Stability of the Io plasma torus/atmosphere interaction

1993 ◽  
Vol 20 (16) ◽  
pp. 1735-1738 ◽  
Author(s):  
R. E. Johnson ◽  
Melissa McGrath
Keyword(s):  
Atmosphere Interaction ◽  
Plasma Torus ◽  
Io Plasma Torus

The plasma/atmosphere interaction at Io: revisiting the ion/neutral charge-exchange cross-sections and their ion-velocity dependency

2020 ◽  
Author(s):  
Vincent Dols ◽  
Robert Johnson ◽  
Fran Bagenal
Keyword(s):  
Numerical Simulations ◽  
Flow Velocity ◽  
Charge Exchange ◽  
Cross Sections ◽  
Local Interaction ◽  
Ion Temperature ◽  
Atmosphere Interaction ◽  
Ion Velocity ◽  
Plasma Torus ◽  
Io Plasma Torus

<p>The Io Torus plasma is mostly composed of singly and multi-charged S and O ions. These ions interact with the neutrals of Io’s atmosphere (S, O, SO<sub>2</sub> and SO) through symmetrical (i.e. O<sup>+</sup> + O => O + O<sup>+</sup>) and asymmetrical (i.e. S<sup>++</sup> + O => S + O<sup>++</sup>) charge-exchanges. Charge-exchange cross-sections were estimated in Johnson & Strobel, 1982 and McGrath & Johnson, 1989 at 60 km/s (the plasma corotation velocity in Io’s frame), and are used in numerical simulations of the torus/neutral cloud interaction (i.e. Delamere and Bagenal, 2003).</p> <p>Dols et al., 2008 proposed numerical simulations of the multi-species chemistry interaction at Io using these cross-sections at 60 km/s. The plasma/atmosphere interaction at Io is strong and the flow velocity and ion temperature are drastically reduced close to Io (v < 10 km/s). Thus, velocity-dependent charge-exchange cross-sections are critical for such numerical simulations and their effect on the local plasma and neutral supply at Io should be explored.</p> <p>We propose to revisit the calculation of ion/neutral charge-exchange cross-sections following Johnson & Strobel, 1982’s approach for plasma velocities relevant to the local interaction at Io (V=10-120 km/s). More sophisticated calculations were proposed in McGrath & Johnson, 1989 but both publications offered very few details about their procedure.</p> <p>We will illustrate the effect of using velocity-depend charge-exchange cross-sections in numerical simulations of the multi-species plasma/atmosphere interaction at Io.</p> <p>More generally, this presentation aimed at providing an incentive for the community to expand the work of McGrath & Johnson, 1989.</p> <p> </p> <p><em>Johnson & Strobel, Charge-exchange in the Io torus and exosphere, JGR, 87,1982</em></p> <p><em>McGrath & Johnson, Charge exchange cross sections for the Io plasma torus, JGR, 94, 1989</em></p> <p><em>Delamere & Bagenal, Modeling variability of plasma conditions in the Io torus, JGR, 108, 2003</em></p> <p><em>Dols, Delamere, Bagenal, Kurth, Paterson, A multi-species chemistry model of Io’s local interaction with the plasma torus, JGR, 113, 2008</em></p>

How much Io material reaches Europa?

2020 ◽  
Author(s):  
Fran Bagenal ◽  
Vincent Dols ◽  
Edward Nerney ◽  
Frank Crary ◽  
Tim Cassidy
Keyword(s):  
Charge Exchange ◽  
Neutral Atoms ◽  
Plasma Interaction ◽  
High Energies ◽  
Energetic Neutral Atoms ◽  
Neutral Clouds ◽  
Atmosphere Interaction ◽  
Plasma Torus ◽  
Io Plasma Torus

<p>The plasma interaction with Io’s atmosphere results in at least a ton per second of escaping neutrals. Most of these neutrals supply extended neutral clouds along Io's orbit  and eventually become ionized and accelerated to corotation with Jupiter, populating the Io plasma torus as well as spreading out to fill Jupiter’s vast magnetosphere. About half to two-thirds of the plasma torus ions charge-exchange with the extended neutral clouds  and leave the torus as energetic neutral atoms, passing Europa’s orbit. Energetic neutrals are also produced directly in the plasma-atmosphere interaction, escaping with sufficient speed to reach Europa’s orbit before being ionized. The iogenic ions that are accelerated to high energies in the middle magnetosphere ultimately move back inward, again crossing Europa’s orbit. We present estimates of the fluxes of these various iogenic populations and how much oxygen, sulfur and sodium might be hitting Europa.</p>

Io plasma torus and the source of jovian narrow-band kilometric radiation

Nature ◽  
1987 ◽  
Vol 327 (6122) ◽  
pp. 492-495 ◽  
Author(s):  
Dyfrig Jones
Keyword(s):  
Narrow Band ◽  
Plasma Torus ◽  
Io Plasma Torus

scholarly journals Cassini UVIS observations of the Io plasma torus

Icarus ◽  
2008 ◽  
Vol 194 (1) ◽  
pp. 153-165 ◽  
Author(s):  
A.J. Steffl ◽  
P.A. Delamere ◽  
F. Bagenal
Keyword(s):  
Plasma Torus ◽  
Io Plasma Torus

The proton concentration in the vicinity of the Io plasma torus

1982 ◽  
Vol 87 (A12) ◽  
pp. 10395 ◽  
Author(s):  
R. L. Tokar ◽  
D. A. Gurnett ◽  
F. Bagenal
Keyword(s):  
Proton Concentration ◽  
Plasma Torus ◽  
Io Plasma Torus

Ground-based observations of the [SII] 6731 Å emission lines of the Io plasma torus

2016 ◽  
Vol 12 (S328) ◽  
pp. 227-229
Author(s):  
P. Magalhães Fabíola ◽  
Walter Gonzalez ◽  
Ezequiel Echer ◽  
Mariza P. Souza-Echer ◽  
Rosaly Lopes ◽  
...  
Keyword(s):  
Charged Particles ◽  
Emission Lines ◽  
Solar Telescope ◽  
The Moon ◽  
Active Object ◽  
Oxygen Ions ◽  
Galilean Moons ◽  
Plasma Torus ◽  
Io Plasma Torus ◽  
Galilean Moons Of Jupiter

AbstractThe Io Plasma Torus (IPT) is a doughnut-shaped structure of charged particles, composed mainly of sulfur and oxygen ions. The main source of the IPT is the moon Io, the most volcanically active object in the Solar System. Io is the innermost of the Galilean moons of Jupiter, the main source of the magnetospheric plasma and responsible for injecting nearly 1 ton/s of ions into Jupiter's magnetosphere. In this work ground-based observations of the [SII] 6731 Å emission lines are observed, obtained at the MacMath-Pierce Solar Telescope. The results shown here were obtained in late 1997 and occurred shortly after a period of important eruptions observed by the Galileo mission (1996-2003). Several outbursts were observed and periods of intense volcanic activity are important to correlate with periods of brightness enhancements observed at the IPT. The time of response between an eruption and enhancement at IPT is still not well understood.

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