First observations of noctilucent clouds by lidar at Svalbard, 78°N
In summer 2001 a potassium lidar was installed near Longyearbyen (78° N) on the north polar island of Spitsbergen which is part of the archipelago Svalbard. At the same place a series of meteorological rockets ("falling spheres", FS) were launched which gave temperatures from the lower the...
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ftcopernicus:oai:publications.copernicus.org:acp3379 2023-05-15T17:08:32+02:00 First observations of noctilucent clouds by lidar at Svalbard, 78°N Höffner, J. Fricke-Begemann, C. Lübken, F.-J. 2018-06-28 application/pdf https://doi.org/10.5194/acp-3-1101-2003 https://www.atmos-chem-phys.net/3/1101/2003/ eng eng doi:10.5194/acp-3-1101-2003 https://www.atmos-chem-phys.net/3/1101/2003/ eISSN: 1680-7324 Text 2018 ftcopernicus https://doi.org/10.5194/acp-3-1101-2003 2019-12-24T09:59:30Z In summer 2001 a potassium lidar was installed near Longyearbyen (78° N) on the north polar island of Spitsbergen which is part of the archipelago Svalbard. At the same place a series of meteorological rockets ("falling spheres", FS) were launched which gave temperatures from the lower thermosphere to the stratosphere. The potassium lidar is capable of detecting noctilucent clouds (NLCs) and of measuring temperatures in the lower thermosphere, both under daylight conditions. In this paper we give an overview on the NLC measurements (the first at this latitude) and compare the results with temperatures from meteorological rockets which have been published recently (Lübken and Mülleman, 2003) NLCs were observed from 12 June (the first day of operation) until 12 August when a period of bad weather started. When the lidar was switched on again on 26 August, no NLC was observed. The mean occurrence frequency in the period 12 June -- 12 August ("lidar NLC period") is 77%. The mean of all individual NLC peak altitudes is 83.6 km (variability: 1.1 km). The mean peak NLC altitude does not show a significant variation with season. The average top and bottom altitude of the NLC layer is 85.1 and 82.5 km, respectively, with a variability of ~1.2 km. The mean of the maximum volume backscatter coefficient b max at our wavelength of 770 nm is 3.9 x 10 -10 /m/sr with a large variability of ±3.8 x 10 -10 /m/sr. Comparison of NLC characteristics with measurements at ALOMAR (69° N) shows that the peak altitude and the maximum volume backscatter coefficient are similar at both locations but NLCs occur more frequently at higher latitudes. Simultaneous temperature and NLC measurements are available for 3 flights and show that the NLC layer occurs in the lower part of the height range with super-saturation. The NLC peak occurs over a large range of degree of saturation ( S ) whereas most models predict the peak at S = 1. This demonstrates that steady-state considerations may not be applicable when relating individual NLC properties to background conditions. On the other hand, the mean variation of the NLC appearance with height and season is in agreement with the climatological variation of super-saturation derived from the FS temperature measurements. Text Longyearbyen Svalbard Spitsbergen Copernicus Publications: E-Journals Alomar ENVELOPE(-67.083,-67.083,-68.133,-68.133) Longyearbyen Svalbard Atmospheric Chemistry and Physics 3 4 1101 1111 |
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Open Polar |
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Copernicus Publications: E-Journals |
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ftcopernicus |
language |
English |
description |
In summer 2001 a potassium lidar was installed near Longyearbyen (78° N) on the north polar island of Spitsbergen which is part of the archipelago Svalbard. At the same place a series of meteorological rockets ("falling spheres", FS) were launched which gave temperatures from the lower thermosphere to the stratosphere. The potassium lidar is capable of detecting noctilucent clouds (NLCs) and of measuring temperatures in the lower thermosphere, both under daylight conditions. In this paper we give an overview on the NLC measurements (the first at this latitude) and compare the results with temperatures from meteorological rockets which have been published recently (Lübken and Mülleman, 2003) NLCs were observed from 12 June (the first day of operation) until 12 August when a period of bad weather started. When the lidar was switched on again on 26 August, no NLC was observed. The mean occurrence frequency in the period 12 June -- 12 August ("lidar NLC period") is 77%. The mean of all individual NLC peak altitudes is 83.6 km (variability: 1.1 km). The mean peak NLC altitude does not show a significant variation with season. The average top and bottom altitude of the NLC layer is 85.1 and 82.5 km, respectively, with a variability of ~1.2 km. The mean of the maximum volume backscatter coefficient b max at our wavelength of 770 nm is 3.9 x 10 -10 /m/sr with a large variability of ±3.8 x 10 -10 /m/sr. Comparison of NLC characteristics with measurements at ALOMAR (69° N) shows that the peak altitude and the maximum volume backscatter coefficient are similar at both locations but NLCs occur more frequently at higher latitudes. Simultaneous temperature and NLC measurements are available for 3 flights and show that the NLC layer occurs in the lower part of the height range with super-saturation. The NLC peak occurs over a large range of degree of saturation ( S ) whereas most models predict the peak at S = 1. This demonstrates that steady-state considerations may not be applicable when relating individual NLC properties to background conditions. On the other hand, the mean variation of the NLC appearance with height and season is in agreement with the climatological variation of super-saturation derived from the FS temperature measurements. |
format |
Text |
author |
Höffner, J. Fricke-Begemann, C. Lübken, F.-J. |
spellingShingle |
Höffner, J. Fricke-Begemann, C. Lübken, F.-J. First observations of noctilucent clouds by lidar at Svalbard, 78°N |
author_facet |
Höffner, J. Fricke-Begemann, C. Lübken, F.-J. |
author_sort |
Höffner, J. |
title |
First observations of noctilucent clouds by lidar at Svalbard, 78°N |
title_short |
First observations of noctilucent clouds by lidar at Svalbard, 78°N |
title_full |
First observations of noctilucent clouds by lidar at Svalbard, 78°N |
title_fullStr |
First observations of noctilucent clouds by lidar at Svalbard, 78°N |
title_full_unstemmed |
First observations of noctilucent clouds by lidar at Svalbard, 78°N |
title_sort |
first observations of noctilucent clouds by lidar at svalbard, 78°n |
publishDate |
2018 |
url |
https://doi.org/10.5194/acp-3-1101-2003 https://www.atmos-chem-phys.net/3/1101/2003/ |
long_lat |
ENVELOPE(-67.083,-67.083,-68.133,-68.133) |
geographic |
Alomar Longyearbyen Svalbard |
geographic_facet |
Alomar Longyearbyen Svalbard |
genre |
Longyearbyen Svalbard Spitsbergen |
genre_facet |
Longyearbyen Svalbard Spitsbergen |
op_source |
eISSN: 1680-7324 |
op_relation |
doi:10.5194/acp-3-1101-2003 https://www.atmos-chem-phys.net/3/1101/2003/ |
op_doi |
https://doi.org/10.5194/acp-3-1101-2003 |
container_title |
Atmospheric Chemistry and Physics |
container_volume |
3 |
container_issue |
4 |
container_start_page |
1101 |
op_container_end_page |
1111 |
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1766064306980388864 |