Atmospheric Dynamics of a Saharan Dust Outbreak Over Mindelo, Cape Verde Islands, Preceded by Rossby Wave Breaking: Multiscale Observational Analyses and Simulations
We investigate the synoptic precursors to the Harmattan wind and dust frontogenesis during the high impact Saharan dust outbreak over the Cape Verde Islands on 13 November 2017. We employ multiscale observations and the Weather Research and Forecasting model Coupled with Chemistry simulations. The a...
Published in: | Journal of Geophysical Research: Atmospheres |
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Language: | English |
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AGU (American Geophysical Union)
2020
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Online Access: | https://oceanrep.geomar.de/id/eprint/57567/ https://oceanrep.geomar.de/id/eprint/57567/1/JGR%20Atmospheres%20-%202020%20-%20Dhital%20-%20Atmospheric%20Dynamics%20of%20a%20Saharan%20Dust%20Outbreak%20Over%20Mindelo%20Cape%20Verde%20Islands%20.pdf https://doi.org/10.1029/2020JD032975 |
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ftoceanrep:oai:oceanrep.geomar.de:57567 2023-05-15T17:35:14+02:00 Atmospheric Dynamics of a Saharan Dust Outbreak Over Mindelo, Cape Verde Islands, Preceded by Rossby Wave Breaking: Multiscale Observational Analyses and Simulations Dhital, S. Kaplan, M. L. Orza, J. A. G. Fiedler, Stephanie 2020-09-27 text https://oceanrep.geomar.de/id/eprint/57567/ https://oceanrep.geomar.de/id/eprint/57567/1/JGR%20Atmospheres%20-%202020%20-%20Dhital%20-%20Atmospheric%20Dynamics%20of%20a%20Saharan%20Dust%20Outbreak%20Over%20Mindelo%20Cape%20Verde%20Islands%20.pdf https://doi.org/10.1029/2020JD032975 en eng AGU (American Geophysical Union) https://oceanrep.geomar.de/id/eprint/57567/1/JGR%20Atmospheres%20-%202020%20-%20Dhital%20-%20Atmospheric%20Dynamics%20of%20a%20Saharan%20Dust%20Outbreak%20Over%20Mindelo%20Cape%20Verde%20Islands%20.pdf Dhital, S., Kaplan, M. L., Orza, J. A. G. and Fiedler, S. (2020) Atmospheric Dynamics of a Saharan Dust Outbreak Over Mindelo, Cape Verde Islands, Preceded by Rossby Wave Breaking: Multiscale Observational Analyses and Simulations. Journal of Geophysical Research: Atmospheres, 125 (18). Art.Nr. e2020JD032975. DOI 10.1029/2020JD032975 <https://doi.org/10.1029/2020JD032975>. doi:10.1029/2020JD032975 info:eu-repo/semantics/restrictedAccess Article PeerReviewed 2020 ftoceanrep https://doi.org/10.1029/2020JD032975 2023-04-07T16:05:36Z We investigate the synoptic precursors to the Harmattan wind and dust frontogenesis during the high impact Saharan dust outbreak over the Cape Verde Islands on 13 November 2017. We employ multiscale observations and the Weather Research and Forecasting model Coupled with Chemistry simulations. The analyses indicate that the dust storm was initiated on the lee side of the Saharan Atlas Mountains (SAM) in Algeria on 10 November 2017. This dust storm was associated with a double Rossby wave break linked through nonlinear wave reflection. Two successive Rossby wave breaks contributed to the wave amplification over the Eastern North Atlantic Ocean which transported large magnitude potential vorticity air into the North African continent. The resulting coupled pressure surge was associated with cold air advected equatorward over the SAM which organized the strong near-surface wind that ablated the dust. The simulation results indicate that the dust front was initially related to a density current-like cold front which formed due to the downslope transport of cold airflow over the SAM and then triggered undular bores on the lee side. Each bore perturbed the dust loading and then the subsequent diurnal heating generated differential planetary boundary layer turbulence kinetic energy strengthening the dust frontogenesis. Dust became confined behind the cold surge and interacted with the daytime Saharan planetary boundary layer leading to increased dust loading, while the dust front propagated equatorward. Two distinct dust plumes arrived successively at low levels at Mindelo, Cape Verde Islands: (1) from the coasts of Mauritania and Senegal and (2) from the SAM southern flank. Article in Journal/Newspaper North Atlantic OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) Journal of Geophysical Research: Atmospheres 125 18 |
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Open Polar |
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OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) |
op_collection_id |
ftoceanrep |
language |
English |
description |
