Effect of solar cycle 23 in foF2 trend estimation

Autores
Elias, Ana Georgina; de Haro Barbás, Blas F.; Shibasaki, Kiyoto; Souza, Jonas R.
Año de publicación
2014
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
The effect of including solar cycle 23 in foF2 trend estimation is assessed using experimental values for Slough (51.5°N, 359.4°E) and Kokobunji (35.7°N, 139.5°E), and values obtained from two models: (1) the Sheffield University Plasmasphere-Ionosphere model, SUPIM, and (2) the International Reference Ionosphere, IRI. The dominant influence on the F2 layer is solar extreme ultraviolet (EUV) radiation, evinced by the almost 90% variance of its parameters explained by solar EUV proxies such as the solar activity indices Rz and F10.7. This makes necessary to filter out solar activity effects prior to long-term trend estimation. Solar cycle 23 seems to have had an EUV emission different from that deduced from traditional solar EUV proxies. During maximum and descending phase of the cycle, Rz and F10.7 seem to underestimate EUV solar radiation, while during minimum, they overestimate EUV levels. Including this solar cycle in trend estimations then, and using traditional filtering techniques, may induce some spurious results. In the present work, filtering is done in the usual way considering the residuals of the linear regression between foF2 and F10.7, for both experimental and modeled values. foF2 trends become less negative as we include years after 2000, since foF2 systematically exceeds the values predicted by a linear fit between foF2 and F10.7. Trends become more negative again when solar cycle 23 minimum is included, since for this period, foF2 is systematically lower than values predicted by the linear fit. foF2 trends assessed with modeled foF2 values are less strong than those obtained with experimental foF2 values and more stable as solar cycle 23 is included in the trend estimation. Modeled trends may be thought of as a ‘zero level’ trend due to the assumptions made in the process of trend estimation considering also that we are not dealing with ideal conditions or infinite time series.
Fil: Elias, Ana Georgina. Universidad Nacional de Tucuman. Facultad de Ciencias Exactas y Tecnologia. Departamento de Fisica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina
Fil: de Haro Barbás, Blas F.. Universidad Nacional de Tucuman. Facultad de Ciencias Exactas y Tecnologia. Departamento de Fisica; Argentina
Fil: Shibasaki, Kiyoto . Nobeyama Solar Radio Observatory; Japón
Fil: Souza, Jonas R.. Centro de Previsao de Tempo E Estudos Climaticos. Instituto Nacional de Pesquisas Espaciais; Brasil
Materia
Ionospheric trends
Solar cycle 23
EUV proxies
Nivel de accesibilidad
acceso abierto
Condiciones de uso
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
Repositorio
CONICET Digital (CONICET)
Institución
Consejo Nacional de Investigaciones Científicas y Técnicas
OAI Identificador
oai:ri.conicet.gov.ar:11336/12585

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network_name_str CONICET Digital (CONICET)
spelling Effect of solar cycle 23 in foF2 trend estimationElias, Ana Georginade Haro Barbás, Blas F.Shibasaki, Kiyoto Souza, Jonas R.Ionospheric trendsSolar cycle 23EUV proxieshttps://purl.org/becyt/ford/1.5https://purl.org/becyt/ford/1The effect of including solar cycle 23 in foF2 trend estimation is assessed using experimental values for Slough (51.5°N, 359.4°E) and Kokobunji (35.7°N, 139.5°E), and values obtained from two models: (1) the Sheffield University Plasmasphere-Ionosphere model, SUPIM, and (2) the International Reference Ionosphere, IRI. The dominant influence on the F2 layer is solar extreme ultraviolet (EUV) radiation, evinced by the almost 90% variance of its parameters explained by solar EUV proxies such as the solar activity indices Rz and F10.7. This makes necessary to filter out solar activity effects prior to long-term trend estimation. Solar cycle 23 seems to have had an EUV emission different from that deduced from traditional solar EUV proxies. During maximum and descending phase of the cycle, Rz and F10.7 seem to underestimate EUV solar radiation, while during minimum, they overestimate EUV levels. Including this solar cycle in trend estimations then, and using traditional filtering techniques, may induce some spurious results. In the present work, filtering is done in the usual way considering the residuals of the linear regression between foF2 and F10.7, for both experimental and modeled values. foF2 trends become less negative as we include years after 2000, since foF2 systematically exceeds the values predicted by a linear fit between foF2 and F10.7. Trends become more negative again when solar cycle 23 minimum is included, since for this period, foF2 is systematically lower than values predicted by the linear fit. foF2 trends assessed with modeled foF2 values are less strong than those obtained with experimental foF2 values and more stable as solar cycle 23 is