Atmospheric Chemistry and Physics Discussions www.atmos-chem-phys-discuss.net 1680-7367 1680-7375 7 1 2007 10.5194/acpd-7-849-2007 http://www.atmos-chem-phys-discuss.net/7/849/2007/ http://www.atmos-chem-phys-discuss.net/7/849/2007/acpd-7-849-2007.html http://www.atmos-chem-phys-discuss.net/7/849/2007/acpd-7-849-2007.pdf 849 910 2007-01-18 Reformulating atmospheric aerosol thermodynamics and hygroscopic growth into haze and clouds S. Metzger metzger@mpch-mainz.mpg.de J. Lelieveld Max Planck Institute for Chemistry, Mainz, Germany Modeling atmospheric aerosol and cloud microphysics is rather complex, even if chemical and thermodynamical equilibrium is assumed. We show, however, that the thermodynamics can be considerably simplified by reformulating equilibrium to include water, and transform laboratory-based concepts to atmospheric conditions. We generalize the thermodynamic principles that explain hydration and osmosis – merely based on solute solubilities. In chemical and thermodynamical equilibrium the relative humidity (RH) determines the saturation molality, including solute and solvent activities (and activity coefficients), since the water content is fixed by RH for a given aerosol concentration and type. As a consequence, gas/liquid/solid aerosol equilibrium partitioning can be solved analytically and non-iteratively. Our new concept enables an efficient and accurate calculation of the aerosol water mass and to directly link the aerosol hygroscopic growth to haze and cloud formation. We apply our new concept in the 3rd Equilibrium Simplified Aerosol Model (EQSAM3). Its input is limited to the species' solubilities from which a newly introduced stoichiometric coefficient for water is derived. Analogously, we introduce effective stochiometric coefficients for the solutes to account for complete or incomplete dissociation. We show that these coefficients can be assumed constant over the entire activity range and calculated for various inorganic, organic and non-electrolyte compounds, including alcohols, sugars and dissolved gases. EQSAM3 calculates the aerosol composition and gas/liquid/solid partitioning of mixed inorganic/organic multicomponent solutions and the associated water uptake for almost 100 major compounds. It explicitly accounts for particle hygroscopic growth by computing aerosol properties such as single solute molalities, molal based activities, including activity coefficients for volatile compounds, and deliquescence relative humidities of mixed solutes. Various applications and a model inter-comparison indicate that a) the application is not limited to dilute binary solutions, b) sensitive aerosol properties such as the pH of binary and mixed inorganic/organic salt solutions up to saturation can be computed accurately, and c) aerosol associated water is important for atmospheric chemistry, visibility, weather and climate. Arrhenius, S.: Z. physik. Chem., 1, 631, 1887. Chan, C. K., Flagan, R. C., and Seinfeld, J. H., Water activities of NH4NO3/(NH$_4)_2$SO4 solutions, Atmos. Environ. 26A, 1661–1673, 1992. Cohen, M. D., Flagan, R. C., and Seinfeld, J. H. Studies of concentrated electrolyte solutions using the electrodynamic balance. 1. Water activities for single electrolyte solutions, J. Phys. Chem., 91, 4563–4574, 1987a. Cohen, M. D., Flagan, R. C., and Seinfeld, J. H. Studies of concentrated electrolyte solutions using the electrodynamic balance. 2. Water activities for mixed electrolyte solutions, J. Phys. Chem., 91, 4575–4582, 1987b. Chemical Rubber Company (CRC) Handbook of Chemistry and Physics, 86th Edition, Taylor and Francis Group LLC, 2004–2005, CD-ROM version 2006. Denbigh, K.: The Principles of Chemical Equilibrium, 4th ed., Cambridge Univ. Press, New York, 1981. Dufour, L. and Defay, R.: Thermodynamics of Clouds, Academic Press, New York, 1963, 1427–1434, 1998. Environmental Protection Agency (EPA), Air quality criteria for particulate matter, EPA/600/P-95/001cF, 1996. Gibbs, J. W.: On the equilibrium of heterogeneous substances (1876), in Collected Works, volume~1. Longmans, Green, and Co., 1928. Heyrovska, R.: A Reappraisal of Arrhenius' Theory of Partial Dissociation of Electrolytes, American Chem. Soc., 1989. Hofmeister, F.: Zur Lehre von der Wirkung der Salze, Arch. Exp. Pathol. Pharmakol. (Leipzig) 24 (1888) 247–260; translated in: Zur Lehre von der Wirkung der Salze (about the science of the effect of salts: Franz Hofmeister's historical papers, edited by: Kunz, W., Henle, J., and Ninham, B. W., Curr. Opin. Coll. Interface Sci., 9, 19–37, 