Physicochemical Properties of Atmospheric Aerosol Particles over Suburban and Remote Locations and Development of Techniques for the Improvement of their Determination Methods

摘要

Aerosol particles affect the Earth's climate directly by absorbing or scattering solar radiation and indirectly by acting as cloud condensation nuclei. The contribution of the aerosol effects on the global climate depends on their size and chemical composition which in turn defines their hygroscopicity (i.e. the ability to take up water). Despite that thermodynamic models can be used to accurately predict the hygroscopic behavior of particles consisting of inorganic matter, existing knowledge leads to inaccurate predictions in cases of particles consisting purely of organic or mixtures of inorganic and organic matter. The use of the hygroscopic parameter κ allows more accurate approximation of the hygroscopic behavior of mixed particles when the hygroscopicity and the volume fraction of each species composing the particle are known. However, the estimation of atmospheric aerosols hygroscopicity poses difficulties due to their complex and diverse chemical composition which varies spatially and temporally. Thus, high temporal resolution, direct observations of particles hygroscopicity and/or chemical composition in different regions are needed in order to reduce the uncertainties of their impact on the climate.