On polar daily geomagnetic variation
<p style="-qt-block-indent: 0; text-indent: 0px; margin: 0px;">The aim of this work is to investigate the nature of the daily magnetic field perturbations produced by ionospheric and magnetospheric currents at high latitudes. We analyse the hourly means of the X and Y geomagnetic fie...
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Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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Online Access: | http://www.annalsofgeophysics.eu/index.php/annals/article/view/6801 |
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doaj-1e17375153ca4190add52632531f22ee2020-11-24T22:35:52ZengIstituto Nazionale di Geofisica e Vulcanologia (INGV)Annals of Geophysics1593-52132037-416X2015-11-0158510.4401/ag-68016056On polar daily geomagnetic variationPaola De Michelis0Giuseppe Consolini1Istituto Nazionale di Geofisica e Vulcanologia, Rome,INAF - Istituto di Astrofisica e Planetologia Spaziali, Rome,<p style="-qt-block-indent: 0; text-indent: 0px; margin: 0px;">The aim of this work is to investigate the nature of the daily magnetic field perturbations produced by ionospheric and magnetospheric currents at high latitudes. We analyse the hourly means of the X and Y geomagnetic field components recorded by a meridian chain of permanent geomagnetic observatories in the polar region of the Northern Hemisphere during a period of four years (1995-1998) around the solar minimum. We apply a mathematical method, known as natural orthogonal component (NOC), which is capable of characterizing the dominant modes of the geomagnetic field daily variability through a set of empirical orthogonal functions (EOFs). Using the first two modes we reconstruct a two-dimensional equivalent current representation of the ionospheric electric currents, which contribute substantially to the geomagnetic daily variations. The obtained current structures resemble the equivalent current patterns of DP2 and DP1. We characterize these currents by studying their evolution with the geomagnetic activity level and by analysing their dependence on the interplanetary magnetic field. The obtained results support the idea of a coexistence of two main processes during all analysed period although one of them, the directly driven process, represents the dominant component of the geomagnetic daily variation.</p>http://www.annalsofgeophysics.eu/index.php/annals/article/view/6801Daily geomagnetic variationSun-Earth interactionNatural orthogonal component analysis |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Paola De Michelis Giuseppe Consolini |
spellingShingle |
Paola De Michelis Giuseppe Consolini On polar daily geomagnetic variation Annals of Geophysics Daily geomagnetic variation Sun-Earth interaction Natural orthogonal component analysis |
author_facet |
Paola De Michelis Giuseppe Consolini |
author_sort |
Paola De Michelis |
title |
On polar daily geomagnetic variation |
title_short |
On polar daily geomagnetic variation |
title_full |
On polar daily geomagnetic variation |
title_fullStr |
On polar daily geomagnetic variation |
title_full_unstemmed |
On polar daily geomagnetic variation |
title_sort |
on polar daily geomagnetic variation |
publisher |
Istituto Nazionale di Geofisica e Vulcanologia (INGV) |
series |
Annals of Geophysics |
issn |
1593-5213 2037-416X |
publishDate |
2015-11-01 |
description |
<p style="-qt-block-indent: 0; text-indent: 0px; margin: 0px;">The aim of this work is to investigate the nature of the daily magnetic field perturbations produced by ionospheric and magnetospheric currents at high latitudes. We analyse the hourly means of the X and Y geomagnetic field components recorded by a meridian chain of permanent geomagnetic observatories in the polar region of the Northern Hemisphere during a period of four years (1995-1998) around the solar minimum. We apply a mathematical method, known as natural orthogonal component (NOC), which is capable of characterizing the dominant modes of the geomagnetic field daily variability through a set of empirical orthogonal functions (EOFs). Using the first two modes we reconstruct a two-dimensional equivalent current representation of the ionospheric electric currents, which contribute substantially to the geomagnetic daily variations. The obtained current structures resemble the equivalent current patterns of DP2 and DP1. We characterize these currents by studying their evolution with the geomagnetic activity level and by analysing their dependence on the interplanetary magnetic field. The obtained results support the idea of a coexistence of two main processes during all analysed period although one of them, the directly driven process, represents the dominant component of the geomagnetic daily variation.</p> |
topic |
Daily geomagnetic variation Sun-Earth interaction Natural orthogonal component analysis |
url |
http://www.annalsofgeophysics.eu/index.php/annals/article/view/6801 |
work_keys_str_mv |
AT paolademichelis onpolardailygeomagneticvariation AT giuseppeconsolini onpolardailygeomagneticvariation |
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1725722530199633920 |