Boundary-Layer Meteorology

, Volume 103, Issue 3, pp 391–407 | Cite as

Momentum Transfer By A Mountain Meadow Canopy: A Simulation Analysis Based On Massman's (1997) Model

  • Georg Wohlfahrt
  • Alexander Cernusca


Using a mountain meadow as a case study it is the objective of the present paper todevelop a simple parameterisation for the within-canopy variation of the phytoelementdrag (Cd) and sheltering (Pm) coefficients required for Massman's model of momentum transfer by vegetation. A constant ratio between Cd and Pm is found to overestimate wind speed in the upper canopy and underestimate it in the lower canopy.Two simple parameterisations of Cd/Pm as a function of the plant area density and the cumulative plant area index are developed, using values optimised by least-squares regression between measured and predicted within-canopy wind speeds. A validation with independently measured data indicates that both parameterisations work reliably for simulating wind speed in the investigated meadow. Model predictions of the normalised zero-plane displacement height and the momentum roughness length fall only partly within the range of values given in literature, which may be explained by the accumulation of plantmatter close to the soil surface specific for the investigated canopies. The seasonal course of the normalised zero-plane displacement height and the momentum roughness length are discussed in terms of the seasonal variation of the amount and density of plant matter.

Canopy structure Drag coefficient Roughness length Sheltering coefficient Wind speed Zero-plane displacement height 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Albini, F. A.: 1981, 'A Phenomenological Model for Wind Speed and Shear Stress Profiles in Vegetation Cover Layers', J. Appl. Meteorol. 20, 1325–1335.CrossRefGoogle Scholar
  2. Amiro, B. D.: 1990, 'Drag Coefficients and Turbulence Spectra within Three Boreal Forest Canopies', Boundary-Layer Meteorol. 52, 227–246.CrossRefGoogle Scholar
  3. Brunet, Y., Finnigan, J. J., and Raupach, M. R.: 1994, 'A Wind Tunnel Study of Air Flow in Waving Wheat: Single-Point Velocity Statistics', Boundary-Layer Meteorol. 70, 95–132.CrossRefGoogle Scholar
  4. Goudriaan, J. and Van Laar, H. H.: 1994, Modelling Potential Crop Growth Processes, Kluwer Academic Publishers, Dordrecht, 238 pp.CrossRefGoogle Scholar
  5. Grant, R. H.: 1984, 'The Mutual Interference of Spruce Canopy Structural Elements', Agric. For. Meteorol. 32, 145–156.CrossRefGoogle Scholar
  6. Landsberg, J. J. and Powell, D. B. B.: 1973, 'Surface Exchange Characteristics of Leaves Subject to Mutual Interference', Agric. Meteorol. 12, 169–184.CrossRefGoogle Scholar
  7. Landsberg, J. J. and Thom, A. S.: 1971, 'Aerodynamic Properties of a Plant of Complex Structure', Quart. J. Roy. Meteorol. Soc. 97, 565–570.CrossRefGoogle Scholar
  8. Leuning, R., Kelliher, F.M., De Pury, D. G. G., and Schulze, E. D.: 1995, 'Leaf Nitrogen, Photosynthesis, Conductance and Transpiration: Scaling from Leaves to Canopies', Plant Cell Environ. 18, 1183–1200.CrossRefGoogle Scholar
  9. Li, Z. J., Miller, D. R., and Lin, J. D.: 1985, 'A First-Order Closure Scheme to Describe Counter-Gradient Momentum Transport in Plant Canopies', Boundary-Layer Meteorol. 33, 77–83.CrossRefGoogle Scholar
  10. Massman, W. J.: 1987, 'A Comparative Study of Some Mathematical Models of the Mean Wind Structure and Aerodynamic Drag of Plant Canopies', Boundary-Layer Meteorol. 40, 179–197.CrossRefGoogle Scholar
  11. Massman, W. J.: 1997, 'An Analytical One-Dimensional Model of Momentum Transfer by Vegetation of Arbitrary Structure', Boundary-Layer Meteorol. 83, 407–421.CrossRefGoogle Scholar
