Hostname: page-component-cd9895bd7-fscjk Total loading time: 0 Render date: 2024-12-29T14:27:44.119Z Has data issue: false hasContentIssue false

Microscale temperature and velocity spectra in the atmospheric boundary layer

Published online by Cambridge University Press:  12 April 2006

R. M. Williams
Affiliation:
School of Oceanography, Oregon State University, Corvallis
C. A. Paulson
Affiliation:
School of Oceanography, Oregon State University, Corvallis

Abstract

High-frequency fluctuations in temperature and velocity were measured at a height of 2 m above a harvested, nearly level field of rye grass. Conditions were both stably and unstably stratified. Reynolds numbers ranged from 370000 to 740000. Measurements of velocity were made with a hot-wire anemometer and measurements of temperature with a platinum resistance element which had a diameter of 0[sdot ]5 μm and a length of 1 mm. Thirteen runs ranging in length from 78 to 238 s were analysed.

Spectra of velocity fluctuations are consistent with previously reported universal forms. Spectra of temperature, however, exhibit an increase in slope with increasing wavenumber as the maximum in the one-dimensional dissipation spectrum is approached. The peak of the one-dimensional dissipation spectrum for temperature fluctuations occurs at a higher wavenumber than that of simultaneous spectra of the dissipation of velocity fluctuations. It is suggested that the change in slope of the temperature spectra and the dissimilarity between temperature and velocity spectra may be due to spatial dissimilarity in the dissipation of temperature and velocity fluctuations. The temperature spectra are compared with a theoretical prediction for fluids with large Prandtl number, due to Batchelor (1959). Even though air has a Prandtl number of 0[sdot ]7, the observations are in qualitative agreement with predictions of the theory. The non-dimensional wavenumber at which the increase in slope occurs is about 0[sdot ]02, in good agreement with observations in the ocean reported by Grant et al. (1968).

For the two runs for which the stratification was stable, the normalized spectra of the temperature derivative fall on average slightly below the mean of the spectra of the remaining runs in the range in which the slope is approximately one-third. Hence the Reynolds number may not have always been sufficiently high to satisfy completely the conditions for an inertial subrange.

Universal inertial-subrange constants were directly evaluated from one-dimensional dissipation spectra and found to be 0[sdot ]54 and 1[sdot ]00 for velocity and temperature, respectively. The constant for velocity is consistent with previously reported values, while the value for temperature differs from some of the previous direct estimates but is only 20% greater than the mean of the indirect estimates. This discrepancy may be explained by the neglect in the indirect estimates of the divergence terms in the conservation equation for the variance of temperature fluctuations. There is weak evidence that the one-dimensional constant, and hence the temperature spectra, may depend upon the turbulence Reynolds number, which varied from 1200 to 4300 in the observations reported.

