Location of Repository

EISCAT Svalbard radar observations of SPEAR-induced E- and F-region spectral enhancements in the polar cap ionosphere

By R. S. Dhillon, T. R. Robinson and Tim K. Yeoman

Abstract

The Space Plasma Exploration by Active Radar (SPEAR) facility has successfully operated in the high-power heater and low-power radar modes and has returned its first results. The high-power results include observations of SPEAR-induced ion and plasma line spectral enhancements recorded by the EISCAT Svalbard UHF incoherent scatter radar system (ESR), which is collocated with SPEAR. These SPEAR-enhanced spectra possess features that are consistent with excitation of both the purely growing mode and the parametric decay instability. In this paper, we present observations of upper and lower E-region SPEAR-induced ion and plasma line enhancements, together with F-region spectral enhancements, which indicate excitation of both instabilities and which are consistent with previous theoretical treatments of instability excitation in sporadic E-layers. In agreement with previous observations, spectra from the lower E-region have the single-peaked form characteristic of collisional plasma. Our observations of the SPEAR-enhanced E-region spectra suggest the presence of variable drifting regions of patchy overdense plasma, which is a finding also consistent with previous results

Publisher: Copernicus Publications on behalf of the European Geosciences Union (EGU)
Year: 2007
DOI identifier: 10.5194/angeo-25-1801-2007
OAI identifier: oai:lra.le.ac.uk:2381/8119
Journal:

Suggested articles

Preview

Citations

  1. (1987). A modification event of the auroral E region as studied with EISCAT and other diagnostics, doi
  2. (1994). Altitude characteristics of plasma turbulence excited with the Tromsø superheater, doi
  3. (1974). Arecibo heating experiments, doi
  4. (1999). Aspect angle dependence of HF enhanced incoherent backscatter, doi
  5. (2007). Dhillon et al.: SPEAR-enhanced E- and F-region ESR spectra
  6. (2002). Effects of multiple scatter on the propagation and absorption of electromagnetic waves in a field-aligned-striated cold magneto-plasma: implications for ionospheric modification experiments, doi
  7. (1984). Frequency dependence of anomalous absorption caused by high power radio waves, doi
  8. (1977). Generation of density cavities and localized electric fields in a nonuniform plasma, doi
  9. (2002). HFpump-induced parametric instabilities in the auroral E-region, doi
  10. (1997). Initial backscatter occurrence statistics from the CUTLASS HF radars, doi
  11. (1992). Langmuir turbulence and ionospheric modification, doi
  12. (1998). Langmuir turbulence associated with ionospheric modification: Challenges associated with recent observations during a sporadic-E event,
  13. (1978). Langmuir wave propagation and the enhanced plasma line in sporadic E, doi
  14. (1999). Large airglow enhancements produced via wave-plasma interactions in sporadic E, doi
  15. (1997). Linear mode conversion in inhomogeneous magnetized plasmas during ionospheric modification by HF radio waves, doi
  16. (2000). Measurements of HF-enhanced plasma and ion lines at EISCAT with high-altitude resolution, doi
  17. (2004). Multi-frequency HF radar measurements of artificial F-region field-aligned irregularities, doi
  18. (2004). On the onset of HF-induced airglow at HAARP, doi
  19. (1971). On the role of plasma instabilities in ionospheric heating by radio waves, doi
  20. (1971). Parametric instabilities in inhomogeneous plasmas, doi
  21. (1972). Purely growing parametric instability in an inhomogeneous plasma, doi
  22. (1996). Review of ionospheric modification experiments at Tromsø, doi
  23. (1997). The EISCAT Svalbard radar: a case study in modern incoherent scatter radar system design, doi
  24. (1976). The excitation of plasma lines in blanketing sporadic E, doi
  25. (1989). The heating of the high latitude ionosphere by high power radio waves, doi
  26. (2007). Using radio-induced aurora to measure the horizontal structure of ion layers in the lower thermosphere, doi

To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.