Boundary-Layer Meteorology

, Volume 67, Issue 3, pp 229–250 | Cite as

A saline laboratory model of the planetary convective boundary layer

  • M. F. Hibberd
  • B. L. Sawford


A laboratory water-analog of clear-air penetrative convection in the atmosphere has been constructed to continue studies of the turbulent dispersion of buoyant plumes in the convective boundary layer (CBL). A unique feature is the utilization of saline rather than thermal convection, which has been made possible by the development of a reliable method for delivering a controllable buoyancy flux through a porous membrane. It has been shown in an earlier paper that at typical laboratory scales, a saline convection tank is well suited to modelling buoyant plume dipersion under strongly convective (light wind) conditions.

A range of experiments has clearly demonstrated the validity of the model. Results for density and velocity variances show much less scatter than most comparable measurements because of the greatly improved sampling that is possible in the tank. The results are generally in good agreement with field data and other laboratory simulations but the improved accuracy of the data has highlighted the anomalously low values for the horizontal velocity variances produced by large-eddy simulations of the CBL. The cause of this apparent underprediction remains unresolved.


Convection Horizontal Velocity Velocity Variance Convective Boundary Layer Thermal Convection 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Adrian, R. J., Ferreira, R. T. D. S., and Boberg, T.: 1986, ‘Turbulent Thermal Convection in Wide Horizontal Fluid Layers’,Experiments in Fluids 4, 121–141.Google Scholar
  2. Briggs, G. A.: 1985, ‘Analytical Parameterizations of Diffusion: The Convective Boundary Layer’,J. Clim. Appl. Meteorol. 24, 1167–1186.Google Scholar
  3. Caughey, S. J. and Palmer, S. G.: 1979, ‘Some Aspects of Turbulence Structure Through the Depth of the Convective Boundary Layer’,Quart. J. R. Meteorol. Soc. 105, 811–827.Google Scholar
  4. Cenedese, A. and Querzoli, G.: 1991, ‘A Laboratory Model of Turbulent Convection in the Atmospheric Boundary Layer’,Fifth International Workshop on Wind and Water Tunnel Modelling of Atmospheric Flow and Dispersion, 30 Oct–1 Nov, Stevenage, UK.Google Scholar
  5. Coulman, C. E.: 1978, ‘Boundary-Layer Evolution and Nocturnal Inversion Dispersal — Part II’,Boundary-Layer Meteorol. 14, 493–513.Google Scholar
  6. Deardorff, J. W.: 1970, ‘Convective Velocity and Temperature Scales for the Unstable Planetary Boundary Layer and for Rayleigh Convection’,J. Atmos. Sci. 27, 1211–1213.Google Scholar
  7. Deardorff, J. W.: 1985, ‘Laboratory Experiments on Diffusion: The Use of Convective Mixed-Layer Scaling’,J. Clim. Appl. Meteorol. 24, 1143–1151.Google Scholar
  8. Deardorff, J. W. and Willis, G. E.: 1975, ‘A Parameterization of Diffusion into the Mixed Layer’,J. Appl. Meteorol. 14, 1451–1458.Google Scholar
  9. Deardorff, J. W. and Willis, G. E.: 1984, ‘Groundlevel Concentration Fluctuations from a Buoyant and a Non-buoyant Source within a Laboratory Convectively Mixed Layer’,Atmos. Environ. 18, 1297–1309. See also discussion inAtmos. Environ. 19 (1985), 1210–1213.Google Scholar
  10. Deardorff, J. W. and Willis, G. E.: 1985, ‘Further Results From a Laboratory Model of the Convective Planetary Boundary Layer’,Boundary-Layer Meteorol. 32, 205–236.Google Scholar
