Large amplitude solitary waves in and near the Earth's magnetosphere, magnetopause and bow shock: Polar and Cluster observations

Abstract. Solitary waves with large electric fields (up to 100's of mV/m) have been observed throughout the magnetosphere and in the bow shock. We discuss observations by Polar at high altitudes ( ~ 4-8 RE ), during crossings of the plasma sheet boundary and cusp, and new measurements by Polar at the equatorial magnetopause and by Cluster near the bow shock, in the cusp and at the plasma sheet boundary. We describe the results of a statistical study of electron solitary waves observed by Polar at high altitudes. The mean solitary wave duration was ~ 2 ms. The waves have velocities from ~ 1000 km/s to  > 2500 km/s. Observed scale sizes (parallel to the magnetic field) are on the order of 1-10 l D, with e F /kTe from ~ 0.01 to O(1). The average speed of solitary waves at the plasma sheet boundary is faster than the average speed observed in the cusp and at cusp injections. The amplitude increases with both velocity and scale size. These observations are all consistent with the identification of the solitary waves as electron hole modes. We also report the discovery of solitary waves at the magnetopause, observed in Polar data obtained at the subsolar equatorial magnetopause. Both positive and negative potential structures have been observed with amplitudes up to ~ 25 mV/m. The velocities range from 150 km/s to >2500 km/s, with scale sizes the order of a kilometer (comparable to the Debye length). Initial observations of solitary waves by the four Cluster satellites are utilized to discuss the scale sizes and time variability of the regions where the solitary waves occur. Preliminary results from the four Cluster satellites have given a glimpse of the spatial and temporal variability of the occurrence of solitary waves and their association with other wave modes. In all the events studied, significant differences were observed in the waveforms observed simultaneously at the four locations separated by ~ 1000 km. When solitary waves were seen at one satellite, they were usually also seen at the other satellites within an interval of a few seconds. In association with an energetic electron injection and a highly compressed magnetosphere, Cluster has observed the largest amplitude solitary waves (>750 mV/m) ever reported in the outer magnetosphere.

[1]  Daniel N. Baker,et al.  A telescopic and microscopic view of a magnetospheric substorm on 31 March 2001 , 2002 .

[2]  F. Mozer,et al.  Magnetic bubbles and kinetic Alfvén waves in the high-latitude magnetopause boundary , 2001 .

[3]  John R Wygant,et al.  Polar observations of solitary waves at the Earth's magnetopause , 2001 .

[4]  W.K. (Bill) Peterson,et al.  Observed trends in auroral zone ion mode solitary wave structure characteristics using data from Polar , 2001 .

[5]  P. Kintner,et al.  Plasma waves observed in the cusp turbulent boundary layer: An analysis of high time resolution wave and particle measurements from the Polar spacecraft , 2001 .

[6]  R. Lysak,et al.  Studies of ion solitary waves using simulations including hydrogen and oxygen beams , 2001 .

[7]  S. Bale,et al.  On the beam speed and wavenumber of intense electron plasma waves near the foreshock edge , 2000 .

[8]  P. Kintner,et al.  On the perpendicular scale of electron phase‐space holes , 2000 .

[9]  S. Knowlton,et al.  Solitary potential structures associated with ion and electron beams near , 1999 .

[10]  M. Oppenheim,et al.  Nonlinear two‐stream instabilities as an explanation for auroral bipolar wave structures , 1999 .

[11]  R. Ergun,et al.  Phase‐space electron holes along magnetic field lines , 1999 .

[12]  A. Mangeney,et al.  WIND observations of coherent electrostatic waves in the solar wind , 1999 .

[13]  C. Russell,et al.  Comparisons of Polar satellite observations of solitary wave velocities in the plasma sheet boundary and the high altitude cusp to those in the auroral zone , 1999 .

[14]  H. Kojima,et al.  Generation mechanism of ESW based on GEOTAIL plasma wave observation, plasma observation and particle simulation , 1999 .

[15]  D. Gurnett,et al.  Plasma waves in the dayside polar cap boundary layer: Bipolar and monopolar electric pulses and whistler mode waves , 1998 .

[16]  S. Bale,et al.  Bipolar electrostatic structures in the shock transition region: Evidence of electron phase space holes , 1998 .

[17]  David Klumpar,et al.  FAST satellite observations of large‐amplitude solitary structures , 1998 .

[18]  P. Kintner,et al.  POLAR observations of coherent electric field structures , 1998 .

[19]  M. Temerin,et al.  Observations of large amplitude parallel electric field wave packets at the plasma sheet boundary , 1998 .

[20]  M. Temerin,et al.  New Features of Time Domain Electric-Field Structures in the Auroral Acceleration Region , 1997 .

[21]  P. Louarn,et al.  Coherent structures in the magnetotail triggered by counterstreaming electron beams , 1997 .

[22]  H. Matsumoto,et al.  Electron beam instabilities as generation mechanism of electrostatic solitary waves in the magnetotail , 1996 .

[23]  F. Mozer,et al.  ISEE 1 and Geotail observations of low-frequency waves at the magnetopause , 1995 .

[24]  A. Pedersen,et al.  Solar wind and magnetosphere plasma diagnostics by spacecraft electrostatic potential measurements , 1995 .

[25]  D. Pierce,et al.  The GGS/POLAR magnetic fields investigation , 1995 .

[26]  John R Wygant,et al.  The electric field instrument on the polar satellite , 1995 .

[27]  B. A. Whalen,et al.  The Toroidal Imaging Mass-Angle Spectrograph (TIMAS) for the polar mission , 1995 .

[28]  T. Zawistowski,et al.  Hydra — A 3-dimensional electron and ion hot plasma instrument for the POLAR spacecraft of the GGS mission , 1995 .

[29]  Minoru Tsutsui,et al.  Electrostatic solitary waves (ESW) in the magnetotail: BEN wave forms observed by GEOTAIL , 1994 .

[30]  D. Gurnett,et al.  The spherical probe electric field and wave experiment. [Cluster mission] , 1988 .

[31]  Gustafsson,et al.  Characteristics of solitary waves and weak double layers in the magnetospheric plasma. , 1988, Physical review letters.

[32]  K. Černý,et al.  Observations of double layers and solitary waves in the auroral plasma , 1982 .

[33]  F. Mozer,et al.  Nonlinear Steepening of the Electrostatic Ion Cyclotron Wave , 1979 .

[34]  M. Hudson,et al.  Comparison of Solitary Waves and Wave Packets Observed at Plasma Sheet Boundary to Results from the Auroral Zone , 2001 .

[35]  R. Lysak,et al.  Polar observations of solitary waves at high and low altitudes and comparison to theory , 2001 .

[36]  C. Russell,et al.  Plasma waves observed during cusp energetic particle events and their correlation with Polar and akebono satellite and ground data , 1999 .