Dust plume formation in the free troposphere and aerosol size distribution during the Saharan Mineral Dust Experiment in North Africa
Dust particles mixed in the free troposphere have longer lifetimes than airborne particles near the surface. Their cumulative radiative impact on earth's meteorological processes and climate might be significant despite their relatively small contribution to total dust abundance. One example is...
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ftdoajarticles:oai:doaj.org/article:a300a20f374b470f8e722392a0235c05 2023-05-15T17:35:56+02:00 Dust plume formation in the free troposphere and aerosol size distribution during the Saharan Mineral Dust Experiment in North Africa Basit Khan Georgiy Stenchikov Bernadett Weinzierl Stoitchko Kalenderski Sergey Osipov 2015-11-01T00:00:00Z https://doi.org/10.3402/tellusb.v67.27170 https://doaj.org/article/a300a20f374b470f8e722392a0235c05 EN eng Stockholm University Press http://www.tellusb.net/index.php/tellusb/article/view/27170/pdf_50 https://doaj.org/toc/1600-0889 1600-0889 doi:10.3402/tellusb.v67.27170 https://doaj.org/article/a300a20f374b470f8e722392a0235c05 Tellus: Series B, Chemical and Physical Meteorology, Vol 67, Iss 0, Pp 1-22 (2015) regional modelling high resolution WRF-Chem SAL boundary layer dust load Meteorology. Climatology QC851-999 article 2015 ftdoajarticles https://doi.org/10.3402/tellusb.v67.27170 2022-12-30T23:53:48Z Dust particles mixed in the free troposphere have longer lifetimes than airborne particles near the surface. Their cumulative radiative impact on earth's meteorological processes and climate might be significant despite their relatively small contribution to total dust abundance. One example is the elevated dust-laden Saharan Air Layer (SAL) over the tropical and subtropical North Atlantic, which cools the sea surface. To understand the formation mechanisms of a dust layer in the free troposphere, this study combines model simulations and dust observations collected during the first stage of the Saharan Mineral Dust Experiment (SAMUM-I), which sampled dust events that extended from Morocco to Portugal, and investigated the spatial distribution and the microphysical, optical, chemical, and radiative properties of Saharan mineral dust. The Weather Research Forecast model coupled with the Chemistry/Aerosol module (WRF-Chem) is employed to reproduce the meteorological environment and spatial and size distributions of dust. The model domain covers northwest Africa and adjacent water with 5 km horizontal grid spacing and 51 vertical layers. The experiments were run from 20 May to 9 June 2006, covering the period of the most intensive dust outbreaks. Comparisons of model results with available airborne and ground-based observations show that WRF-Chem reproduces observed meteorological fields as well as aerosol distribution across the entire region and along the airplane's tracks. Several mechanisms that cause aerosol entrainment into the free troposphere are evaluated and it is found that orographic lifting, and interaction of sea breeze with the continental outflow are key mechanisms that form a surface-detached aerosol plume over the ocean. The model dust emission scheme is tuned to simultaneously fit the observed total optical depth and the ratio of aerosol optical depths generated by fine and coarse dust modes. Comparisons of simulated dust size distributions with airplane and ground-based observations are good for ... Article in Journal/Newspaper North Atlantic Directory of Open Access Journals: DOAJ Articles Tellus B: Chemical and Physical Meteorology 67 1 27170 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
regional modelling high resolution WRF-Chem SAL boundary layer dust load Meteorology. Climatology QC851-999 |
spellingShingle |
regional modelling high resolution WRF-Chem SAL boundary layer dust load Meteorology. Climatology QC851-999 Basit Khan Georgiy Stenchikov Bernadett Weinzierl Stoitchko Kalenderski Sergey Osipov Dust plume formation in the free troposphere and aerosol size distribution during the Saharan Mineral Dust Experiment in North Africa |
topic_facet |
regional modelling high resolution WRF-Chem SAL boundary layer dust load Meteorology. Climatology QC851-999 |
description |
Dust particles mixed in the free troposphere have longer lifetimes than airborne particles near the surface. Their cumulative radiative impact on earth's meteorological processes and climate might be significant despite their relatively small contribution to total dust abundance. One example is the elevated dust-laden Saharan Air Layer (SAL) over the tropical and subtropical North Atlantic, which cools the sea surface. To understand the formation mechanisms of a dust layer in the free troposphere, this study combines model simulations and dust observations collected during the first stage of the Saharan Mineral Dust Experiment (SAMUM-I), which sampled dust events that extended from Morocco to Portugal, and investigated the spatial distribution and the microphysical, optical, chemical, and radiative properties of Saharan mineral dust. The Weather Research Forecast model coupled with the Chemistry/Aerosol module (WRF-Chem) is employed to reproduce the meteorological environment and spatial and size distributions of dust. The model domain covers northwest Africa and adjacent water with 5 km horizontal grid spacing and 51 vertical layers. The experiments were run from 20 May to 9 June 2006, covering the period of the most intensive dust outbreaks. Comparisons of model results with available airborne and ground-based observations show that WRF-Chem reproduces observed meteorological fields as well as aerosol distribution across the entire region and along the airplane's tracks. Several mechanisms that cause aerosol entrainment into the free troposphere are evaluated and it is found that orographic lifting, and interaction of sea breeze with the continental outflow are key mechanisms that form a surface-detached aerosol plume over the ocean. The model dust emission scheme is tuned to simultaneously fit the observed total optical depth and the ratio of aerosol optical depths generated by fine and coarse dust modes. Comparisons of simulated dust size distributions with airplane and ground-based observations are good for ... |
format |
Article in Journal/Newspaper |
author |
Basit Khan Georgiy Stenchikov Bernadett Weinzierl Stoitchko Kalenderski Sergey Osipov |
author_facet |
Basit Khan Georgiy Stenchikov Bernadett Weinzierl Stoitchko Kalenderski Sergey Osipov |
author_sort |
Basit Khan |
title |
Dust plume formation in the free troposphere and aerosol size distribution during the Saharan Mineral Dust Experiment in North Africa |
title_short |
Dust plume formation in the free troposphere and aerosol size distribution during the Saharan Mineral Dust Experiment in North Africa |
title_full |
Dust plume formation in the free troposphere and aerosol size distribution during the Saharan Mineral Dust Experiment in North Africa |
title_fullStr |
Dust plume formation in the free troposphere and aerosol size distribution during the Saharan Mineral Dust Experiment in North Africa |
title_full_unstemmed |
Dust plume formation in the free troposphere and aerosol size distribution during the Saharan Mineral Dust Experiment in North Africa |
title_sort |
dust plume formation in the free troposphere and aerosol size distribution during the saharan mineral dust experiment in north africa |
publisher |
Stockholm University Press |
publishDate |
2015 |
url |
https://doi.org/10.3402/tellusb.v67.27170 https://doaj.org/article/a300a20f374b470f8e722392a0235c05 |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
Tellus: Series B, Chemical and Physical Meteorology, Vol 67, Iss 0, Pp 1-22 (2015) |
op_relation |
http://www.tellusb.net/index.php/tellusb/article/view/27170/pdf_50 https://doaj.org/toc/1600-0889 1600-0889 doi:10.3402/tellusb.v67.27170 https://doaj.org/article/a300a20f374b470f8e722392a0235c05 |
op_doi |
https://doi.org/10.3402/tellusb.v67.27170 |
container_title |
Tellus B: Chemical and Physical Meteorology |
container_volume |
67 |
container_issue |
1 |
container_start_page |
27170 |
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1766135232766935040 |