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Publications (3)3.44 Total impact

  • EGU, Vienna, Austria; 04/2014
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    ABSTRACT: The Mediterranean basin is a very complex area where high concentrations of atmospheric aerosols of different origin and types may be found. The North-Western part of the Mediterranean basin, due to its closeness with high polluted industrialized areas (such as the Po Valley and the Fos/Berre region) and coastal high populated cities (such as Barcelona, Marseille, Nice, or Genes), is frequently affected by severe pollution episodes. The strength of these episodes is particularly intense during summer when stable meteorological conditions favour the accumulation of pollutants in the lowermost atmospheric layers. In addition to these phenomena, also the export of Saharan dust aerosols, which is more favoured during summer in this part of the basin, strongly contributes to the high aerosol load. An intensive airborne campaign (TRAQA, TRansport and Air QuAlity) was conducted in June-July 2012 over the North-Western Mediterranean basin with the SAFIRE ATR-42 aircraft. Observations performed during TRAQA have given the opportunity to analyse the microphysical and optical properties of atmospheric aerosols in a large area of the western Mediterranean basin (Gulf of Genes, western Corsica, Gulf of Lion, north-eastern Spain). During the campaign the western Mediterranean basin was interested by different synoptic conditions which lead to the export of anthropogenic plumes from different polluted source regions (northern Italy and the Po Valley, Marseille and the Fos/Berre region, and Barcelona), as well as to a strong Saharan dust intrusion. Measurements of the aerosol optical properties (scattering and backscattering coefficients at 450, 550, and 700 nm with a TSI nephelometer; absorption coefficient at seven wavelengths between 370 and 950 nm with a Magee Sci. aethalomether), size distribution (PCASP, 0.1 μm
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    ABSTRACT: This paper presents data on elemental and mineralogical composition of mineral dust from various source regions of Africa collected during the African Monsoon Multidisciplinary Analyses (AMMA) SOP0/DABEX and Dust Ouflow and Deposition to the Ocean (DODO) DODO1 experiments (January-February 2006), and the DODO2 campaign (August 2006). Bulk filter samples were collected at the AMMA supersite of Banizoumbou, Niger, as well as on board the Facility for Airborne Atmospheric Measurements (FAAM) BAe-146 aircraft. Both mineral dust and biomass burning in external mixing occurred in surface and elevated layers during the winter field phase of the campaign. However, mineral dust was overwhelming, accounting for 72% of the estimated aerosol mass in aged elevated biomass burning layers and up to 93% in plumes of mineral dust, which generally occurred in the boundary layer. A number of well-defined episodes of advection of mineral dust could be identified both at the ground and on the aircraft. The elemental and mineralogical composition varied depending on source region. This variability could be well traced by the calcium content, which is enhanced in dust from North Africa but depleted in dust from the Sahel. Iron oxides in the form of hematite and goethite are enriched in dust emitted within Sahel and in Mauritania, whereas dust from the Bodélé depression is iron-oxide depleted. Iron oxides represented between 2.4% and 4.5% of the total estimated dust oxide mass. This regional variability will have to be taken into account in estimating the optical properties of absorption of mineral dust from western Africa.
    Journal of Geophysical Research Atmospheres 01/2008; 113. DOI:10.1029/2008JD009903 · 3.44 Impact Factor