Temperature structure in the atmospheric surface layer

✍ Scribed by R. A. Antonia; A. J. Chambers; E. F. Bradley

• Publisher: Springer
• Year: 1981
• Tongue: English
• Weight: 826 KB
• Volume: 20
• Category: Article
• ISSN: 0006-8314
• DOI: 10.1007/bf00121374

✦ Synopsis

Production, transport and dissipation terms in the mean cube temperature equation have been evaluated from measurements in the atmospheric surface layer under moderately unstable conditions. The transpart term, calcuIated by making use of the quasi-Gaussian approximation, is, on average, comparable with the production term. The molecular destruction or dissipation term is approximately equal to the production. Since the transport and production terms are of the same sign, the magnitude of the dissipation term is only about half thal of the sum of transport and production terms. II is suggested that the imbalance is caused primarily by the assumption of isotropy in the analysis for the mean dissipation rate, II?, and the effects of various parameterizations for this quantity are discussed. The measured value of the inertial subrange co-spectral constant for the third moment of temperature is 1.17. It is subject to the uncertainty in the estimate of II?, but is unlikely to be significantly different from the spectral constant for the second moment. The ratio of dissipative time values for the thermal and velocity fields is 0.5 near neutral, reducing with increasing instability.