Ionospheric plasma response to HF waves operating at frequencies close to the third harmonic of the electron gyrofrequency
Experimental results concerning European incoherent scatter observations of heater-induced electron temperature enhancements, anomalous absorption of low-power HF probe waves, and the spectrum of stimulated electromagnetic emission (SEE) in the sidebands of a high-power HF electromagnetic wave are p...
Published in: | Journal of Geophysical Research: Space Physics |
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1995
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Online Access: | https://eprints.lancs.ac.uk/id/eprint/9985/ https://eprints.lancs.ac.uk/id/eprint/9985/1/art_85.pdf https://doi.org/10.1029/95JA02098 |
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ftulancaster:oai:eprints.lancs.ac.uk:9985 2023-08-27T04:12:23+02:00 Ionospheric plasma response to HF waves operating at frequencies close to the third harmonic of the electron gyrofrequency Honary, Farideh Stocker, A. J. Robinson, T. R. Stubbe, P. 1995-11-01 application/pdf https://eprints.lancs.ac.uk/id/eprint/9985/ https://eprints.lancs.ac.uk/id/eprint/9985/1/art_85.pdf https://doi.org/10.1029/95JA02098 en eng https://eprints.lancs.ac.uk/id/eprint/9985/1/art_85.pdf Honary, Farideh and Stocker, A. J. and Robinson, T. R. and Stubbe, P. (1995) Ionospheric plasma response to HF waves operating at frequencies close to the third harmonic of the electron gyrofrequency. Journal of Geophysical Research, 100 (A11). pp. 21489-21501. ISSN 0148-0227 Journal Article PeerReviewed 1995 ftulancaster https://doi.org/10.1029/95JA02098 2023-08-03T22:16:39Z Experimental results concerning European incoherent scatter observations of heater-induced electron temperature enhancements, anomalous absorption of low-power HF probe waves, and the spectrum of stimulated electromagnetic emission (SEE) in the sidebands of a high-power HF electromagnetic wave are presented. For the experiments reported in this paper, an O mode pump wave was transmitted vertically into the F region above Tromsø, Norway, while the injected frequency was varied in small steps around the third harmonic of the electron gyrofrequency. Systematic variations with pump frequency were observed in the data obtained from all three diagnostics. Measurements of anomalous absorption, the downshifted maximum (DM) spectral feature, and heater-induced electron temperature enhancements all exhibited broad minima as the heater frequency approached the third harmonic of the electron gyrofrequency. In addition, the signal strength of the HF probe wave measured during heater off periods is also reduced at these and higher heater frequencies. The experimental findings suggest that at heater frequencies in the vicinity of the third gyroharmonic, small-scale field-aligned irregularities are not excited, whereas very small scale irregularities, of the order of a few electron cyclotron radii, which are responsible for the production of fast electrons, may be generated. The observed reduction in the diagnostic signal strength is then attributed to the ionized patches produced by these energetic electrons. Article in Journal/Newspaper Tromsø Lancaster University: Lancaster Eprints Norway Tromsø Journal of Geophysical Research: Space Physics 100 A11 21489 21501 |
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Lancaster University: Lancaster Eprints |
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ftulancaster |
language |
English |
description |
Experimental results concerning European incoherent scatter observations of heater-induced electron temperature enhancements, anomalous absorption of low-power HF probe waves, and the spectrum of stimulated electromagnetic emission (SEE) in the sidebands of a high-power HF electromagnetic wave are presented. For the experiments reported in this paper, an O mode pump wave was transmitted vertically into the F region above Tromsø, Norway, while the injected frequency was varied in small steps around the third harmonic of the electron gyrofrequency. Systematic variations with pump frequency were observed in the data obtained from all three diagnostics. Measurements of anomalous absorption, the downshifted maximum (DM) spectral feature, and heater-induced electron temperature enhancements all exhibited broad minima as the heater frequency approached the third harmonic of the electron gyrofrequency. In addition, the signal strength of the HF probe wave measured during heater off periods is also reduced at these and higher heater frequencies. The experimental findings suggest that at heater frequencies in the vicinity of the third gyroharmonic, small-scale field-aligned irregularities are not excited, whereas very small scale irregularities, of the order of a few electron cyclotron radii, which are responsible for the production of fast electrons, may be generated. The observed reduction in the diagnostic signal strength is then attributed to the ionized patches produced by these energetic electrons. |
format |
Article in Journal/Newspaper |
author |
Honary, Farideh Stocker, A. J. Robinson, T. R. Stubbe, P. |
spellingShingle |
Honary, Farideh Stocker, A. J. Robinson, T. R. Stubbe, P. Ionospheric plasma response to HF waves operating at frequencies close to the third harmonic of the electron gyrofrequency |
author_facet |
Honary, Farideh Stocker, A. J. Robinson, T. R. Stubbe, P. |
author_sort |
Honary, Farideh |
title |
Ionospheric plasma response to HF waves operating at frequencies close to the third harmonic of the electron gyrofrequency |
title_short |
Ionospheric plasma response to HF waves operating at frequencies close to the third harmonic of the electron gyrofrequency |
title_full |
Ionospheric plasma response to HF waves operating at frequencies close to the third harmonic of the electron gyrofrequency |
title_fullStr |
Ionospheric plasma response to HF waves operating at frequencies close to the third harmonic of the electron gyrofrequency |
title_full_unstemmed |
Ionospheric plasma response to HF waves operating at frequencies close to the third harmonic of the electron gyrofrequency |
title_sort |
ionospheric plasma response to hf waves operating at frequencies close to the third harmonic of the electron gyrofrequency |
publishDate |
1995 |
url |
https://eprints.lancs.ac.uk/id/eprint/9985/ https://eprints.lancs.ac.uk/id/eprint/9985/1/art_85.pdf https://doi.org/10.1029/95JA02098 |
geographic |
Norway Tromsø |
geographic_facet |
Norway Tromsø |
genre |
Tromsø |
genre_facet |
Tromsø |
op_relation |
https://eprints.lancs.ac.uk/id/eprint/9985/1/art_85.pdf Honary, Farideh and Stocker, A. J. and Robinson, T. R. and Stubbe, P. (1995) Ionospheric plasma response to HF waves operating at frequencies close to the third harmonic of the electron gyrofrequency. Journal of Geophysical Research, 100 (A11). pp. 21489-21501. ISSN 0148-0227 |
op_doi |
https://doi.org/10.1029/95JA02098 |
container_title |
Journal of Geophysical Research: Space Physics |
container_volume |
100 |
container_issue |
A11 |
container_start_page |
21489 |
op_container_end_page |
21501 |
_version_ |
1775356456076312576 |