Dissemin is shutting down on January 1st, 2025

Published in

Wiley, Journal of Geophysical Research. Space Physics, 4(129), 2024

DOI: 10.1029/2023ja032280

Links

Tools

Export citation

Search in Google Scholar

Generation Mechanism and Beaming of Jovian nKOM From 3D Numerical Modeling of Juno/Waves Observations

Journal article published in 2024 by A. Boudouma ORCID, P. Zarka ORCID, C. K. Louis ORCID, C. Briand ORCID, M. Imai ORCID
Distributing this paper is prohibited by the publisher
Distributing this paper is prohibited by the publisher

Full text: Unavailable

Red circle
Preprint: archiving forbidden
Orange circle
Postprint: archiving restricted
Red circle
Published version: archiving forbidden
Data provided by SHERPA/RoMEO

Abstract

AbstractThe narrowband kilometric radiation (nKOM) is a Jovian low‐frequency radio component identified as a plasma emission produced in the region of the Io plasma torus. Measurements from the Waves instrument onboard the Juno spacecraft permitted to establish the distribution of nKOM occurrence and intensity as a function of frequency and latitude. We have developed a 3D geometrical model that can simulate at large scale the plasma emissions occurrence observed by a spacecraft based on an internal Jovian magnetic field model and a diffusive equilibrium model of the plasma density in Jupiter's inner magnetosphere. With this model, we propose a new method to discriminate the generation mechanism, wave mode, beaming and radio source location of plasma emissions. Here, this method is applied to the study of the nKOM observed from all latitudes by the Juno/Waves experiment to identify which conditions reasonably reproduce the observed occurrence distribution versus frequency and latitude. The results allow us to exclude the two main nKOM models published so far, and to show that the emission is produced at the local plasma frequency and then beamed anti‐parallel to the local density gradient into free space. We also propose that depending on its latitude, Juno observes two distinct kinds of nKOM: the low frequency nKOM in ordinary mode at high latitudes, and the high frequency nKOM on extraordinary mode at low latitudes. Both radio source locations are found to be distributed near the centrifugal equator ranging from the outer edge to the inner edge of the Io plasma torus.