Lagrangian formation pathways of moist anomalies in the trade-wind region during the dry season: two case studies from EUREC4A
Shallow clouds in the trade-wind region over the North Atlantic contribute substantially to the global radiative budget. In the vicinity of the Caribbean island of Barbados, they appear in different mesoscale organization patterns with distinct net cloud radiative effects (CREs). Cloud formation pro...
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ftdlr:oai:elib.dlr.de:148387 2024-02-11T10:06:47+01:00 Lagrangian formation pathways of moist anomalies in the trade-wind region during the dry season: two case studies from EUREC4A Villiger, Leonie Wernli, Heini Boettcher, Maxi Hagen, Martin Aemisegger, Franziska 2022-01-18 application/pdf https://elib.dlr.de/148387/ https://elib.dlr.de/148387/1/wcd-3-59-2022.pdf https://doi.org/10.5194/wcd-3-59-2022 en eng Copernicus Publications https://elib.dlr.de/148387/1/wcd-3-59-2022.pdf Villiger, Leonie und Wernli, Heini und Boettcher, Maxi und Hagen, Martin und Aemisegger, Franziska (2022) Lagrangian formation pathways of moist anomalies in the trade-wind region during the dry season: two case studies from EUREC4A. Weather and Climate Dynamics, 3 (1), Seiten 59-88. Copernicus Publications. doi:10.5194/wcd-3-59-2022 <https://doi.org/10.5194/wcd-3-59-2022>. ISSN 2698-4016. cc_by Lidar Zeitschriftenbeitrag PeerReviewed 2022 ftdlr https://doi.org/10.5194/wcd-3-59-2022 2024-01-22T00:23:49Z Shallow clouds in the trade-wind region over the North Atlantic contribute substantially to the global radiative budget. In the vicinity of the Caribbean island of Barbados, they appear in different mesoscale organization patterns with distinct net cloud radiative effects (CREs). Cloud formation processes in this region are typically controlled by the prevailing large-scale subsidence. However, occasionally weather systems from remote origin cause significant disturbances. This study investigates the complex cloud-circulation interactions during the field campaign EUREC4A (Elucidate the Couplings Between Clouds, Convection and Circulation) from 16 January to 20 February 2020, using a combination of Eulerian and Lagrangian diagnostics. Based on observations and ERA5 reanalyses, we identify the relevant processes and characterize the formation pathways of two moist anomalies above the Barbados Cloud Observatory (BCO), one in the lower troposphere (~ 1000-650 hPa) and one in the middle troposphere (~ 650-300 hPa). These moist anomalies are associated with strongly negative CRE values and with contrasting long-range transport processes from the extratropics and the tropics, respectively. The first case study about the low-level moist anomaly is characterized by an unusually thick cloud layer, high precipitation totals, and a strongly negative CRE. The formation of the low-level moist anomaly is connected to an extratropical dry intrusion (EDI) that interacts with a trailing cold front. A quasi-climatological (2010-2020) analysis reveals that EDIs lead to different conditions at the BCO depending on how they interact with the associated trailing cold front. Based on this climatology, we discuss the relevance of the strong large-scale forcing by EDIs for the low-cloud patterns near the BCO and the related CRE. The second case study about the mid-tropospheric moist anomaly is associated with an extended and persistent mixed-phase shelf cloud and the lowest daily CRE value observed during the campaign. The formation of ... Article in Journal/Newspaper North Atlantic German Aerospace Center: elib - DLR electronic library Weather and Climate Dynamics 3 1 59 88 |
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Lidar Villiger, Leonie Wernli, Heini Boettcher, Maxi Hagen, Martin Aemisegger, Franziska Lagrangian formation pathways of moist anomalies in the trade-wind region during the dry season: two case studies from EUREC4A |
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description |
Shallow clouds in the trade-wind region over the North Atlantic contribute substantially to the global radiative budget. In the vicinity of the Caribbean island of Barbados, they appear in different mesoscale organization patterns with distinct net cloud radiative effects (CREs). Cloud formation processes in this region are typically controlled by the prevailing large-scale subsidence. However, occasionally weather systems from remote origin cause significant disturbances. This study investigates the complex cloud-circulation interactions during the field campaign EUREC4A (Elucidate the Couplings Between Clouds, Convection and Circulation) from 16 January to 20 February 2020, using a combination of Eulerian and Lagrangian diagnostics. Based on observations and ERA5 reanalyses, we identify the relevant processes and characterize the formation pathways of two moist anomalies above the Barbados Cloud Observatory (BCO), one in the lower troposphere (~ 1000-650 hPa) and one in the middle troposphere (~ 650-300 hPa). These moist anomalies are associated with strongly negative CRE values and with contrasting long-range transport processes from the extratropics and the tropics, respectively. The first case study about the low-level moist anomaly is characterized by an unusually thick cloud layer, high precipitation totals, and a strongly negative CRE. The formation of the low-level moist anomaly is connected to an extratropical dry intrusion (EDI) that interacts with a trailing cold front. A quasi-climatological (2010-2020) analysis reveals that EDIs lead to different conditions at the BCO depending on how they interact with the associated trailing cold front. Based on this climatology, we discuss the relevance of the strong large-scale forcing by EDIs for the low-cloud patterns near the BCO and the related CRE. The second case study about the mid-tropospheric moist anomaly is associated with an extended and persistent mixed-phase shelf cloud and the lowest daily CRE value observed during the campaign. The formation of ... |
format |
Article in Journal/Newspaper |
author |
Villiger, Leonie Wernli, Heini Boettcher, Maxi Hagen, Martin Aemisegger, Franziska |
author_facet |
Villiger, Leonie Wernli, Heini Boettcher, Maxi Hagen, Martin Aemisegger, Franziska |
author_sort |
Villiger, Leonie |
title |
Lagrangian formation pathways of moist anomalies in the trade-wind region during the dry season: two case studies from EUREC4A |
title_short |
Lagrangian formation pathways of moist anomalies in the trade-wind region during the dry season: two case studies from EUREC4A |
title_full |
Lagrangian formation pathways of moist anomalies in the trade-wind region during the dry season: two case studies from EUREC4A |
title_fullStr |
Lagrangian formation pathways of moist anomalies in the trade-wind region during the dry season: two case studies from EUREC4A |
title_full_unstemmed |
Lagrangian formation pathways of moist anomalies in the trade-wind region during the dry season: two case studies from EUREC4A |
title_sort |
lagrangian formation pathways of moist anomalies in the trade-wind region during the dry season: two case studies from eurec4a |
publisher |
Copernicus Publications |
publishDate |
2022 |
url |
https://elib.dlr.de/148387/ https://elib.dlr.de/148387/1/wcd-3-59-2022.pdf https://doi.org/10.5194/wcd-3-59-2022 |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_relation |
https://elib.dlr.de/148387/1/wcd-3-59-2022.pdf Villiger, Leonie und Wernli, Heini und Boettcher, Maxi und Hagen, Martin und Aemisegger, Franziska (2022) Lagrangian formation pathways of moist anomalies in the trade-wind region during the dry season: two case studies from EUREC4A. Weather and Climate Dynamics, 3 (1), Seiten 59-88. Copernicus Publications. doi:10.5194/wcd-3-59-2022 <https://doi.org/10.5194/wcd-3-59-2022>. ISSN 2698-4016. |
op_rights |
cc_by |
op_doi |
https://doi.org/10.5194/wcd-3-59-2022 |
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Weather and Climate Dynamics |
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3 |
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59 |
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