included in the trend estimation. Modeled trends may be thought of as a ‘zero level’ trend due to the assumptions made in the process of trend estimation considering also that we are not dealing with ideal conditions or infinite time series.Fil: Elias, Ana Georgina. Universidad Nacional de Tucuman. Facultad de Ciencias Exactas y Tecnologia. Departamento de Fisica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: de Haro Barbás, Blas F.. Universidad Nacional de Tucuman. Facultad de Ciencias Exactas y Tecnologia. Departamento de Fisica; ArgentinaFil: Shibasaki, Kiyoto . Nobeyama Solar Radio Observatory; JapónFil: Souza, Jonas R.. Centro de Previsao de Tempo E Estudos Climaticos. Instituto Nacional de Pesquisas Espaciais; BrasilSpringer2014-09info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfapplication/pdfapplication/pdfhttp://hdl.handle.net/11336/12585Elias, Ana Georgina; de Haro Barbás, Blas F.; Shibasaki, Kiyoto ; Souza, Jonas R.; Effect of solar cycle 23 in foF2 trend estimation; Springer; Earth Planets And Space; 66; 111; 9-2014; 1-51880-5981enginfo:eu-repo/semantics/altIdentifier/url/https://earth-planets-space.springeropen.com/articles/10.1186/1880-5981-66-111info:eu-repo/semantics/altIdentifier/url/http://link.springer.com/article/10.1186/1880-5981-66-111info:eu-repo/semantics/altIdentifier/doi/10.1186/1880-5981-66-111info:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by-nc-sa/2.5/ar/reponame:CONICET Digital (CONICET)instname:Consejo Nacional de Investigaciones Científicas y Técnicas2025-09-29T10:46:50Zoai:ri.conicet.gov.ar:11336/12585instacron:CONICETInstitucionalhttp://ri.conicet.gov.ar/Organismo científico-tecnológicoNo correspondehttp://ri.conicet.gov.ar/oai/requestdasensio@conicet.gov.ar; lcarlino@conicet.gov.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:34982025-09-29 10:46:50.315CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicasfalse
dc.title.none.fl_str_mv Effect of solar cycle 23 in foF2 trend estimation
title Effect of solar cycle 23 in foF2 trend estimation
spellingShingle Effect of solar cycle 23 in foF2 trend estimation
Elias, Ana Georgina
Ionospheric trends
Solar cycle 23
EUV proxies
title_short Effect of solar cycle 23 in foF2 trend estimation
title_full Effect of solar cycle 23 in foF2 trend estimation
title_fullStr Effect of solar cycle 23 in foF2 trend estimation
title_full_unstemmed Effect of solar cycle 23 in foF2 trend estimation
title_sort Effect of solar cycle 23 in foF2 trend estimation
dc.creator.none.fl_str_mv Elias, Ana Georgina
de Haro Barbás, Blas F.
Shibasaki, Kiyoto
Souza, Jonas R.
author Elias, Ana Georgina
author_facet Elias, Ana Georgina
de Haro Barbás, Blas F.
Shibasaki, Kiyoto
Souza, Jonas R.
author_role author
author2 de Haro Barbás, Blas F.
Shibasaki, Kiyoto
Souza, Jonas R.
author2_role author
author
author
dc.subject.none.fl_str_mv Ionospheric trends
Solar cycle 23
EUV proxies
topic Ionospheric trends
Solar cycle 23
EUV proxies
purl_subject.fl_str_mv https://purl.org/becyt/ford/1.5
https://purl.org/becyt/ford/1
dc.description.none.fl_txt_mv The effect of including solar cycle 23 in foF2 trend estimation is assessed using experimental values for Slough (51.5°N, 359.4°E) and Kokobunji (35.7°N, 139.5°E), and values obtained from two models: (1) the Sheffield University Plasmasphere-Ionosphere model, SUPIM, and (2) the International Reference Ionosphere, IRI. The dominant influence on the F2 layer is solar extreme ultraviolet (EUV) radiation, evinced by the almost 90% variance of its parameters explained by solar EUV proxies such as the solar activity indices Rz and F10.7. This makes necessary to filter out solar activity effects prior to long-term trend estimation. Solar cycle 23 seems to have had an EUV emission different from that deduced from traditional solar EUV proxies. During maximum and descending phase of the cycle, Rz and F10.7 seem to underestimate EUV solar radiation, while during minimum, they overestimate EUV levels. Including this solar cycle in trend estimations then, and using traditional filtering techniques, may induce some spurious results. In the present work, filtering is done in the usual way considering the residuals of the linear regression between foF2 and F10.7, for both experimental and modeled values. foF2 trends become less negative as we include years after 2000, since foF2 systematically exceeds the values predicted by a linear fit between foF2 and F10.7. Trends become more negative again when solar cycle 23 minimum is included, since for this period, foF2 is systematically lower than values predicted by the linear fit. foF2 trends assessed with modeled foF2 values are less strong than those obtained with experimental foF2 values and more stable as solar cycle 23 is included in the trend estimation. Modeled trends may be thought of as a ‘zero level’ trend due to the assumptions made in the process of trend estimation considering also that we are not dealing with ideal conditions or infinite time series.
