Simultaneous observations at different altitudes of ionospheric backscatter in the eastward electrojet
A common feature of evening near-range ionospheric backscatter in the CUTLASS Iceland radar field of view is two parallel, approximately L -shell-aligned regions of westward flow which are attributed to irregularities in the auroral eastward electrojet region of the ionosphere. These backscatter cha...
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ftdoajarticles:oai:doaj.org/article:0b23af162f4b41adb02ddb6b8a607f93 2023-05-15T16:48:44+02:00 Simultaneous observations at different altitudes of ionospheric backscatter in the eastward electrojet S. E. Milan M. Lester 1998-01-01T00:00:00Z https://doi.org/10.1007/s00585-997-0055-9 https://doaj.org/article/0b23af162f4b41adb02ddb6b8a607f93 EN eng Copernicus Publications https://www.ann-geophys.net/16/55/1998/angeo-16-55-1998.pdf https://doaj.org/toc/0992-7689 https://doaj.org/toc/1432-0576 doi:10.1007/s00585-997-0055-9 0992-7689 1432-0576 https://doaj.org/article/0b23af162f4b41adb02ddb6b8a607f93 Annales Geophysicae, Vol 16, Pp 55-68 (1998) Science Q Physics QC1-999 Geophysics. Cosmic physics QC801-809 article 1998 ftdoajarticles https://doi.org/10.1007/s00585-997-0055-9 2022-12-31T14:52:02Z A common feature of evening near-range ionospheric backscatter in the CUTLASS Iceland radar field of view is two parallel, approximately L -shell-aligned regions of westward flow which are attributed to irregularities in the auroral eastward electrojet region of the ionosphere. These backscatter channels are separated by approximately 100–200 km in range. The orientation of the CUTLASS Iceland radar beams and the zonally aligned nature of the flow allows an approximate determination of flow angle to be made without the necessity of bistatic measurements. The two flow channels have different azimuthal variations in flow velocity and spectral width. The nearer of the two regions has two distinct spectral signatures. The eastern beams detect spectra with velocities which saturate at or near the ion-acoustic speed, and have low spectral widths (less than 100 m s –1 ), while the western beams detect lower velocities and higher spectral widths (above 200 m s –1 ). The more distant of the two channels has only one spectral signature with velocities above the ion-acoustic speed and high spectral widths. The spectral characteristics of the backscatter are consistent with E-region scatter in the nearer channel and upper-E-region or F-region scatter in the further channel. Temporal variations in the characteristics of both channels support current theories of E-region turbulent heating and previous observations of velocity-dependent backscatter cross-section. In future, observations of this nature will provide a powerful tool for the investigation of simultaneous E- and F-region irregularity generation under similar (nearly co-located or magnetically conjugate) electric field conditions. Key words. Auroral ionosphere · Ionospheric irregularities · Plasma convection Article in Journal/Newspaper Iceland Directory of Open Access Journals: DOAJ Articles Annales Geophysicae 16 1 55 68 |
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Open Polar |
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Directory of Open Access Journals: DOAJ Articles |
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English |
topic |
Science Q Physics QC1-999 Geophysics. Cosmic physics QC801-809 |
spellingShingle |
Science Q Physics QC1-999 Geophysics. Cosmic physics QC801-809 S. E. Milan M. Lester Simultaneous observations at different altitudes of ionospheric backscatter in the eastward electrojet |
topic_facet |
Science Q Physics QC1-999 Geophysics. Cosmic physics QC801-809 |
description |
A common feature of evening near-range ionospheric backscatter in the CUTLASS Iceland radar field of view is two parallel, approximately L -shell-aligned regions of westward flow which are attributed to irregularities in the auroral eastward electrojet region of the ionosphere. These backscatter channels are separated by approximately 100–200 km in range. The orientation of the CUTLASS Iceland radar beams and the zonally aligned nature of the flow allows an approximate determination of flow angle to be made without the necessity of bistatic measurements. The two flow channels have different azimuthal variations in flow velocity and spectral width. The nearer of the two regions has two distinct spectral signatures. The eastern beams detect spectra with velocities which saturate at or near the ion-acoustic speed, and have low spectral widths (less than 100 m s –1 ), while the western beams detect lower velocities and higher spectral widths (above 200 m s –1 ). The more distant of the two channels has only one spectral signature with velocities above the ion-acoustic speed and high spectral widths. The spectral characteristics of the backscatter are consistent with E-region scatter in the nearer channel and upper-E-region or F-region scatter in the further channel. Temporal variations in the characteristics of both channels support current theories of E-region turbulent heating and previous observations of velocity-dependent backscatter cross-section. In future, observations of this nature will provide a powerful tool for the investigation of simultaneous E- and F-region irregularity generation under similar (nearly co-located or magnetically conjugate) electric field conditions. Key words. Auroral ionosphere · Ionospheric irregularities · Plasma convection |
format |
Article in Journal/Newspaper |
author |
S. E. Milan M. Lester |
author_facet |
S. E. Milan M. Lester |
author_sort |
S. E. Milan |
title |
Simultaneous observations at different altitudes of ionospheric backscatter in the eastward electrojet |
title_short |
Simultaneous observations at different altitudes of ionospheric backscatter in the eastward electrojet |
title_full |
Simultaneous observations at different altitudes of ionospheric backscatter in the eastward electrojet |
title_fullStr |
Simultaneous observations at different altitudes of ionospheric backscatter in the eastward electrojet |
title_full_unstemmed |
Simultaneous observations at different altitudes of ionospheric backscatter in the eastward electrojet |
title_sort |
simultaneous observations at different altitudes of ionospheric backscatter in the eastward electrojet |
publisher |
Copernicus Publications |
publishDate |
1998 |
url |
https://doi.org/10.1007/s00585-997-0055-9 https://doaj.org/article/0b23af162f4b41adb02ddb6b8a607f93 |
genre |
Iceland |
genre_facet |
Iceland |
op_source |
Annales Geophysicae, Vol 16, Pp 55-68 (1998) |
op_relation |
https://www.ann-geophys.net/16/55/1998/angeo-16-55-1998.pdf https://doaj.org/toc/0992-7689 https://doaj.org/toc/1432-0576 doi:10.1007/s00585-997-0055-9 0992-7689 1432-0576 https://doaj.org/article/0b23af162f4b41adb02ddb6b8a607f93 |
op_doi |
https://doi.org/10.1007/s00585-997-0055-9 |
container_title |
Annales Geophysicae |
container_volume |
16 |
container_issue |
1 |
container_start_page |
55 |
op_container_end_page |
68 |
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1766038806955294720 |