Characteristic nature of vertical motions observed in Arctic mixed-phase stratocumulus
Over the Arctic Ocean, little is known on cloud-generated buoyant overturning vertical motions within mixed-phase stratocumulus clouds. Characteristics of such motions are important for understanding the diabatic processes associated with the vertical motions, the lifetime of the cloud layer and its...
Published in: | Atmospheric Chemistry and Physics |
---|---|
Main Authors: | , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Copernicus Publications
2014
|
Subjects: | |
Online Access: | https://doi.org/10.5194/acp-14-3461-2014 https://noa.gwlb.de/receive/cop_mods_00045079 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00044699/acp-14-3461-2014.pdf https://acp.copernicus.org/articles/14/3461/2014/acp-14-3461-2014.pdf |
id |
ftnonlinearchiv:oai:noa.gwlb.de:cop_mods_00045079 |
---|---|
record_format |
openpolar |
spelling |
ftnonlinearchiv:oai:noa.gwlb.de:cop_mods_00045079 2023-05-15T14:49:55+02:00 Characteristic nature of vertical motions observed in Arctic mixed-phase stratocumulus Sedlar, J. Shupe, M. D. 2014-04 electronic https://doi.org/10.5194/acp-14-3461-2014 https://noa.gwlb.de/receive/cop_mods_00045079 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00044699/acp-14-3461-2014.pdf https://acp.copernicus.org/articles/14/3461/2014/acp-14-3461-2014.pdf eng eng Copernicus Publications Atmospheric Chemistry and Physics -- http://www.atmos-chem-phys.net/volumes_and_issues.html -- http://www.bibliothek.uni-regensburg.de/ezeit/?2069847 -- 1680-7324 https://doi.org/10.5194/acp-14-3461-2014 https://noa.gwlb.de/receive/cop_mods_00045079 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00044699/acp-14-3461-2014.pdf https://acp.copernicus.org/articles/14/3461/2014/acp-14-3461-2014.pdf uneingeschränkt info:eu-repo/semantics/openAccess article Verlagsveröffentlichung article Text doc-type:article 2014 ftnonlinearchiv https://doi.org/10.5194/acp-14-3461-2014 2022-02-08T22:39:45Z Over the Arctic Ocean, little is known on cloud-generated buoyant overturning vertical motions within mixed-phase stratocumulus clouds. Characteristics of such motions are important for understanding the diabatic processes associated with the vertical motions, the lifetime of the cloud layer and its micro- and macrophysical characteristics. In this study, we exploit a suite of surface-based remote sensors over the high-Arctic sea ice during a weeklong period of persistent stratocumulus in August 2008 to derive the in-cloud vertical motion characteristics. In-cloud vertical velocity skewness and variance profiles are found to be strikingly different from observations within lower-latitude stratocumulus, suggesting these Arctic mixed-phase clouds interact differently with the atmospheric thermodynamics (cloud tops extending above a stable temperature inversion base) and with a different coupling state between surface and cloud. We find evidence of cloud-generated vertical mixing below cloud base, regardless of surface–cloud coupling state, although a decoupled surface–cloud state occurred most frequently. Detailed case studies are examined, focusing on three levels within the cloud layer, where wavelet and power spectral analyses are applied to characterize the dominant temporal and horizontal scales associated with cloud-generated vertical motions. In general, we find a positively correlated vertical motion signal amongst vertical levels within the cloud and across the full cloud layer depth. The coherency is dependent upon other non-cloud controlled factors, such as larger, mesoscale weather passages and radiative shielding of low-level stratocumulus by one or more cloud layers above. Despite the coherency in vertical velocity across the cloud, the velocity variances were always weaker near cloud top, relative to cloud middle and base. Taken in combination with the skewness, variance and thermodynamic profile characteristics, we observe vertical motions near cloud top that behave differently than those from lower within the cloud layer. Spectral analysis indicates peak cloud-generated w variance timescales slowed only modestly during decoupled cases relative to coupled; horizontal wavelengths only slightly increased when transitioning from coupling to decoupling. The similarities in scales suggests that perhaps the dominant forcing for all cases is generated from the cloud layer, and it is not the surface forcing that characterizes the time- and space scales of in-cloud vertical velocity variance. This points toward the resilient nature of Arctic mixed-phase clouds to persist when characterized by thermodynamic regimes unique to the Arctic. Article in Journal/Newspaper Arctic Arctic Ocean Sea ice Niedersächsisches Online-Archiv NOA Arctic Arctic Ocean Atmospheric Chemistry and Physics 14 7 3461 3478 |
institution |
Open Polar |
collection |
Niedersächsisches Online-Archiv NOA |
op_collection_id |
