Organic surfaces in aerosols and their microphysical significance

COLL 281

Yinon Rudich, yinon.rudich@weizmann.ac.il, Environmental Sciences, Weizmann Institute, Rehovot, 76100, Israel
Organics compose a major fraction of atmospheric aerosols. They modify aerosol properties such as reactivity, hygroscopicity, surface tension and optical properties. In this talk I will describe recent laboratory measurements on how organic surfaces affect several different properties of aerosols. Specifically, we will present Cavity Ring Down measurements on the optical properties of coated aerosols and on the absorption of pollutants by organic surfaces. We will show that thin coatings of a non-absorbing layer on an absorbing core can be modeled by a core/shell Mie code, while this approach performs less successfully for thick coating. We will also describe the optical properties of humic like substances and discuss how they can affect the absorption of radiation in the atmosphere. We will also describe new experiments on the effect of water vapor on the adsorption of pollutants by organic surfaces.