A new auroral phenomenon, the anti-black aurora
Black auroras are small-scale features embedded in the diffuse background aurora, typically occurring post-substorm after magnetic midnight and with an eastward drift imposed. Black auroras show a significant reduction in optical brightness compared to the surrounding diffuse aurora, and can appear...
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ftpubmed:oai:pubmedcentral.nih.gov:7815772 2023-05-15T18:34:38+02:00 A new auroral phenomenon, the anti-black aurora Nel, A. E. Kosch, M. J. Whiter, D. Gustavsson, B. Aslaksen, T. 2021-01-19 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7815772/ https://doi.org/10.1038/s41598-021-81363-9 en eng Nature Publishing Group UK http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7815772/ http://dx.doi.org/10.1038/s41598-021-81363-9 © The Author(s) 2021 Open AccessThis article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. CC-BY Sci Rep Article Text 2021 ftpubmed https://doi.org/10.1038/s41598-021-81363-9 2021-01-24T01:34:08Z Black auroras are small-scale features embedded in the diffuse background aurora, typically occurring post-substorm after magnetic midnight and with an eastward drift imposed. Black auroras show a significant reduction in optical brightness compared to the surrounding diffuse aurora, and can appear as slow-moving arcs or rapidly-moving patches and arc segments. We report, for the first time, an even more elusive small-scale optical structure that has always been observed occurring paired with [Formula: see text] 10% of black aurora patches. A patch or arc segment of enhanced luminosity, distinctly brighter than the diffuse background, which we name the anti-black aurora, may appear adjacent to the black aurora. The anti-black aurora is of similar shape and size, and always moves in parallel to the drifting black aurora, although it may suddenly switch sides for no apparent reason. The paired phenomenon always drifts with the same average speed in an easterly direction. From the first dual-wavelength (427.8 nm and 844.6 nm) optical observations of the phenomenon recorded on 12 March 2016 outside Tromsø Norway, we show that the anti-black and black auroras have a higher and lower mean energy, respectively, of the precipitating electrons compared to the diffuse background. Text Tromsø PubMed Central (PMC) Norway Tromsø Scientific Reports 11 1 |
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Article Nel, A. E. Kosch, M. J. Whiter, D. Gustavsson, B. Aslaksen, T. A new auroral phenomenon, the anti-black aurora |
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Article |
description |
Black auroras are small-scale features embedded in the diffuse background aurora, typically occurring post-substorm after magnetic midnight and with an eastward drift imposed. Black auroras show a significant reduction in optical brightness compared to the surrounding diffuse aurora, and can appear as slow-moving arcs or rapidly-moving patches and arc segments. We report, for the first time, an even more elusive small-scale optical structure that has always been observed occurring paired with [Formula: see text] 10% of black aurora patches. A patch or arc segment of enhanced luminosity, distinctly brighter than the diffuse background, which we name the anti-black aurora, may appear adjacent to the black aurora. The anti-black aurora is of similar shape and size, and always moves in parallel to the drifting black aurora, although it may suddenly switch sides for no apparent reason. The paired phenomenon always drifts with the same average speed in an easterly direction. From the first dual-wavelength (427.8 nm and 844.6 nm) optical observations of the phenomenon recorded on 12 March 2016 outside Tromsø Norway, we show that the anti-black and black auroras have a higher and lower mean energy, respectively, of the precipitating electrons compared to the diffuse background. |
format |
Text |
author |
Nel, A. E. Kosch, M. J. Whiter, D. Gustavsson, B. Aslaksen, T. |
author_facet |
Nel, A. E. Kosch, M. J. Whiter, D. Gustavsson, B. Aslaksen, T. |
author_sort |
Nel, A. E. |
title |
A new auroral phenomenon, the anti-black aurora |
title_short |
A new auroral phenomenon, the anti-black aurora |
title_full |
A new auroral phenomenon, the anti-black aurora |
title_fullStr |
A new auroral phenomenon, the anti-black aurora |
title_full_unstemmed |
A new auroral phenomenon, the anti-black aurora |
title_sort |
new auroral phenomenon, the anti-black aurora |
publisher |
Nature Publishing Group UK |
publishDate |
2021 |
url |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7815772/ https://doi.org/10.1038/s41598-021-81363-9 |
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Norway Tromsø |
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Norway Tromsø |
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Tromsø |
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Tromsø |
op_source |
Sci Rep |
op_relation |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7815772/ http://dx.doi.org/10.1038/s41598-021-81363-9 |
op_rights |
© The Author(s) 2021 Open AccessThis article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. |
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CC-BY |
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https://doi.org/10.1038/s41598-021-81363-9 |
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Scientific Reports |
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11 |
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