Cosmic radio noise absorption events associated with equatorward drifting arcs during a substorm growth phase
Cosmic radio noise absorption (CNA) events associated with equatorward drifting arcs during a substorm growth phase are studied by using simultaneous optical auroral, IRIS imaging riometer and EISCAT incoherent scatter radar measurements. The CNA is generally attributed to energetic particle precipi...
Published in: | Annales Geophysicae |
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ftnonlinearchiv:oai:noa.gwlb.de:cop_mods_00034953 2023-05-15T16:04:46+02:00 Cosmic radio noise absorption events associated with equatorward drifting arcs during a substorm growth phase Jussila, J. R. T. Aikio, A. T. Shalimov, S. Marple, S. R. 2004-04 electronic https://doi.org/10.5194/angeo-22-1675-2004 https://noa.gwlb.de/receive/cop_mods_00034953 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00034907/angeo-22-1675-2004.pdf https://angeo.copernicus.org/articles/22/1675/2004/angeo-22-1675-2004.pdf eng eng Copernicus Publications Annales Geophysicae -- http://www.bibliothek.uni-regensburg.de/ezeit/?1458425 -- https://www.ann-geophys.net/ -- https://www.ann-geophys.net/volumes.html -- http://link.springer.com/journal/585 -- 1432-0576 https://doi.org/10.5194/angeo-22-1675-2004 https://noa.gwlb.de/receive/cop_mods_00034953 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00034907/angeo-22-1675-2004.pdf https://angeo.copernicus.org/articles/22/1675/2004/angeo-22-1675-2004.pdf uneingeschränkt info:eu-repo/semantics/openAccess article Verlagsveröffentlichung article Text doc-type:article 2004 ftnonlinearchiv https://doi.org/10.5194/angeo-22-1675-2004 2022-02-08T22:44:59Z Cosmic radio noise absorption (CNA) events associated with equatorward drifting arcs during a substorm growth phase are studied by using simultaneous optical auroral, IRIS imaging riometer and EISCAT incoherent scatter radar measurements. The CNA is generally attributed to energetic particle precipitation in the D-region. However, it has been argued that plasma irregularities or enhanced electron temperature (Te) in the E-region could also produce CNA. Both of the latter mechanisms are related to intense electric fields in the ionosphere. We present two events which occur during a substorm growth phase in the evening MLT sector. In both of the events, an auroral arc is drifting equatorward, together with a region of CNA (auroral absorption bay) located on the equatorward side and outside of the arc. Both of the events are associated with enhanced D-region electron density on the equatorward side of the auroral arc, but in the second event, a region of intense electric field and enhanced electron temperature in the E-region is also located on the equatorward side of the arc. We show that in the studied events neither plasma instabilities nor enhanced Te play a significant role in producing the measured CNA, but the CNA in the vicinity of the equatorward drifting arcs is produced by D-region energetic electron precipitation. Key words. Ionosphere (auroral ionosphere; particle precipitation; electric fields and currents) Article in Journal/Newspaper EISCAT Niedersächsisches Online-Archiv NOA Annales Geophysicae 22 5 1675 1686 |
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English |
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article Verlagsveröffentlichung Jussila, J. R. T. Aikio, A. T. Shalimov, S. Marple, S. R. Cosmic radio noise absorption events associated with equatorward drifting arcs during a substorm growth phase |
topic_facet |
article Verlagsveröffentlichung |
description |
Cosmic radio noise absorption (CNA) events associated with equatorward drifting arcs during a substorm growth phase are studied by using simultaneous optical auroral, IRIS imaging riometer and EISCAT incoherent scatter radar measurements. The CNA is generally attributed to energetic particle precipitation in the D-region. However, it has been argued that plasma irregularities or enhanced electron temperature (Te) in the E-region could also produce CNA. Both of the latter mechanisms are related to intense electric fields in the ionosphere. We present two events which occur during a substorm growth phase in the evening MLT sector. In both of the events, an auroral arc is drifting equatorward, together with a region of CNA (auroral absorption bay) located on the equatorward side and outside of the arc. Both of the events are associated with enhanced D-region electron density on the equatorward side of the auroral arc, but in the second event, a region of intense electric field and enhanced electron temperature in the E-region is also located on the equatorward side of the arc. We show that in the studied events neither plasma instabilities nor enhanced Te play a significant role in producing the measured CNA, but the CNA in the vicinity of the equatorward drifting arcs is produced by D-region energetic electron precipitation. Key words. Ionosphere (auroral ionosphere; particle precipitation; electric fields and currents) |
format |
Article in Journal/Newspaper |
author |
Jussila, J. R. T. Aikio, A. T. Shalimov, S. Marple, S. R. |
author_facet |
Jussila, J. R. T. Aikio, A. T. Shalimov, S. Marple, S. R. |
author_sort |
Jussila, J. R. T. |
title |
Cosmic radio noise absorption events associated with equatorward drifting arcs during a substorm growth phase |
title_short |
Cosmic radio noise absorption events associated with equatorward drifting arcs during a substorm growth phase |
title_full |
Cosmic radio noise absorption events associated with equatorward drifting arcs during a substorm growth phase |
title_fullStr |
Cosmic radio noise absorption events associated with equatorward drifting arcs during a substorm growth phase |
title_full_unstemmed |
Cosmic radio noise absorption events associated with equatorward drifting arcs during a substorm growth phase |
title_sort |
cosmic radio noise absorption events associated with equatorward drifting arcs during a substorm growth phase |
publisher |
Copernicus Publications |
publishDate |
2004 |
url |
https://doi.org/10.5194/angeo-22-1675-2004 https://noa.gwlb.de/receive/cop_mods_00034953 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00034907/angeo-22-1675-2004.pdf https://angeo.copernicus.org/articles/22/1675/2004/angeo-22-1675-2004.pdf |
genre |
EISCAT |
genre_facet |
EISCAT |
op_relation |
Annales Geophysicae -- http://www.bibliothek.uni-regensburg.de/ezeit/?1458425 -- https://www.ann-geophys.net/ -- https://www.ann-geophys.net/volumes.html -- http://link.springer.com/journal/585 -- 1432-0576 https://doi.org/10.5194/angeo-22-1675-2004 https://noa.gwlb.de/receive/cop_mods_00034953 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00034907/angeo-22-1675-2004.pdf https://angeo.copernicus.org/articles/22/1675/2004/angeo-22-1675-2004.pdf |
op_rights |
uneingeschränkt info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.5194/angeo-22-1675-2004 |
container_title |
Annales Geophysicae |
container_volume |
22 |
container_issue |
5 |
container_start_page |
1675 |
op_container_end_page |
1686 |
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1766400395275403264 |