Simulated and observed horizontal inhomogeneities of optical thickness of Arctic stratus
Two-dimensional horizontal fields of cloud optical thickness τ derived from airborne measurements of solar spectral, cloud-reflected radiance are compared with semi-idealized large eddy simulations (LESs) of Arctic stratus performed with the Consortium for Small-scale Modeling (COSMO) atmospheric mo...
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ftdatacite:10.5445/ir/1000085946 2023-05-15T14:51:07+02:00 Simulated and observed horizontal inhomogeneities of optical thickness of Arctic stratus Schäfer, Michael Loewe, Katharina Ehrlich, André Hoose, Corinna Wendisch, Manfred 2018 https://dx.doi.org/10.5445/ir/1000085946 https://publikationen.bibliothek.kit.edu/1000085946 en eng Karlsruhe Creative Commons Namensnennung 4.0 International Open Access info:eu-repo/semantics/openAccess https://creativecommons.org/licenses/by/4.0/deed.de CC-BY Text article-journal Journal Article ScholarlyArticle 2018 ftdatacite https://doi.org/10.5445/ir/1000085946 2021-11-05T12:55:41Z Two-dimensional horizontal fields of cloud optical thickness τ derived from airborne measurements of solar spectral, cloud-reflected radiance are compared with semi-idealized large eddy simulations (LESs) of Arctic stratus performed with the Consortium for Small-scale Modeling (COSMO) atmospheric model. The measurements were collected during the Vertical Distribution of Ice in Arctic Clouds (VERDI) campaign carried out in Inuvik, Canada, in April/May 2012. The input for the LESs is obtained from collocated airborne dropsonde observations of a persistent Arctic stratus above the sea-ice-free Beaufort Sea. Simulations are performed for spatial resolutions of 50m (1.6km × 1.6km domain) and 100m (6.4km × 6.4km domain). Macrophysical cloud properties, such as cloud top altitude and vertical extent, are well captured by the COSMO simulations. However, COSMO produces rather homogeneous clouds compared to the measurements, in particular for the simulations with coarser spatial resolution. For both spatial resolutions, the directional structure of the cloud inhomogeneity is well represented by the model. Differences between the individual cases are mainly associated with the wind shear near cloud top and the vertical structure of the atmospheric boundary layer. A sensitivity study changing the wind velocity in COSMO by a vertically constant scaling factor shows that the directional, small-scale cloud inhomogeneity structures can range from 250 to 800m, depending on the mean wind speed, if the simulated domain is large enough to capture also large-scale structures, which then influence the small-scale structures. For those cases, a threshold wind velocity is identified, which determines when the cloud inhomogeneity stops increasing with increasing wind velocity. Text Arctic Beaufort Sea Inuvik Sea ice DataCite Metadata Store (German National Library of Science and Technology) Arctic Canada Inuvik ENVELOPE(-133.610,-133.610,68.341,68.341) |
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Open Polar |
collection |
DataCite Metadata Store (German National Library of Science and Technology) |
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ftdatacite |
language |
English |
description |
Two-dimensional horizontal fields of cloud optical thickness τ derived from airborne measurements of solar spectral, cloud-reflected radiance are compared with semi-idealized large eddy simulations (LESs) of Arctic stratus performed with the Consortium for Small-scale Modeling (COSMO) atmospheric model. The measurements were collected during the Vertical Distribution of Ice in Arctic Clouds (VERDI) campaign carried out in Inuvik, Canada, in April/May 2012. The input for the LESs is obtained from collocated airborne dropsonde observations of a persistent Arctic stratus above the sea-ice-free Beaufort Sea. Simulations are performed for spatial resolutions of 50m (1.6km × 1.6km domain) and 100m (6.4km × 6.4km domain). Macrophysical cloud properties, such as cloud top altitude and vertical extent, are well captured by the COSMO simulations. However, COSMO produces rather homogeneous clouds compared to the measurements, in particular for the simulations with coarser spatial resolution. For both spatial resolutions, the directional structure of the cloud inhomogeneity is well represented by the model. Differences between the individual cases are mainly associated with the wind shear near cloud top and the vertical structure of the atmospheric boundary layer. A sensitivity study changing the wind velocity in COSMO by a vertically constant scaling factor shows that the directional, small-scale cloud inhomogeneity structures can range from 250 to 800m, depending on the mean wind speed, if the simulated domain is large enough to capture also large-scale structures, which then influence the small-scale structures. For those cases, a threshold wind velocity is identified, which determines when the cloud inhomogeneity stops increasing with increasing wind velocity. |
format |
Text |
author |
Schäfer, Michael Loewe, Katharina Ehrlich, André Hoose, Corinna Wendisch, Manfred |
spellingShingle |
Schäfer, Michael Loewe, Katharina Ehrlich, André Hoose, Corinna Wendisch, Manfred Simulated and observed horizontal inhomogeneities of optical thickness of Arctic stratus |
author_facet |
Schäfer, Michael Loewe, Katharina Ehrlich, André Hoose, Corinna Wendisch, Manfred |
author_sort |
Schäfer, Michael |
title |
Simulated and observed horizontal inhomogeneities of optical thickness of Arctic stratus |
title_short |
Simulated and observed horizontal inhomogeneities of optical thickness of Arctic stratus |
title_full |
Simulated and observed horizontal inhomogeneities of optical thickness of Arctic stratus |
title_fullStr |
Simulated and observed horizontal inhomogeneities of optical thickness of Arctic stratus |
title_full_unstemmed |
Simulated and observed horizontal inhomogeneities of optical thickness of Arctic stratus |
title_sort |
simulated and observed horizontal inhomogeneities of optical thickness of arctic stratus |
publisher |
Karlsruhe |
publishDate |
2018 |
url |
https://dx.doi.org/10.5445/ir/1000085946 https://publikationen.bibliothek.kit.edu/1000085946 |
long_lat |
ENVELOPE(-133.610,-133.610,68.341,68.341) |
geographic |
Arctic Canada Inuvik |
geographic_facet |
Arctic Canada Inuvik |
genre |
Arctic Beaufort Sea Inuvik Sea ice |
genre_facet |
Arctic Beaufort Sea Inuvik Sea ice |
op_rights |
Creative Commons Namensnennung 4.0 International Open Access info:eu-repo/semantics/openAccess https://creativecommons.org/licenses/by/4.0/deed.de |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.5445/ir/1000085946 |
_version_ |
1766322190204010496 |