The geomagnetic semiannual anomaly on the four <i>Dst</i>-fundamental observatories: Dependences with Sun-Earth physical parameters

Autores
Azpilicueta, Francisco Javier; Brunini, Claudio Antonio; Camilion, Emilio
Año de publicación
2012
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
The semiannual anomaly (also known as semiannual variation) on the magnetic activity is a phenomenon that produces clear minima during March and September and maxima in June and December on the horizontal components of the geomagnetic field. This phenomenon has been known since the middle of the nineteenth century, but in spite of the accumulation of measurements and the development of three theoretical models, a conclusive physical explanation for it has not been developed. The usual approach to study the semiannual anomaly is by means of geomagnetic indices like the disturbance storm time, Dst, which is based on combining measurements registered on four magnetic observatories. This work follows a different approach based on the raw horizontal components registered at the four observatories. The analyses performed aimed to study and assess the impact of several external parameters, characteristics of the Sun-Earth environment, on the semiannual anomaly. The influence of the global geomagnetic activity level, the solar activity level, the solar magnetic polarity, and the rising/declining phase of the solar radiation cycle is analyzed in detail. The most important finding is that the semiannual anomaly is always present and that none of the previously mentioned parameters significantly favor the development of it. A second result is the presence of a 27 day signal superposed to the semiannual anomaly which is significantly affected by the solar activity level.
Facultad de Ciencias Astronómicas y Geofísicas
Materia
Astronomía
Ionosphere
Semiannual anomaly
Dst index
Geomagnetic activity
Geomagnetic semiannual anomaly
Geomagnetic semiannual variation
Nivel de accesibilidad
acceso abierto
Condiciones de uso
http://creativecommons.org/licenses/by-nc-sa/4.0/
Repositorio
SEDICI (UNLP)
Institución
Universidad Nacional de La Plata
OAI Identificador
oai:sedici.unlp.edu.ar:10915/97581

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spelling The geomagnetic semiannual anomaly on the four <i>Dst</i>-fundamental observatories: Dependences with Sun-Earth physical parametersAzpilicueta, Francisco JavierBrunini, Claudio AntonioCamilion, EmilioAstronomíaIonosphereSemiannual anomalyDst indexGeomagnetic activityGeomagnetic semiannual anomalyGeomagnetic semiannual variationThe semiannual anomaly (also known as semiannual variation) on the magnetic activity is a phenomenon that produces clear minima during March and September and maxima in June and December on the horizontal components of the geomagnetic field. This phenomenon has been known since the middle of the nineteenth century, but in spite of the accumulation of measurements and the development of three theoretical models, a conclusive physical explanation for it has not been developed. The usual approach to study the semiannual anomaly is by means of geomagnetic indices like the disturbance storm time, <i>Dst</i>, which is based on combining measurements registered on four magnetic observatories. This work follows a different approach based on the raw horizontal components registered at the four observatories. The analyses performed aimed to study and assess the impact of several external parameters, characteristics of the Sun-Earth environment, on the semiannual anomaly. The influence of the global geomagnetic activity level, the solar activity level, the solar magnetic polarity, and the rising/declining phase of the solar radiation cycle is analyzed in detail. The most important finding is that the semiannual anomaly is always present and that none of the previously mentioned parameters significantly favor the development of it. A second result is the presence of a 27 day signal superposed to the semiannual anomaly which is significantly affected by the solar activity level.Facultad de Ciencias Astronómicas y Geofísicas2012-07info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionArticulohttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfhttp://sedici.unlp.edu.ar/handle/10915/97581enginfo:eu-repo/semantics/altIdentifier/url/https://ri.conicet.gov.ar/11336/94996info:eu-repo/semantics/altIdentifier/url/https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2012JA017730info:eu-repo/semantics/altIdentifier/issn/0148-0227info:eu-repo/semantics/altIdentifier/doi/10.1029/2012JA017730info:eu-repo/semantics/altIdentifier/hdl/11336/94996info:eu-repo/semantics/openAccesshttp://creativecommons.org/licenses/by-nc-sa/4.0/Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)reponame:SEDICI (UNLP)instname:Universidad Nacional de La Platainstacron:UNLP2025-09-29T11:20:16Zoai:sedici.unlp.edu.ar:10915/97581Institucionalhttp://sedici.unlp.edu.ar/Universidad públicaNo correspondehttp://sedici.unlp.edu.ar/oai/snrdalira@sedici.unlp.edu.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:13292025-09-29 11:20:16.939SEDICI (UNLP) - Universidad Nacional de La Platafalse
dc.title.none.fl_str_mv The geomagnetic semiannual anomaly on the four <i>Dst</i>-fundamental observatories: Dependences with Sun-Earth physical parameters
title The geomagnetic semiannual anomaly on the four <i>Dst</i>-fundamental observatories: Dependences with Sun-Earth physical parameters
spellingShingle The geomagnetic semiannual anomaly on the four <i>Dst</i>-fundamental observatories: Dependences with Sun-Earth physical parameters
Azpilicueta, Francisco Javier
Astronomía
Ionosphere
Semiannual anomaly
Dst index
Geomagnetic activity
Geomagnetic semiannual anomaly
Geomagnetic semiannual variation
title_short The geomagnetic semiannual anomaly on the four <i>Dst</i>-fundamental observatories: Dependences with Sun-Earth physical parameters