2004. Holgate, S. T., Samet, J. M., Koren, H. S., and Maynard, R. L.: Air pollution and health, Academic Press, San Diego, 1999. Intergovernmental Panel on Climate Change (IPCC): Climate change: the scientific basis, Cambridge University Press, UK, 2001. IUPAC Solubility Data Series, International Union of Pure and Applied Chemistry. Volumes 1 to 53 were published by Pergamon Press, Oxford, from 1979 to 1994; subsequent volumes were published by Oxford University Press, Oxford. Jöckel, P., Tost, H., Pozzer, A., Brühl, C., Buchholz, J., Ganzeveld, L., Hoor, P., Kerkweg, A., Lawrence, M. G., Sander, R., Steil, B., Stiller, G., Tanarhte, M., Taraborrelli, D., van Aardenne, J., and Lelieveld, J.: The atmospheric chemistry general circulation model ECHAM5/MESSy1: consistent simulation of ozone from the surface to the mesosphere, Atmos. Chem. Phys., 6, 5067–5104, 2006. Kim, Y. P., Seinfeld, J. H., and Saxena, P.: Atmospheric gas/aerosol equilibrium I. Thermodynamic model, Aerosol Sci. Technol., 19, 157–181, 1993a. Kim, Y. P., Seinfeld, J. H., and Saxena, P.: Atmospheric gas/aerosol equilibrium II. Analysis of common approximations and activity coefficient calculation methods, Aerosol Sci. Technol., 19, 182–198, 1993b. Kim, Y. P. and Seinfeld, J. H.: Atmospheric gas/aerosol equilibrium III. Thermodynamics of crustal elements Ca$^2+$, K$^+$, and Mg$^2+$, Aerosol Sci. Technol., 22, 93–110, 1995. Köhler, H.: The nucleus in and the growth of hygroscopic droplets, Trans Faraday Soc., 32, 1152-1162, 1936. Meng, Z., Seinfeld, J. H., Saxena, P., and Kim, Y. P.: Atmospheric gas/aerosol equilibrium. IV: Thermodynamics of carbonates, Aerosol Sci. Technol., 131–154, 1995. Metzger, S. M.: Gas/Aerosol Partitioning: A simplified Method for Global Modeling, Ph.D. Thesis, University Utrecht, The Netherlands, ISBN:90-393-2510-3, http://igitur-archive.library.uu.nl/dissertations/1930853/inhoud.htm, 2000. Metzger, S. M., Dentener, F. J., Lelieveld, J., and Pandis, S. N.: Gas/aerosol partitioning I: A computationally efficient model, J. Geophys. Res., 107(D16), doi:10.1029/2001JD001102, 2002. Metzger, S., Mihalopoulos, N., and Lelieveld, J.: Importance of mineral cations and organics in gas-aerosol partitioning of reactive nitrogen compounds: case study based on MINOS results, Atmos. Chem. Phys., 6, 2549–2567, 2006. Nenes, A., Pilinis, C., and Pandis, S. N.: Isorropia: A new thermodynamic model for multiphase multicomponent inorganic aerosols, Aquatic Geochemistry, 4, 123–152, 1998. Nernst, W.: Z. Phys. Chem., 4, 129, 1889. Pfeffer, W.: Pflanzenphysiologie. Leipzig: Verlag von W. Engelmann, 1881. Pruppacher, H. R. and Klett, J. D.: Microphysics of Clouds and Precipitation, Dordrecht, Holland, D. Reidel Publ. Co., 950p, 1997. Raoult, F. M.: Z. physik. Chem., 2, 353, 1888. Robinson, R. A. and Stokes, R. H.: Electrolyte solutions, Second Ed., Butterworths, London, 1965. Roeckner, E., Bäuml, G., Bonaventura, L., Brokopf, R., Esch, M., Giorgetta, M., Hagemann, S., Kirchner, I., Kornblueh, L., Manzini, E., Rhodin, A., Schlese, U., Schulzweida, U., and Tompkins, A.: The atmospheric general circulation model ECHAM5. PART I: Model description, Max Planck Institute for Meteorology, MPI-Report 349, http://www.mpimet.mpg. de/fileadmin/publikationen/Reports/max scirep 349.pdf, 2003. Seinfeld, J. H. and Pandis, S. N.: Atmospheric chemistry and physics, J. Wiley and Sons, Inc., New York, 1998. Stokes, R. H. and Robinson, R. A.: Interactions in aqueous nonelectrolyte solutions. I. Solute solvent equilibria, J. Phys. Chem., 70, 2126–2130, 1966. Tang, I. N. and Munkelwitz, H. R.: Water activities, densities, and refractive indices of aqueous sulfates and sodium nitrate droplets of atmospheric importance, J. Geophys. Res. 99, 18 801–18 808, 1994. van't Hoff, J. H.: Die Rolle des osmotischen Druckes in der Analogie zwischen Lösungen und Gasen, Z. physik. Chem., 1, 481, 1887. Vignati E., Wilson, J., and Stier, P.: M7: An efficient size-resolved aerosol microphysics module for large-scale aerosol transport models, J. Geophys. Res., 109, D22202, doi:10.1029/2003JD004485, 2004. Wexler, A. S. and Potukuchi, S.: Kinetics and Thermodynamics of Tropospheric Aerosols, Atmospheric Particles, John Wiley & Sons Ltd., 1998. Zadanovskii, A. B.: New methods of calculating solubilities of electrolytes in multicomponent systems, Zhu. Fiz. Khim., 22, 1475–1485, 1948. Zaveri, R. A., Easter, R. C., and Wexler, A. S.: A new method for multicomponent activity coefficients of electrolytes in aqueous atmospheric aerosols, J. Geophys. Res.-Atmos., 110, doi:10.1029/2004JD004681, 2005.