Optical observations geomagnetically conjugate to sprite-producing lightning discharges
Theoretical studies have predicted that large positive cloud-to-ground discharges can trigger a runaway avalanche process of relativistic electrons, forming a geomagnetically trapped electron beam. The beam may undergo pitch angle and energy scattering during its traverse of the Earth's magneto...
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ftdoajarticles:oai:doaj.org/article:02c5a8c91b9d40fba9ea653f7573a44e 2023-05-15T13:36:38+02:00 Optical observations geomagnetically conjugate to sprite-producing lightning discharges R. A. Marshall U. S. Inan T. Neubert A. Hughes G. Sátori J. Bór A. Collier T. H. Allin 2005-09-01T00:00:00Z https://doi.org/10.5194/angeo-23-2231-2005 https://doaj.org/article/02c5a8c91b9d40fba9ea653f7573a44e EN eng Copernicus Publications https://www.ann-geophys.net/23/2231/2005/angeo-23-2231-2005.pdf https://doaj.org/toc/0992-7689 https://doaj.org/toc/1432-0576 doi:10.5194/angeo-23-2231-2005 0992-7689 1432-0576 https://doaj.org/article/02c5a8c91b9d40fba9ea653f7573a44e Annales Geophysicae, Vol 23, Pp 2231-2237 (2005) Science Q Physics QC1-999 Geophysics. Cosmic physics QC801-809 article 2005 ftdoajarticles https://doi.org/10.5194/angeo-23-2231-2005 2022-12-31T02:10:12Z Theoretical studies have predicted that large positive cloud-to-ground discharges can trigger a runaway avalanche process of relativistic electrons, forming a geomagnetically trapped electron beam. The beam may undergo pitch angle and energy scattering during its traverse of the Earth's magnetosphere, with a small percentage of electrons remaining in the loss cone and precipitating in the magnetically conjugate atmosphere. In particular, N 2 1P and N 2 + 1N optical emissions are expected to be observable. In July and August 2003, an attempt was made to detect these optical emissions, called "conjugate sprites", in correlation with sprite observations in Europe near . Sprite observations were made from the Observatoire du Pic du Midi (OMP) in the French Pyrenées, and VLF receivers were installed in Europe to detect causative sferics and ionospheric disturbances associated with sprites. In the Southern Hemisphere conjugate region, the Wide-angle Array for Sprite Photometry (WASP) was deployed at the South African Astronomical Observatory (SAAO), near Sutherland, South Africa, to observe optical emissions with a field-of-view magnetically conjugate to the Northern Hemisphere observing region. Observations at OMP revealed over 130 documented sprites, with WASP observations covering the conjugate region successfully for 30 of these events. However, no incidences of optical emissions in the conjugate hemisphere were found. Analysis of the conjugate optical data from SAAO, along with ELF energy measurements from Palmer Station, Antarctica, and charge-moment analysis, show that the lightning events during the course of this experiment likely had insufficient intensity to create a relativistic beam. Keywords. Ionosphere (Ionsophere-magnetosphere interactions; Ionospheric disturbances; Instruments and techniques) Article in Journal/Newspaper Antarc* Antarctica Directory of Open Access Journals: DOAJ Articles Palmer Station ENVELOPE(-64.050,-64.050,-64.770,-64.770) Palmer-Station ENVELOPE(-64.050,-64.050,-64.770,-64.770) Sutherland ENVELOPE(168.467,168.467,-77.500,-77.500) Annales Geophysicae 23 6 2231 2237 |
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Open Polar |
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Directory of Open Access Journals: DOAJ Articles |
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ftdoajarticles |
language |
English |
topic |
Science Q Physics QC1-999 Geophysics. Cosmic physics QC801-809 |
spellingShingle |
Science Q Physics QC1-999 Geophysics. Cosmic physics QC801-809 R. A. Marshall U. S. Inan T. Neubert A. Hughes G. Sátori J. Bór A. Collier T. H. Allin Optical observations geomagnetically conjugate to sprite-producing lightning discharges |
