The effects of high frequency ULF wave activity on the spectral characteristics of coherent HF radar returns: a case study
It is now a common practice to employ ground-based radars in an attempt to distinguish between those regions of the Earth's upper atmosphere which are magnetically conjugate to open and closed magnetic field lines. Radar returns from ionospheric irregularities inside the polar cap and cusp regi...
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ftleicesterunfig:oai:figshare.com:article/10089917 2023-05-15T18:34:43+02:00 The effects of high frequency ULF wave activity on the spectral characteristics of coherent HF radar returns: a case study D. M. Wright Tim K. Yeoman E. E. Woodfield 2004-04-08T00:00:00Z https://figshare.com/articles/journal_contribution/The_effects_of_high_frequency_ULF_wave_activity_on_the_spectral_characteristics_of_coherent_HF_radar_returns_a_case_study/10089917 unknown 2381/714 https://figshare.com/articles/journal_contribution/The_effects_of_high_frequency_ULF_wave_activity_on_the_spectral_characteristics_of_coherent_HF_radar_returns_a_case_study/10089917 All Rights Reserved Uncategorized Ionosphere (auroral ionosphere) Magnetospheric physics (MHD waves and instabilities) Radio science (ionospheric physics) Text Journal contribution 2004 ftleicesterunfig 2021-11-11T20:12:27Z It is now a common practice to employ ground-based radars in an attempt to distinguish between those regions of the Earth's upper atmosphere which are magnetically conjugate to open and closed magnetic field lines. Radar returns from ionospheric irregularities inside the polar cap and cusp regions generally exhibit large spectral widths in contrast to those which exist on closed field lines at lower latitudes. It has been suggested that the so-called Spectral Width Boundary (SWB) might act as a proxy for the open-closed field line boundary (OCFLB), which would then be an invaluable tool for investigating reconnection rates in the magnetosphere. The exact cause of the increased spectral widths observed at very high latitudes is still subject to considerable debate. Several mechanisms have been proposed. This paper compares a dusk-sector interval of coherent HF radar data with measurements made by an induction coil magnetometer located at Tromsø, Norway (66° N geomagnetic). On this occasion, a number of equatorward excursions of the SWB in the radar backscatter are accompanied by increases in spectral power of ULF waves in the Pc1-2 frequency band as the SWB passes overhead. Thus, these observations support the possibility that high-frequency magnetospheric wave activity at least contribute to the observed spectral characteristics and that such wave activity might play a significant role in the nightside ionosphere. Other Non-Article Part of Journal/Newspaper Tromsø University of Leicester: Figshare Norway Tromsø |
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Open Polar |
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University of Leicester: Figshare |
op_collection_id |
ftleicesterunfig |
language |
unknown |
topic |
Uncategorized Ionosphere (auroral ionosphere) Magnetospheric physics (MHD waves and instabilities) Radio science (ionospheric physics) |
spellingShingle |
Uncategorized Ionosphere (auroral ionosphere) Magnetospheric physics (MHD waves and instabilities) Radio science (ionospheric physics) D. M. Wright Tim K. Yeoman E. E. Woodfield The effects of high frequency ULF wave activity on the spectral characteristics of coherent HF radar returns: a case study |
topic_facet |
Uncategorized Ionosphere (auroral ionosphere) Magnetospheric physics (MHD waves and instabilities) Radio science (ionospheric physics) |
description |
It is now a common practice to employ ground-based radars in an attempt to distinguish between those regions of the Earth's upper atmosphere which are magnetically conjugate to open and closed magnetic field lines. Radar returns from ionospheric irregularities inside the polar cap and cusp regions generally exhibit large spectral widths in contrast to those which exist on closed field lines at lower latitudes. It has been suggested that the so-called Spectral Width Boundary (SWB) might act as a proxy for the open-closed field line boundary (OCFLB), which would then be an invaluable tool for investigating reconnection rates in the magnetosphere. The exact cause of the increased spectral widths observed at very high latitudes is still subject to considerable debate. Several mechanisms have been proposed. This paper compares a dusk-sector interval of coherent HF radar data with measurements made by an induction coil magnetometer located at Tromsø, Norway (66° N geomagnetic). On this occasion, a number of equatorward excursions of the SWB in the radar backscatter are accompanied by increases in spectral power of ULF waves in the Pc1-2 frequency band as the SWB passes overhead. Thus, these observations support the possibility that high-frequency magnetospheric wave activity at least contribute to the observed spectral characteristics and that such wave activity might play a significant role in the nightside ionosphere. |
format |
Other Non-Article Part of Journal/Newspaper |
author |
D. M. Wright Tim K. Yeoman E. E. Woodfield |
author_facet |
D. M. Wright Tim K. Yeoman E. E. Woodfield |
author_sort |
D. M. Wright |
title |
The effects of high frequency ULF wave activity on the spectral characteristics of coherent HF radar returns: a case study |
title_short |
The effects of high frequency ULF wave activity on the spectral characteristics of coherent HF radar returns: a case study |
title_full |
The effects of high frequency ULF wave activity on the spectral characteristics of coherent HF radar returns: a case study |
title_fullStr |
The effects of high frequency ULF wave activity on the spectral characteristics of coherent HF radar returns: a case study |
title_full_unstemmed |
The effects of high frequency ULF wave activity on the spectral characteristics of coherent HF radar returns: a case study |
title_sort |
effects of high frequency ulf wave activity on the spectral characteristics of coherent hf radar returns: a case study |
publishDate |
2004 |
url |
https://figshare.com/articles/journal_contribution/The_effects_of_high_frequency_ULF_wave_activity_on_the_spectral_characteristics_of_coherent_HF_radar_returns_a_case_study/10089917 |
geographic |
Norway Tromsø |
geographic_facet |
Norway Tromsø |
genre |
Tromsø |
genre_facet |
Tromsø |
op_relation |
2381/714 https://figshare.com/articles/journal_contribution/The_effects_of_high_frequency_ULF_wave_activity_on_the_spectral_characteristics_of_coherent_HF_radar_returns_a_case_study/10089917 |
op_rights |
All Rights Reserved |
_version_ |
1766219613693018112 |