Evidence for thermospheric gravity waves in the southern polar cap from ground-based vertical velocity and photometric observations
Zenith-directed Fabry-Perot Spectrometer (FPS) and 3-Field Photometer (3FP) observations of the λ630 nm emission (~240 km altitude) were obtained at Davis station, Antarctica, during the austral winter of 1999. Eleven nights of suitable data were searched for significant periodicities com...
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Online Access: | https://doi.org/10.5194/angeo-19-533-2001 https://angeo.copernicus.org/articles/19/533/2001/ |
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ftcopernicus:oai:publications.copernicus.org:angeo34643 2023-05-15T13:36:36+02:00 Evidence for thermospheric gravity waves in the southern polar cap from ground-based vertical velocity and photometric observations Innis, J. L. Greet, P. A. Dyson, P. L. 2018-09-27 application/pdf https://doi.org/10.5194/angeo-19-533-2001 https://angeo.copernicus.org/articles/19/533/2001/ eng eng doi:10.5194/angeo-19-533-2001 https://angeo.copernicus.org/articles/19/533/2001/ eISSN: 1432-0576 Text 2018 ftcopernicus https://doi.org/10.5194/angeo-19-533-2001 2020-07-20T16:27:54Z Zenith-directed Fabry-Perot Spectrometer (FPS) and 3-Field Photometer (3FP) observations of the λ630 nm emission (~240 km altitude) were obtained at Davis station, Antarctica, during the austral winter of 1999. Eleven nights of suitable data were searched for significant periodicities common to vertical winds from the FPS and photo-metric variations from the 3FP. Three wave-like events were found, each of around one or more hours in duration, with periods around 15 minutes, vertical velocity amplitudes near 60 ms –1 , horizontal phase velocities around 300 ms –1 , and horizontal wavelengths from 240 to 400 km. These characteristics appear consistent with polar cap gravity waves seen by other workers, and we conclude this is a likely interpretation of our data. Assuming a source height near 125 km altitude, we determine the approximate source location by calculating back along the wave trajectory using the gravity wave property relating angle of ascent and frequency. The wave sources appear to be in the vicinity of the poleward border of the auroral oval, at magnetic local times up to 5 hours before local magnetic midnight. Key words. Meteorology and atmospheric dynamics (thermospheric dynamics; waves and tides) Text Antarc* Antarctica Copernicus Publications: E-Journals Austral Davis Station ENVELOPE(77.968,77.968,-68.576,-68.576) Davis-Station ENVELOPE(77.968,77.968,-68.576,-68.576) Annales Geophysicae 19 5 533 543 |
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Open Polar |
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Copernicus Publications: E-Journals |
op_collection_id |
ftcopernicus |
language |
English |
description |
Zenith-directed Fabry-Perot Spectrometer (FPS) and 3-Field Photometer (3FP) observations of the λ630 nm emission (~240 km altitude) were obtained at Davis station, Antarctica, during the austral winter of 1999. Eleven nights of suitable data were searched for significant periodicities common to vertical winds from the FPS and photo-metric variations from the 3FP. Three wave-like events were found, each of around one or more hours in duration, with periods around 15 minutes, vertical velocity amplitudes near 60 ms –1 , horizontal phase velocities around 300 ms –1 , and horizontal wavelengths from 240 to 400 km. These characteristics appear consistent with polar cap gravity waves seen by other workers, and we conclude this is a likely interpretation of our data. Assuming a source height near 125 km altitude, we determine the approximate source location by calculating back along the wave trajectory using the gravity wave property relating angle of ascent and frequency. The wave sources appear to be in the vicinity of the poleward border of the auroral oval, at magnetic local times up to 5 hours before local magnetic midnight. Key words. Meteorology and atmospheric dynamics (thermospheric dynamics; waves and tides) |
format |
Text |
author |
Innis, J. L. Greet, P. A. Dyson, P. L. |
spellingShingle |
Innis, J. L. Greet, P. A. Dyson, P. L. Evidence for thermospheric gravity waves in the southern polar cap from ground-based vertical velocity and photometric observations |
author_facet |
Innis, J. L. Greet, P. A. Dyson, P. L. |
author_sort |
Innis, J. L. |
title |
Evidence for thermospheric gravity waves in the southern polar cap from ground-based vertical velocity and photometric observations |
title_short |
Evidence for thermospheric gravity waves in the southern polar cap from ground-based vertical velocity and photometric observations |
title_full |
Evidence for thermospheric gravity waves in the southern polar cap from ground-based vertical velocity and photometric observations |
title_fullStr |
Evidence for thermospheric gravity waves in the southern polar cap from ground-based vertical velocity and photometric observations |
title_full_unstemmed |
Evidence for thermospheric gravity waves in the southern polar cap from ground-based vertical velocity and photometric observations |
title_sort |
evidence for thermospheric gravity waves in the southern polar cap from ground-based vertical velocity and photometric observations |
publishDate |
2018 |
url |
https://doi.org/10.5194/angeo-19-533-2001 https://angeo.copernicus.org/articles/19/533/2001/ |
long_lat |
ENVELOPE(77.968,77.968,-68.576,-68.576) ENVELOPE(77.968,77.968,-68.576,-68.576) |
geographic |
Austral Davis Station Davis-Station |
geographic_facet |
Austral Davis Station Davis-Station |
genre |
Antarc* Antarctica |
genre_facet |
Antarc* Antarctica |
op_source |
eISSN: 1432-0576 |
op_relation |
doi:10.5194/angeo-19-533-2001 https://angeo.copernicus.org/articles/19/533/2001/ |
op_doi |
https://doi.org/10.5194/angeo-19-533-2001 |
container_title |
Annales Geophysicae |
container_volume |
19 |
container_issue |
5 |
container_start_page |
533 |
op_container_end_page |
543 |
_version_ |
1766081625360171008 |