topic_facet |
Science Q Physics QC1-999 Geophysics. Cosmic physics QC801-809 |
description |
Theoretical studies have predicted that large positive cloud-to-ground discharges can trigger a runaway avalanche process of relativistic electrons, forming a geomagnetically trapped electron beam. The beam may undergo pitch angle and energy scattering during its traverse of the Earth's magnetosphere, with a small percentage of electrons remaining in the loss cone and precipitating in the magnetically conjugate atmosphere. In particular, N 2 1P and N 2 + 1N optical emissions are expected to be observable. In July and August 2003, an attempt was made to detect these optical emissions, called "conjugate sprites", in correlation with sprite observations in Europe near . Sprite observations were made from the Observatoire du Pic du Midi (OMP) in the French Pyrenées, and VLF receivers were installed in Europe to detect causative sferics and ionospheric disturbances associated with sprites. In the Southern Hemisphere conjugate region, the Wide-angle Array for Sprite Photometry (WASP) was deployed at the South African Astronomical Observatory (SAAO), near Sutherland, South Africa, to observe optical emissions with a field-of-view magnetically conjugate to the Northern Hemisphere observing region. Observations at OMP revealed over 130 documented sprites, with WASP observations covering the conjugate region successfully for 30 of these events. However, no incidences of optical emissions in the conjugate hemisphere were found. Analysis of the conjugate optical data from SAAO, along with ELF energy measurements from Palmer Station, Antarctica, and charge-moment analysis, show that the lightning events during the course of this experiment likely had insufficient intensity to create a relativistic beam. Keywords. Ionosphere (Ionsophere-magnetosphere interactions; Ionospheric disturbances; Instruments and techniques) |
format |
Article in Journal/Newspaper |
author |
R. A. Marshall U. S. Inan T. Neubert A. Hughes G. Sátori J. Bór A. Collier T. H. Allin |
author_facet |
R. A. Marshall U. S. Inan T. Neubert A. Hughes G. Sátori J. Bór A. Collier T. H. Allin |
author_sort |
R. A. Marshall |
title |
Optical observations geomagnetically conjugate to sprite-producing lightning discharges |
title_short |
Optical observations geomagnetically conjugate to sprite-producing lightning discharges |
title_full |
Optical observations geomagnetically conjugate to sprite-producing lightning discharges |
title_fullStr |
Optical observations geomagnetically conjugate to sprite-producing lightning discharges |
title_full_unstemmed |
Optical observations geomagnetically conjugate to sprite-producing lightning discharges |
title_sort |
optical observations geomagnetically conjugate to sprite-producing lightning discharges |
publisher |
Copernicus Publications |
publishDate |
2005 |
url |
https://doi.org/10.5194/angeo-23-2231-2005 https://doaj.org/article/02c5a8c91b9d40fba9ea653f7573a44e |
long_lat |
ENVELOPE(-64.050,-64.050,-64.770,-64.770) ENVELOPE(-64.050,-64.050,-64.770,-64.770) ENVELOPE(168.467,168.467,-77.500,-77.500) |
geographic |
Palmer Station Palmer-Station Sutherland |
geographic_facet |
Palmer Station Palmer-Station Sutherland |
genre |
Antarc* Antarctica |
genre_facet |
Antarc* Antarctica |
op_source |
Annales Geophysicae, Vol 23, Pp 2231-2237 (2005) |
op_relation |
https://www.ann-geophys.net/23/2231/2005/angeo-23-2231-2005.pdf https://doaj.org/toc/0992-7689 https://doaj.org/toc/1432-0576 doi:10.5194/angeo-23-2231-2005 0992-7689 1432-0576 https://doaj.org/article/02c5a8c91b9d40fba9ea653f7573a44e |
op_doi |
https://doi.org/10.5194/angeo-23-2231-2005 |
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Annales Geophysicae |
container_volume |
23 |
container_issue |
6 |
container_start_page |
2231 |
op_container_end_page |
2237 |
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