Repeat station data compared to a global geomagnetic field model
<p>Geomagnetic repeat station surveys with local variometers for improved data reductions have been carried out in Germany for about ten years. For nearly the same time interval the satellites Ørsted and CHAMP have provided a good magnetic field data coverage of the whole globe. Recent global...
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| Format: | Article |
| Language: | English |
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Istituto Nazionale di Geofisica e Vulcanologia (INGV)
2013-03-01
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| Series: | Annals of Geophysics |
| Subjects: | |
| Online Access: | http://www.annalsofgeophysics.eu/index.php/annals/article/view/5410 |
| _version_ | 1819267666504843264 |
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| author | Monika Korte Vincent Lesur |
| author_facet | Monika Korte Vincent Lesur |
| author_sort | Monika Korte |
| collection | DOAJ |
| description | <p>Geomagnetic repeat station surveys with local variometers for improved data reductions have been carried out in Germany for about ten years. For nearly the same time interval the satellites Ørsted and CHAMP have provided a good magnetic field data coverage of the whole globe. Recent global field models based on these satellite data together with geomagnetic observatory data provide an improved description of the core field and secular variation. We use the latest version of the GFZ Reference Internal Magnetic Model to compare the magnetic field evolution predicted by that model between 2001 and 2010 to the independent repeat station data collected over the same time interval in Germany. Estimates of crustal bias at the repeat station locations are obtained as averages of the residuals, and the scatter or trend around each average provides information about influences in the data from field sources not (fully) described by the global model. We find that external magnetic field signal in the order of several nT, including long-term trends, remains both in processed annual mean and quiet night time repeat station data. We conclude that the geomagnetic core field secular variation in this area is described to high accuracy (better than 1 nT/yr) by the global model. Weak long-term trends in the residuals between repeat station data and the model might indicate induced lithospheric anomalies, but more data are necessary for a robust analysis of such signals characterized by very unfavorable signal-to-noise ratio.</p> |
| first_indexed | 2024-12-23T21:20:48Z |
| format | Article |
| id | doaj.art-750b9d8738a143aa93145a67e0634f36 |
| institution | Directory Open Access Journal |
| issn | 1593-5213 2037-416X |
| language | English |
| last_indexed | 2024-12-23T21:20:48Z |
| publishDate | 2013-03-01 |
| publisher | Istituto Nazionale di Geofisica e Vulcanologia (INGV) |
| record_format | Article |
| series | Annals of Geophysics |
| spelling | doaj.art-750b9d8738a143aa93145a67e0634f362022-12-21T17:30:45ZengIstituto Nazionale di Geofisica e Vulcanologia (INGV)Annals of Geophysics1593-52132037-416X2013-03-0155610.4401/ag-54105822Repeat station data compared to a global geomagnetic field modelMonika Korte0Vincent Lesur1Helmholtz-Centre Potsdam, GFZ German Research Centre for Geosciences, PotsdamHelmholtz-Centre Potsdam, GFZ German Research Centre for Geosciences, Potsdam<p>Geomagnetic repeat station surveys with local variometers for improved data reductions have been carried out in Germany for about ten years. For nearly the same time interval the satellites Ørsted and CHAMP have provided a good magnetic field data coverage of the whole globe. Recent global field models based on these satellite data together with geomagnetic observatory data provide an improved description of the core field and secular variation. We use the latest version of the GFZ Reference Internal Magnetic Model to compare the magnetic field evolution predicted by that model between 2001 and 2010 to the independent repeat station data collected over the same time interval in Germany. Estimates of crustal bias at the repeat station locations are obtained as averages of the residuals, and the scatter or trend around each average provides information about influences in the data from field sources not (fully) described by the global model. We find that external magnetic field signal in the order of several nT, including long-term trends, remains both in processed annual mean and quiet night time repeat station data. We conclude that the geomagnetic core field secular variation in this area is described to high accuracy (better than 1 nT/yr) by the global model. Weak long-term trends in the residuals between repeat station data and the model might indicate induced lithospheric anomalies, but more data are necessary for a robust analysis of such signals characterized by very unfavorable signal-to-noise ratio.</p>http://www.annalsofgeophysics.eu/index.php/annals/article/view/5410Geomagnetic repeat station datacrustal bias |
| spellingShingle | Monika Korte Vincent Lesur Repeat station data compared to a global geomagnetic field model Annals of Geophysics Geomagnetic repeat station data crustal bias |
| title | Repeat station data compared to a global geomagnetic field model |
| title_full | Repeat station data compared to a global geomagnetic field model |
| title_fullStr | Repeat station data compared to a global geomagnetic field model |
| title_full_unstemmed | Repeat station data compared to a global geomagnetic field model |
| title_short | Repeat station data compared to a global geomagnetic field model |
| title_sort | repeat station data compared to a global geomagnetic field model |
| topic | Geomagnetic repeat station data crustal bias |
| url | http://www.annalsofgeophysics.eu/index.php/annals/article/view/5410 |
| work_keys_str_mv | AT monikakorte repeatstationdatacomparedtoaglobalgeomagneticfieldmodel AT vincentlesur repeatstationdatacomparedtoaglobalgeomagneticfieldmodel |