Analysis and interpretation of the shocklike electrostatic noise observed during the AMPTE solar wind lithium releases

Journal Article · Sat Feb 01 04:00:00 EST 1986 · J. Geophys. Res.; (United States)

DOI:https://doi.org/10.1029/JA091iA02p01301· OSTI ID:6098262

Gurnett, D A; Ma, T Z; Anderson, R R; Bauer, O H; Haerendel, G; Haeusler, B; Paschmann, G; Treumann, R A; Koons, H C; Holzworth, R

During the Active Magnetospheric Particle Tracer Explorers (AMPTE) solar wind lithium release on September 11, 1984, 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 a 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. The noise may also play a role in the pitch angle scattering and diffusion of energetic electrons observed in the vicinity of the ion cloud. Because of the similarity to the solar wind interaction with the gaseous envelope of a comet, it is expected that similar types of wave-particle effects may occur upstream of comets.

• Research Organization: Department of Physics and Astronomy, University of Iowa, Iowa City
• OSTI ID: 6098262
• Journal Information: J. Geophys. Res.; (United States), Journal Name: J. Geophys. Res.; (United States) Vol. 91:A2; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

640302* -- Atomic
Molecular & Chemical Physics-- Atomic & Molecular Properties & Theory
74 ATOMIC AND MOLECULAR PHYSICS
BEAMS
CHARGED PARTICLES
COMETS
EARTH ATMOSPHERE
EARTH MAGNETOSPHERE
ELECTROMAGNETIC RADIATION
ELECTRONS
ELECTROSTATICS
ELEMENTARY PARTICLES
ENERGY LEVELS
FERMIONS
INSTABILITY
ION BEAMS
ION DENSITY
ION TEMPERATURE
IONS
LEPTONS
LITHIUM IONS
MOMENTUM TRANSFER
NOISE
NUCLEON BEAMS
PARTICLE BEAMS
PLASMA INSTABILITY
PLASMA WAVES
PROTON BEAMS
PROTON DENSITY
RADIATIONS
RADIO NOISE
RADIOWAVE RADIATION
SHOCK WAVES
SOLAR ACTIVITY
SOLAR WIND
SPACE VEHICLES
TURBULENCE
VEHICLES