Showing papers by "Harald Saathoff published in 2000"
6 citations
TL;DR: In this article, an intensive soot aerosol campaign was organized at the 84 m 3 large aerosol chamber AIDA of the research centre in Karlsruhe (FZK) with the participation of 8 Austrian, German and Swiss institutes.
1 citations
01 Jan 2000
TL;DR: In this article, the Rayleigh-DebyeGans (RDG) approximation for fractal-like particle clusters was discussed in the framework of the DAG. But, the results of the analysis were limited.
Abstract: Extinction coefficients of pure Diesel soot aerosol, ammonium sulfate aerosol, their mixtures, and organically coated soot aerosol were measured in the 230–1000 nm range using the large (84 m 3 ) AIDA chamber as buffer. Single scattering albedos and hemispheric backscatter ratios were measured simultaneously at 450, 550 and 700 nm. Aerosol size distributions were determined with a scanning mobility particle sizer (SMPS). Aerosol dynamics in the AIDA chamber were simulated with the COSIMA model on the experimental time scale of ~2 days. While the size distributions show a significant coagulation-induced particle growth, almost no change in spectral extinction and scattering was observed. This is discussed in the framework of the Rayleigh-DebyeGans (RDG) approximation for fractal-like particle clusters which leads to approximated values for the complex refractive index of Diesel soot in the visible. The organic coating of the soot aerosol led to a strong increase of the scattering albedo and to a change in the wavelength dependence of the extinction coefficient. The scattering albedo of the soot/sulfate composite aerosol - externally mixed at the beginning - decreased with time and degree of internal mixing.