Importance of Heterogeneous Processes to Tropospheric Chemistry: Studies With a One-Dimensional Model

  1. David R. Schryer
  1. R. P. Turco1,
  2. O. B. Toon2,
  3. R. C. Whitten2,
  4. R. G. Keesee2 and
  5. P. Hamill3

Published Online: 21 MAR 2013

DOI: 10.1029/GM026p0231

Heterogeneous Atmospheric Chemistry

Heterogeneous Atmospheric Chemistry

How to Cite

Turco, R. P., Toon, O. B., Whitten, R. C., Keesee, R. G. and Hamill, P. (1982) Importance of Heterogeneous Processes to Tropospheric Chemistry: Studies With a One-Dimensional Model, in Heterogeneous Atmospheric Chemistry (ed D. R. Schryer), American Geophysical Union, Washington, D. C.. doi: 10.1029/GM026p0231

Author Information

  1. 1

    R & D Associates, Marina Del Rey, California 90291

  2. 2

    NASA Ames Research Center, Moffett Field, California 94035

  3. 3

    Systems and Applied Sciences Corp., Palo Alto, California 94306

Publication History

  1. Published Online: 21 MAR 2013
  2. Published Print: 1 JAN 1982

ISBN Information

Print ISBN: 9780875900513

Online ISBN: 9781118663813



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The chemistry of the troposphere is affected by processes which involve the interactions between gases, aerosols and cloud droplets. Such “heterogeneous” processes are not usually considered in studies of the global tropospheric chemical cycles. (In the present context, the term “heterogeneous processes” refers to multiphase processes, processes involving particles and particle interactions, surface phenomena, and chemistry in solution, all as opposed to “homogeneous” gas-phase processes.) We have developed a one-dimensional model of tropospheric air composition which incorporates a number of heterogeneous physical and chemical processes. Gases, aerosols, and hydrometeors interact through the physical mechanisms of nucleation, condensation, evaporation, coagulation, coalescence, and deliquescence. Material is removed from the atmosphere by precipitation, sedimentation, and dry deposition. Chemical transformations occur both in the vapor and condensed (aerosol, raindrop) phases. The model also accounts for the sources and vertical diffusion of gases and particles, and for the changes in solar intensity caused by light-scattering from aerosols and clouds. We describe the structure of the model and compare preliminary computational results with other simulations and field data to demonstrate the accuracy of the model. It is shown that rainout and washout processes strongly influence the distributions of tropospheric gases and aerosols under certain conditions.