Slide 1

Slide 2

The PROTOTYPE – Earth


Major features

The PROTOTYPE – Earth

Dynamics

Sources and losses of plasma

Group planetary
magnetospheres -

Structure and dynamics depend on

PLANETS &
MAGNETOSPHERES

Properties of
     external plasma

Consequences of external plasma properties

The magnetic field orientation of external plasma also matters

More consequences

Mirror mode waves in
Earth’s magnetosheath

Plasma sources

Jupiter’s magnetosphere

Rotational forces produce a disk of current in Jupiter’s magnetosphere

Jupiter - losses

Convection (or circulation)–
a form of interchange but there are differences

Like convection, interchange implies plasma transport

Form of interchange
       at Jupiter

IC waves from pickup near Io, & 10 s interchange event with DB >1% in a low beta (0.04) plasma.  (Galileo MAG data inbound to Io.)

Interchange near Io
and probably throughout magnetosphere

How is plasma lost?

Galileo fields and particle instruments have identified a bursty pattern in various ways

C21 inbound: “plasmoid” near 26 RJ post midnight.  Note negative Bq and Br, Bf perturbations.

Slide 28

Dynamic events
at Jupiter vs.
Earth’s substorms

Tail convective flows: bipolar signatures post midnight as suggested by Vasyliunas, ‘83

Jupiter’s coupled
atmosphere,
ionosphere,
magnetosphere system

Field-aligned electric fields

Jovian UV aurora
J. Clarke,
U. Michigan

Auroras differ at Earth & Jupiter

What produces the local time structure of Jupiter’s aurora?

Does the solar wind control dynamics
at Jupiter?

Contrary to intuition
we propose

Ganymede

Alfvén wing

Ganymede’s magnetosphere:
the other extreme

Topology familiar
(as illustrated by a vacuum field model)
but configuration is not

Slide 42

Convection in Ganymede’s magnetosphere

Closed field region supports “field line resonances”

Field line resonances probe ionospheric conductivity & plasma density

Why is the density low on “upstream” closed field lines?

Slide 47

Particles in Ganymede’s
magnetosphere move
subject to magnetic
field gradients &“cross-magnetosphere electric field”

Some selective comparisons

Simulations:
A growth area

Simulations of Jupiter & Ganymede are challenging

Planetary magnetospheres

Slide 53