Abstract
When the wind profiles measured at the 200 m meteorological tower at Cabauw are observed, we see that under nearly neutral conditions two logarithmic parts can be distinguished with a junction at about 20 m height. This is attributed to perturbations in the upstream surface condition. Two effects are important, viz., the increase of shear stress with height, and deviations from the ordinary flux-profile relationships. The former effect is illustrated by means of a simple model for sparsely distributed obstructions in a smooth area. The latter effect is discussed on the basis of existing data on heat and momentum fluxes. Conclusions are drawn about the possibility of deriving fluxes from profiles in perturbed situations.
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Antonia, R. A. and Luxton, R. E.: 1971, ‘‘The Response of a Turbulent Boundary Layer to a Step Change in Surface Roughness’, Part 1: ‘Smooth to Rough’, ’, J. Fluid Mech. 48, 721. Part 2: ‘Rough to Smooth’, J. Fluid Mech. 53, 737.
Bruin, H. A. R. de: 1982, ‘Energy Balance of the Earth's Surface: A Practical Approach’, Ph.-D. Thesis, KNMI, The Netherlands.
Businger, J. A., Wyngaard, J. C., Izumi, Y., and Bradley, E. F.: 1971, ‘Flux-Profile Relationships in the Atmospheric Surface Layer’, J. Atmos. Sci. 28, 181–189.
Davenport, A. G.: 1960, ‘Rationale for Determining Design Wind Velocities’, J. Am. Soc. Civ. Eng. (Struct. Div.) 86, 39–68.
Driedonks, A. G. M., Dop, H. van, and Kohsiek, W. H.: 1978, 4th Symp. Met. Obs. Instr., Denver, Colorado.
Dyer, A. J. and Hicks, B. B.: 1970, ‘Flux-Gradient Relationships in the Constant Flux Layer’, Quart. J. Roy. Meteorol. Soc. 96, 715–721.
Fiedler, F. and Panofsky, H. A.: 1972, ‘The Geostrophic Drag Coefficient and the “Effective Roughness Length”’, Quart. J. Roy. Meteorol. Soc. 98, 213–220.
Korrell, A., Panofsky, H. A., and Rossi, R. J.: 1982, ‘Wind Profiles at the Boulder Tower’, Boundary-Layer Meteorol. 22, 295–312.
Nieuwstadt, F. T. M.: 1978, ‘The Computation of the Friction Velocity u * and the Temperature Scale T * from Temperature and Wind Velocity Profiles by Least Square Methods’, Boundary-Layer Meteorol. 14, 235–246.
Panofsky, H. A. and Townsend, A. A.: 1964, ‘Change of Terrain Roughness and the Wind Profile’, Quart. J. Roy. Meteorol. Soc. 90, 147–155.
Panofsky, H.: 1972, ‘Tower Micrometeorology’, in D. A. Haugen (ed.), Workshop on Micrometeorology. Am. Meteorol. Soc., Boston, Mass.
Peterson, E. W.: 1969, ‘On the Relation between the Shear Stress and the Velocity Profile after a Change in Surface Roughness’, J. Atmos. Sci. 26, 773–774.
Plate, E. J.: 1971, ‘Aerodynamic Characteristics of Atmospheric Boundary Layers’, AEC Critical Review Series, Washington, D.C.
Taylor, P. A.: 1981, ‘Model Predictions of Neutrally Stratified Planetary Boundary Layer over Ridges’, Quart. J. Roy. Meteorol. Soc. 107, 111–120.
Tennekes, H.: 1972, ‘Similarity Laws and Scale Relations in Planetary Boundary Layers’, in D. A. Haugen (ed.), Workshop on Micrometeorology, Am. Meteorol. Soc., Boston, Mass.
Townsend, A. A.: 1965, ‘The Response of a Turbulent Boundary Layer to Abrupt Changes in Surface Conditions’, J. Fluid Mech. 22, 799.
Wieringa, J.: 1976, ‘An Objective Exposure Correction Method for Average Wind Speeds Measured at a Sheltered Location’, Quart. J. Roy. Meteorol. Soc. 102, 241–253.
Wieringa, J.: 1980, ‘Representativeness of Wind Observations at Airports’, Bull. Am. Meteorol. Soc. 61, 962.
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Beljaars, A.C.M. The derivation of fluxes from profiles in perturbed areas. Boundary-Layer Meteorol 24, 35–55 (1982). https://doi.org/10.1007/BF00121798
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DOI: https://doi.org/10.1007/BF00121798