First in‐situ observations of strong ionospheric perturbations generated by a powerful VLF ground‐based transmitter

[1] This paper is related to observations by the satellite DEMETER of strong ionospheric perturbations close to the VLF transmitter NWC in Australia (L = 1.41). Electrostatic waves from HF to ELF ranges are generated and strong turbulence appears. Fluctuations of electron and ion densities are observed as well as increase of temperature. The perturbations are located to the geographic North of the transmitter and cover an area of ∼500,000 km2 which is centred at the altitude of the satellite (700 km) around the magnetic field line at L = 1.41. The phenomenon is due to the electron and ion heating induced by the powerful transmitter VLF wave. This perturbation is in addition to the already known precipitation of energetic particles which interact with the VLF wave through a cyclotron resonance mechanism. The particle precipitation zone is located south of the transmitter at a slightly larger L-shell value (1.9).

[1]  Marie-Anne Clair,et al.  The Demeter microsatellite and ground segment , 2006 .

[2]  F. Lefeuvre,et al.  The magnetic field experiment IMSC and its data processing onboard DEMETER: Scientific objectives, description and first results , 2006 .

[3]  F. Lefeuvre,et al.  Application of bicoherence analysis in study of wave interactions in space plasma , 1989 .

[4]  B. Thidé,et al.  Ionospheric modification experiments in northern Scandinavia , 1982 .

[5]  T. Bell,et al.  Electrostatic lower hybrid waves excited by electromagnetic whistler mode waves scattering from planar magnetic‐field‐aligned plasma density irregularities , 1990 .

[6]  D. Nunn,et al.  The numerical simulation of VLF nonlinear wave-particle interactions in collision-free plasmas using the Vlasov hybrid simulation technique , 1990 .

[7]  H. Matsumoto,et al.  A review of observational, theoretical and numerical studies of VLF triggered emissions , 1991 .

[8]  P. Gilbert,et al.  IAP, the thermal plasma analyzer on DEMETER , 2006 .

[9]  P.-L. Blelly,et al.  The ISL Langmuir probe experiment processing onboard DEMETER: Scientific objectives, description and first results , 2006 .

[10]  T. Bell,et al.  Electrostatic waves stimulated by coherent VLF signals propagating in and near the inner radiation belt , 1988 .

[11]  R. Helliwell.  A theory of discrete VLF emissions from the magnetosphere , 1967 .

[12]  U. Inan,et al.  Precipitation of radiation belt electrons by man-made waves: A comparison between theory and measurement , 1985 .

[13]  U. Inan,et al.  ionospheric modification with a VLF transmitter , 1992 .

[14]  S. Sazhin,et al.  An investigation into the nonlinear frequency shift in magnetospherically propagated VLF pulses , 1992 .

[15]  Umran S. Inan,et al.  Electron precipitation zones around major ground‐based VLF signal sources , 1984 .

[16]  Umran S. Inan,et al.  VLF heating of the lower ionosphere , 1990 .

[17]  Umran S. Inan,et al.  Heating of the nighttime D region by very low frequency transmitters , 1994 .

[18]  M. Parrot,et al.  Physical mechanisms of man-made influences on the magnetosphere , 1996 .

[19]  M. Gangloff,et al.  The DEMETER Science Mission Centre , 2006 .

[20]  Lukyanov,et al.  Stationary striations developed in the ionospheric modification. , 1995, Physical review letters.

[21]  J. Fejer.  Ionospheric modification and parametric instabilities , 1979 .

[22]  Harry C. Koons,et al.  Linear and nonlinear amplification in the magnetosphere during a 6.6‐kHz transmission , 1978 .

[23]  D. Nunn.  A THEORY OF VLF EMISSIONS , 1971 .

[24]  B. C. Edgar,et al.  Precipitation of inner zone electrons by whistler mode waves from the VLF transmitters UMS and NWC , 1981 .

[25]  D. Nunn.  A SELF-CONSISTENT THEORY OF TRIGGERED VLF EMISSIONS , 1974 .

[26]  Richard M. Thorne,et al.  Electron scattering loss in Earth's inner magnetosphere: 1. Dominant physical processes , 1998 .

[27]  F. Leblanc,et al.  ICE, the electric field experiment on DEMETER , 2006 .

[28]  M. Kelley,et al.  The possible production of lower hybrid parametric instabilities by VLF ground transmitters and by natural emissions , 1982 .

[29]  J. Galejs.  Ionospheric interaction of VLF radio waves , 1972 .

[30]  Paul M. Kintner,et al.  Large amplitude wave packets observed in the ionosphere in association with transverse ion acceleration , 1986 .

[31]  T. Bell,et al.  Particle precipitation induced by short‐duration VLF waves in the magnetosphere , 1982 .

[32]  C. Seyler.  Lower hybrid wave phenomena associated with density depletions , 1994 .

[33]  A. Vampola.  Electron precipitation in the vicinity of a VLF transmitter , 1987 .

[34]  A. Vampola.  In-situ observations of magnetospheric electron scattering by a VLF transmitter , 1990 .

[35]  M. Walt,et al.  Slot region electron precipitation by lightning, VLF chorus, and plasmaspheric hiss , 1986 .

[36]  Paul M. Kintner,et al.  Freja observatons of correlated small-scale density depletions and enhanced lower hybrid waves , 1994 .

[37]  M. Gangloff,et al.  High-energy electron detection onboard DEMETER: The IDP spectrometer, description and first results on the inner belt , 2006 .

[38]  T. Bell,et al.  Lower hybrid waves excited through linear mode coupling and the heating of ions in the auroral and subauroral magnetosphere , 1991 .

[39]  S. Golian,et al.  Excitation of upper hybrid resonance in the ionospheric plasma by an intense radio wave , 1986 .

[40]  R. Barr,et al.  VLF heating of the lower ionosphere: Variation with magnetic latitude and electron density profile , 1992 .