Analysis and interpretation of the shock-like electrostatic noise observed during the AMPTE (Active Magnetospheric Particle Tracer Explorers) solar-wind lithium releases. Progress report for period ending January 1985

Technical Report · Wed May 01 04:00:00 EDT 1985

OSTI ID:5014560

Gurnett, D A; Ma, T Z; Anderson, R R; Bauer, O H; Haerendel, G

During the AMPTE (Active Magnetospheric Particle Tracer Explorers) solar-wind lithium release on September 11, and again on September 20, 1984, an intense burst of electrostatic noise was observed near the upstream edge of the ion cloud. Comparisons with measurements by the IMP-6 and ISEE-1 spacecraft show that the spectrum and overall features of this noise are very similar to electrostatic noise observed at the earth's bow shock. A stability analysis using realistic parameters shows that the electrostatic noise can be accounted for by an ion beam-plasma instability caused by the solar-wind proton beam streaming through the nearly stationary lithium cloud. The growth rate of this instability is largest when the ion density and solar-wind proton density are similar, which explains why the noise only occurs near the outer edge of the ion cloud. The similarity to the noise in the earth's bow shock suggests that a shock may exist in the solar-wind plasma flow upstream of the ion cloud. If the noise is associated with a shock, then it must be an electrostatic shock, since the ion-cyclotron radii are too small for the existence of an MHD shock. Since the electrostatic instability occurs at phase velocities near the lithium thermal velocity, the electrostatic turbulence may play a role in heating the lithium ions and transferring momentum from the solar wind to the ion cloud.

• Research Organization: Iowa Univ., Iowa City (USA). Dept. of Physics and Astronomy
• OSTI ID: 5014560
• Report Number(s): AD-A-157512/5/XAB
• Country of Publication: United States
• Language: English

Related Subjects

640203* -- Atmospheric Physics-- Magnetospheric Phenomena-- (-1987)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ALKALI METALS
BARYONS
BEAMS
CHARGED PARTICLES
CLOUDS
DENSITY
EARTH ATMOSPHERE
EARTH MAGNETOSPHERE
ELECTROSTATICS
ELEMENTARY PARTICLES
ELEMENTS
FERMIONS
HADRONS
INSTABILITY
ION BEAMS
ION DENSITY
IONS
LITHIUM
METALS
MOMENTUM TRANSFER
NUCLEON BEAMS
NUCLEONS
PARTICLE BEAMS
PARTICLE KINEMATICS
PHYSICAL PROPERTIES
PLASMA INSTABILITY
PROTON BEAMS
PROTONS
SOLAR ACTIVITY
SOLAR WIND
STABILITY
TURBULENCE
VELOCITY