  11. Deardorff, J. W. and Willis, G. E.: 1988, ‘Concentration Fluctuations Within a Laboratory Convectively Mixed Layer’, in A. Venkatram and J. C. Wyngaard (eds.),Lectures on Air Pollution Modeling, Am. Meteorol. Soc., Boston, pp. 357–384.Google Scholar
  12. Deardorff, J. W., Willis, G. E., and Stockton, B. H.: 1980, ‘Laboratory Studies of the Entrainment Zone of a Convectively Mixed Layer’,J. Fluid Mech. 100, 41–64.Google Scholar
  13. Hadfield, M. G., Cotton, W. R., and Pielke, R. A.: 1992, ‘Large-Eddy Simulations of Thermally forced Circulations in the Convective Boundary Layer. Part II: The Effects of Changes in Wavelength and Wind Speed’,Boundary-Layer Meteorol. 58, 307–327.Google Scholar
  14. Hibberd, M. F.: 1992, ‘Turbulence Statistics from a Multi-frame particle Tracking Technique’,Eleventh Australasian Fl. Mech. Conf. 14–18 Dec., Hobart, Australia, Vol.II, 1073–1076.Google Scholar
  15. Hibberd, M. F. and Sawford, B. L.: 1994, ‘Design Criteria for Water Tank Models of Dispersion in the Planetary Convective Boundary Layer’,Boundary-Layer Metoerol. (in press).Google Scholar
  16. Hicks, B. B.: 1985, ‘Behavior of Turbulence Statistics in the Convective Boundary Layer’,J. Clim. Appl. Meteorol. 24, 607–614.Google Scholar
  17. Hildebrand, P. H. and Ackerman, B.: 1984, ‘Urban Effects on the Convective Boundary Layer’,J. Atmos. Sci. 41, 76–91.Google Scholar
  18. Imberger, J., Thompson, R., and Fandry, C.: 1976, ‘Selective Withdrawal From a Finite Rectangular Tank’,J. Fluid Mech. 78, 489–512.Google Scholar
  19. Kumar, R. and Adrian, R. J.: 1986, ‘Higher Order Moments in the Entrainment Zone of Turbulent Penetrative Thermal Convection’,Trans. ASME, J. Heat Transfer 108, 323–329.Google Scholar
  20. Lenschow, D. H. and Stephens, P. L.: 1980, ‘The Role of Thermals in the Convective Boundary Layer’,Boundary-Layer Meteorol. 19, 509–532.Google Scholar
  21. Lenschow, D. H., Wyngaard, J. C., and Pennell, W. T.: 1980, ‘Mean-Field and Second-Moment Budgets in a Baroclinic, Convective Boundary Layer’,J. Atmos. Sci. 37, 1313–1326.Google Scholar
  22. Mason, P. J.: 1989, ‘Large-Eddy Simulation of the Convective Atmospheric Boundary Layer’,J. Atmos. Sci. 46, 1492–1516.Google Scholar
  23. Melbourne, W. H., Taylor, T. J., and Grainger, C. F.: 1993, ‘Dispersion Modelling in Convective Wind Flows’,Atmos. Environ. (submitted).Google Scholar
  24. Meroney, R. N. and Melbourne, W. H.: 1992, ‘Operating Ranges of Meteorological Wind Tunnels for the Simulation of Convective Boundary Layer (CBL) Phenomena’,Boundary-Layer Meteorol. 61, 145–174.Google Scholar
  25. Nicholls, S. and LeMone, M. A.: 1980, ‘The Fair Weather Boundary Layer in GATE: The Relationship of Subcloud Fluxes and Structure to the Distribution and Enhancement of Cumulus Clouds’,J. Atmos. Sci. 37, 2051–2067.Google Scholar
  26. Nieuwstadt, F. T. M., Mason, P. J., Moeng, C. H., and Schumann, U.: 1992, ‘Large-eddy Simulation of the Convective Boundary Layer: A Comparison of Four Computer Codes’,Turbulent Shear Flows 8, Springer, pp. 343–367.Google Scholar
  27. Ohba, R., Kakishima, S., and Ito, S.: 1991, ‘Water Tank Experiment of Gas Diffusion From a Stack in Stably and Unstably Stratified Layers Under Calm Conditions’,Atmos. Environ. 25A, 2063–2076.Google Scholar
