The association of polar mesosphere summer echo layers with tial modes
The occurrence of PMSEs with time of day shows a semi-diurnal variation with minima at 8 and 20 h LT. PMSE layers observed for more than 30 min show an average rate of descent of 2 km h<sup>–1</sup>. These characteristics suggest the influence of tidal winds. When the obs...
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| Format: | Article |
| Language: | English |
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Copernicus Publications
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| Series: | Annales Geophysicae |
| Online Access: | http://www.ann-geophys.net/13/454/1995/angeo-13-454-1995.html |
| _version_ | 1811245681202954240 |
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| author | P. J. S. Williams G. O. L. Jones J. R. Palmer H. Rishbeth |
| author_facet | P. J. S. Williams G. O. L. Jones J. R. Palmer H. Rishbeth |
| author_sort | P. J. S. Williams |
| collection | DOAJ |
| description | The occurrence of PMSEs with time of day shows a semi-diurnal variation with minima at 8 and 20 h LT. PMSE layers observed for more than 30 min show an average rate of descent of 2 km h<sup>–1</sup>. These characteristics suggest the influence of tidal winds. When the observed steady wind and diurnal and semi-diurnal tides at EISCAT are added, the overall magnitude shows a time-variation which matches the occurrence of PMSEs, and the observed rate of descent, approximately 2 km h<sup>–1</sup>. Atmospheric gravity waves also contribute to the velocity of the neutral wind. When the wave reinforces the background wind, the PMSEs are stronger and descend more rapidly, but when the wave-related velocity opposes the background wind the PMSE is weaker and it descends more slowly. |
| first_indexed | 2024-04-12T14:43:00Z |
| format | Article |
| id | doaj.art-e5922742395748cb96aa8dd60a41c2a7 |
| institution | Directory Open Access Journal |
| issn | 0992-7689 1432-0576 |
| language | English |
| last_indexed | 2024-04-12T14:43:00Z |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Annales Geophysicae |
| spelling | doaj.art-e5922742395748cb96aa8dd60a41c2a72022-12-22T03:28:46ZengCopernicus PublicationsAnnales Geophysicae0992-76891432-0576134454457The association of polar mesosphere summer echo layers with tial modesP. J. S. WilliamsG. O. L. JonesJ. R. PalmerH. RishbethThe occurrence of PMSEs with time of day shows a semi-diurnal variation with minima at 8 and 20 h LT. PMSE layers observed for more than 30 min show an average rate of descent of 2 km h<sup>–1</sup>. These characteristics suggest the influence of tidal winds. When the observed steady wind and diurnal and semi-diurnal tides at EISCAT are added, the overall magnitude shows a time-variation which matches the occurrence of PMSEs, and the observed rate of descent, approximately 2 km h<sup>–1</sup>. Atmospheric gravity waves also contribute to the velocity of the neutral wind. When the wave reinforces the background wind, the PMSEs are stronger and descend more rapidly, but when the wave-related velocity opposes the background wind the PMSE is weaker and it descends more slowly.http://www.ann-geophys.net/13/454/1995/angeo-13-454-1995.html |
| spellingShingle | P. J. S. Williams G. O. L. Jones J. R. Palmer H. Rishbeth The association of polar mesosphere summer echo layers with tial modes Annales Geophysicae |
| title | The association of polar mesosphere summer echo layers with tial modes |
| title_full | The association of polar mesosphere summer echo layers with tial modes |
| title_fullStr | The association of polar mesosphere summer echo layers with tial modes |
| title_full_unstemmed | The association of polar mesosphere summer echo layers with tial modes |
| title_short | The association of polar mesosphere summer echo layers with tial modes |
| title_sort | association of polar mesosphere summer echo layers with tial modes |
| url | http://www.ann-geophys.net/13/454/1995/angeo-13-454-1995.html |
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