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...
Main Authors: | , , |
---|---|
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
München : European Geopyhsical Union
2002
|
Subjects: | |
Online Access: | https://doi.org/10.34657/1528 https://oa.tib.eu/renate/handle/123456789/4073 |
id |
ftleibnizopen:oai:oai.leibnizopen.de:hhN2DYsBBwLIz6xGxOtN |
---|---|
record_format |
openpolar |
spelling |
ftleibnizopen:oai:oai.leibnizopen.de:hhN2DYsBBwLIz6xGxOtN 2023-11-05T03:44:19+01:00 First observation of one noctilucent cloud by a twin lidar in two different directions Baumgarten, G. Lübken, F.-J. Fricke, K.-H. 2002 application/pdf https://doi.org/10.34657/1528 https://oa.tib.eu/renate/handle/123456789/4073 eng eng München : European Geopyhsical Union CC BY 3.0 Unported https://creativecommons.org/licenses/by/3.0/ Annales Geophysicae, Volume 20, Issue 11, Page 1863-1868 Atmospheric composition and structure (cloud physics and chemistry aerosols and particles) Meteorology and atmospheric dynamics (middle atmosphere dynamics) 530 article Text 2002 ftleibnizopen https://doi.org/10.34657/1528 2023-10-08T23:10:43Z 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. publishedVersion Article in Journal/Newspaper Northern Norway LeibnizOpen (The Leibniz Association) |
institution |
Open Polar |
collection |
LeibnizOpen (The Leibniz Association) |
op_collection_id |
ftleibnizopen |
language |
English |
topic |
Atmospheric composition and structure (cloud physics and chemistry aerosols and particles) Meteorology and atmospheric dynamics (middle atmosphere dynamics) 530 |
spellingShingle |
Atmospheric composition and structure (cloud physics and chemistry aerosols and particles) Meteorology and atmospheric dynamics (middle atmosphere dynamics) 530 Baumgarten, G. Lübken, F.-J. Fricke, K.-H. First observation of one noctilucent cloud by a twin lidar in two different directions |
topic_facet |
Atmospheric composition and structure (cloud physics and chemistry aerosols and particles) Meteorology and atmospheric dynamics (middle atmosphere dynamics) 530 |
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. publishedVersion |
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 |
München : European Geopyhsical Union |
publishDate |
2002 |
url |
https://doi.org/10.34657/1528 https://oa.tib.eu/renate/handle/123456789/4073 |
genre |
Northern Norway |
genre_facet |
Northern Norway |
op_source |
Annales Geophysicae, Volume 20, Issue 11, Page 1863-1868 |
op_rights |
CC BY 3.0 Unported https://creativecommons.org/licenses/by/3.0/ |
op_doi |
https://doi.org/10.34657/1528 |
_version_ |
1781703896764252160 |