Ali Abo Riziq

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Atmospheric aerosols absorb and reflect solar radiation causing surface cooling and heating of the atmosphere. The interaction between aerosols and radiation depends on their complex index of refraction, which is related to the particles' chemical composition. The contribution of light absorbing organic compounds, such as HUmic-LIke Substances (HULIS) to(More)
This study focuses on the retrieval of the normalized mass absorption cross section (MAC) of soot using theoretical calculations that incorporate new measurements of the optical properties of organic carbon (OC) intrinsic to fresh diesel soot. Intrinsic OC was extracted by water and an organic solvent, and the complex refractive index of the extracted OC(More)
In this study, we measure the extinction efficiency at 532 nm of absorbing aerosol particles coated with a non-absorbing solid and liquid organic shell with coating thickness varying between 5 and 100 nm using cavity ring down aerosol spectrometry. For this purpose, we use nigrosin, an organic black dye, as a model absorbing core and two 5 non–absorbing(More)
This study focuses on the heterogeneous reactions of gas phase glyoxal with aerosols of glycine, the most abundant amino acid in atmospheric aerosols, as well as with a mixture of glycine and ammonium sulfate (AS) at a molar ratio of 1:100 (glycine-AS 1:100). Aerosols were exposed to varying relative humidity (RH) conditions in the presence of gas phase(More)
Extinction efficiencies of coated absorbing aerosols measured by cavity ring down aerosol spectrometry A. A. Riziq, M. Trainic, C. Erlick, E. Segre, and Y. Rudich Department of Environmental Sciences, Weizmann Institute, Rehovot, 76100, Israel Dept. of Atmospheric Sciences, The Hebrew Univ. of Jerusalem, Jerusalem, 91904, Israel Physics Services, Weizmann(More)
Application of cavity ring down (CRD) spectrometry for measuring the optical properties of pure and mixed laboratory-generated aerosols is presented. The extinction coefficient (α ext), extinction cross section (σ ext) and extinction efficiency (Q ext) were measured for polystyrene spheres (PSS), ammonium sulphate ((NH 4) 2 (SO 4)), sodium 5 chloride(More)
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