  12. Massman, W. J.: 1999, 'A Model Study of kB–1H for Vegetated Surfaces Using “Localised Near-Field” Lagrangian Theory', J. Hydrol. 223, 27–43.CrossRefGoogle Scholar
  13. Massman, W. J. and Weil, J. C.: 1999, 'An Analytical One-Dimensional Second-Order Closure Model of Turbulence Statistics and the Lagrangian Time Scale within and above Plant Canopies of Arbitrary Structure', Boundary-Layer Meteorol. 91, 81–107.CrossRefGoogle Scholar
  14. Meyers, T. and Paw U, K. T.: 1986, 'Testing of a Higher-Order Closure Model for Modelling Airflow within and above Plant Canopies', Boundary-Layer Meteorol. 37, 297–311.CrossRefGoogle Scholar
  15. Monsi, M. and Saeki, T.: 1953, 'Ñber den Lichtfaktor in den Pflanzengesellschaften und seine Bedeutung für die Stoffproduktion', Japanese J. Bot. 14, 22–52.Google Scholar
  16. Ragsdale, C. T.: 2001, Spreadsheet Modeling and Decision Analysis: A Practical Introduction to Management Science, 3rd edn. South-Western College Publishing, Australia, Cincinnati, OH, 794 pp.Google Scholar
  17. Raupach, M. R.: 1994, 'Simplified Expressions for Vegetation Roughnes Length and Zero-Plane Displacement as Functions of Canopy Height and Area Index', Boundary-Layer Meteorol. 71, 211–216.CrossRefGoogle Scholar
  18. Shaw, R. H.: 1977, 'Secondary Wind Speed Maxima Inside Plant Canopies', J. Appl. Meteorol. 16, 514–521.CrossRefGoogle Scholar
  19. Shaw, R. H. and Pereira, A. R.: 1982, 'Aerodynamic Roughness of a Plant Canopy: A Numerical Experiment', Agric. Meteorol. 26, 51–65.CrossRefGoogle Scholar
  20. Su, Z., Schmugge, T., Kustas, W. P., and Massman, W. J.: 2001, 'An Evaluation of Two Models for Estimation of the Roughness Height for Heat Transfer between the Land Surface and the Atmosphere', J. Appl. Meteorol., in press.Google Scholar
  21. Tappeiner, U. and Cernusca, A.: 1998, 'Model Simulation of Spatial Distribution of Photosynthesis in Structurally Differing Plant Communities in the Central Caucasus', Ecol. Model. 113, 201–223.CrossRefGoogle Scholar
  22. Thom, A. S.: 1968, 'The Exchange of Momentum, Mass and Heat between an Artificial Leaf and the Airflow in a Wind-Tunnel', Quart. J. Roy. Meteorol. Soc. 94, 44–55.CrossRefGoogle Scholar
  23. Thom, A. S.: 1971, 'Momentum Absorption by Vegetation', Quart. J. Roy. Meteorol. Soc. 97, 414–428.CrossRefGoogle Scholar
  24. Watanabe, T. and Kondo, J.: 1990, 'The Influence of Canopy Structure and Density upon the Mixing Length within and above Vegetation', J. Meteorol. Soc. Japan 68, 227–235.Google Scholar
  25. Wilson, N. R. and Shaw, R. H.: 1977, 'A Higher-Order Closure Model for Canopy Flow', J. Appl. Meteorol. 16, 1197–1205.CrossRefGoogle Scholar
  26. Wohlfahrt, G., Bahn, M., Tappeiner, U., and Cernusca, A.: 2000, 'A Model of Whole Plant Gas Exchange for Herbaceous Species from Mountain Grassland Sites Differing in Land Use', Ecol. Model. 125, 173–201.CrossRefGoogle Scholar
  27. Wohlfahrt, G., Bahn, M., Tappeiner, U., and Cernusca, A.: 2001, 'A Multi-Component,Multi-Species Model of Vegetation-Atmosphere CO2 and Energy Exchange for Mountain Grasslands', Agric. For. Meteorol. 106, 261–287.CrossRefGoogle Scholar
  28. Zeng, P. and Takahashi, H.: 2000, 'A First-Order Closure Model for theWind Flow within and above Vegetation Canopies', Agric. For. Meteorol. 103, 310–313.CrossRefGoogle Scholar

Copyright information

© Kluwer Academic Publishers 2002

Authors and Affiliations

  • Georg Wohlfahrt
    • 1
  • Alexander Cernusca
    • 2
  1. 1.Institut für BotanikUniversität InnsbruckInnsbruckAustria
  2. 2.Institut für BotanikUniversität InnsbruckInnsbruckAustria

Personalised recommendations