Auroral Structure and Dynamics From GOLD.
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| Title: | Auroral Structure and Dynamics From GOLD. |
|---|---|
| Authors: | Michell, R. G.1,2 robert.g.michell@nasa.gov |
| Source: | Journal of Geophysical Research. Space Physics. Mar2020, Vol. 125 Issue 3, p1-10. 10p. |
| Subject Terms: | *Geomagnetism, Aurora spectra, Airglow, Geostationary satellites, Spectrographs |
| Abstract: | The Global‐scale Observations of the Limb and Disk (GOLD) mission data contain significant quantitative information about the aurora on a global scale. Here we present techniques for quantifying such information, including the temporal development of the structure within the auroral oval using the GOLD images. These techniques are applied to auroral observations in the GOLD data, in particular showing an example of how the longitudinal structure within the aurora varies over the course of six consecutive days with differing levels of geomagnetic activity. A simple model of the solar‐induced airglow is presented that is used to remove the sunlight contamination from the dayside auroral observations. Comparisons to ground‐based auroral imaging are used for the overall auroral context and to make estimates of the proportionality between the intensities of the green line (557.7 nm) emission in the visible and the 135.6 nm emissions in the GOLD data. These observations are consistent with the intensity of the 135.6 nm auroral emission being on the same order as the intensity of the 557.7 nm auroral emission. They were both found to be around 1 kR for a stable auroral arc on a day with low geomagnetic activity (3 November 2018) and around 10 kR for an active auroral display on a day with higher levels of geomagnetic activity (5 November 2018). This could have important implications for making direct comparisons between space‐based ultraviolet auroral imaging and ground‐based visible‐light auroral imaging and the total energy input estimates that are derived from them. Key Points: Longitudinal keograms created over long time series of GOLD dayside images quantify significant auroral structure and developmentA simple estimate of the solar‐induced airglow is used to remove most of the solar contamination of the sunlit auroraThe intensity of the 135.6 nm aurora and the intensity of the 557.7 nm aurora are similar (1 kR for weak aurora and 10 kR for strong aurora) [ABSTRACT FROM AUTHOR] |
| Copyright of Journal of Geophysical Research. Space Physics is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) | |
| Database: | GreenFILE |
| FullText | Text: Availability: 0 |
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| Header | DbId: 8gh DbLabel: GreenFILE An: 142422918 AccessLevel: 6 PubType: Academic Journal PubTypeId: academicJournal PreciseRelevancyScore: 0 |
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| Items | – Name: Title Label: Title Group: Ti Data: Auroral Structure and Dynamics From GOLD. – Name: Author Label: Authors Group: Au Data: <searchLink fieldCode="AR" term="%22Michell%2C+R%2E+G%2E%22">Michell, R. G.</searchLink><relatesTo>1,2</relatesTo><i> robert.g.michell@nasa.gov</i> – Name: TitleSource Label: Source Group: Src Data: <searchLink fieldCode="JN" term="%22Journal+of+Geophysical+Research%2E+Space+Physics%22">Journal of Geophysical Research. Space Physics</searchLink>. Mar2020, Vol. 125 Issue 3, p1-10. 10p. – Name: Subject Label: Subject Terms Group: Su Data: *<searchLink fieldCode="DE" term="%22Geomagnetism%22">Geomagnetism</searchLink><br /><searchLink fieldCode="DE" term="%22Aurora+spectra%22">Aurora spectra</searchLink><br /><searchLink fieldCode="DE" term="%22Airglow%22">Airglow</searchLink><br /><searchLink fieldCode="DE" term="%22Geostationary+satellites%22">Geostationary satellites</searchLink><br /><searchLink fieldCode="DE" term="%22Spectrographs%22">Spectrographs</searchLink> – Name: Abstract Label: Abstract Group: Ab Data: The Global‐scale Observations of the Limb and Disk (GOLD) mission data contain significant quantitative information about the aurora on a global scale. Here we present techniques for quantifying such information, including the temporal development of the structure within the auroral oval using the GOLD images. These techniques are applied to auroral observations in the GOLD data, in particular showing an example of how the longitudinal structure within the aurora varies over the course of six consecutive days with differing levels of geomagnetic activity. A simple model of the solar‐induced airglow is presented that is used to remove the sunlight contamination from the dayside auroral observations. Comparisons to ground‐based auroral imaging are used for the overall auroral context and to make estimates of the proportionality between the intensities of the green line (557.7 nm) emission in the visible and the 135.6 nm emissions in the GOLD data. These observations are consistent with the intensity of the 135.6 nm auroral emission being on the same order as the intensity of the 557.7 nm auroral emission. They were both found to be around 1 kR for a stable auroral arc on a day with low geomagnetic activity (3 November 2018) and around 10 kR for an active auroral display on a day with higher levels of geomagnetic activity (5 November 2018). This could have important implications for making direct comparisons between space‐based ultraviolet auroral imaging and ground‐based visible‐light auroral imaging and the total energy input estimates that are derived from them. Key Points: Longitudinal keograms created over long time series of GOLD dayside images quantify significant auroral structure and developmentA simple estimate of the solar‐induced airglow is used to remove most of the solar contamination of the sunlit auroraThe intensity of the 135.6 nm aurora and the intensity of the 557.7 nm aurora are similar (1 kR for weak aurora and 10 kR for strong aurora) [ABSTRACT FROM AUTHOR] – Name: AbstractSuppliedCopyright Label: Group: Ab Data: <i>Copyright of Journal of Geophysical Research. Space Physics is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract.</i> (Copyright applies to all Abstracts.) |
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| RecordInfo | BibRecord: BibEntity: Identifiers: – Type: doi Value: 10.1029/2019JA027650 Languages: – Code: eng Text: English PhysicalDescription: Pagination: PageCount: 10 StartPage: 1 Subjects: – SubjectFull: Geomagnetism Type: general – SubjectFull: Aurora spectra Type: general – SubjectFull: Airglow Type: general – SubjectFull: Geostationary satellites Type: general – SubjectFull: Spectrographs Type: general Titles: – TitleFull: Auroral Structure and Dynamics From GOLD. Type: main BibRelationships: HasContributorRelationships: – PersonEntity: Name: NameFull: Michell, R. G. IsPartOfRelationships: – BibEntity: Dates: – D: 01 M: 03 Text: Mar2020 Type: published Y: 2020 Identifiers: – Type: issn-print Value: 21699380 Numbering: – Type: volume Value: 125 – Type: issue Value: 3 Titles: – TitleFull: Journal of Geophysical Research. Space Physics Type: main |
| ResultId | 1 |
