Quantification of waves in lidar observations of noctilucent clouds at scales from seconds to minutes
We present small-scale structures and waves observed in noctilucent clouds (NLC) by lidar at an unprecedented temporal resolution of 30 s or less. The measurements were taken with the Rayleigh/Mie/Raman lidar at the ALOMAR observatory in northern Norway (69° N) in the years 2008–2011. We find multip...
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Online Access: | https://doi.org/10.5194/acp-13-11757-2013 https://www.atmos-chem-phys.net/13/11757/2013/ |
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ftcopernicus:oai:publications.copernicus.org:acp18358 2023-05-15T17:43:30+02:00 Quantification of waves in lidar observations of noctilucent clouds at scales from seconds to minutes Kaifler, N. Baumgarten, G. Fiedler, J. Lübken, F.-J. 2018-01-15 application/pdf https://doi.org/10.5194/acp-13-11757-2013 https://www.atmos-chem-phys.net/13/11757/2013/ eng eng doi:10.5194/acp-13-11757-2013 https://www.atmos-chem-phys.net/13/11757/2013/ eISSN: 1680-7324 Text 2018 ftcopernicus https://doi.org/10.5194/acp-13-11757-2013 2019-12-24T09:54:49Z We present small-scale structures and waves observed in noctilucent clouds (NLC) by lidar at an unprecedented temporal resolution of 30 s or less. The measurements were taken with the Rayleigh/Mie/Raman lidar at the ALOMAR observatory in northern Norway (69° N) in the years 2008–2011. We find multiple layer NLC in 7.9% of the time for a brightness threshold of δ β = 12 × 10 −10 m −1 sr −1 . In comparison to 10 min averaged data, the 30 s dataset shows considerably more structure. For limited periods, quasi-monochromatic waves in NLC altitude variations are common, in accord with ground-based NLC imagery. For the combined dataset, on the other hand, we do not find preferred periods but rather significant periods at all timescales observed (1 min to 1 h). Typical wave amplitudes in the layer vertical displacements are 0.2 km with maximum amplitudes up to 2.3 km. Average spectral slopes of temporal altitude and brightness variations are −2.01 ± 0.25 for centroid altitude, −1.41 ± 0.24 for peak brightness and −1.73 ± 0.25 for integrated brightness. Evaluating a new single-pulse detection system, we observe altitude variations of 70 s period and spectral slopes down to a scale of 10 s. We evaluate the suitability of NLC parameters as tracers for gravity waves. Text Northern Norway Copernicus Publications: E-Journals Alomar ENVELOPE(-67.083,-67.083,-68.133,-68.133) Norway Atmospheric Chemistry and Physics 13 23 11757 11768 |
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Copernicus Publications: E-Journals |
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ftcopernicus |
language |
English |
description |
We present small-scale structures and waves observed in noctilucent clouds (NLC) by lidar at an unprecedented temporal resolution of 30 s or less. The measurements were taken with the Rayleigh/Mie/Raman lidar at the ALOMAR observatory in northern Norway (69° N) in the years 2008–2011. We find multiple layer NLC in 7.9% of the time for a brightness threshold of δ β = 12 × 10 −10 m −1 sr −1 . In comparison to 10 min averaged data, the 30 s dataset shows considerably more structure. For limited periods, quasi-monochromatic waves in NLC altitude variations are common, in accord with ground-based NLC imagery. For the combined dataset, on the other hand, we do not find preferred periods but rather significant periods at all timescales observed (1 min to 1 h). Typical wave amplitudes in the layer vertical displacements are 0.2 km with maximum amplitudes up to 2.3 km. Average spectral slopes of temporal altitude and brightness variations are −2.01 ± 0.25 for centroid altitude, −1.41 ± 0.24 for peak brightness and −1.73 ± 0.25 for integrated brightness. Evaluating a new single-pulse detection system, we observe altitude variations of 70 s period and spectral slopes down to a scale of 10 s. We evaluate the suitability of NLC parameters as tracers for gravity waves. |
format |
Text |
author |
Kaifler, N. Baumgarten, G. Fiedler, J. Lübken, F.-J. |
spellingShingle |
Kaifler, N. Baumgarten, G. Fiedler, J. Lübken, F.-J. Quantification of waves in lidar observations of noctilucent clouds at scales from seconds to minutes |
author_facet |
Kaifler, N. Baumgarten, G. Fiedler, J. Lübken, F.-J. |
author_sort |
Kaifler, N. |
title |
Quantification of waves in lidar observations of noctilucent clouds at scales from seconds to minutes |
title_short |
Quantification of waves in lidar observations of noctilucent clouds at scales from seconds to minutes |
title_full |
Quantification of waves in lidar observations of noctilucent clouds at scales from seconds to minutes |
title_fullStr |
Quantification of waves in lidar observations of noctilucent clouds at scales from seconds to minutes |
title_full_unstemmed |
Quantification of waves in lidar observations of noctilucent clouds at scales from seconds to minutes |
title_sort |
quantification of waves in lidar observations of noctilucent clouds at scales from seconds to minutes |
publishDate |
2018 |
url |
https://doi.org/10.5194/acp-13-11757-2013 https://www.atmos-chem-phys.net/13/11757/2013/ |
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_source |
eISSN: 1680-7324 |
op_relation |
doi:10.5194/acp-13-11757-2013 https://www.atmos-chem-phys.net/13/11757/2013/ |
op_doi |
https://doi.org/10.5194/acp-13-11757-2013 |
container_title |
Atmospheric Chemistry and Physics |
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13 |
container_issue |
23 |
container_start_page |
11757 |
op_container_end_page |
11768 |
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1766145595051868160 |