SOLUBILITY DATA REQUIREMENTS AND NEW EXPERIMENTAL METHODS IN ATMOSPHERIC AEROSOL RESEARCH

The uptake of trace gases by atmospheric aerosols and cloud droplets p lays a critical role in the atmospheric chemistry of both the troposph ere and stratosphere. The transfer of gaseous species through the inte rfacial boundary layer and into the liquid phase involves a number of closely entwined processes, including: gas phase diffusion, mass accom modation, evaporation, Henry's law solubility, liquid phase diffusion, and, in some cases, chemical reaction at the gas/liquid interface or in the bulk liquid. Ln the atmosphere or in the laboratory these physi cal processes are seldom isolated and must be addressed together for m any trace,eases of interest. Mathematical parameterizations of trace g as uptake for cloud droplets and aerosols will be discussed. During th e past decade several new experimental approaches have been developed to investigate trace gas uptake by aqueous/acid liquid and ice surface s and to distinguish and quantify the physical and chemical parameters governing the uptake process. Here, particular emphasis is on three t echniques: the droplet train/flow reactor, the bubble column reactor, and the bubble train reactor, all jointly developed in our laboratorie s. Examples of measured temperature dependent kinetic uptake parameter s and their dependence on the measured Henry's law solubility will be presented for trace species important in stratospheric ozone depletion , tropospheric ozone production and tropospheric sulfate aerosol forma tion.