Atmospheric Chemistry and Physics Discussions
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10.5194/acpd-8-7289-2008
http://www.atmos-chem-phys-discuss.net/8/7289/2008/
http://www.atmos-chem-phys-discuss.net/8/7289/2008/acpd-8-7289-2008.html
http://www.atmos-chem-phys-discuss.net/8/7289/2008/acpd-8-7289-2008.pdf
7289
7313
2008-04-16
Monte Carlo simulations of two-component drop growth by stochastic coalescence
L. Alfonso
lesterson@yahoo.com
G. B. Raga
D. Baumgardner
Universidad Autónoma de la Ciudad de México, México City, 09790 México
Centro de Ciencias de la Atmósfera, Universidad Nacional Autónoma de México, México City, 04510 México
The evolution of two-dimensional drop distributions is simulated in this
study using a Monte Carlo method.~The stochastic algorithm of Gillespie (1976)
for chemical reactions in the formulation proposed by Laurenzi et
al. (2002) was used to simulate the kinetic behavior of the drop population.
Within this framework species are defined as droplets of specific size and
aerosol composition. The performance of the algorithm was checked by
comparing the numerical with the analytical solutions found by Lushnikov (1975).
Very good agreement was observed between the Monte Carlo simulations
and the analytical solution.
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Simulation results are presented for bi-variate constant and hydrodynamic
kernels. The algorithm can be easily extended to incorporate various
properties of clouds such as including several crystal habits, different
types of soluble CCN, particle charging and drop breakup.
Alfonso, L. and Raga, G. B.: The influence of organic compounds in the development of precipitation acidity in maritime clouds, Atmos. Chem. Phys., 4, 1097–1111, 2004.
Alfonso, L., Raga, G. B., and Baumgardner, D. G.: Monte Carlo simulations of drop growth by stochastic coalescence and collision-induced breakup, 12th Conference in cloud physics, Madison, Wisconsin, 2006.
Bott, A. A.: A flux method for the numerical solution of the stochastic collection equation: Extension to two-dimensional particle distribution, J. Atmos. Sci., 57, 284–294, 2000.
Drake, R. L.: The scalar transport equation of coalescence theory: Moments and kernels, J. Atmos. Sci., 29, 537–547, 1972.
Drake, R. L. and Wright, T. J.: The scalar transport equation of coalescence theory: New families of exact solutions, J. Atmos. Sci., 29, 548–556, 1972.
Feingold, G. and Kreindenweis, S. M.: Cloud processing of aerosol as modeled by a large eddy simulation with coupled microphysics and chemistry, J. Geophys. Res., 107, 4687, 2002.
Flossmann, A. I.: A 2-D spectral model simulation of the scavenging of gaseous and particulate sulfate by a warm marine cloud, Atmos. Res., 32, 233–248, 1994.
Gillespie, D.T.: An exact method for numerically simulating the stochastic coalescence process in a cloud, J. Atmos. Sci., 32, 1977–1989, 1975.
Gillespie, D. T.: A general method for numerically simulating the stochastic time evolution of coupled chemical reactions, J. Comput. Phys., 22, 403–434, 1976.
Golovin, A. M.: The solution of the coagulating equation for cloud droplets is a rising air current, Bull. Acad. Sci. USSR, Geophys. Ser., 5, 482–487, 1963.
Laurenzi, I. J., Bartels, S. L., and Diamond, S. L.: A general algorithm for exact simulation of multicomponent aggregation, J. Comput. Phys., 177, 418, 2002.
Liu, Q.: Modeling of the aerosol-cloud interactions in marine stratocumulus, PhD Thesis, Cooperative Institute for Mesoscale Meteorological Studies, Norman, Oklahoma 73019, Report, 109, 1998.
Long, A. B.: Solutions to the droplet collection equation for polynomial kernels, J. Atmos. Sci., 31, 1040–1051, 1974.
Lushnikov, A. A.: Evolution of coagulating systems III: Coagulating mixtures, J. Coll. Int. Sci., 54, 1, 94–101, 1975.
Scott, W. T.: Analytic studies of cloud droplet coalescence, J. Atmos. Sci., 25, 54–65, 1968.