Journal article
Quantification of Diffuse Auroral Electron Precipitation Driven by Whistler Mode Waves at Jupiter
Geophysical research letters, Vol.48(19), e2021GL095457
10/16/2021
DOI: 10.1029/2021GL095457
Abstract
While previous studies suggested whistler mode waves as a potential driver of Jupiter's diffuse aurora, their quantitative contribution to generate diffuse aurora remains unclear. We perform an in‐depth analysis of an intriguing diffuse auroral electron precipitation event using coordinated observations of precipitating electrons and whistler mode waves from the Juno satellite. A physics‐based technique is used to quantify energetic electron precipitation driven by whistler mode waves. We find that the modeled electron precipitation features are consistent with the electron measurements from several keV to several hundred keV over M‐shells of 8–18, while additional mechanisms are needed to explain the observed electron precipitation at lower energies (<several keV). Our result provides new quantitative evidence that whistler mode waves are potentially a primary driver of precipitating electrons from several keV to several hundred keV through pitch angle scattering over M ∼ 8–18 and thus generate Jupiter's diffuse aurora.
Plain Language Summary
Diffuse aurorae, which are naturally occurring phenomena without discernible patterns or structures, are commonly observed at various planets in our solar system. At Jupiter, diffuse aurorae are usually observed between the footprint of the Io and the main auroral emission. Although Jupiter's diffuse aurorae are known to be generated by precipitating energetic electrons, their primary driver remains unclear. In the present study, we use the coordinated observations from the Juno spacecraft, together with a physics‐based technique, to identify the primary driver of diffuse auroral electron precipitation at Jupiter. Our result provides new quantitative evidence that whistler mode waves are potentially a primary driver of precipitating electrons with energies from several keV to several hundred keV through pitch angle scattering over a region with equatorial crossing distances of 8–18 Jovian radii and thus generate Jupiter's diffuse aurora. Our findings are critical to evaluate electron energy inputs from the magnetosphere into the atmosphere through wave‐particle interactions at Jupiter.
Key Points
Electron precipitation responsible for generating Jupiter's diffuse aurora is observed by Juno at low altitudes over M‐shells of ∼8–18
The modeled electron precipitation above several keV driven by whistler mode waves is consistent with the Juno observation over M ∼ 8–18
The data‐model comparison indicates whistler mode waves as a primary driver of diffuse auroral precipitation from several keV to several hundred keV
Details
- Title: Subtitle
- Quantification of Diffuse Auroral Electron Precipitation Driven by Whistler Mode Waves at Jupiter
- Creators
- Wen Li - Boston UniversityQ. Ma - Boston UniversityX.‐C. Shen - Boston UniversityX.‐J. Zhang - University of CaliforniaB. H. Mauk - Johns Hopkins University Applied Physics LaboratoryG. Clark - Johns Hopkins University Applied Physics LaboratoryF. Allegrini - Southwest Research InstituteW. S. Kurth - University of IowaG. B. Hospodarsky - University of IowaV. Hue - Southwest Research InstituteG. R. Gladstone - Southwest Research InstituteT. K. Greathouse - Southwest Research InstituteS. J. Bolton - Southwest Research Institute
- Resource Type
- Journal article
- Publication Details
- Geophysical research letters, Vol.48(19), e2021GL095457
- DOI
- 10.1029/2021GL095457
- ISSN
- 0094-8276
- eISSN
- 1944-8007
- Number of pages
- 11
- Grant note
- National Aeronautics and Space Administration (NASA) (80NSSC20K0557) Alfred P. Sloan Foundation (The Alfred P. Sloan Foundation) (FG‐2018‐10936)
- Language
- English
- Date published
- 10/16/2021
- Academic Unit
- Physics and Astronomy
- Record Identifier
- 9984455363802771
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