Impact of particle shape on the morphology of noctilucent clouds
Noctilucent clouds (NLCs) occur during summer in the polar region at altitudes around 83 km. They consist of ice particles with a typical size around 50 nm. The shape of NLC particles is less well known but is important both for interpreting optical measurements and modeling ice cloud characteristic...
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ftdoajarticles:oai:doaj.org/article:a7ba69a04227453d9201d745b9c945a7 2023-05-15T15:06:45+02:00 Impact of particle shape on the morphology of noctilucent clouds J. Kiliani G. Baumgarten F.-J. Lübken U. Berger 2015-11-01T00:00:00Z https://doi.org/10.5194/acp-15-12897-2015 https://doaj.org/article/a7ba69a04227453d9201d745b9c945a7 EN eng Copernicus Publications http://www.atmos-chem-phys.net/15/12897/2015/acp-15-12897-2015.pdf https://doaj.org/toc/1680-7316 https://doaj.org/toc/1680-7324 1680-7316 1680-7324 doi:10.5194/acp-15-12897-2015 https://doaj.org/article/a7ba69a04227453d9201d745b9c945a7 Atmospheric Chemistry and Physics, Vol 15, Iss 22, Pp 12897-12907 (2015) Physics QC1-999 Chemistry QD1-999 article 2015 ftdoajarticles https://doi.org/10.5194/acp-15-12897-2015 2022-12-31T14:43:39Z Noctilucent clouds (NLCs) occur during summer in the polar region at altitudes around 83 km. They consist of ice particles with a typical size around 50 nm. The shape of NLC particles is less well known but is important both for interpreting optical measurements and modeling ice cloud characteristics. In this paper, NLC modeling of microphysics and optics is adapted to use cylindrical instead of spherical particle shape. The optical properties of the resulting ice clouds are compared directly to NLC three-color measurements by the Arctic Lidar Observatory for Middle Atmosphere Research (ALOMAR) Rayleigh/Mie/Raman (RMR) lidar between 1998 and 2014. Shape distributions including both needle- and disc-shaped particles are consistent with lidar measurements. The best agreement occurs if disc shapes are 60 % more common than needles, with a mean axis ratio of 2.8. Cylindrical particles cause stronger ice clouds on average than spherical shapes with an increase of backscatter at 532 nm by ≈ 30 % and about 20 % in ice mass density. This difference is less pronounced for bright than for weak ice clouds. Cylindrical shapes also cause NLCs to have larger but a smaller number of ice particles than for spherical shapes. Article in Journal/Newspaper Arctic Directory of Open Access Journals: DOAJ Articles Alomar ENVELOPE(-67.083,-67.083,-68.133,-68.133) Arctic Atmospheric Chemistry and Physics 15 22 12897 12907 |
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Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Physics QC1-999 Chemistry QD1-999 |
spellingShingle |
Physics QC1-999 Chemistry QD1-999 J. Kiliani G. Baumgarten F.-J. Lübken U. Berger Impact of particle shape on the morphology of noctilucent clouds |
topic_facet |
Physics QC1-999 Chemistry QD1-999 |
description |
Noctilucent clouds (NLCs) occur during summer in the polar region at altitudes around 83 km. They consist of ice particles with a typical size around 50 nm. The shape of NLC particles is less well known but is important both for interpreting optical measurements and modeling ice cloud characteristics. In this paper, NLC modeling of microphysics and optics is adapted to use cylindrical instead of spherical particle shape. The optical properties of the resulting ice clouds are compared directly to NLC three-color measurements by the Arctic Lidar Observatory for Middle Atmosphere Research (ALOMAR) Rayleigh/Mie/Raman (RMR) lidar between 1998 and 2014. Shape distributions including both needle- and disc-shaped particles are consistent with lidar measurements. The best agreement occurs if disc shapes are 60 % more common than needles, with a mean axis ratio of 2.8. Cylindrical particles cause stronger ice clouds on average than spherical shapes with an increase of backscatter at 532 nm by ≈ 30 % and about 20 % in ice mass density. This difference is less pronounced for bright than for weak ice clouds. Cylindrical shapes also cause NLCs to have larger but a smaller number of ice particles than for spherical shapes. |
format |
Article in Journal/Newspaper |
author |
J. Kiliani G. Baumgarten F.-J. Lübken U. Berger |
author_facet |
J. Kiliani G. Baumgarten F.-J. Lübken U. Berger |
author_sort |
J. Kiliani |
title |
Impact of particle shape on the morphology of noctilucent clouds |
title_short |
Impact of particle shape on the morphology of noctilucent clouds |
title_full |
Impact of particle shape on the morphology of noctilucent clouds |
title_fullStr |
Impact of particle shape on the morphology of noctilucent clouds |
title_full_unstemmed |
Impact of particle shape on the morphology of noctilucent clouds |
title_sort |
impact of particle shape on the morphology of noctilucent clouds |
publisher |
Copernicus Publications |
publishDate |
2015 |
url |
https://doi.org/10.5194/acp-15-12897-2015 https://doaj.org/article/a7ba69a04227453d9201d745b9c945a7 |
long_lat |
ENVELOPE(-67.083,-67.083,-68.133,-68.133) |
geographic |
Alomar Arctic |
geographic_facet |
Alomar Arctic |
genre |
Arctic |
genre_facet |
Arctic |
op_source |
Atmospheric Chemistry and Physics, Vol 15, Iss 22, Pp 12897-12907 (2015) |
op_relation |
http://www.atmos-chem-phys.net/15/12897/2015/acp-15-12897-2015.pdf https://doaj.org/toc/1680-7316 https://doaj.org/toc/1680-7324 1680-7316 1680-7324 doi:10.5194/acp-15-12897-2015 https://doaj.org/article/a7ba69a04227453d9201d745b9c945a7 |
op_doi |
https://doi.org/10.5194/acp-15-12897-2015 |
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Atmospheric Chemistry and Physics |
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15 |
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22 |
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12897 |
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12907 |
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