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Titel |
Optical properties and mineralogical composition of different Saharan mineral dust samples: a laboratory study |
VerfasserIn |
C. Linke, O. Möhler, A. Veres, A. Mohacsi, Z. Bozóki, G. Szabó, M. Schnaiter |
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 ; 6, no. 11 ; Nr. 6, no. 11 (2006-08-10), S.3315-3323 |
Datensatznummer |
250004056
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Publikation (Nr.) |
copernicus.org/acp-6-3315-2006.pdf |
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Zusammenfassung |
In aerosol chamber experiments optical properties of resuspended mineral
dust samples of defined size distributions were measured. Extinction
coefficients (bext) and mass specific extinction cross sections
(σext) were determined for Saharan dust samples from different
locations. The results for σext were not very sensitive to the
type of dust and varied at λ=550 nm between 3.3±0.4 m2 g−1 and 3.7±0.4 m2 g−1. The absorption
coefficients (babs) and mass specific absorption cross sections
(σabs) were determined with a novel multi-wavelength
photo-acoustic absorption spectrometer (PAS). The single scattering albedo
was close to 1 (0.98 to 0.99) at 532 nm and 1064 nm, but significantly lower
(0.63 to 0.76) at 266 nm. Additionally the chemical and mineralogical
composition of the dust samples were analysed with special regard to the
iron oxide phases hematite and goethite. At λ=266 nm the mineral
dust sample without any detectable iron oxides showed a significantly higher
SSA compared to the sample with a hematite content of 0.6 wt-%. |
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