Regional variations of mesospheric gravity-wave momentum flux over Antarctica
Images of mesospheric airglow and radar-wind measurements have been combined to estimate the difference in the vertical flux of horizontal momentum carried by high-frequency gravity waves over two dissimilar Antarctic stations. Rothera (67° S, 68° W) is situated in the mountains of the Peninsula nea...
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ftdoajarticles:oai:doaj.org/article:f63124c7497d428b877a76b6a672ba9c 2023-05-15T13:57:12+02:00 Regional variations of mesospheric gravity-wave momentum flux over Antarctica P. J. Espy R. E. Hibbins G. R. Swenson J. Tang M. J. Taylor D. M. Riggin D. C. Fritts 2006-03-01T00:00:00Z https://doi.org/10.5194/angeo-24-81-2006 https://doaj.org/article/f63124c7497d428b877a76b6a672ba9c EN eng Copernicus Publications https://www.ann-geophys.net/24/81/2006/angeo-24-81-2006.pdf https://doaj.org/toc/0992-7689 https://doaj.org/toc/1432-0576 doi:10.5194/angeo-24-81-2006 0992-7689 1432-0576 https://doaj.org/article/f63124c7497d428b877a76b6a672ba9c Annales Geophysicae, Vol 24, Pp 81-88 (2006) Science Q Physics QC1-999 Geophysics. Cosmic physics QC801-809 article 2006 ftdoajarticles https://doi.org/10.5194/angeo-24-81-2006 2022-12-31T11:24:36Z Images of mesospheric airglow and radar-wind measurements have been combined to estimate the difference in the vertical flux of horizontal momentum carried by high-frequency gravity waves over two dissimilar Antarctic stations. Rothera (67° S, 68° W) is situated in the mountains of the Peninsula near the edge of the wintertime polar vortex. In contrast, Halley (76° S, 27° W), some 1658 km to the southeast, is located on an ice sheet at the edge of the Antarctic Plateau and deep within the polar vortex during winter. The cross-correlation coefficients between the vertical and horizontal wind perturbations were calculated from sodium (Na) airglow imager data collected during the austral winter seasons of 2002 and 2003 at Rothera for comparison with the 2000 and 2001 results from Halley reported previously (Espy et al., 2004). These cross-correlation coefficients were combined with wind-velocity variances from coincident radar measurements to estimate the daily averaged upper-limit of the vertical flux of horizontal momentum due to gravity waves near the peak emission altitude of the Na nightglow layer, 90km. The resulting momentum flux at both stations displayed a large day-to-day variability and showed a marked seasonal rotation from the northwest to the southwest throughout the winter. However, the magnitude of the flux at Rothera was about 4 times larger than that at Halley, suggesting that the differences in the gravity-wave source functions and filtering by the underlying winds at the two stations create significant regional differences in wave forcing on the scale of the station separation. Article in Journal/Newspaper Antarc* Antarctic Antarctica Ice Sheet Directory of Open Access Journals: DOAJ Articles Antarctic Austral Rothera ENVELOPE(-68.130,-68.130,-67.568,-67.568) The Antarctic Annales Geophysicae 24 1 81 88 |
institution |
Open Polar |
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Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
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 P. J. Espy R. E. Hibbins G. R. Swenson J. Tang M. J. Taylor D. M. Riggin D. C. Fritts Regional variations of mesospheric gravity-wave momentum flux over Antarctica |
topic_facet |
Science Q Physics QC1-999 Geophysics. Cosmic physics QC801-809 |
description |
Images of mesospheric airglow and radar-wind measurements have been combined to estimate the difference in the vertical flux of horizontal momentum carried by high-frequency gravity waves over two dissimilar Antarctic stations. Rothera (67° S, 68° W) is situated in the mountains of the Peninsula near the edge of the wintertime polar vortex. In contrast, Halley (76° S, 27° W), some 1658 km to the southeast, is located on an ice sheet at the edge of the Antarctic Plateau and deep within the polar vortex during winter. The cross-correlation coefficients between the vertical and horizontal wind perturbations were calculated from sodium (Na) airglow imager data collected during the austral winter seasons of 2002 and 2003 at Rothera for comparison with the 2000 and 2001 results from Halley reported previously (Espy et al., 2004). These cross-correlation coefficients were combined with wind-velocity variances from coincident radar measurements to estimate the daily averaged upper-limit of the vertical flux of horizontal momentum due to gravity waves near the peak emission altitude of the Na nightglow layer, 90km. The resulting momentum flux at both stations displayed a large day-to-day variability and showed a marked seasonal rotation from the northwest to the southwest throughout the winter. However, the magnitude of the flux at Rothera was about 4 times larger than that at Halley, suggesting that the differences in the gravity-wave source functions and filtering by the underlying winds at the two stations create significant regional differences in wave forcing on the scale of the station separation. |
format |
Article in Journal/Newspaper |
author |
P. J. Espy R. E. Hibbins G. R. Swenson J. Tang M. J. Taylor D. M. Riggin D. C. Fritts |
author_facet |
P. J. Espy R. E. Hibbins G. R. Swenson J. Tang M. J. Taylor D. M. Riggin D. C. Fritts |
author_sort |
P. J. Espy |
title |
Regional variations of mesospheric gravity-wave momentum flux over Antarctica |
title_short |
Regional variations of mesospheric gravity-wave momentum flux over Antarctica |
title_full |
Regional variations of mesospheric gravity-wave momentum flux over Antarctica |
title_fullStr |
Regional variations of mesospheric gravity-wave momentum flux over Antarctica |
title_full_unstemmed |
Regional variations of mesospheric gravity-wave momentum flux over Antarctica |
title_sort |
regional variations of mesospheric gravity-wave momentum flux over antarctica |
publisher |
Copernicus Publications |
publishDate |
2006 |
url |
https://doi.org/10.5194/angeo-24-81-2006 https://doaj.org/article/f63124c7497d428b877a76b6a672ba9c |
long_lat |
ENVELOPE(-68.130,-68.130,-67.568,-67.568) |
geographic |
Antarctic Austral Rothera The Antarctic |
geographic_facet |
Antarctic Austral Rothera The Antarctic |
genre |
Antarc* Antarctic Antarctica Ice Sheet |
genre_facet |
Antarc* Antarctic Antarctica Ice Sheet |
op_source |
Annales Geophysicae, Vol 24, Pp 81-88 (2006) |
op_relation |
https://www.ann-geophys.net/24/81/2006/angeo-24-81-2006.pdf https://doaj.org/toc/0992-7689 https://doaj.org/toc/1432-0576 doi:10.5194/angeo-24-81-2006 0992-7689 1432-0576 https://doaj.org/article/f63124c7497d428b877a76b6a672ba9c |
op_doi |
https://doi.org/10.5194/angeo-24-81-2006 |
container_title |
Annales Geophysicae |
container_volume |
24 |
container_issue |
1 |
container_start_page |
81 |
op_container_end_page |
88 |
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1766264799115608064 |