Magnetic Field Observations on Interhemispheric Conjugate Chains
Abstract A chain of magnetometers has been placed in Antarctica for comparisons with magnetic field measurements taken in the Northern Hemisphere. The locations were chosen to be on magnetic field lines that connect to magnetometers on the western coast of Greenland, despite the difficulty of reachi...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
American Geophysical Union (AGU)
2023-09-01
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| Series: | Earth and Space Science |
| Subjects: | |
| Online Access: | https://doi.org/10.1029/2023EA003046 |
| _version_ | 1797658126285012992 |
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| author | D. R. Weimer C. R. Clauer Z. Xu S. Coyle M. D. Hartinger |
| author_facet | D. R. Weimer C. R. Clauer Z. Xu S. Coyle M. D. Hartinger |
| author_sort | D. R. Weimer |
| collection | DOAJ |
| description | Abstract A chain of magnetometers has been placed in Antarctica for comparisons with magnetic field measurements taken in the Northern Hemisphere. The locations were chosen to be on magnetic field lines that connect to magnetometers on the western coast of Greenland, despite the difficulty of reaching and working at such remote locations. We report on some basic comparisons of the similarities and differences in the conjugate measurements. Our results presented here confirm that the conjugate sites do have very similar (symmetric) magnetic perturbations in a handful of cases, as expected. Sign reversals are required for two components in order to obtain this agreement, which is not commonly known. More frequently, a strong Y component of the Interplanetary Magnetic Field (IMF) breaks the symmetry, as well as the unequal conductivities in the opposite hemispheres, as shown in two examples. In one event the IMF Y component reversed signs twice within 2 hours, while the magnetometer chains were approaching local noon. This switch provided an opportunity to observe the effects at the conjugate locations and to measure time lags. It was found that the magnetic fields at the most poleward sites started to respond to the sudden IMF reversals 20 min after the IMF reaches the bow shock, a measure of the time it takes for the electromagnetic signal to travel to the magnetopause, and then along magnetic field lines to the polar ionospheres. An additional 9–14 min is required for the magnetic perturbations to complete their transition. |
| first_indexed | 2024-03-11T17:54:36Z |
| format | Article |
| id | doaj.art-eb9bac54f3cc4c6eae4e062285890939 |
| institution | Directory Open Access Journal |
| issn | 2333-5084 |
| language | English |
| last_indexed | 2024-03-11T17:54:36Z |
| publishDate | 2023-09-01 |
| publisher | American Geophysical Union (AGU) |
| record_format | Article |
| series | Earth and Space Science |
| spelling | doaj.art-eb9bac54f3cc4c6eae4e0622858909392023-10-17T21:35:39ZengAmerican Geophysical Union (AGU)Earth and Space Science2333-50842023-09-01109n/an/a10.1029/2023EA003046Magnetic Field Observations on Interhemispheric Conjugate ChainsD. R. Weimer0C. R. Clauer1Z. Xu2S. Coyle3M. D. Hartinger4Center for Space Science and Engineering Research Blacksburg VA USACenter for Space Science and Engineering Research Blacksburg VA USACenter for Space Science and Engineering Research Blacksburg VA USACenter for Space Science and Engineering Research Blacksburg VA USASpace Science Institute Boulder CO USAAbstract A chain of magnetometers has been placed in Antarctica for comparisons with magnetic field measurements taken in the Northern Hemisphere. The locations were chosen to be on magnetic field lines that connect to magnetometers on the western coast of Greenland, despite the difficulty of reaching and working at such remote locations. We report on some basic comparisons of the similarities and differences in the conjugate measurements. Our results presented here confirm that the conjugate sites do have very similar (symmetric) magnetic perturbations in a handful of cases, as expected. Sign reversals are required for two components in order to obtain this agreement, which is not commonly known. More frequently, a strong Y component of the Interplanetary Magnetic Field (IMF) breaks the symmetry, as well as the unequal conductivities in the opposite hemispheres, as shown in two examples. In one event the IMF Y component reversed signs twice within 2 hours, while the magnetometer chains were approaching local noon. This switch provided an opportunity to observe the effects at the conjugate locations and to measure time lags. It was found that the magnetic fields at the most poleward sites started to respond to the sudden IMF reversals 20 min after the IMF reaches the bow shock, a measure of the time it takes for the electromagnetic signal to travel to the magnetopause, and then along magnetic field lines to the polar ionospheres. An additional 9–14 min is required for the magnetic perturbations to complete their transition.https://doi.org/10.1029/2023EA003046magnetic field measurementsinterhemispheric comparisonsionospheric currentsAntarctica |
| spellingShingle | D. R. Weimer C. R. Clauer Z. Xu S. Coyle M. D. Hartinger Magnetic Field Observations on Interhemispheric Conjugate Chains Earth and Space Science magnetic field measurements interhemispheric comparisons ionospheric currents Antarctica |
| title | Magnetic Field Observations on Interhemispheric Conjugate Chains |
| title_full | Magnetic Field Observations on Interhemispheric Conjugate Chains |
| title_fullStr | Magnetic Field Observations on Interhemispheric Conjugate Chains |
| title_full_unstemmed | Magnetic Field Observations on Interhemispheric Conjugate Chains |
| title_short | Magnetic Field Observations on Interhemispheric Conjugate Chains |
| title_sort | magnetic field observations on interhemispheric conjugate chains |
| topic | magnetic field measurements interhemispheric comparisons ionospheric currents Antarctica |
| url | https://doi.org/10.1029/2023EA003046 |
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