Geostrophic departure and the functions A and B of Rossby-number similarity theory Article

Received: 13 February 1974 DOI :
10.1007/BF00240832

Cite this article as: Clarke, R.H. & Hess, G.D. Boundary-Layer Meteorol (1974) 7: 267. doi:10.1007/BF00240832
Abstract A new empirical assessment of the functions A and B of Rossby-number similarity theory is made based on the Wangara data. Variations of these functions with stability, baroclinicity and time of day are discussed. It is found that B is dependent on stability in agreement with older data but contradicting the prediction of Csanady (1972). Coefficients expressing the variation of A and B with the two components of baroclinicity have been derived from the data, and these are claimed to be correct in regard to sign and approximately in regard to magnitude. Longer period time changes, represented by the diurnal cycle, are shown to result in systematic differences in A and B between the case of increasing stability and that of decreasing stability, for the same value of the stability parameter.

The first attempt, to our knowledge, to present the actual functional form of the wind departure components (based on field data) is made. As the surface layer is approached in near-neutral conditions, the departure component in the direction of the surface wind assumes the expected logarithmic form.

References Arya, S. P. S.: 1974, ‘Geostrophic Drag and Heat Transfer Relations for the Atmospheric Boundary Layer’, to be published.

Blackadar, A. K.: 1965, ‘A Single Layer Theory of the Vertical Distribution of Wind in a Baroclinic Neutral Atmospheric Boundary Layer’, in Flux of Heat and Momentum in the Planetary Boundary Layer of the Atmosphere ', Final report, pp. 1–22, Penn. State Univ., Meteorology Dept., Contract AFCRL-65-531.

Bradley, E. F.: 1972, The Influence of Thermal Stability on a Drag Coefficient Measured Close to the Ground,

Agric. Meteorol.
9 , 183–190.

Google Scholar Clarke, R. H.: 1970a, Observational Studies in the Atmospheric Boundary Layer,

Quart. J. Roy. Meteorol. Soc.
96 , 91–114.

Google Scholar Clarke, R. H.: 1970b, Recommended Methods for the Treatment of the Boundary Layer in Numerical Models,

Australian Meteorol. Mag.
18 , 51–73.

Google Scholar Clarke, R. H.: 1972, Discussion of “Observational Studies in the Atmospheric Boundary Layer”,

Quart. J. Roy. Meteorol. Soc.
98 , 234–235.

Google Scholar Clarke, R. H.: 1973, Note on the Variability of Empirical Determinations of the Functions

A (Μ) and

B (Μ) of Rossby-Number Similarity Theory,

Beiträge Phys. Atmos.
46 , 64–65.

Google Scholar Clarke, R. H. and Hess, G. D.: 1973, On the Appropriate Scaling for Velocity and Temperature in the Planetary Boundary Layer,

J. Atmospheric Sci.
30 , 1346–1353.

Google Scholar Clarke, R. H., Dyer, A. J., Brook, R. R., Reid, D. G., and Troup, A. J.: 1971, ‘The Wangara Experiment: Boundary Layer Data‘, Technical Paper No. 19, CSIRO, Div. Meteorol. Phys. 362 pp.

Csanady, G. T.: 1972, Geostrophic Drag, Heat and Mass Transfer Coefficients for the Diabatic Ekman Layer,

J. Atmospheric Sci.
29 , 488–496.

Google Scholar Csanady, G. T.: 1973, Reply to Comments on “Geostrophic Drag, Heat and Mass Transfer Coefficients for the Diabatic Ekman Layer”,

J. Atmospheric Sci.
30 , 155–156.

Google Scholar Deacon, E. L.: 1957, Wind Profiles and Shearing Stress — an Anomaly Resolved,

Quart. J. Roy. Meteorol. Soc.
83 , 537–540.

Google Scholar Deacon, E. L.: 1973, Geostrophic Drag Coefficients,

Boundary-Layer Meteorol.
5 , 321–340.

Google Scholar Deardorff, J. W.: 1972, Numerical Investigation of Neutral and Unstable Planetary Boundary Layers,

J. Atmospheric Sci.
29 , 91–115.

Google Scholar Fiedler, F.: 1972, The Effect of Baroclinicity on the Resistance Law in a Diabatic Ekman Layer,

Beiträge Phys. Atmos.
45 , 164–173.

Google Scholar Gill, A. E.: 1968, Similarity Theory and Geostrophic Adjustment,

Quart. J. Roy. Meteorol. Soc.
94 , 586–588.

Google Scholar Hess, G. D.: 1973, On Rossby-Number Similarity Theory for a Baroclinic Planetary Boundary Layer,

J. Atmospheric Sci.
30 , 1722–1723.

Google Scholar Kazansky, A. B. and Monin, A. S.: 1960, A Turbulent Regime Above the Ground Atmospheric Layer,

Izv Acad. Sci. U.S.S.R. Geophys. Ser.
1 , 110–112.

Google Scholar Swinbank, W. C. and Dyer, A. J.: 1968, ‘Micrometeorological Experiments 1962–1964’, Technical Paper No. 17, CSIRO, Div. Meteorol. Phys. 48 pp.

Vager, B. G. and Zilitinkevich, S. S.: 1968, A Theoretical Model of the Daily Oscillation of Meteorological Fields,

Meteorol. Hydrol. U.S.S.R.
7 , 3–18.

Google Scholar Webb, E. K.: 1970, Profile Relationships: the Log-Linear Range, and Extension to Strong Stability,

Quart. J. Roy. Meteorol. Soc.
96 , 67–90.

Google Scholar Wippermann, F.: 1972, Baroclinic Effects on the Resistance Law of the Planetary Boundary Layer of the Atmosphere,

Beiträge Phys. Atmos.
45 , 244–259.

Google Scholar Zilitinkevich, S. S. and Chalikov, D. V.: 1968, The Laws of Resistance and of Heat and Moisture Exchange in the Interaction Between the Atmosphere and Underlying Surface,

Izv. Atmospheric Oceanic Phys.
4 , 438–441.

Google Scholar © D. Reidel Publishing Company 1974

Authors and Affiliations 1. CSIRO Division of Atmospheric Physics Aspendale Australia