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...
Saved in:
| Main Authors: | , , |
|---|---|
| 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 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Summary: | <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> |
|---|---|
| ISSN: | 0992-7689 1432-0576 |