A Step-wise Hydration Model of Organics and Electrolytes

ANTHONY S. WEXLER, University of California, Davis

     Abstract Number: 287
     Working Group: Aerosol Physical Chemistry and Microphysics

Abstract
Atmospheric aerosol particles may contain an aqueous phase and one or more organic or solid phases. The aqueous phase solute concentrations are usually high since the water activity is governed by the ambient relative humidity. In many situations, the solute may supersaturate leading to concentrations beyond the available data. At high concentrations, the transport properties of the aerosol particles also change reducing diffusivity within the particle. These high concentrations challenge current aerosol thermodynamics modelling approaches. Here we present a simple step-wise hydration modelling paradigm for modelling the activity of organic and electrolyte solutes and water as the solvent at high concentration while also predicting the amount of water bound to the solutes and the amount that is free.