Investigation of Io's Auroral Hiss Emissions Due To Its Motion in Jupiter's Magnetosphere

TL;DR

This study analyzes Io's auroral hiss emissions observed by Galileo, using whistler-mode propagation to locate the source near Io's surface, revealing insights into Io's magnetospheric interactions.

Contribution

It introduces a geometry-based method to locate Io's auroral hiss source considering both point and sheet sources along magnetic field lines.

Findings

Whistler mode radiation originates near Io's surface.

Emission source is close to Io, consistent with funnel-shaped frequency-time patterns.

Both point and sheet source models suggest similar source locations.

Abstract

The left-hand side of the auroral hiss emission observed by Galileo has a frequency time shaped very similar to the funnel shape observed in the earth's auroral region. This close similarity indicates that we can use the whistler-mode propagation near resonance cone to locate the emission source. In this paper the general characteristic of the whistler mode are discussed. Then the position of the emission source has been investigated using a geometry method that takes into account the Galileo's trajectory. Initially it is assumed the source is a point. Then the possibility of sheet source aligned along the magnetic field lines which are tangent to the surface of Io is investigated. Both of two types of sources show that the whistler mode radiation originates very close to the surface of the Io.