Mean diurnal variations of noctilucent clouds during 7 years of lidar observations at ALOMAR
International audience From 1997 to 2003, noctilucent clouds (NLC) were observed by lidar above the ALOMAR observatory in Northern Norway (69° N) during a total of 1880 measurement hours. This data set contains NLC signatures for 640h, covering all local times, even during the highest solar backgrou...
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ftccsdartic:oai:HAL:hal-00317695v1 2023-05-15T17:43:34+02:00 Mean diurnal variations of noctilucent clouds during 7 years of lidar observations at ALOMAR Fiedler, J. Baumgarten, G. Von Cossart, G. Leibniz-Institut für Atmosphärenphysik (IAP) Universität Rostock-Leibniz Association 2005-06-03 https://hal.archives-ouvertes.fr/hal-00317695 https://hal.archives-ouvertes.fr/hal-00317695/document https://hal.archives-ouvertes.fr/hal-00317695/file/angeo-23-1175-2005.pdf en eng HAL CCSD European Geosciences Union hal-00317695 https://hal.archives-ouvertes.fr/hal-00317695 https://hal.archives-ouvertes.fr/hal-00317695/document https://hal.archives-ouvertes.fr/hal-00317695/file/angeo-23-1175-2005.pdf info:eu-repo/semantics/OpenAccess ISSN: 0992-7689 EISSN: 1432-0576 Annales Geophysicae https://hal.archives-ouvertes.fr/hal-00317695 Annales Geophysicae, European Geosciences Union, 2005, 23 (4), pp.1175-1181 [SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere [SDU.STU]Sciences of the Universe [physics]/Earth Sciences info:eu-repo/semantics/article Journal articles 2005 ftccsdartic 2021-10-31T12:36:12Z International audience From 1997 to 2003, noctilucent clouds (NLC) were observed by lidar above the ALOMAR observatory in Northern Norway (69° N) during a total of 1880 measurement hours. This data set contains NLC signatures for 640h, covering all local times, even during the highest solar background conditions. After data limitation imposing a threshold value of 4x10 -10 m -1 sr -1 for the volume backscatter coefficient of the NLC particles, a measure for the cloud brightness, local time dependencies of the NLC occurrence frequency, altitude, and brightness were determined. On average, over the 7 years NLC occurred during the whole day and preferably in the early morning hours, with a maximum occurrence frequency of ~40% between 4 and 7 LT. Splitting the data into weak and strong clouds yields almost identical amplitudes of diurnal and semidiurnal variations for the occurrence of weak clouds, whereas the strong clouds are dominated by the diurnal variation. NLC occurrence, altitude, as well as brightness, show a remarkable persistence concerning diurnal and semidiurnal variations from 1997 to 2003, suggesting that NLC above ALOMAR are significantly controlled by atmospheric tides. The observed mean anti-phase behavior between cloud altitude and brightness is attributed to a phase shift between the semidiurnal components by ~6h. Investigation of data for each individual year regarding the prevailing oscillation periods of the NLC parameters showed different phase relationships, leading to a complex variability in the cloud parameters. Article in Journal/Newspaper Northern Norway Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) Norway Alomar ENVELOPE(-67.083,-67.083,-68.133,-68.133) |
institution |
Open Polar |
collection |
Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) |
op_collection_id |
ftccsdartic |
language |
English |
topic |
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere [SDU.STU]Sciences of the Universe [physics]/Earth Sciences |
spellingShingle |
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere [SDU.STU]Sciences of the Universe [physics]/Earth Sciences Fiedler, J. Baumgarten, G. Von Cossart, G. Mean diurnal variations of noctilucent clouds during 7 years of lidar observations at ALOMAR |
topic_facet |
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere [SDU.STU]Sciences of the Universe [physics]/Earth Sciences |
description |
International audience From 1997 to 2003, noctilucent clouds (NLC) were observed by lidar above the ALOMAR observatory in Northern Norway (69° N) during a total of 1880 measurement hours. This data set contains NLC signatures for 640h, covering all local times, even during the highest solar background conditions. After data limitation imposing a threshold value of 4x10 -10 m -1 sr -1 for the volume backscatter coefficient of the NLC particles, a measure for the cloud brightness, local time dependencies of the NLC occurrence frequency, altitude, and brightness were determined. On average, over the 7 years NLC occurred during the whole day and preferably in the early morning hours, with a maximum occurrence frequency of ~40% between 4 and 7 LT. Splitting the data into weak and strong clouds yields almost identical amplitudes of diurnal and semidiurnal variations for the occurrence of weak clouds, whereas the strong clouds are dominated by the diurnal variation. NLC occurrence, altitude, as well as brightness, show a remarkable persistence concerning diurnal and semidiurnal variations from 1997 to 2003, suggesting that NLC above ALOMAR are significantly controlled by atmospheric tides. The observed mean anti-phase behavior between cloud altitude and brightness is attributed to a phase shift between the semidiurnal components by ~6h. Investigation of data for each individual year regarding the prevailing oscillation periods of the NLC parameters showed different phase relationships, leading to a complex variability in the cloud parameters. |
author2 |
Leibniz-Institut für Atmosphärenphysik (IAP) Universität Rostock-Leibniz Association |
format |
Article in Journal/Newspaper |
author |
Fiedler, J. Baumgarten, G. Von Cossart, G. |
author_facet |
Fiedler, J. Baumgarten, G. Von Cossart, G. |
author_sort |
Fiedler, J. |
title |
Mean diurnal variations of noctilucent clouds during 7 years of lidar observations at ALOMAR |
title_short |
Mean diurnal variations of noctilucent clouds during 7 years of lidar observations at ALOMAR |
title_full |
Mean diurnal variations of noctilucent clouds during 7 years of lidar observations at ALOMAR |
title_fullStr |
Mean diurnal variations of noctilucent clouds during 7 years of lidar observations at ALOMAR |
title_full_unstemmed |
Mean diurnal variations of noctilucent clouds during 7 years of lidar observations at ALOMAR |
title_sort |
mean diurnal variations of noctilucent clouds during 7 years of lidar observations at alomar |
publisher |
HAL CCSD |
publishDate |
2005 |
url |
https://hal.archives-ouvertes.fr/hal-00317695 https://hal.archives-ouvertes.fr/hal-00317695/document https://hal.archives-ouvertes.fr/hal-00317695/file/angeo-23-1175-2005.pdf |
long_lat |
ENVELOPE(-67.083,-67.083,-68.133,-68.133) |
geographic |
Norway Alomar |
geographic_facet |
Norway Alomar |
genre |
Northern Norway |
genre_facet |
Northern Norway |
op_source |
ISSN: 0992-7689 EISSN: 1432-0576 Annales Geophysicae https://hal.archives-ouvertes.fr/hal-00317695 Annales Geophysicae, European Geosciences Union, 2005, 23 (4), pp.1175-1181 |
op_relation |
hal-00317695 https://hal.archives-ouvertes.fr/hal-00317695 https://hal.archives-ouvertes.fr/hal-00317695/document https://hal.archives-ouvertes.fr/hal-00317695/file/angeo-23-1175-2005.pdf |
op_rights |
info:eu-repo/semantics/OpenAccess |
_version_ |
1766145672574140416 |