Quantifying dust plume formation and aerosol size distribution during the Saharan Mineral Dust Experiment in North Africa

Handle URI:
http://hdl.handle.net/10754/338014
Title:
Quantifying dust plume formation and aerosol size distribution during the Saharan Mineral Dust Experiment in North Africa
Authors:
Khan, Basit Ali ( 0000-0002-3410-4479 ) ; Stenchikov, Georgiy L. ( 0000-0001-9033-4925 ) ; Weinzierl, Bernadett; Kalenderski, Stoitchko; Osipov, Sergey
Abstract:
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 equatorial North Atlantic, which cools the sea surface and likely suppresses hurricane activity. To understand the formation mechanisms of SAL, we combine 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. We employed the Weather Research Forecast model coupled with the Chemistry/Aerosol module (WRF--Chem) to reproduce the meteorological environment and spatial and size distributions of dust. The experimental domain covers northwest Africa including the southern Sahara, Morocco and part of the Atlantic Ocean 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 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. We evaluated several aerosol uplift processes and found that orographic lifting, aerosol transport through the land/sea interface with steep gradients of meteorological characteristics, and interaction of sea breezes with the continental outflow are key mechanisms that form a surface--detached aerosol plume over the ocean. Comparisons of simulated dust size distributions with airplane and ground--based observations are generally good, but suggest that more detailed treatment of microphysics in the model is required to capture the full--scale effect of large aerosol particles.
KAUST Department:
Physical Sciences and Engineering (PSE) Division
Publisher:
Co-Action Publishing
Journal:
Tellus B
Issue Date:
Jan-2015
Type:
Article
ISSN:
1600-0889
Appears in Collections:
Articles; Physical Sciences and Engineering (PSE) Division

Full metadata record

DC FieldValue Language
dc.contributor.authorKhan, Basit Alien
dc.contributor.authorStenchikov, Georgiy L.en
dc.contributor.authorWeinzierl, Bernadetten
dc.contributor.authorKalenderski, Stoitchkoen
dc.contributor.authorOsipov, Sergeyen
dc.date.accessioned2015-01-11T11:52:16Z-
dc.date.available2015-01-11T11:52:16Z-
dc.date.issued2015-01en
dc.identifier.issn1600-0889en
dc.identifier.urihttp://hdl.handle.net/10754/338014en
dc.description.abstractDust 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 equatorial North Atlantic, which cools the sea surface and likely suppresses hurricane activity. To understand the formation mechanisms of SAL, we combine 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. We employed the Weather Research Forecast model coupled with the Chemistry/Aerosol module (WRF--Chem) to reproduce the meteorological environment and spatial and size distributions of dust. The experimental domain covers northwest Africa including the southern Sahara, Morocco and part of the Atlantic Ocean 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 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. We evaluated several aerosol uplift processes and found that orographic lifting, aerosol transport through the land/sea interface with steep gradients of meteorological characteristics, and interaction of sea breezes with the continental outflow are key mechanisms that form a surface--detached aerosol plume over the ocean. Comparisons of simulated dust size distributions with airplane and ground--based observations are generally good, but suggest that more detailed treatment of microphysics in the model is required to capture the full--scale effect of large aerosol particles.en
dc.language.isoenen
dc.publisherCo-Action Publishingen
dc.subjectRegional modelingen
dc.subjectfine resolutionen
dc.subjectWRF--Chemen
dc.subjectSALen
dc.subjectboundary layeren
dc.subjectdust loaden
dc.titleQuantifying dust plume formation and aerosol size distribution during the Saharan Mineral Dust Experiment in North Africaen
dc.typeArticleen
dc.contributor.departmentPhysical Sciences and Engineering (PSE) Divisionen
dc.identifier.journalTellus Ben
dc.eprint.versionPost-printen
dc.contributor.institutionDeutsches Zentrum fur Luft und Raumfahrt, Oberpfaffenhofen, Germanyen
dc.contributor.affiliationKing Abdullah University of Science and Technology (KAUST)en
All Items in KAUST are protected by copyright, with all rights reserved, unless otherwise indicated.