nerc.ac.uk

Formation of electron radiation belts at Saturn by Z-mode wave acceleration

Woodfield, EE ORCID: https://orcid.org/0000-0002-0531-8814; Horne, RB ORCID: https://orcid.org/0000-0002-0412-6407; Glauert, SA ORCID: https://orcid.org/0000-0003-0149-8608; Menietti, JD; Shprits, YY; Kurth, WS. 2018 Formation of electron radiation belts at Saturn by Z-mode wave acceleration. Nature Communications, 9, 5062. 10.1038/s41467-018-07549-4

Before downloading, please read NORA policies.
[thumbnail of Open Access]
Preview
Text (Open Access)
Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/. © The Author(s) 2018
Woodfield_et_al-2018-Nature_Communications.pdf - Published Version
Available under License Creative Commons Attribution 4.0.

Download (3MB) | Preview

Abstract/Summary

At Saturn electrons are trapped in the planet’s magnetic field and accelerated to relativistic energies to form the radiation belts, but how this dramatic increase in electron energy occurs is still unknown. Until now the mechanism of radial diffusion has been assumed but we show here that in-situ acceleration through wave particle interactions, which initial studies dismissed as ineffectual at Saturn, is in fact a vital part of the energetic particle dynamics there. We present evidence from numerical simulations based on Cassini spacecraft data that a particular plasma wave, known as Z-mode, accelerates electrons to MeV energies inside 4 RS (1 RS = 60,330 km) through a Doppler shifted cyclotron resonant interaction. Our results show that the Z-mode waves observed are not oblique as previously assumed and are much better accelerators than O-mode waves, resulting in an lectron energy spectrum that closely approaches observed values without any transport effects included.

Item Type: Publication - Article
Digital Object Identifier (DOI): 10.1038/s41467-018-07549-4
ISSN: 20411723
Date made live: 30 Nov 2018 14:29 +0 (UTC)
URI: https://nora.nerc.ac.uk/id/eprint/517060

Actions (login required)

View Item View Item

Document Downloads

Downloads for past 30 days

Downloads per month over past year

More statistics for this item...