Abstract
During the Limagne and Beauce experiments, the INAG-IGN Aerocommander FL 280 aircraft made extensive ‘in situ’ measurements of turbulent fluctuations in diurnally evolving convective boundary layers. In this paper, these measurements were used to investigate characteristics of the molecular dissipation of turbulent fluctuations through the mixed layer and well into the overlying stable layer. The dimensionless dissipation rates of turbulent kinetic energy, temperature and humidity variances, and temperature-humidity covariance (ψ, ψθ, ψ qand ψ θq) were computed and their height variations analysed.
The behaviour of the dissipation rate ψ was found to differ significantly from those observed for the other rates. In the lowest region of the mixed layer, ψ does not obey the local free convection prediction. Instead, it follows practically a relationship similar to the one established in the surface layer by Wyngaard et al. (1971). The dissipation rate ψ remains fairly constant in the bulk of the mixed layer (0.3 ≤ z/Z i≤ 0.8) and shows a very rapid decrease above the inversion. These results confirm those reported previously from the Minnesota and Ashchurch data by Kaimal et al. (1976), Caughey and Palmer (1979), etc.
The height variations for the other dissipation rates were found to obey, as expected, the (z/Z i)-4/3 decrease predicted under the local free convection similarity hypothesis in the lowest region of the mixed layer. This region extends to the height z/Z i- 0.4, 0.1, and 0.3, respectively, for ψθ, ψq, and ψθq. Above these levels, the dissipation rates ψθ and ψq show, on average, a slight increase to reach peak-values near the mixed-layer top, while the ‘dissipation’ rate ψ θqchanges sign from positive to negative around the height z/Z i, - 0.7. These characteristics confirm the fact that the structures of temperature and humidity fluctuations are considerably affected by their entrainment-induced fluctuations. Therefore, an attempt has been made to non-dimensionalize the dissipation rates near the mixed-layer top with the interfacial scaling factors.
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References
André, J. C. and Artaz, M. A.: 1980, ‘Paramétrisation du profil de la variance de température dans la couche limite planétaire convective’, C. R. Acad. Sci., Paris 290B, 191–194.
Busch, N. E.: 1973, in D. A. Haugen (ed.), ‘On the Mechanics of Atmospheric Turbulence’, Workshop on Micrometeorotogy, American Meteorological Society, Boston.
Caughey, S. J. and Rayment, R.: 1974, ‘High-Frequency Temperature Fluctuations in the Atmospheric Boundary Layer’, Boundary-Layer Meteorol. 4, 489–504.
Caughey, S. J. and Wyngaard, J. C.: 1979, ‘The Turbulence Kinetic Energy Budget in Convective Conditions’, Quart. J. Roy. Meteorol. Soc. 105, 231–239.
Caughey, S. J. and Palmer, S. G.: 1979, ‘Some Aspects of Turbulence Structure Through the Depth of the Convective Boundary Layer’, Quart. J. Roy. Meteorol. Soc. 105, 811–827.
Champagne, F. H., Friehe, C. A., La Rue, J. C., and Wyngaard, J. C.: 1977, ‘Flux Measurements, Flux Estimation Techniques and Fine Scale Turbulence Measurements in the Unstable Surface Layer over Land’, J. Atmos. Sci. 34, 515–530.
Coulman, C. E.: 1978, ‘Boundary-Layer Evolution and Nocturnal Inversion Dispersal — Part II’, Boundary-Layer Meteorol. 14, 493–513.
Deardorff, J. W.: 1974a, ‘Three-Dimensional Numerical Study of the Height and Mean Structure of a Heated Planetary Boundary Layer’, Boundary-Layer Meteorol. 7, 81–106.
Deardorff, J. W.: 1974b, ‘Three-Dimensional Numerical Study of Turbulence in an Entraining Mixed Layer’, Boundary-Layer Meteorol. 7, 199–226.
Donelan, M. and Miyake, M.: 1973, ‘Spectra and Fluxes in the Boundary Layer of the Trade-Wind Zone’, J. Atmos. Sci. 30, 444–464.
Frangi, J. P.: 1979, ‘Contribution à l'étude de la structure verticale des principales caractéristiques turbulentes de la couche limite planétaire’, Thèse de 3ème cycle, Université de Paris 7, 108 pp.
Guillemet, B., Mascart, P., Ravaut, M., and Isaka, H.: 1977, ‘Calibrage autonome et correction d'un système aéroporté pour la mesure du vent horizontal’, J. Rech. Atmos. 11, 9–37.
Guillemet, B., Jouvenaux, S., Mascart, P., and Isaka, H.: 1978, ‘Normalisation des ts du deuxième ordre de la vitesse verticale de l'air et de la température dans la couche limite convective’, J. Rech. Atmos. 12, 229–243.