We investigate the synoptic precursors to the Harmattan wind and dust frontogenesis during the high impact Saharan dust outbreak over the Cape Verde Islands on 13 November 2017. We employ multiscale observations and the Weather Research and Forecasting model Coupled with Chemistry simulations. The analyses indicate that the dust storm was initiated on the lee side of the Saharan Atlas Mountains (SAM) in Algeria on 10 November 2017. This dust storm was associated with a double Rossby wave break linked through nonlinear wave reflection. Two successive Rossby wave breaks contributed to the wave amplification over the Eastern North Atlantic Ocean which transported large magnitude potential vorticity air into the North African continent. The resulting coupled pressure surge was associated with cold air advected equatorward over the SAM which organized the strong near-surface wind that ablated the dust. The simulation results indicate that the dust front was initially related to a density current-like cold front which formed due to the downslope transport of cold airflow over the SAM and then triggered undular bores on the lee side. Each bore perturbed the dust loading and then the subsequent diurnal heating generated differential planetary boundary layer turbulence kinetic energy strengthening the dust frontogenesis. Dust became confined behind the cold surge and interacted with the daytime Saharan planetary boundary layer leading to increased dust loading, while the dust front propagated equatorward. Two distinct dust plumes arrived successively at low levels at Mindelo, Cape Verde Islands: (1) from the coasts of Mauritania and Senegal and (2) from the SAM southern flank. |
format |
Article in Journal/Newspaper |
author |
Dhital, S. Kaplan, M. L. Orza, J. A. G. Fiedler, Stephanie |
spellingShingle |
Dhital, S. Kaplan, M. L. Orza, J. A. G. Fiedler, Stephanie Atmospheric Dynamics of a Saharan Dust Outbreak Over Mindelo, Cape Verde Islands, Preceded by Rossby Wave Breaking: Multiscale Observational Analyses and Simulations |
author_facet |
Dhital, S. Kaplan, M. L. Orza, J. A. G. Fiedler, Stephanie |
author_sort |
Dhital, S. |
title |
Atmospheric Dynamics of a Saharan Dust Outbreak Over Mindelo, Cape Verde Islands, Preceded by Rossby Wave Breaking: Multiscale Observational Analyses and Simulations |
title_short |
Atmospheric Dynamics of a Saharan Dust Outbreak Over Mindelo, Cape Verde Islands, Preceded by Rossby Wave Breaking: Multiscale Observational Analyses and Simulations |
title_full |
Atmospheric Dynamics of a Saharan Dust Outbreak Over Mindelo, Cape Verde Islands, Preceded by Rossby Wave Breaking: Multiscale Observational Analyses and Simulations |
title_fullStr |
Atmospheric Dynamics of a Saharan Dust Outbreak Over Mindelo, Cape Verde Islands, Preceded by Rossby Wave Breaking: Multiscale Observational Analyses and Simulations |
title_full_unstemmed |
Atmospheric Dynamics of a Saharan Dust Outbreak Over Mindelo, Cape Verde Islands, Preceded by Rossby Wave Breaking: Multiscale Observational Analyses and Simulations |
title_sort |
atmospheric dynamics of a saharan dust outbreak over mindelo, cape verde islands, preceded by rossby wave breaking: multiscale observational analyses and simulations |
publisher |
AGU (American Geophysical Union) |
publishDate |
2020 |
url |
https://oceanrep.geomar.de/id/eprint/57567/ https://oceanrep.geomar.de/id/eprint/57567/1/JGR%20Atmospheres%20-%202020%20-%20Dhital%20-%20Atmospheric%20Dynamics%20of%20a%20Saharan%20Dust%20Outbreak%20Over%20Mindelo%20Cape%20Verde%20Islands%20.pdf https://doi.org/10.1029/2020JD032975 |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_relation |
https://oceanrep.geomar.de/id/eprint/57567/1/JGR%20Atmospheres%20-%202020%20-%20Dhital%20-%20Atmospheric%20Dynamics%20of%20a%20Saharan%20Dust%20Outbreak%20Over%20Mindelo%20Cape%20Verde%20Islands%20.pdf Dhital, S., Kaplan, M. L., Orza, J. A. G. and Fiedler, S. (2020) Atmospheric Dynamics of a Saharan Dust Outbreak Over Mindelo, Cape Verde Islands, Preceded by Rossby Wave Breaking: Multiscale Observational Analyses and Simulations. Journal of Geophysical Research: Atmospheres, 125 (18). Art.Nr. e2020JD032975. DOI 10.1029/2020JD032975 <https://doi.org/10.1029/2020JD032975>. doi:10.1029/2020JD032975 |
op_rights |
info:eu-repo/semantics/restrictedAccess |
op_doi |
https://doi.org/10.1029/2020JD032975 |
container_title |
Journal of Geophysical Research: Atmospheres |
container_volume |
125 |
container_issue |
18 |
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1766134338932441088 |