A new inorganic atmospheric aerosol phase equilibrium model (UHAERO) N. R. Amundson1, A. Caboussat1, J. W. He1, A. V. Martynenko1, V. B. Savarin2, J. H. Seinfeld3, and K. Y. Yoo4 1Department of Mathematics, University of Houston, Houston, USA 2Ecole Nationale Supérieure de Techniques Avancées, Paris, France 3Departments of Chemical Engineering and Environmental Science and Engineering, California Institute of Technology, Pasadena, USA 4Department of Chemical Engineering, Seoul National University of Technology, Seoul, Korea
Abstract. A variety of thermodynamic models have been developed to predict inorganic
gas-aerosol equilibrium. To achieve computational efficiency a number of the
models rely on a priori specification of the phases present in certain
relative humidity regimes. Presented here is a new computational model, named
UHAERO, that is both efficient and rigorously computes phase behavior without
any a priori specification. The computational implementation is based on
minimization of the Gibbs free energy using a primal-dual method, coupled to
a Newton iteration. The mathematical details of the solution are given
The model computes deliquescence behavior
without any a priori specification of the relative humidities of
Also included in the model is a
formulation based on classical theory of nucleation kinetics that
predicts crystallization behavior.
Detailed phase diagrams of the
sulfate/nitrate/ammonium/water system are presented as a function of relative
humidity at 298.15 K over the complete space of composition.
Citation: Amundson, N. R., Caboussat, A., He, J. W., Martynenko, A. V., Savarin, V. B., Seinfeld, J. H., and Yoo, K. Y.: A new inorganic atmospheric aerosol phase equilibrium model (UHAERO), Atmos. Chem. Phys., 6, 975-992, doi:10.5194/acp-6-975-2006, 2006.