Magnetosheath lion roars

Journal Article · Sat May 01 00:00:00 EDT 1976 · J. Geophys. Res.; (United States)

DOI:https://doi.org/10.1029/JA081i013p02261· OSTI ID:7181641

Smith, E J; Tsurutani, B T

Lion roars, which are intense packets of electromagnetic waves characteristically found in the magneosheath, have been studied. On the basis of these observations, several possible wave generation mechanisms are examined. Landau resonance is considered to be an unlikely source because this mechanism requires a substantial component of the wave electric field paralle to B, and the observation that the waves propagate along the ambient field is contrary to this requirement. It is not obvious that electron cyclotron resonance is responsible, because the field magnitude decreases should cause T/sub parallel//T/sub perpendicular/ to increase, and this rise could lead to wave damping rather than wave growth. A model which is consistent with all the observations of this study is a proton cyclotron overstability involving 10-keV protons streaming through the magnetosheath. It appears possible that the streaming protons could produce both the waves and the field decreases and that all three would be coincident. (AIP)

• Research Organization: Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California 91103
• OSTI ID: 7181641
• Journal Information: J. Geophys. Res.; (United States), Vol. 81:13
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
MAGNETOSHEATH
ELECTROMAGNETIC RADIATION
CYCLOTRON INSTABILITY
CYCLOTRON RESONANCE
GEOMAGNETIC FIELD
OGO SATELLITES
PROTONS
BARYONS
ELEMENTARY PARTICLES
FERMIONS
HADRONS
INSTABILITY
MAGNETIC FIELDS
NUCLEONS
PLASMA INSTABILITY
PLASMA MICROINSTABILITIES
RADIATIONS
RESONANCE
SATELLITES
640203* - Atmospheric Physics- Magnetospheric Phenomena- (-1987)