Work

New Plasma Regime in Jupiter’s Auroral Zones

Year: 2025

Type: article

Abstract: Observations from the Juno satellite have indicated very low electron densities, as low as 10^{-3} cm^{-3}, at high-latitudes in Jupiter's magnetosphere. This region is strongly magnetized, with surface magnetic fields at the one-bar level up to 20 G, or 2 mT, leading to the unusual situation that the electron plasma frequency is less than the ion gyrofrequency. In this extremely low-density plasma, the Alfven wave becomes a plasma oscillation at the electron plasma frequency at shorter perpendicular wavelengths. Analysis of this mode with a kinetic low-frequency dispersion solver indicates that at large wave number, this mode has the characteristics of the Langmuir wave. Thus, this mode can be called an Alfvén-Langmuir mode. Below the plasma frequency, the high-wave number behavior of this mode exhibits a resonance cone, with frequency determined by the angle of the wave vector with the background magnetic field. These waves can be excited by the upward electron beams observed by Juno.

Source: Physical Review Letters

DOI: 10.1103/fn63-qmb7

Authors: R. L. Lysak, A. H. Sulaiman, S. S. Elliott, W. S. Kurth, S. J. Bolton

Institutions: University of Minnesota, University of Iowa, Southwest Research Institute

Language: English

Topic: Ionosphere and magnetosphere dynamics

Subfield: Astronomy and Astrophysics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $3,750