 plasma wave spectra
Journal of geophysical research. Space physics, Vol.114(A5), pp.A05218-n/a
05/2009
DOI: 10.1029/2009JA014069
Abstract
This paper presents an electron plasma density data set for Jupiter's outer magnetosphere derived from high-resolution wideband measurements of low-frequency radio and plasma waves obtained by Voyagers 1 and 2 during their 1979 flybys. This work utilizes a new data processing tool that makes important improvements in the identification of the plasma frequency and other characteristic frequencies of the plasma, thereby allowing for the determination of the electron density within the Jovian magnetosphere. Furthermore, this work includes the interpretation of complex spectra including sometimes overlapping wave phenomena including continuum radiation, Z mode emissions, and whistler mode waves. Using the theory of cold plasmas and measurements of the magnetic field from which the electron cyclotron frequency can be calculated, we establish an extensive set of reasoning for interpreting cutoffs and resonances in the wave spectra to identify characteristic frequencies of the plasma, including the electron plasma frequency, R = 0 cutoff, L = 0 cutoff, and upper hybrid resonance frequency. While most Voyager plasma wave data used are obtained in the plasma sheet where the plasma frequency is greater than the cyclotron frequency, this investigation also analyzes observations in the lobe where the cyclotron frequency is greater than the plasma frequency to interpret the various cutoffs and resonances in the spectrum. The resulting data set for the electron densities has higher temporal resolution than any others that exist today. Also, given the identification of spectral features to accuracies of similar to 100 Hz or better, the density measurements are among the most accurate for Jupiter's magnetosphere.
Details
- Title: Subtitle
- Electron densities in Jupiter's outer magnetosphere determined from Voyager 1 and 2 plasma wave spectra
- Creators
- B. L. Barnhart - University of IowaW. S. Kurth - University of IowaJ. B. Groene - University of IowaJ. B. Faden - University of IowaO. Santolik - Charles UniversityD. A. Gurnett - University of Iowa
- Resource Type
- Journal article
- Publication Details
- Journal of geophysical research. Space physics, Vol.114(A5), pp.A05218-n/a
- Publisher
- Amer Geophysical Union
- DOI
- 10.1029/2009JA014069
- ISSN
- 2169-9380
- eISSN
- 2169-9402
- Number of pages
- 14
- Grant note
- NNG05GG98G / NASA; National Aeronautics & Space Administration (NASA)
- Language
- English
- Date published
- 05/2009
- Academic Unit
- Physics and Astronomy
- Record Identifier
- 9984455276902771
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