Geomagnetic storm effects at F1-layer heights from incoherent scatter observations
Storm effects at F1-layer heights (160–200 km) were analyzed for the first time using Millstone Hill (mid-latitudes) and EISCAT (auroral zone) incoherent scatter (IS) observations. The morphological study has shown both increases (positive effect) and decreases (negative effect) in electron concentr...
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ftdoajarticles:oai:doaj.org/article:e0088dab562b4c5187441d3b0324b4b3 2023-05-15T16:04:36+02:00 Geomagnetic storm effects at F1-layer heights from incoherent scatter observations A. V. Mikhailov K. Schlegel 2003-02-01T00:00:00Z https://doi.org/10.5194/angeo-21-583-2003 https://doaj.org/article/e0088dab562b4c5187441d3b0324b4b3 EN eng Copernicus Publications https://www.ann-geophys.net/21/583/2003/angeo-21-583-2003.pdf https://doaj.org/toc/0992-7689 https://doaj.org/toc/1432-0576 doi:10.5194/angeo-21-583-2003 0992-7689 1432-0576 https://doaj.org/article/e0088dab562b4c5187441d3b0324b4b3 Annales Geophysicae, Vol 21, Pp 583-596 (2003) Science Q Physics QC1-999 Geophysics. Cosmic physics QC801-809 article 2003 ftdoajarticles https://doi.org/10.5194/angeo-21-583-2003 2022-12-30T21:00:08Z Storm effects at F1-layer heights (160–200 km) were analyzed for the first time using Millstone Hill (mid-latitudes) and EISCAT (auroral zone) incoherent scatter (IS) observations. The morphological study has shown both increases (positive effect) and decreases (negative effect) in electron concentration. Negative storm effects prevail for all seasons and show a larger magnitude than positive ones, the magnitude of the effect normally increasing with height. At Millstone Hill the summer storm effects are small compared to other seasons, but they are well detectable. At EISCAT this summer decrease takes place only with respect to the autumnal period and the autumn/spring asymmetry in the storm effects is well pronounced. Direct and significant correlation exists between deviations in electron concentration at the F1-layer heights and in the F2-layer maximum. Unlike the F2-layer the F1-region demonstrates a relatively small reaction to geomagnetic disturbances despite large perturbations in thermospheric parameters. Aeronomic parameters extracted from IS observations are used to explain the revealed morphology. A competition between atomic and molecular ion contributions to Ne variations was found to be the main physical mechanism controlling the F1-layer storm effect. The revealed morphology is shown to be related with neutral composition (O, O 2 , N 2 ) seasonal and storm-time variations. The present day understanding of the F1-region formation mechanisms is sufficient to explain the observed storm effects. Key words. Atmospheric composition and structure (thermosphere-composition and chemistry); ionosphere (ion chemistry and composition; ionospheric disturbances) Article in Journal/Newspaper EISCAT Directory of Open Access Journals: DOAJ Articles Annales Geophysicae 21 2 583 596 |
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Open Polar |
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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 A. V. Mikhailov K. Schlegel Geomagnetic storm effects at F1-layer heights from incoherent scatter observations |
topic_facet |
Science Q Physics QC1-999 Geophysics. Cosmic physics QC801-809 |
description |
Storm effects at F1-layer heights (160–200 km) were analyzed for the first time using Millstone Hill (mid-latitudes) and EISCAT (auroral zone) incoherent scatter (IS) observations. The morphological study has shown both increases (positive effect) and decreases (negative effect) in electron concentration. Negative storm effects prevail for all seasons and show a larger magnitude than positive ones, the magnitude of the effect normally increasing with height. At Millstone Hill the summer storm effects are small compared to other seasons, but they are well detectable. At EISCAT this summer decrease takes place only with respect to the autumnal period and the autumn/spring asymmetry in the storm effects is well pronounced. Direct and significant correlation exists between deviations in electron concentration at the F1-layer heights and in the F2-layer maximum. Unlike the F2-layer the F1-region demonstrates a relatively small reaction to geomagnetic disturbances despite large perturbations in thermospheric parameters. Aeronomic parameters extracted from IS observations are used to explain the revealed morphology. A competition between atomic and molecular ion contributions to Ne variations was found to be the main physical mechanism controlling the F1-layer storm effect. The revealed morphology is shown to be related with neutral composition (O, O 2 , N 2 ) seasonal and storm-time variations. The present day understanding of the F1-region formation mechanisms is sufficient to explain the observed storm effects. Key words. Atmospheric composition and structure (thermosphere-composition and chemistry); ionosphere (ion chemistry and composition; ionospheric disturbances) |
format |
Article in Journal/Newspaper |
author |
A. V. Mikhailov K. Schlegel |
author_facet |
A. V. Mikhailov K. Schlegel |
author_sort |
A. V. Mikhailov |
title |
Geomagnetic storm effects at F1-layer heights from incoherent scatter observations |
title_short |
Geomagnetic storm effects at F1-layer heights from incoherent scatter observations |
title_full |
Geomagnetic storm effects at F1-layer heights from incoherent scatter observations |
title_fullStr |
Geomagnetic storm effects at F1-layer heights from incoherent scatter observations |
title_full_unstemmed |
Geomagnetic storm effects at F1-layer heights from incoherent scatter observations |
title_sort |
geomagnetic storm effects at f1-layer heights from incoherent scatter observations |
publisher |
Copernicus Publications |
publishDate |
2003 |
url |
https://doi.org/10.5194/angeo-21-583-2003 https://doaj.org/article/e0088dab562b4c5187441d3b0324b4b3 |
genre |
EISCAT |
genre_facet |
EISCAT |
op_source |
Annales Geophysicae, Vol 21, Pp 583-596 (2003) |
op_relation |
https://www.ann-geophys.net/21/583/2003/angeo-21-583-2003.pdf https://doaj.org/toc/0992-7689 https://doaj.org/toc/1432-0576 doi:10.5194/angeo-21-583-2003 0992-7689 1432-0576 https://doaj.org/article/e0088dab562b4c5187441d3b0324b4b3 |
op_doi |
https://doi.org/10.5194/angeo-21-583-2003 |
container_title |
Annales Geophysicae |
container_volume |
21 |
container_issue |
2 |
container_start_page |
583 |
op_container_end_page |
596 |
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1766400209124851712 |