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| Titel |
Three-dimensional dust aerosol distribution and extinction climatology over northern Africa simulated with the ALADIN numerical prediction model from 2006 to 2010 |
| VerfasserIn |
M. Mokhtari, P. Tulet, C. Fischer, Y. Bouteloup, F. Bouyssel, O. Brachemi |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1680-7316
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 15, no. 15 ; Nr. 15, no. 15 (2015-08-14), S.9063-9082 |
| Datensatznummer |
250119967
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| Publikation (Nr.) |
 copernicus.org/acp-15-9063-2015.pdf |
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| Zusammenfassung |
The seasonal
cycle and optical properties of mineral dust aerosols in northern Africa were
simulated for the period from 2006 to 2010 using the numerical atmospheric
model ALADIN (Aire Limitée Adaptation dynamique Développement
InterNational) coupled to the surface scheme SURFEX (SURFace
EXternalisée). The particularity of the simulations is that the major
physical processes responsible for dust emission and transport, as well as
radiative effects, are taken into account on short timescales and at
mesoscale resolution. The aim of these simulations is to quantify the dust
emission and deposition, locate the major areas of dust emission and
establish a climatology of aerosol optical properties in northern Africa. The
mean monthly aerosol optical thickness (AOT) simulated by ALADIN is compared
with the AOTs derived from the standard Dark Target (DT) and Deep Blue (DB)
algorithms of the Aqua-MODIS (MODerate resolution Imaging Spectroradiometer)
products over northern Africa and with a set of sun photometer measurements
located at Banizoumbou, Cinzana, Soroa, Mbour and Cape Verde. The vertical
distribution of dust aerosol represented by extinction profiles is also
analysed using CALIOP (Cloud-Aerosol Lidar with Orthogonal Polarization)
observations.
The annual dust emission simulated by ALADIN over northern Africa is
878 Tg year−1. The Bodélé Depression appears to be the main
area of dust emission in northern Africa, with an average estimate of about
21.6 Tg year−1.
The simulated AOTs are in good agreement with satellite and sun photometer
observations. The positions of the maxima of the modelled AOTs over northern
Africa match the observed positions, and the ALADIN simulations
satisfactorily reproduce the various dust events over the 2006–2010 period.
The AOT climatology proposed in this paper provides a solid database of
optical properties and consolidates the existing climatology over this
region derived from satellites, the AERONET network and regional climate
models. Moreover, the 3-D distribution of the simulated AOTs
also provides information about the vertical structure of the dust aerosol
extinction. |
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