First observation of one noctilucent cloud by a twin lidar in two different directions
In the early morning hours of 14 July 1999, a noctilucent cloud (NLC) was observed simultaneously by the two branches of a twin lidar system located at the ALOMAR observatory in northern Norway (69° N). The telescopes of the two lidars were pointing vertical (L^) and off the zenith by 30° (L30°). Th...
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Language: | English |
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Copernicus Publications
2002
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ftnonlinearchiv:oai:noa.gwlb.de:cop_mods_00035775 2023-05-15T17:43:39+02:00 First observation of one noctilucent cloud by a twin lidar in two different directions Baumgarten, G. Lübken, F.-J. Fricke, K. H. 2002-11 electronic https://doi.org/10.5194/angeo-20-1863-2002 https://noa.gwlb.de/receive/cop_mods_00035775 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00035729/angeo-20-1863-2002.pdf https://angeo.copernicus.org/articles/20/1863/2002/angeo-20-1863-2002.pdf eng eng Copernicus Publications Annales Geophysicae -- http://www.bibliothek.uni-regensburg.de/ezeit/?1458425 -- https://www.ann-geophys.net/ -- https://www.ann-geophys.net/volumes.html -- http://link.springer.com/journal/585 -- 1432-0576 https://doi.org/10.5194/angeo-20-1863-2002 https://noa.gwlb.de/receive/cop_mods_00035775 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00035729/angeo-20-1863-2002.pdf https://angeo.copernicus.org/articles/20/1863/2002/angeo-20-1863-2002.pdf uneingeschränkt info:eu-repo/semantics/openAccess article Verlagsveröffentlichung article Text doc-type:article 2002 ftnonlinearchiv https://doi.org/10.5194/angeo-20-1863-2002 2022-02-08T22:44:26Z In the early morning hours of 14 July 1999, a noctilucent cloud (NLC) was observed simultaneously by the two branches of a twin lidar system located at the ALOMAR observatory in northern Norway (69° N). The telescopes of the two lidars were pointing vertical (L^) and off the zenith by 30° (L30°). The two lidars detected an enhancement in the altitude profile of backscattered light (relative to the molecular background) for more than 5 h, starting approximately at 01:00 UT. These measurements constitute the detection of one NLC by two lidars under different directions and allow for a detailed study of the morphology of the NLC layer. A cross-correlation analysis of the NLC signals demonstrates that the main structures seen by both lidars are practically identical. This implies that a temporal evolution of the microphysics within the NLC during its drift from one lidar beam to the other is negligible. From the time delay of the NLC structures, a drift velocity of 55–65 m/s is derived which agrees nicely with radar wind measurements. During the observation period, the mean NLC altitude decreases by ~0.5 km/h (=14 cm/s) at both observation volumes. Further-more, the NLC is consistently observed approximately 500 m lower in altitude at L30° compared to L^. Supplementing these data by observations from rocket-borne and ground-based instruments, we show that the general downward progression of the NLC layer through the night, as seen by both lidars, is caused by a combination of particle sedimentation by 4–5 cm/s and a downward directed vertical wind by 9–10 cm/s, whereas a tilt of the layer in drift direction can be excluded. Key words. Atmospheric composition and structure (cloud physics and chemistry; aerosols and particles) Meteorology and atmospheric dynamics (middle atmosphere dynamics) Article in Journal/Newspaper Northern Norway Niedersächsisches Online-Archiv NOA Alomar ENVELOPE(-67.083,-67.083,-68.133,-68.133) Norway Annales Geophysicae 20 11 1863 1868 |
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Open Polar |
collection |
Niedersächsisches Online-Archiv NOA |
op_collection_id |
ftnonlinearchiv |
language |
English |
topic |
article Verlagsveröffentlichung |
spellingShingle |
article Verlagsveröffentlichung Baumgarten, G. Lübken, F.-J. Fricke, K. H. First observation of one noctilucent cloud by a twin lidar in two different directions |
topic_facet |
article Verlagsveröffentlichung |
description |
In the early morning hours of 14 July 1999, a noctilucent cloud (NLC) was observed simultaneously by the two branches of a twin lidar system located at the ALOMAR observatory in northern Norway (69° N). The telescopes of the two lidars were pointing vertical (L^) and off the zenith by 30° (L30°). The two lidars detected an enhancement in the altitude profile of backscattered light (relative to the molecular background) for more than 5 h, starting approximately at 01:00 UT. These measurements constitute the detection of one NLC by two lidars under different directions and allow for a detailed study of the morphology of the NLC layer. A cross-correlation analysis of the NLC signals demonstrates that the main structures seen by both lidars are practically identical. This implies that a temporal evolution of the microphysics within the NLC during its drift from one lidar beam to the other is negligible. From the time delay of the NLC structures, a drift velocity of 55–65 m/s is derived which agrees nicely with radar wind measurements. During the observation period, the mean NLC altitude decreases by ~0.5 km/h (=14 cm/s) at both observation volumes. Further-more, the NLC is consistently observed approximately 500 m lower in altitude at L30° compared to L^. Supplementing these data by observations from rocket-borne and ground-based instruments, we show that the general downward progression of the NLC layer through the night, as seen by both lidars, is caused by a combination of particle sedimentation by 4–5 cm/s and a downward directed vertical wind by 9–10 cm/s, whereas a tilt of the layer in drift direction can be excluded. Key words. Atmospheric composition and structure (cloud physics and chemistry; aerosols and particles) Meteorology and atmospheric dynamics (middle atmosphere dynamics) |
format |
Article in Journal/Newspaper |
author |
Baumgarten, G. Lübken, F.-J. Fricke, K. H. |
author_facet |
Baumgarten, G. Lübken, F.-J. Fricke, K. H. |
author_sort |
Baumgarten, G. |
title |
First observation of one noctilucent cloud by a twin lidar in two different directions |
title_short |
First observation of one noctilucent cloud by a twin lidar in two different directions |
title_full |
First observation of one noctilucent cloud by a twin lidar in two different directions |
title_fullStr |
First observation of one noctilucent cloud by a twin lidar in two different directions |
title_full_unstemmed |
First observation of one noctilucent cloud by a twin lidar in two different directions |
title_sort |
first observation of one noctilucent cloud by a twin lidar in two different directions |
publisher |
Copernicus Publications |
publishDate |
2002 |
url |
https://doi.org/10.5194/angeo-20-1863-2002 https://noa.gwlb.de/receive/cop_mods_00035775 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00035729/angeo-20-1863-2002.pdf https://angeo.copernicus.org/articles/20/1863/2002/angeo-20-1863-2002.pdf |
long_lat |
ENVELOPE(-67.083,-67.083,-68.133,-68.133) |
geographic |
Alomar Norway |
geographic_facet |
Alomar Norway |
genre |
Northern Norway |
genre_facet |
Northern Norway |
op_relation |
Annales Geophysicae -- http://www.bibliothek.uni-regensburg.de/ezeit/?1458425 -- https://www.ann-geophys.net/ -- https://www.ann-geophys.net/volumes.html -- http://link.springer.com/journal/585 -- 1432-0576 https://doi.org/10.5194/angeo-20-1863-2002 https://noa.gwlb.de/receive/cop_mods_00035775 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00035729/angeo-20-1863-2002.pdf https://angeo.copernicus.org/articles/20/1863/2002/angeo-20-1863-2002.pdf |
op_rights |
uneingeschränkt info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.5194/angeo-20-1863-2002 |
container_title |
Annales Geophysicae |
container_volume |
20 |
container_issue |
11 |
container_start_page |
1863 |
op_container_end_page |
1868 |
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1766145787939520512 |