Optical, radar, and magnetic observations of magnetosheath plasma capture during a positive IMF B z impulse
We present a multi-instrument study of the ionospheric response to a northward turning of the IMF. The observations were made in the near-noon (11:00 MLT) sector on Svalbard (at 75° MLAT). The data set includes auroral observations, ionospheric flows obtained from the EISCAT and CUTLASS radars, the...
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ftdoajarticles:oai:doaj.org/article:5fac45cb954647a8b5c94d9a2c70ed4e 2023-05-15T16:04:47+02:00 Optical, radar, and magnetic observations of magnetosheath plasma capture during a positive IMF B z impulse V. Safargaleev A. Kozlovsky T. Sergienko T. K. Yeoman M. Uspensky D. M. Wright H. Nilsson T. Turunen A. Kotikov 2008-03-01T00:00:00Z https://doi.org/10.5194/angeo-26-517-2008 https://doaj.org/article/5fac45cb954647a8b5c94d9a2c70ed4e EN eng Copernicus Publications https://www.ann-geophys.net/26/517/2008/angeo-26-517-2008.pdf https://doaj.org/toc/0992-7689 https://doaj.org/toc/1432-0576 doi:10.5194/angeo-26-517-2008 0992-7689 1432-0576 https://doaj.org/article/5fac45cb954647a8b5c94d9a2c70ed4e Annales Geophysicae, Vol 26, Pp 517-531 (2008) Science Q Physics QC1-999 Geophysics. Cosmic physics QC801-809 article 2008 ftdoajarticles https://doi.org/10.5194/angeo-26-517-2008 2022-12-31T08:49:23Z We present a multi-instrument study of the ionospheric response to a northward turning of the IMF. The observations were made in the near-noon (11:00 MLT) sector on Svalbard (at 75° MLAT). The data set includes auroral observations, ionospheric flows obtained from the EISCAT and CUTLASS radars, the spectral width of the HF radar backscatter, particle precipitation and plasma flow data from the DMSP F13 satellite, and Pc1 frequency band pulsations observed by induction magnetometers. Careful collocation of all the observations has been made with the HF radar backscatter located by a ray-tracing procedure utilizing the elevation angle of arrival of the signals and an ionospheric plasma density profile. Prior to IMF turning northward, three auroral arcs were observed at the poleward boundary of the closed llbl , inside the llbl , and in the equatorward part of the llbl , respectively. The northward IMF turning was accompanied by enhanced HF radar returns with a broad Doppler spectrum collocated with the arcs. The auroral arcs shifted poleward whereas the backscatter region moved in the opposite direction, which is consistent, respectively, with reconnection beyond the cusp and the capturing of magnetosheath plasma during northward IMF. Locally, magnetic noise enhancement in the Pc1 frequency band occurred simultaneously with the anomalous radar backscatter, and the absence of such signals at more remote magnetic observatories indicates a local generation of the Pc1 turbulence, which is collocated with the radar backscatter. Finally, we discuss possible interpretation errors which may be caused by limited observational data. Article in Journal/Newspaper EISCAT Svalbard Directory of Open Access Journals: DOAJ Articles Svalbard Annales Geophysicae 26 3 517 531 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Science Q Physics QC1-999 Geophysics. Cosmic physics QC801-809 |
spellingShingle |
Science Q Physics QC1-999 Geophysics. Cosmic physics QC801-809 V. Safargaleev A. Kozlovsky T. Sergienko T. K. Yeoman M. Uspensky D. M. Wright H. Nilsson T. Turunen A. Kotikov Optical, radar, and magnetic observations of magnetosheath plasma capture during a positive IMF B z impulse |
topic_facet |
Science Q Physics QC1-999 Geophysics. Cosmic physics QC801-809 |
description |
We present a multi-instrument study of the ionospheric response to a northward turning of the IMF. The observations were made in the near-noon (11:00 MLT) sector on Svalbard (at 75° MLAT). The data set includes auroral observations, ionospheric flows obtained from the EISCAT and CUTLASS radars, the spectral width of the HF radar backscatter, particle precipitation and plasma flow data from the DMSP F13 satellite, and Pc1 frequency band pulsations observed by induction magnetometers. Careful collocation of all the observations has been made with the HF radar backscatter located by a ray-tracing procedure utilizing the elevation angle of arrival of the signals and an ionospheric plasma density profile. Prior to IMF turning northward, three auroral arcs were observed at the poleward boundary of the closed llbl , inside the llbl , and in the equatorward part of the llbl , respectively. The northward IMF turning was accompanied by enhanced HF radar returns with a broad Doppler spectrum collocated with the arcs. The auroral arcs shifted poleward whereas the backscatter region moved in the opposite direction, which is consistent, respectively, with reconnection beyond the cusp and the capturing of magnetosheath plasma during northward IMF. Locally, magnetic noise enhancement in the Pc1 frequency band occurred simultaneously with the anomalous radar backscatter, and the absence of such signals at more remote magnetic observatories indicates a local generation of the Pc1 turbulence, which is collocated with the radar backscatter. Finally, we discuss possible interpretation errors which may be caused by limited observational data. |
format |
Article in Journal/Newspaper |
author |
V. Safargaleev A. Kozlovsky T. Sergienko T. K. Yeoman M. Uspensky D. M. Wright H. Nilsson T. Turunen A. Kotikov |
author_facet |
V. Safargaleev A. Kozlovsky T. Sergienko T. K. Yeoman M. Uspensky D. M. Wright H. Nilsson T. Turunen A. Kotikov |
author_sort |
V. Safargaleev |
title |
Optical, radar, and magnetic observations of magnetosheath plasma capture during a positive IMF B z impulse |
title_short |
Optical, radar, and magnetic observations of magnetosheath plasma capture during a positive IMF B z impulse |
title_full |
Optical, radar, and magnetic observations of magnetosheath plasma capture during a positive IMF B z impulse |
title_fullStr |
Optical, radar, and magnetic observations of magnetosheath plasma capture during a positive IMF B z impulse |
title_full_unstemmed |
Optical, radar, and magnetic observations of magnetosheath plasma capture during a positive IMF B z impulse |
title_sort |
optical, radar, and magnetic observations of magnetosheath plasma capture during a positive imf b z impulse |
publisher |
Copernicus Publications |
publishDate |
2008 |
url |
https://doi.org/10.5194/angeo-26-517-2008 https://doaj.org/article/5fac45cb954647a8b5c94d9a2c70ed4e |
geographic |
Svalbard |
geographic_facet |
Svalbard |
genre |
EISCAT Svalbard |
genre_facet |
EISCAT Svalbard |
op_source |
Annales Geophysicae, Vol 26, Pp 517-531 (2008) |
op_relation |
https://www.ann-geophys.net/26/517/2008/angeo-26-517-2008.pdf https://doaj.org/toc/0992-7689 https://doaj.org/toc/1432-0576 doi:10.5194/angeo-26-517-2008 0992-7689 1432-0576 https://doaj.org/article/5fac45cb954647a8b5c94d9a2c70ed4e |
op_doi |
https://doi.org/10.5194/angeo-26-517-2008 |
container_title |
Annales Geophysicae |
container_volume |
26 |
container_issue |
3 |
container_start_page |
517 |
op_container_end_page |
531 |
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1766400417596440576 |