Guillemet, B. and Isaka, H.: 1983, ‘Spectral Analysis of Turbulence Structure in Convective Boundary Layer’, (in prep.).
Jouvenaux, S.: 1978, ‘Etude expérimentale de la structure turbulente de la couche de mélange convective’, Thèse de 3ème cycle, Université de Clermont-Ferrand II, 119 pp.
Kaimal, J. C.: 1973, ‘Turbulence Spectra, Length Scales, and Structure Parameters in the Stable Surface Layer’, Boundary-Layer Meteorol. 4, 289–309.
Kaimal, J. C., Wyngaard, J. C., Haugen, D. A., Coté, O. R., Izumi, Y., Caughey, S. J., and Reading, C. J.: 1976, ‘Turbulent Structure in the Convective Boundary Layer’, J. Atmos. Sci. 33, 2153–2169.
Lenschow, D. H.: 1970, ‘Airplane Measurements of Planetary Boundary Layer’, J. Appl. Meteorol. 9, 874–884.
Lenschow, D. H., Wyngaard, J. C., and Pennell, W. T.: 1980, ‘Mean-Field Second-Moment Budgets in a Baroclinic Convective Boundary Layer’, J. Atmos. Sci. 37, 1313–1326.
Mascart, P., Guillemet, B., and Isaka, H.: 1978a, ‘Ondes de gravité interfaciales marginalement instables dans la couche limite planétaire’, Boundary Layer Meteorol. 14, 283–299.
Mascart, P., Isaka, H., and Guillemet, B.: 1978b, ‘Kelvin-Helmholtz Waves Observed by Aircraft at Different Stages of their Life-Cycle in a Low-Level Inversion’, Boundary-Layer Meteorol. 15, 31–55.
Pennell, W. T. and LeMone, M. A.: 1974, ‘An Experimental Study of Turbulence Structure in the Fair-Weather Trade Wind Boundary Layer’, J. Atmos. Sci. 31, 1308–1323.
Ravaut, M.: 1975, in M. Ravaut and H. Isaka (eds.), ‘L'avion de recherche atmosphérique INAG-IGN’, Méthodologie des mesures aériennes en météorologie, Laboratoire Associé de Météorologie Physique, Université de Clermont-Ferrand II, 103 pp.
Rayment, R.: 1973, ‘An Observational Study of the Vertical Profile of the High-Frequency Fluctuations of the Wind in the Atmospheric Boundary Layer’, Boundary-Layer Meteorol. 3, 284–300.
Tuzet, A.: 1982, ‘Contribution à l'étude des lois de similitude dans la couche limite planétaire en régime convectif’, Thèse de 3ème cycle, Université de Clermont-Ferrand II, 71 pp.
Tuzet, A., Guillemet, B., and Isaka, H.: 1983, ‘Sur les échelles interfaciales de fluctuations de température et d'humidité’, submitted to J. Rech. Atmos.
Williams, R. M., Jr. and Paulson, C. A.: 1977, ‘Microscale Temperature and Velocity Spectra in the Atmospheric Boundary Layer’, J. Fluid Mech. 83, 547–567.
Wyngaard, J. C.: 1973, in A. Haugen (ed.), ‘On Surface Layer Turbulence’, Workshop on Micrometeorology, American Meteorological Society, 101–148.
Wyngaard, J. C. and Coté, O. R.: 1971, ‘The Budgets of Turbulent Kinetic Energy and Temperature Variance in the Atmospheric Surface Layer’, J. Atmos. Sci. 28, 190–201.
Wyngaard, J. C., Coté, O. R., and Izumi, Y.: 1971, ‘Local Free Convection, Similarity, and the Budgets of Shear Stress and Heat Flux’, J. Atmos. Sci. 28, 1171–1182.
Wyngaard, J. C., Pennell, W. T., Lenschow, D. H., and LeMone, M. A.: 1978, ‘The Temperature-Humidity Covariance Budget in the Convective Boundary Layer’, J. Atmos. Sci. 35, 47–58.
Wyngaard, J. C. and LeMone, M. A.: 1980, ‘Behavior of the Refractive Index Structure Parameter in the Entraining Convective Boundary Layer’, J. Atmos. Sci. 37, 1573–1585.
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On leave from Observatoire du Puy de Dôme, Université de Clermont II, France.
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Guillemet, B., Isaka, H. & Mascart, P. Molecular dissipation of turbulent fluctuations in the convective mixed layer part I: Height variations of dissipation rates. Boundary-Layer Meteorol 27, 141–162 (1983). https://doi.org/10.1007/BF00239611
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DOI: https://doi.org/10.1007/BF00239611