Type
Research Article
Copyright
© 1977 Cambridge University Press

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Antonia, R. A. & Van Atta, C. W. 1975 On the correlation between temperature and velocity dissipation fields in a heated turbulent jet. J. Fluid Mech. 67, 273.Google Scholar
Batchelor, G. K. 1959 Small-scale variation of convected quantities like temperature in a turbulent fluid. Part 1. J. Fluid Mech. 5, 113.Google Scholar
Boston, N. E. J. 1970 An investigation of high wavenumber temperature and velocity spectra in air. Ph.D. dissertation, University of British Columbia.
Boston, N. E. J. & Burling, R. W. 1972 An investigation of high-wavenumber temperature and velocity spectra in air. J. Fluid Mech. 55, 473.Google Scholar
Businger, J. A., Wyngaard, J. C., Izumi, Y. & Bradley, E. F. 1971 Flux-profile relationships in the atmospheric surface layer. J. Atmos. Sci. 28, 181.Google Scholar
Champagne, F. H., Friehe, C. A., LaRue, J. C. & Wyngaard, J. C. 1977 Flux measurements, flux estimation techniques and fine scale turbulent measurements in the surface layer over land. J. Atmos. Sci. 34, 515.Google Scholar
Clay, J. P. 1973 Turbulent mixing of temperature in water, air and mercury. Ph.D. dissertation, University of California at San Diego.
Corrsin, S. 1951 On the spectrum of isotropic temperature fluctuations in an isotropic turbulence. J. Appl. Phys. 22, 469.Google Scholar
Gibson, C. H. 1968 Fine structure of scalar fields mixed by turbulence. II. Spectral theory. Phys. Fluids 11, 2316.Google Scholar
Gibson, C. H., Lyon, R. R. & Hirschsohn, I. 1970 Reaction product fluctuations in a sphere wake. A.I.A.A. J. 8, 1859.Google Scholar
Gibson, C. H. & Schwarz, W. H. 1963 The universal equilibrium spectra of turbulent velocity and scalar fields. J. Fluid Mech. 16, 365.Google Scholar
Gibson, C. H., Stegen, G. R. & Williams, R. B. 1970 Statistics of the fine structure of turbulent velocity and temperature fields measured at high Reynolds number. J. Fluid Mech. 41, 153.Google Scholar
Grant, H. L., Hughes, B. A., Vogel, W. M. & Moilliet, A. 1968 The spectrum of temperature fluctuations in turbulent flow. J. Fluid Mech. 34, 423.Google Scholar
Gurvich, A. S. & Yaglom, A. M. 1967 Breakdown of eddies and probability distributions for small-scale turbulence. Phys. Fluids Suppl. 10, S59.Google Scholar
Kaimal, J. C., Wyngaard, J. C., Izumi, Y. & Coté, O. R. 1972 Spectral characteristics of surface-layer turbulence. Quart. J. Roy. Met. Soc. 98, 563.Google Scholar
Kistler, A. L. & Vrebalovich, T. 1966 Grid turbulence at large Reynolds numbers. J. Fluid Mech. 26, 37.Google Scholar
Kolmogorov, A. N. 1941 The local structure of turbulence in incompressible viscous fluids for very large Reynolds numbers. C. R. Acad. Sci. U.S.S.R. 30, 301.Google Scholar
Kolmogorov, A. N. 1962 A refinement of previous hypotheses concerning the local structure of turbulence in a viscous incompressible fluid at high Reynolds number. J. Fluid Mech. 13, 82.Google Scholar
Lumley, J. L. 1965 Interpretation of time spectra measured in high-intensity shear flows. Phys. Fluids 8, 6, 1056.Google Scholar
Monin, A. S. & Yaglom, A. M. 1975 Statistical Hydrodynamics, vol. 2. M.I.T. Press.
Nasmyth, P. W. 1970 Oceanic turbulence. Ph.D. dissertation, University of British Columbia.
Oboukhov, A. M. 1949 Structure of the temperature field in turbulent streams. Bull. Acad. Sci. U.S.S.R. Geogr. Geophys. Sci. 13, 58.Google Scholar
Oboukhov, A. M. 1962 Some specific features of atmospheric turbulence. J. Fluid Mech. 13, 77.Google Scholar
Paquin, J. E. & Pond, S. 1971 The determination of the Kolmogorov constants for velocity, temperature and humidity fluctuations from second- and third-order structure functions. J. Fluid Mech. 50, 257.Google Scholar
Pond, S., Smith, S. D., Hamblin, P. F. & Burling, R. W. 1966 Spectra of velocity and temperature fluctuations in the atmospheric boundary layer over the sea. J. Atmos. Sci. 23, 376.Google Scholar
Sandborn, V. A. 1972 Resistance Temperature Transducers Fort Collins, Colorado: Metrology Press.
Schedvin, J., Stegen, G. R. & Gibson, C. H. 1974 Universal similarity at high grid Reynolds numbers. J. Fluid Mech. 65, 561.Google Scholar
Schmitt, K. F., Friehe, C. A. & Gibson, C. H. 1977 Humidity sensitivity of atmospheric temperature sensors by salt contamination. Submitted to J. Phys. Ocean.Google Scholar
Schmitz, P. D. 1968 Effects of dissipation fluctuations on spectra of convected quantities. Oral presentation at Symp. Theor. Problems in Turbulence Res., Pennsylvania State Univ.
Shieh, C. M., Tennekes, H. & Lumley, J. L. 1971 Airborne hot-wire measurements of the small-scale structure of atmospheric turbulence. Phys. Fluids 14, 201.Google Scholar
Van Atta, C. W. 1971 Influence of fluctuations in local dissipation rates on turbulent scalar characteristics in the inertial subrange. Phys. Fluids 14, 1803. (Errata in Phys. Fluids 16, 574, 1973.)Google Scholar
Williams, R. M. 1974 High frequency temperature and velocity fluctuations in the atmospheric boundary layer. Ph.D. dissertation, Oregon State University.
Wyngaard, J. C. 1968 Measurement of small-scale turbulence structure with hot wires. J. Sci. Instrum. 1, 1105.Google Scholar
Wyngaard, J. C. 1971a Spatial resolution of a resistance wire temperature sensor. Phys. Fluids 14, 2052.
Wyngaard, J. C. 1971b The effect of velocity sensitivity on temperature derivative statistics in isotropic turbulence. J. Fluid Mech. 48, 763.Google Scholar
Wyngaard, J. C. & Coté, O. R. 1971 The budgets of turbulent kinetic energy and temperature variance in the atmospheric surface layer. J. Atmos. Sci. 28, 190.Google Scholar
Wyngaard, J. C. & Pao, Y. H. 1971 Some measurements of the fine structure of large Reynolds number turbulence. In Statistical Models and Turbulence, p. 384. Springer.
Wyngaard, J. C. & Tennekes, H. 1970 Measurements of the small-scale structure of turbulence at moderate Reynolds numbers. Phys. Fluids 13, 1962.Google Scholar
Yaglom, A. M. 1966 Dokl. Akad. Nauk SSSR 166, 49. (See also Sov. Phys. Dokl. 11, 26.)