The oblique whistler instability in the earth's foreshock

The linear Vlasov stability properties of electron velocity distributions, similar to those observed in the upstream foreshock region in association with obliquely propagating whistler waves at approximately 1 Hz, are studied. These distributions are modeled by a sum of bi-Maxwellians with drift speeds parallel to the magnetic field B. We find such distributions to be stable to modes with wavevectors k parallel to B but unstable to whistler waves propagating obliquely to the magnetic field. The frequencies and wavelengths of these unstable modes agree well with those of whistlers observed upstream of the earth's bow shock. The free energy source driving the instability is a region of positive parallel slope partialf/sub e//partialv/sub parallel/>0 at large pitch angles (about 85/sup 0/) and intermediate energies (about 20 eV), probably corresponding to the solar wind electrons magnetostatically reflected from the magnetic ramp of the bow shock. The whistlers grow via electromagnetic Landau resonance with this free energy source.

[1]  Edward J. Smith,et al.  Whistler mode turbulence in the disturbed solar wind , 1982 .

[2]  C. Russell,et al.  Characteristics of the ULF waves associated with upstream ion beams , 1982 .

[3]  R. Anderson,et al.  Plasma electron signature of magnetic connection to the earth's bow shock - ISEE 3 , 1982 .

[4]  D. Sentman,et al.  Instabilities of low frequency, parallel propagating electromagnetic waves in the Earth's foreshock region , 1981 .

[5]  J. Gosling,et al.  The electromagnetic ion beam instability upstream of the Earth's bow shock , 1981 .

[6]  S. Gary.  Microinstabilities upstream of the Earth's bow shock: A brief review , 1981 .

[7]  C. Russell,et al.  Correlated wave and particle observations upstream of the Earth's bow shock , 1981 .

[8]  I. Palmer.  Propagation of energetic electrons in the magnetosheath and upstream solar wind , 1981 .

[9]  C. Kennel,et al.  Plasma rest frame distributions of suprathermal ions in the earth's foreshock region , 1981 .

[10]  R. Stone,et al.  The 2fp circumterrestrial radio radiation as seen from ISEE 3 , 1981 .

[11]  C. Russell,et al.  Upstream hydromagnetic waves and their association with backstreaming ion populations: ISEE 1 and 2 observations , 1981 .

[12]  B. Mauk,et al.  Upstream particle spatial gradients and plasma waves , 1981 .

[13]  K. Anderson.  Measurements of bow shock particles far upstream from the Earth , 1981 .

[14]  C. Bonifazi,et al.  Reflected and diffuse ions backstreaming from the Earth's bow shock 1. Basic properties , 1981 .

[15]  P. Rodriguez,et al.  Upstream waves and particles: An overview of ISEE results , 1981 .

[16]  C. Lin,et al.  Plasma waves excited in the upstream region by density gradient of energetic‐particle streams associated with the Earth's bow shock , 1981 .

[17]  T. Eastman,et al.  Plasma waves associated with energetic particles streaming into the solar wind from the earth's bow shock. Progress report for period ending jul 80 , 1980 .

[18]  C. Russell,et al.  Whistler mode wave packets in the Earth's foreshock region , 1980, Nature.

[19]  G. Gloeckler,et al.  Conditions for acceleration of energetic ions ≳30 keV associated with the Earth's bow shock , 1980 .

[20]  N. Sckopke,et al.  Energization of solar wind ions by reflection from the Earth's bow shock , 1980 .

[21]  S. Orsini,et al.  Backstreaming ions outside the Earth's bow shock and their interaction with the solar wind , 1980 .

[22]  T. Eastman,et al.  Upstream particles observed in the earth's foreshock region. Report for 1977-1978 , 1980 .

[23]  D. Lemons,et al.  A possible closure relation for heat transport in the solar wind , 1979 .

[24]  B. Klecker,et al.  Pitch angle distributions of energetic protons near the earth's bow shock , 1979 .

[25]  G. Parks,et al.  Thin sheets of energetic electrons upstream from the earth's bow shock , 1979 .

[26]  P. Kellogg,et al.  Electrostatic noise at the plasma frequency beyond the earth's bow shock , 1979 .

[27]  C. Russell,et al.  Association of low‐frequency waves with suprathermal ions in the upstream solar wind , 1979 .

[28]  M. Stroscio,et al.  Current driven electromagnetic ion cyclotron instability , 1979, Journal of Plasma Physics.

[29]  N. Sckopke,et al.  Observations of two distinct populations of bow shock ions in the upstream solar wind , 1978 .

[30]  D. Gurnett,et al.  Ion-Acoustic Waves in the Solar Wind. , 1977 .

[31]  W. Feldman,et al.  Solar wind heat flux regulation by the whistler instability , 1977 .

[32]  W. Feldman,et al.  Electron heat flux instabilities in the solar wind , 1975 .

[33]  J. Scudder,et al.  Electron observations in the solar wind and magnetosheath , 1973 .

[34]  W. Feldman,et al.  Solar wind heat transport in the vicinity of the Earth's bow shock , 1973 .

[35]  Masahisa Sugiura,et al.  Electron energy flux in the solar wind , 1971 .

[36]  F. Scarf,et al.  Nonthermal electrons and high‐frequency waves in the upstream solar wind, 2. Analysis and interpretation , 1971 .

[37]  F. Scarf,et al.  Nonthermal electrons and high-frequency waves in the upstream solar wind, 1. Observations , 1971 .

[38]  C. Russell,et al.  Very-Low-Frequency Electric Fields in the Interplanetary Medium: Pioneer 8 G. L. Siscoe, F. L. Scarf, I. M. Green, J. H. Binsack, and H. S. Bridge 828 Ogo 5 Observations of Upstream Waves in the Interplanetary Medium: Discrete Wave Packets , 1971 .

[39]  C. Russell,et al.  Direct correlations of large‐amplitude waves with suprathermal protons in the upstream solar wind , 1970 .

[40]  A. Barnes.  Theory of generation of bow-shock-associated hydromagnetic waves in the upstream interplanetary medium , 1970 .

[41]  J. Asbridge,et al.  Outward flow of protons from the Earth's bow shock , 1968 .

[42]  K. Anderson.  Energetic electrons of terrestrial origin upstream in the solar wind , 1968 .

[43]  C. Kennel,et al.  Resonant particle instabilities in a uniform magnetic field , 1967, Journal of Plasma Physics.

[44]  J. Simpson,et al.  Evidence for >30-keV electrons accelerated in the shock transition region beyond the earth's magnetospheric boundary , 1964 .

[45]  Michelle F. Thomsen,et al.  Electron velocity distributions near the Earth's bow shock , 1983 .

[46]  W. Feldman.  Kinetic processes in the solar wind , 1979 .

[47]  K. Anderson.  Energetic electrons of terrestrial origin behind the bow shock and upstream in the solar wind , 1969 .