title_full The geomagnetic semiannual anomaly on the four <i>Dst</i>-fundamental observatories: Dependences with Sun-Earth physical parameters
title_fullStr The geomagnetic semiannual anomaly on the four <i>Dst</i>-fundamental observatories: Dependences with Sun-Earth physical parameters
title_full_unstemmed The geomagnetic semiannual anomaly on the four <i>Dst</i>-fundamental observatories: Dependences with Sun-Earth physical parameters
title_sort The geomagnetic semiannual anomaly on the four <i>Dst</i>-fundamental observatories: Dependences with Sun-Earth physical parameters
dc.creator.none.fl_str_mv Azpilicueta, Francisco Javier
Brunini, Claudio Antonio
Camilion, Emilio
author Azpilicueta, Francisco Javier
author_facet Azpilicueta, Francisco Javier
Brunini, Claudio Antonio
Camilion, Emilio
author_role author
author2 Brunini, Claudio Antonio
Camilion, Emilio
author2_role author
author
dc.subject.none.fl_str_mv Astronomía
Ionosphere
Semiannual anomaly
Dst index
Geomagnetic activity
Geomagnetic semiannual anomaly
Geomagnetic semiannual variation
topic Astronomía
Ionosphere
Semiannual anomaly
Dst index
Geomagnetic activity
Geomagnetic semiannual anomaly
Geomagnetic semiannual variation
dc.description.none.fl_txt_mv The semiannual anomaly (also known as semiannual variation) on the magnetic activity is a phenomenon that produces clear minima during March and September and maxima in June and December on the horizontal components of the geomagnetic field. This phenomenon has been known since the middle of the nineteenth century, but in spite of the accumulation of measurements and the development of three theoretical models, a conclusive physical explanation for it has not been developed. The usual approach to study the semiannual anomaly is by means of geomagnetic indices like the disturbance storm time, <i>Dst</i>, which is based on combining measurements registered on four magnetic observatories. This work follows a different approach based on the raw horizontal components registered at the four observatories. The analyses performed aimed to study and assess the impact of several external parameters, characteristics of the Sun-Earth environment, on the semiannual anomaly. The influence of the global geomagnetic activity level, the solar activity level, the solar magnetic polarity, and the rising/declining phase of the solar radiation cycle is analyzed in detail. The most important finding is that the semiannual anomaly is always present and that none of the previously mentioned parameters significantly favor the development of it. A second result is the presence of a 27 day signal superposed to the semiannual anomaly which is significantly affected by the solar activity level.
Facultad de Ciencias Astronómicas y Geofísicas
description The semiannual anomaly (also known as semiannual variation) on the magnetic activity is a phenomenon that produces clear minima during March and September and maxima in June and December on the horizontal components of the geomagnetic field. This phenomenon has been known since the middle of the nineteenth century, but in spite of the accumulation of measurements and the development of three theoretical models, a conclusive physical explanation for it has not been developed. The usual approach to study the semiannual anomaly is by means of geomagnetic indices like the disturbance storm time, <i>Dst</i>, which is based on combining measurements registered on four magnetic observatories. This work follows a different approach based on the raw horizontal components registered at the four observatories. The analyses performed aimed to study and assess the impact of several external parameters, characteristics of the Sun-Earth environment, on the semiannual anomaly. The influence of the global geomagnetic activity level, the solar activity level, the solar magnetic polarity, and the rising/declining phase of the solar radiation cycle is analyzed in detail. The most important finding is that the semiannual anomaly is always present and that none of the previously mentioned parameters significantly favor the development of it. A second result is the presence of a 27 day signal superposed to the semiannual anomaly which is significantly affected by the solar activity level.
publishDate 2012
dc.date.none.fl_str_mv 2012-07
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
Articulo
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info:ar-repo/semantics/articulo
format article
status_str publishedVersion
dc.identifier.none.fl_str_mv http://sedici.unlp.edu.ar/handle/10915/97581
url http://sedici.unlp.edu.ar/handle/10915/97581
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/url/https://ri.conicet.gov.ar/11336/94996
info:eu-repo/semantics/altIdentifier/url/https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2012JA017730
info:eu-repo/semantics/altIdentifier/issn/0148-0227
info:eu-repo/semantics/altIdentifier/doi/10.1029/2012JA017730
info:eu-repo/semantics/altIdentifier/hdl/11336/94996
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
http://creativecommons.org/licenses/by-nc-sa/4.0/
Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)
eu_rights_str_mv openAccess
rights_invalid_str_mv http://creativecommons.org/licenses/by-nc-sa/4.0/
Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)
dc.format.none.fl_str_mv application/pdf
dc.source.none.fl_str_mv reponame:SEDICI (UNLP)
instname:Universidad Nacional de La Plata
instacron:UNLP
reponame_str SEDICI (UNLP)
collection SEDICI (UNLP)
instname_str Universidad Nacional de La Plata
instacron_str UNLP
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repository.name.fl_str_mv SEDICI (UNLP) - Universidad Nacional de La Plata
repository.mail.fl_str_mv alira@sedici.unlp.edu.ar
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