Hot plasma environment at jupiter: voyager 2 results

Area of Science:

• Planetary Science
• Plasma Physics
• Space Physics

Background:

• The Jovian magnetosphere's plasma environment is complex and not fully understood.
• Previous models suggested a conventional magnetopause, but direct measurements were lacking.

Purpose of the Study:

• To investigate the hot plasma environment of Jupiter's magnetosphere using Voyager 2 data.
• To characterize the plasma composition, density, energy, and flow dynamics.

Main Methods:

• Analysis of low-energy charged particle (LECP) instrument data from Voyager 2.
• Measurements of ion energies, densities, and energy densities.
• Calculation of plasma flow velocities using Compton-Getting formalism.

Main Results:

• Jupiter's magnetosphere is populated by hot, multicomponent plasma (H, O, S ions) extending to at least 30 Jupiter radii.
• Plasma flows corotationally until the magnetospheric boundary, then forms a "magnetospheric wind" beyond 150 Jupiter radii.
• A discontinuity at 50-60 Jupiter radii, termed the "inner plasmasphere," was identified, with distinct plasma composition ratios.

Conclusions:

• The Jovian magnetosphere is confined by a plasma boundary, not a conventional magnetopause.
• The observed "magnetospheric wind" indicates an outward plasma flow from Jupiter.
• The inner plasmasphere represents a distinct region within Jupiter's magnetosphere with unique plasma characteristics.