ftnonlinearchiv |
language |
English |
topic |
article Verlagsveröffentlichung |
spellingShingle |
article Verlagsveröffentlichung Sedlar, J. Shupe, M. D. Characteristic nature of vertical motions observed in Arctic mixed-phase stratocumulus |
topic_facet |
article Verlagsveröffentlichung |
description |
Over the Arctic Ocean, little is known on cloud-generated buoyant overturning vertical motions within mixed-phase stratocumulus clouds. Characteristics of such motions are important for understanding the diabatic processes associated with the vertical motions, the lifetime of the cloud layer and its micro- and macrophysical characteristics. In this study, we exploit a suite of surface-based remote sensors over the high-Arctic sea ice during a weeklong period of persistent stratocumulus in August 2008 to derive the in-cloud vertical motion characteristics. In-cloud vertical velocity skewness and variance profiles are found to be strikingly different from observations within lower-latitude stratocumulus, suggesting these Arctic mixed-phase clouds interact differently with the atmospheric thermodynamics (cloud tops extending above a stable temperature inversion base) and with a different coupling state between surface and cloud. We find evidence of cloud-generated vertical mixing below cloud base, regardless of surface–cloud coupling state, although a decoupled surface–cloud state occurred most frequently. Detailed case studies are examined, focusing on three levels within the cloud layer, where wavelet and power spectral analyses are applied to characterize the dominant temporal and horizontal scales associated with cloud-generated vertical motions. In general, we find a positively correlated vertical motion signal amongst vertical levels within the cloud and across the full cloud layer depth. The coherency is dependent upon other non-cloud controlled factors, such as larger, mesoscale weather passages and radiative shielding of low-level stratocumulus by one or more cloud layers above. Despite the coherency in vertical velocity across the cloud, the velocity variances were always weaker near cloud top, relative to cloud middle and base. Taken in combination with the skewness, variance and thermodynamic profile characteristics, we observe vertical motions near cloud top that behave differently than those from lower within the cloud layer. Spectral analysis indicates peak cloud-generated w variance timescales slowed only modestly during decoupled cases relative to coupled; horizontal wavelengths only slightly increased when transitioning from coupling to decoupling. The similarities in scales suggests that perhaps the dominant forcing for all cases is generated from the cloud layer, and it is not the surface forcing that characterizes the time- and space scales of in-cloud vertical velocity variance. This points toward the resilient nature of Arctic mixed-phase clouds to persist when characterized by thermodynamic regimes unique to the Arctic. |
format |
Article in Journal/Newspaper |
author |
Sedlar, J. Shupe, M. D. |
author_facet |
Sedlar, J. Shupe, M. D. |
author_sort |
Sedlar, J. |
title |
Characteristic nature of vertical motions observed in Arctic mixed-phase stratocumulus |
title_short |
Characteristic nature of vertical motions observed in Arctic mixed-phase stratocumulus |
title_full |
Characteristic nature of vertical motions observed in Arctic mixed-phase stratocumulus |
title_fullStr |
Characteristic nature of vertical motions observed in Arctic mixed-phase stratocumulus |
title_full_unstemmed |
Characteristic nature of vertical motions observed in Arctic mixed-phase stratocumulus |
title_sort |
characteristic nature of vertical motions observed in arctic mixed-phase stratocumulus |
publisher |
Copernicus Publications |
publishDate |
2014 |
url |
https://doi.org/10.5194/acp-14-3461-2014 https://noa.gwlb.de/receive/cop_mods_00045079 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00044699/acp-14-3461-2014.pdf https://acp.copernicus.org/articles/14/3461/2014/acp-14-3461-2014.pdf |
geographic |
Arctic Arctic Ocean |
geographic_facet |
Arctic Arctic Ocean |
genre |
Arctic Arctic Ocean Sea ice |
genre_facet |
Arctic Arctic Ocean Sea ice |
op_relation |
Atmospheric Chemistry and Physics -- http://www.atmos-chem-phys.net/volumes_and_issues.html -- http://www.bibliothek.uni-regensburg.de/ezeit/?2069847 -- 1680-7324 https://doi.org/10.5194/acp-14-3461-2014 https://noa.gwlb.de/receive/cop_mods_00045079 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00044699/acp-14-3461-2014.pdf https://acp.copernicus.org/articles/14/3461/2014/acp-14-3461-2014.pdf |
op_rights |
uneingeschränkt info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.5194/acp-14-3461-2014 |
container_title |
Atmospheric Chemistry and Physics |
container_volume |
14 |
container_issue |
7 |
container_start_page |
3461 |
op_container_end_page |
3478 |
_version_ |
1766320994906013696 |