A Comparison of Auroral Oval Proxies With the Boundaries of the Auroral Electrojets
Abstract The boundaries of the auroral oval and auroral electrojets are an important source of information for understanding the coupling between the solar wind and the near‐earth plasma environment. Of these two types of boundaries the auroral electrojet boundaries have received comparatively littl...
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| Format: | Article |
| Language: | English |
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Wiley
2024-04-01
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| Series: | Space Weather |
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| Online Access: | https://doi.org/10.1029/2023SW003689 |
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| author | Simon James Walker Karl Magnus Laundal Jone Peter Reistad Anders Ohma Spencer Mark Hatch Gareth Chisham Margot Decotte |
| author_facet | Simon James Walker Karl Magnus Laundal Jone Peter Reistad Anders Ohma Spencer Mark Hatch Gareth Chisham Margot Decotte |
| author_sort | Simon James Walker |
| collection | DOAJ |
| description | Abstract The boundaries of the auroral oval and auroral electrojets are an important source of information for understanding the coupling between the solar wind and the near‐earth plasma environment. Of these two types of boundaries the auroral electrojet boundaries have received comparatively little attention, and even less attention has been given to the connection between the two. Here we introduce a technique for estimating the electrojet boundaries, and other properties such as total current and peak current, from 1‐D latitudinal profiles of the eastward component of equivalent current sheet density. We apply this technique to a preexisting database of such currents along the 105° magnetic meridian, estimated using ground‐based magnetometers, producing a total of 11 years of 1‐min resolution electrojet boundaries during the period 2000–2020. Using statistics and conjunction events we compare our electrojet boundary data set with an existing electrojet boundary data set, based on Swarm satellite measurements, and auroral oval proxies based on particle precipitation and field‐aligned currents. This allows us to validate our data set and investigate the feasibility of an auroral oval proxy based on electrojet boundaries. Through this investigation we find the proton precipitation auroral oval is a closer match with the electrojet boundaries. However, the bimodal nature of the electrojet boundaries as we approach the noon and midnight discontinuities makes an average electrojet oval poorly defined. With this and the direct comparisons differing from the statistics, defining the proton auroral oval from electrojet boundaries across all local and universal times is challenging. |
| format | Article |
| id | doaj-art-0401377a4d974896ab3e3ec45d2b62e9 |
| institution | Kabale University |
| issn | 1542-7390 |
| language | English |
| publishDate | 2024-04-01 |
| publisher | Wiley |
| record_format | Article |
| series | Space Weather |
| spelling | doaj-art-0401377a4d974896ab3e3ec45d2b62e92025-01-14T16:27:28ZengWileySpace Weather1542-73902024-04-01224n/an/a10.1029/2023SW003689A Comparison of Auroral Oval Proxies With the Boundaries of the Auroral ElectrojetsSimon James Walker0Karl Magnus Laundal1Jone Peter Reistad2Anders Ohma3Spencer Mark Hatch4Gareth Chisham5Margot Decotte6Department of Physics and Technology University of Bergen Bergen NorwayDepartment of Physics and Technology University of Bergen Bergen NorwayDepartment of Physics and Technology University of Bergen Bergen NorwayDepartment of Physics and Technology University of Bergen Bergen NorwayDepartment of Physics and Technology University of Bergen Bergen NorwayBritish Antarctic Survey Cambridge UKDepartment of Physics and Technology University of Bergen Bergen NorwayAbstract The boundaries of the auroral oval and auroral electrojets are an important source of information for understanding the coupling between the solar wind and the near‐earth plasma environment. Of these two types of boundaries the auroral electrojet boundaries have received comparatively little attention, and even less attention has been given to the connection between the two. Here we introduce a technique for estimating the electrojet boundaries, and other properties such as total current and peak current, from 1‐D latitudinal profiles of the eastward component of equivalent current sheet density. We apply this technique to a preexisting database of such currents along the 105° magnetic meridian, estimated using ground‐based magnetometers, producing a total of 11 years of 1‐min resolution electrojet boundaries during the period 2000–2020. Using statistics and conjunction events we compare our electrojet boundary data set with an existing electrojet boundary data set, based on Swarm satellite measurements, and auroral oval proxies based on particle precipitation and field‐aligned currents. This allows us to validate our data set and investigate the feasibility of an auroral oval proxy based on electrojet boundaries. Through this investigation we find the proton precipitation auroral oval is a closer match with the electrojet boundaries. However, the bimodal nature of the electrojet boundaries as we approach the noon and midnight discontinuities makes an average electrojet oval poorly defined. With this and the direct comparisons differing from the statistics, defining the proton auroral oval from electrojet boundaries across all local and universal times is challenging.https://doi.org/10.1029/2023SW003689auroral electrojetsauroral ovalspherical elementary currentspolar capauroral electrojets boundaryauroral oval boundary |
| spellingShingle | Simon James Walker Karl Magnus Laundal Jone Peter Reistad Anders Ohma Spencer Mark Hatch Gareth Chisham Margot Decotte A Comparison of Auroral Oval Proxies With the Boundaries of the Auroral Electrojets Space Weather auroral electrojets auroral oval spherical elementary currents polar cap auroral electrojets boundary auroral oval boundary |
| title | A Comparison of Auroral Oval Proxies With the Boundaries of the Auroral Electrojets |
| title_full | A Comparison of Auroral Oval Proxies With the Boundaries of the Auroral Electrojets |
| title_fullStr | A Comparison of Auroral Oval Proxies With the Boundaries of the Auroral Electrojets |
| title_full_unstemmed | A Comparison of Auroral Oval Proxies With the Boundaries of the Auroral Electrojets |
| title_short | A Comparison of Auroral Oval Proxies With the Boundaries of the Auroral Electrojets |
| title_sort | comparison of auroral oval proxies with the boundaries of the auroral electrojets |
| topic | auroral electrojets auroral oval spherical elementary currents polar cap auroral electrojets boundary auroral oval boundary |
| url | https://doi.org/10.1029/2023SW003689 |
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