Four decades of European geomagnetic secular variation and acceleration
<p style="margin: 0.0px 0.0px 0.0px 0.0px; font: 9.0px Times;"><span style="font-family: Verdana, Arial, Helvetica, sans-serif; font-size: x-small;"><span style="font-size: 10px;"><span style="font-family: Times, Ari...
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| Format: | Article |
| Language: | English |
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Istituto Nazionale di Geofisica e Vulcanologia (INGV)
2009-06-01
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| Series: | Annals of Geophysics |
| Subjects: | |
| Online Access: | http://www.annalsofgeophysics.eu/index.php/annals/article/view/4605 |
| _version_ | 1818316377809747968 |
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| author | Monika Korte Giuliana Verbanac Mioara Mioara Mandea |
| author_facet | Monika Korte Giuliana Verbanac Mioara Mioara Mandea |
| author_sort | Monika Korte |
| collection | DOAJ |
| description | <p style="margin: 0.0px 0.0px 0.0px 0.0px; font: 9.0px Times;"><span style="font-family: Verdana, Arial, Helvetica, sans-serif; font-size: x-small;"><span style="font-size: 10px;"><span style="font-family: Times, Arial, Helvetica, sans-serif; font-size: xx-small;"></span></span></span></p><p style="margin: 0.0px 0.0px 0.0px 0.0px; font: 9.0px Times;">Geomagnetic secular variation, the generally slow, continuous change in the core magnetic field, is characterized by occasional rapid variations known as geomagnetic jerks. Recent studies on magnetic data obtained by satellites with a good global coverage suggest that more rapid and smaller scale features than previously thought occur in the field change. We have taken advantage of the comparatively high density of geomagnetic observatories in Europe and have derived a regional model for the detailed study of secular variation and acceleration over the past four decades from 1960 to 2001 by means of improved and regularized spherical cap harmonic analysis. We show the improvements to our regional model over a global model. All the known jerks are seen in our model, but further times with rapid changes in secular variation exist. Moreover, times of zero acceleration in general do not occur simultaneously in all magnetic field components, although this nearly is the case in 1969.6 and 1982.2. Secular variation and acceleration show very dynamic patterns indicating rapid and complex causal processes in the Earth’s fluid core.</p> <br /> <br /><p> </p> <br /> |
| first_indexed | 2024-12-13T09:20:28Z |
| format | Article |
| id | doaj.art-fb8b325b2bc34ad19a4b73d8abc7e2dc |
| institution | Directory Open Access Journal |
| issn | 1593-5213 2037-416X |
| language | English |
| last_indexed | 2024-12-13T09:20:28Z |
| publishDate | 2009-06-01 |
| publisher | Istituto Nazionale di Geofisica e Vulcanologia (INGV) |
| record_format | Article |
| series | Annals of Geophysics |
| spelling | doaj.art-fb8b325b2bc34ad19a4b73d8abc7e2dc2022-12-21T23:52:45ZengIstituto Nazionale di Geofisica e Vulcanologia (INGV)Annals of Geophysics1593-52132037-416X2009-06-0152548750310.4401/ag-4605Four decades of European geomagnetic secular variation and accelerationMonika KorteGiuliana VerbanacMioara Mioara Mandea<p style="margin: 0.0px 0.0px 0.0px 0.0px; font: 9.0px Times;"><span style="font-family: Verdana, Arial, Helvetica, sans-serif; font-size: x-small;"><span style="font-size: 10px;"><span style="font-family: Times, Arial, Helvetica, sans-serif; font-size: xx-small;"></span></span></span></p><p style="margin: 0.0px 0.0px 0.0px 0.0px; font: 9.0px Times;">Geomagnetic secular variation, the generally slow, continuous change in the core magnetic field, is characterized by occasional rapid variations known as geomagnetic jerks. Recent studies on magnetic data obtained by satellites with a good global coverage suggest that more rapid and smaller scale features than previously thought occur in the field change. We have taken advantage of the comparatively high density of geomagnetic observatories in Europe and have derived a regional model for the detailed study of secular variation and acceleration over the past four decades from 1960 to 2001 by means of improved and regularized spherical cap harmonic analysis. We show the improvements to our regional model over a global model. All the known jerks are seen in our model, but further times with rapid changes in secular variation exist. Moreover, times of zero acceleration in general do not occur simultaneously in all magnetic field components, although this nearly is the case in 1969.6 and 1982.2. Secular variation and acceleration show very dynamic patterns indicating rapid and complex causal processes in the Earth’s fluid core.</p> <br /> <br /><p> </p> <br />http://www.annalsofgeophysics.eu/index.php/annals/article/view/4605European secular variation – secular acceleration – geomagnetic jerks |
| spellingShingle | Monika Korte Giuliana Verbanac Mioara Mioara Mandea Four decades of European geomagnetic secular variation and acceleration Annals of Geophysics European secular variation – secular acceleration – geomagnetic jerks |
| title | Four decades of European geomagnetic secular variation and acceleration |
| title_full | Four decades of European geomagnetic secular variation and acceleration |
| title_fullStr | Four decades of European geomagnetic secular variation and acceleration |
| title_full_unstemmed | Four decades of European geomagnetic secular variation and acceleration |
| title_short | Four decades of European geomagnetic secular variation and acceleration |
| title_sort | four decades of european geomagnetic secular variation and acceleration |
| topic | European secular variation – secular acceleration – geomagnetic jerks |
| url | http://www.annalsofgeophysics.eu/index.php/annals/article/view/4605 |
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