  28. Oster, G. and Yamamoto, M.: 1963, ‘Density Gradient Techniques’,Chem. Rev. 63, 257–268.Google Scholar
  29. Poreh, M. and Cermak, J. E.: 1984, ‘Wind Tunnel Simulation of Diffusion in a Convective Boundary Layer’,Boundary-Layer Meteorol. 30, 431–455.Google Scholar
  30. Poreh, M., Rau, M., and Plate, E. J.: 1991, ‘Design Considerations for Wind Tunnel Simulations of Diffusion within the Convective Boundary Layer’,Atmos. Environ. 25A, 1251–1256.Google Scholar
  31. Priestley, C. H. B.: 1960, ‘Temperature Fluctuations in the Atmospheric Boundary Layer’,J. Fluid Mech. 7, 375–384.Google Scholar
  32. Schmidt, H.: 1988,Grobstruktur-Simulation konvektiver Grenzschichten, Dissertation, Ludwig-Maximilians-Universität München, Report DFVLR-FB 88-30.Google Scholar
  33. Schmidt, H. and Schumann, U.: 1989, ‘Coherent Structure of the Convective Boundary Layer Derived from Large-Eddy Simulations’,J. Fluid Mech. 200, 511–562.Google Scholar
  34. Sorbjan, Z.: 1991, ‘Evaluation of Local Similarity Functions in the Convective Boundary Layer’,J. Appl. Meteorol. 30, 1565–1583.Google Scholar
  35. Sykes, R. I. and Henn, D. S.: 1989, ‘Large-Eddy Simulation of Turbulent Sheared Convection’,J. Atmos. Sci. 46, 1106–1118.Google Scholar
  36. Weil, J. C.: 1985, ‘Updating Applied Diffusion Models’,J. Clim. Appl. Meteorol. 24, 1111–1130.Google Scholar
  37. Willis, G. E. and Deardorff, J. W.: 1974, ‘A Laboratory Model of the Unstable Planetary Boundary Layer’,J. Atmos. Sci. 31, 1297–1307.Google Scholar
  38. Willis, G. E. and Deardorff, J. W.: 1976, ‘A Laboratory Model of Diffusion into the Convective Planetary Boundary Layer’,Quart. J. Roy. Meteorol. Soc. 102, 427–445.Google Scholar
  39. Willis, G. E. and Deardorff, J. W.: 1978, ‘A Laboratory Study of Dispersion from an Elevated Source within a Modeled Convective Planetary Boundary Layer’,Atmos. Environ 12, 1305–1311.Google Scholar
  40. Willis, G. E. and Deardorff, J. W.: 1981, ‘A Laboratory Study of Dispersion from a Source in the Middle of the Convectively Mixed Layer’,Atmos. Environ. 15, 109–117.Google Scholar
  41. Willis, G. E. and Deardorff, J. W.: 1983, ‘On Plume Rise Within a Convective Boundary Layer’,Atmos. Environ. 17, 2435–2447. See also discussion inAtmos. Environ. 19 (1985), 1210–1213.Google Scholar
  42. Willis, G. E. and Deardorff, J. W.: 1987, ‘Buoyant Plume Dispersion and Inversion Entrapment In and Above a Laboratory Mixed Layer’,Atmos. Environ. 21, 1725–1735.Google Scholar
  43. Wyngaard, J. C. and LeMone, M. A.: 1980, ‘Behaviour of the Refractive Index Structure Parameter in the Entraining Convective Boundary Layer’,J. Atmos. Sci. 37, 1573–1585.Google Scholar
  44. Young, G. S.: 1988a, ‘Turbulence Structure of the Convective Boundary Layer. Part I: Variability of Normalized Turbulence Statistics’,J. Atmos. Sci. 45, 719–726.Google Scholar
  45. Young, G. S.: 1988b, ‘Turbulence Structure of the Convective Boundary Layer. Part II: Phoenix 78 Aircraft Observations of Thermals and Their Environment’,J. Atmos. Sci. 45, 727–735.Google Scholar
  46. Zilitinkevich, S. S.: 1991,Turbulent Penetrative Convection, Avebury Technical, Aldershot, U.K.Google Scholar

Copyright information

© Kluwer Academic Publishers 1994

Authors and Affiliations

  • M. F. Hibberd
    • 1
  • B. L. Sawford
    • 1
  1. 1.CSIRO Division of Atmospheric ResearchAspendaleAustralia

Personalised recommendations