Fil: Elias, Ana Georgina. Universidad Nacional de Tucuman. Facultad de Ciencias Exactas y Tecnologia. Departamento de Fisica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina
Fil: de Haro Barbás, Blas F.. Universidad Nacional de Tucuman. Facultad de Ciencias Exactas y Tecnologia. Departamento de Fisica; Argentina
Fil: Shibasaki, Kiyoto . Nobeyama Solar Radio Observatory; Japón
Fil: Souza, Jonas R.. Centro de Previsao de Tempo E Estudos Climaticos. Instituto Nacional de Pesquisas Espaciais; Brasil
description The effect of including solar cycle 23 in foF2 trend estimation is assessed using experimental values for Slough (51.5°N, 359.4°E) and Kokobunji (35.7°N, 139.5°E), and values obtained from two models: (1) the Sheffield University Plasmasphere-Ionosphere model, SUPIM, and (2) the International Reference Ionosphere, IRI. The dominant influence on the F2 layer is solar extreme ultraviolet (EUV) radiation, evinced by the almost 90% variance of its parameters explained by solar EUV proxies such as the solar activity indices Rz and F10.7. This makes necessary to filter out solar activity effects prior to long-term trend estimation. Solar cycle 23 seems to have had an EUV emission different from that deduced from traditional solar EUV proxies. During maximum and descending phase of the cycle, Rz and F10.7 seem to underestimate EUV solar radiation, while during minimum, they overestimate EUV levels. Including this solar cycle in trend estimations then, and using traditional filtering techniques, may induce some spurious results. In the present work, filtering is done in the usual way considering the residuals of the linear regression between foF2 and F10.7, for both experimental and modeled values. foF2 trends become less negative as we include years after 2000, since foF2 systematically exceeds the values predicted by a linear fit between foF2 and F10.7. Trends become more negative again when solar cycle 23 minimum is included, since for this period, foF2 is systematically lower than values predicted by the linear fit. foF2 trends assessed with modeled foF2 values are less strong than those obtained with experimental foF2 values and more stable as solar cycle 23 is included in the trend estimation. Modeled trends may be thought of as a ‘zero level’ trend due to the assumptions made in the process of trend estimation considering also that we are not dealing with ideal conditions or infinite time series.
publishDate 2014
dc.date.none.fl_str_mv 2014-09
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
http://purl.org/coar/resource_type/c_6501
info:ar-repo/semantics/articulo
format article
status_str publishedVersion
dc.identifier.none.fl_str_mv http://hdl.handle.net/11336/12585
Elias, Ana Georgina; de Haro Barbás, Blas F.; Shibasaki, Kiyoto ; Souza, Jonas R.; Effect of solar cycle 23 in foF2 trend estimation; Springer; Earth Planets And Space; 66; 111; 9-2014; 1-5
1880-5981
url http://hdl.handle.net/11336/12585
identifier_str_mv Elias, Ana Georgina; de Haro Barbás, Blas F.; Shibasaki, Kiyoto ; Souza, Jonas R.; Effect of solar cycle 23 in foF2 trend estimation; Springer; Earth Planets And Space; 66; 111; 9-2014; 1-5
1880-5981
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/url/https://earth-planets-space.springeropen.com/articles/10.1186/1880-5981-66-111
info:eu-repo/semantics/altIdentifier/url/http://link.springer.com/article/10.1186/1880-5981-66-111
info:eu-repo/semantics/altIdentifier/doi/10.1186/1880-5981-66-111
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
eu_rights_str_mv openAccess
rights_invalid_str_mv https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
dc.format.none.fl_str_mv application/pdf
application/pdf
application/pdf
dc.publisher.none.fl_str_mv Springer
publisher.none.fl_str_mv Springer
dc.source.none.fl_str_mv reponame:CONICET Digital (CONICET)
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