Skip to main content
Journal cover image

Local isotropy and anisotropy in the sheared and heated atmospheric surface layer

Publication ,  Journal Article
Katul, GG; Parlange, MB; Albertson, JD; Chu, CR
Published in: Boundary-Layer Meteorology
January 1, 1995

Longitudinal velocity and temperature measurements above a uniform dry lakebed were used to investigate sources of eddy-motion anisotropy within the inertial subrange. Rather than simply test the adequacy of locally isotropic relations, we investigated directly the sources of anisotropy. These sources, in a daytime desert-like climate, include: (1) direct interaction between the large-scale and small-scale eddy motion, and (2) thermal effects on the small-scale eddy motion. In order to explore these two anisotropy sources, we developed statistical measures that are sensitive to such interactions. It was found that the large-scale/small-scale interaction was significant in the inertial subrange up to 3 decades below the production scale, thus reducing the validity of the local isotropy assumption. The anisotropy generated by thermal effects was also significant and comparable in magnitude to the former anisotropy source. However, this thermal anisotropy was opposite in sign and tended to counteract the anisotropy generated by the large-scale/smallscale interaction. The thermal anisotropy was attributed to organized ramp-like patterns in the temperature measurements. The impact of this anisotropy cancellation on the dynamics of inertial subrange eddy motion was also considered. For that purpose, the Kolmogorov-Obukhov structure function equation, as derived from the Navier-Stokes equations for locally isotropic turbulence, was employed. The Kolmogorov-Obukhov structure function equation in conjunction with Obukhov's constant skewness closure hypothesis reproduced the measured second- and third-order structure functions. Obukhov's constant skewness closure scheme, which is also based on the local isotropy assumption, was verified and was found to be in good agreement with the measurements. The accepted 0.4 constant skewness value derived from grid turbulence experiments overestimated our measurements. A suggested 0.26 constant skewness value, which we derived from Kolmogorov's constant, was found to be adequate. © 1995 Kluwer Academic Publishers.

Duke Scholars

Published In

Boundary-Layer Meteorology

DOI

EISSN

1573-1472

ISSN

0006-8314

Publication Date

January 1, 1995

Volume

72

Issue

1-2

Start / End Page

123 / 148

Related Subject Headings

  • Meteorology & Atmospheric Sciences
  • 3701 Atmospheric sciences
  • 0401 Atmospheric Sciences
 

Citation

APA
Chicago
ICMJE
MLA
NLM
Katul, G. G., Parlange, M. B., Albertson, J. D., & Chu, C. R. (1995). Local isotropy and anisotropy in the sheared and heated atmospheric surface layer. Boundary-Layer Meteorology, 72(1–2), 123–148. https://doi.org/10.1007/BF00712392
Katul, G. G., M. B. Parlange, J. D. Albertson, and C. R. Chu. “Local isotropy and anisotropy in the sheared and heated atmospheric surface layer.” Boundary-Layer Meteorology 72, no. 1–2 (January 1, 1995): 123–48. https://doi.org/10.1007/BF00712392.
Katul GG, Parlange MB, Albertson JD, Chu CR. Local isotropy and anisotropy in the sheared and heated atmospheric surface layer. Boundary-Layer Meteorology. 1995 Jan 1;72(1–2):123–48.
Katul, G. G., et al. “Local isotropy and anisotropy in the sheared and heated atmospheric surface layer.” Boundary-Layer Meteorology, vol. 72, no. 1–2, Jan. 1995, pp. 123–48. Scopus, doi:10.1007/BF00712392.
Katul GG, Parlange MB, Albertson JD, Chu CR. Local isotropy and anisotropy in the sheared and heated atmospheric surface layer. Boundary-Layer Meteorology. 1995 Jan 1;72(1–2):123–148.
Journal cover image

Published In

Boundary-Layer Meteorology

DOI

EISSN

1573-1472

ISSN

0006-8314

Publication Date

January 1, 1995

Volume

72

Issue

1-2

Start / End Page

123 / 148

Related Subject Headings

  • Meteorology & Atmospheric Sciences
  • 3701 Atmospheric sciences
  • 0401 Atmospheric Sciences