Variations in the magnetic declination at mid-latitude European stations during the Carrington-like event on 29 October 2003

<p>Based on the declination observed at mid-latitude European stations (geomagnetic latitudes 34–58° N), we studied the current system that is a candidate for the cause of the sharp drop in horizontal intensity (<span class="inline-formula"><i>H</i></span>) of...

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Main Authors: F. Valach, M. Váczyová, E. Koči
Format: Article
Language:English
Published: Copernicus Publications 2025-08-01
Series:Annales Geophysicae
Online Access:https://angeo.copernicus.org/articles/43/441/2025/angeo-43-441-2025.pdf
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author F. Valach
M. Váczyová
E. Koči
E. Koči
author_facet F. Valach
M. Váczyová
E. Koči
E. Koči
author_sort F. Valach
collection DOAJ
description <p>Based on the declination observed at mid-latitude European stations (geomagnetic latitudes 34–58° N), we studied the current system that is a candidate for the cause of the sharp drop in horizontal intensity (<span class="inline-formula"><i>H</i></span>) of the geomagnetic field that occurred in that part of the globe at <span class="inline-formula">∼</span> 09:00 MLT (magnetic local time) on 29 October 2003. The newest knowledge says that the current system consisted of a pair of field-aligned currents (FACs) forming a dayside current wedge: in the early afternoon sector, it was a stationary upward FAC, and in the dawn sector, it was a westward-moving downward FAC. Simultaneously with the drop in <span class="inline-formula"><i>H</i></span>, the current wedge caused a sine-like profile in declination observed at the mid-latitude European stations. By studying this profile at individual observatories, we found a velocity of <span class="inline-formula">−1.08</span>° min<span class="inline-formula"><sup>−1</sup></span> <span class="inline-formula">±</span> <span class="inline-formula">0.38</span>° min<span class="inline-formula"><sup>−1</sup></span> for the wedge centre, roughly half the velocity of the westward-moving downward FAC. Our results contribute to arguments that the dayside current wedge was the probable cause of the <span class="inline-formula"><i>H</i></span> drop on 29 October 2003.</p>
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spelling doaj-art-4eb4c7044b98409e95bb92052e89b5a12025-08-20T03:58:10ZengCopernicus PublicationsAnnales Geophysicae0992-76891432-05762025-08-014344144510.5194/angeo-43-441-2025Variations in the magnetic declination at mid-latitude European stations during the Carrington-like event on 29 October 2003F. Valach0M. Váczyová1E. Koči2E. Koči3Geomagnetic Observatory, Earth Science Institute, Slovak Academy of Sciences, Komárňanská 108, 947 01 Hurbanovo, SlovakiaGeomagnetic Observatory, Earth Science Institute, Slovak Academy of Sciences, Komárňanská 108, 947 01 Hurbanovo, SlovakiaGeomagnetic Observatory, Earth Science Institute, Slovak Academy of Sciences, Komárňanská 108, 947 01 Hurbanovo, SlovakiaSlovak Central Observatory, Komárňanská 137, 947 01 Hurbanovo, Slovakia<p>Based on the declination observed at mid-latitude European stations (geomagnetic latitudes 34–58° N), we studied the current system that is a candidate for the cause of the sharp drop in horizontal intensity (<span class="inline-formula"><i>H</i></span>) of the geomagnetic field that occurred in that part of the globe at <span class="inline-formula">∼</span> 09:00 MLT (magnetic local time) on 29 October 2003. The newest knowledge says that the current system consisted of a pair of field-aligned currents (FACs) forming a dayside current wedge: in the early afternoon sector, it was a stationary upward FAC, and in the dawn sector, it was a westward-moving downward FAC. Simultaneously with the drop in <span class="inline-formula"><i>H</i></span>, the current wedge caused a sine-like profile in declination observed at the mid-latitude European stations. By studying this profile at individual observatories, we found a velocity of <span class="inline-formula">−1.08</span>° min<span class="inline-formula"><sup>−1</sup></span> <span class="inline-formula">±</span> <span class="inline-formula">0.38</span>° min<span class="inline-formula"><sup>−1</sup></span> for the wedge centre, roughly half the velocity of the westward-moving downward FAC. Our results contribute to arguments that the dayside current wedge was the probable cause of the <span class="inline-formula"><i>H</i></span> drop on 29 October 2003.</p>https://angeo.copernicus.org/articles/43/441/2025/angeo-43-441-2025.pdf
spellingShingle F. Valach
M. Váczyová
E. Koči
E. Koči
Variations in the magnetic declination at mid-latitude European stations during the Carrington-like event on 29 October 2003
Annales Geophysicae
title Variations in the magnetic declination at mid-latitude European stations during the Carrington-like event on 29 October 2003
title_full Variations in the magnetic declination at mid-latitude European stations during the Carrington-like event on 29 October 2003
title_fullStr Variations in the magnetic declination at mid-latitude European stations during the Carrington-like event on 29 October 2003
title_full_unstemmed Variations in the magnetic declination at mid-latitude European stations during the Carrington-like event on 29 October 2003
title_short Variations in the magnetic declination at mid-latitude European stations during the Carrington-like event on 29 October 2003
title_sort variations in the magnetic declination at mid latitude european stations during the carrington like event on 29 october 2003
url https://angeo.copernicus.org/articles/43/441/2025/angeo-43-441-2025.pdf
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AT ekoci variationsinthemagneticdeclinationatmidlatitudeeuropeanstationsduringthecarringtonlikeeventon29october2003
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