Core surface sub-centennial magnetic flux patches: characteristics and evolution
Abstract Short-term constituents of the secular variation, at inter-decadal (20–30 years) and sub-centennial (60–90 years) time scales, present in observatory data and main field models, are also found in the radial field evolution at core surface. The paper is focused on the sub-centennial constitu...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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SpringerOpen
2017-10-01
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| Series: | Earth, Planets and Space |
| Subjects: | |
| Online Access: | http://link.springer.com/article/10.1186/s40623-017-0732-1 |
| _version_ | 1811281379589095424 |
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| author | C. Stefan V. Dobrica C. Demetrescu |
| author_facet | C. Stefan V. Dobrica C. Demetrescu |
| author_sort | C. Stefan |
| collection | DOAJ |
| description | Abstract Short-term constituents of the secular variation, at inter-decadal (20–30 years) and sub-centennial (60–90 years) time scales, present in observatory data and main field models, are also found in the radial field evolution at core surface. The paper is focused on the sub-centennial constituent in the gufm1 model. Time–Longitude (t–λ) plots, covering the 400 years time span of the model, at various latitudes between 70°N and 70°S, show a clear westward movement of the sub-centennial constituent field features in the 20°N–20°S latitude band. The sub-centennial constituent at latitudes larger than 50°N/S stands in fact for the fine structure of high-latitude flux lobes. Since 1900 this fine structure shows a westward displacement. Time–Latitude (t–φ) plots indicate also northward and southward components of the movement. The traveling speeds of the sub-centennial constituent field are derived, on one hand, empirically based on Time–Longitude and Time–Latitude plots, and on the other, mathematically by means of the Radon transform method. Important results of this paper are related to characterization of the evolution of the radial field at core surface at sub-centennial time scales, namely (1) evidencing two types of azimuthal flow, equatorial and high latitude ones, responsible for the observed westward drift of the surface field, and (2) quantitative information on meridional displacements of the core surface magnetic flux patches. |
| first_indexed | 2024-04-13T01:32:34Z |
| format | Article |
| id | doaj.art-ed5f10eac1d547c0a0cceb4605e360e3 |
| institution | Directory Open Access Journal |
| issn | 1880-5981 |
| language | English |
| last_indexed | 2024-04-13T01:32:34Z |
| publishDate | 2017-10-01 |
| publisher | SpringerOpen |
| record_format | Article |
| series | Earth, Planets and Space |
| spelling | doaj.art-ed5f10eac1d547c0a0cceb4605e360e32022-12-22T03:08:29ZengSpringerOpenEarth, Planets and Space1880-59812017-10-0169111410.1186/s40623-017-0732-1Core surface sub-centennial magnetic flux patches: characteristics and evolutionC. Stefan0V. Dobrica1C. Demetrescu2Institute of Geodynamics, Romanian AcademyInstitute of Geodynamics, Romanian AcademyInstitute of Geodynamics, Romanian AcademyAbstract Short-term constituents of the secular variation, at inter-decadal (20–30 years) and sub-centennial (60–90 years) time scales, present in observatory data and main field models, are also found in the radial field evolution at core surface. The paper is focused on the sub-centennial constituent in the gufm1 model. Time–Longitude (t–λ) plots, covering the 400 years time span of the model, at various latitudes between 70°N and 70°S, show a clear westward movement of the sub-centennial constituent field features in the 20°N–20°S latitude band. The sub-centennial constituent at latitudes larger than 50°N/S stands in fact for the fine structure of high-latitude flux lobes. Since 1900 this fine structure shows a westward displacement. Time–Latitude (t–φ) plots indicate also northward and southward components of the movement. The traveling speeds of the sub-centennial constituent field are derived, on one hand, empirically based on Time–Longitude and Time–Latitude plots, and on the other, mathematically by means of the Radon transform method. Important results of this paper are related to characterization of the evolution of the radial field at core surface at sub-centennial time scales, namely (1) evidencing two types of azimuthal flow, equatorial and high latitude ones, responsible for the observed westward drift of the surface field, and (2) quantitative information on meridional displacements of the core surface magnetic flux patches.http://link.springer.com/article/10.1186/s40623-017-0732-1Main radial geomagnetic fieldCore surfaceAzimuthal and meridional movementsMagnetic flux patchesTraveling speeds |
| spellingShingle | C. Stefan V. Dobrica C. Demetrescu Core surface sub-centennial magnetic flux patches: characteristics and evolution Earth, Planets and Space Main radial geomagnetic field Core surface Azimuthal and meridional movements Magnetic flux patches Traveling speeds |
| title | Core surface sub-centennial magnetic flux patches: characteristics and evolution |
| title_full | Core surface sub-centennial magnetic flux patches: characteristics and evolution |
| title_fullStr | Core surface sub-centennial magnetic flux patches: characteristics and evolution |
| title_full_unstemmed | Core surface sub-centennial magnetic flux patches: characteristics and evolution |
| title_short | Core surface sub-centennial magnetic flux patches: characteristics and evolution |
| title_sort | core surface sub centennial magnetic flux patches characteristics and evolution |
| topic | Main radial geomagnetic field Core surface Azimuthal and meridional movements Magnetic flux patches Traveling speeds |
| url | http://link.springer.com/article/10.1186/s40623-017-0732-1 |
| work_keys_str_mv | AT cstefan coresurfacesubcentennialmagneticfluxpatchescharacteristicsandevolution AT vdobrica coresurfacesubcentennialmagneticfluxpatchescharacteristicsandevolution AT cdemetrescu coresurfacesubcentennialmagneticfluxpatchescharacteristicsandevolution |