HR: 1330h
AN: A13A-11    [Abstracts]
TI: Micro-physical Consistent Modeling of the Deliquescence and Efflorescence Hysteresis
AU: * He, J
EM: jiwenhe@math.uh.edu
AF: Department of Mathematics, University of Houston, 4800 Calhoun Road, Houston, TX 77204-3008
AU: Amundson, N R
EM: amundson@uh.edu
AF: Department of Mathematics, University of Houston, 4800 Calhoun Road, Houston, TX 77204-3008
AU: Caboussat, A
EM: caboussat@math.uh.edu
AF: Department of Mathematics, University of Houston, 4800 Calhoun Road, Houston, TX 77204-3008
AU: Seinfeld, J H
EM: seinfeld@caltech.edu
AF: Department of Chemical Engineering, California Institute of Technology, Pasadena, California,
AU: Yoo, K
EM: kyyoo@snut.ac.kr
AF: Department of Chemical Engineering, Seoul National University of Technology, Seoul, Korea,
AB: A difference between deliquescence and efflorescence RH values (i.e., the hysteresis effect) is commonly observed for aqueous salt particles. As the direct aerosol effect is very sensitive to the water uptake properties of the particles, the study of the hysteresis effect is of high importance. Current aerosol dynamic models take account of the deliquescence and efflorescence hysteresis based a priori knowledge of the presence of solid phases at a certain relative humidity and overall composition. They either assume crystallization of a solid in a multicomponent solution once the RH drops below the DRH of the solid salt, or do not assume solidification at all and consider all aerosol particles to be liquid droplets. In this talk, we present a modeling framework based on classical theory of nucleation kinetics to simulate the transformation from a metastable phase into a thermodynamically more favorable phase. We apply classical nucleation theory in the primal-dual active set Newton algorithm in order to predict explicitly the physical state of the aerosol particles and the deliquescence and efflorescence hysteresis. Our micro-physical consistent model is capable of modeling the phase transition and multistage growth of atmospheric aerosols in various relative humidity regimes. We present computational results to illustrate the model performance to simulate aerosol deliquescence, crystallization, solid to solid phase transitions, and acidity transitions.
DE: 0305 Aerosols and particles (0345, 4801)
SC: Atmospheric Sciences [A]
MN: 2005 Joint Assembly