Abstract
Nighttime data collected at the bottom of a valley locatedin southern Brazil are studied. The analyzed quantities includemomentum and sensible heat fluxes, turbulence statistics andintermittency factors, and their relationship to the stability parameter.The proper interval for averaging and flux calculations is foundto be 20 min, based on the comparison of the fluxes and therandom error associated in their determination. Each data seriesis classified as calm or windy, according to the mean windspeed. A much better dependency of the variables in terms of thestability parameter is found under windy conditions. Analysis ofthe wind direction and topographic scales indicates that distortioneffects under calm conditions affect the flow, while the flow is inlocal equilibrium for windy conditions. In this case, the sensible heatflux shows a minimum for a value of z/L=0.08, while the momentumflux and the normalized scales of the wind components andtemperature decrease monotonically as the stability increases. Anintermittency factor is proposed and shown to be larger (moreintermittency) for more stable conditions.
Similar content being viewed by others
References
Acevedo, O. C. and Fitzjarrald, D. R.: 2003, 'In the Core of the Night-Effects on Intermittent Mixing on a Horizontally Heterogeneous Surface', Boundary-Layer Meteorol. 106, 1–33.
Arya, S. P.: 1988, Introduction to Micrometeorology, Academic Press, San Diego, 307 pp.
Beljaars, A. C. M. and Holtslag, A. A. M.: 1991, 'Flux Parameterization over Land Surfaces for Atmospheric Models', J. Appl. Meteorol. 30, 327–341.
Bradley, E. F.: 1980, 'An Experimental Study of the Profiles of the Wind Speed, Shearing Stress and Turbulence at the Crest of a Large Hill', Quart. J. Roy. Meteorol. Soc. 106, 101–124.
Businger, J. A., Wyngaard, J. C., Izumi, Y., and Bradley, E. F.: 1971, 'Flux-Profile Relationships in the Atmospheric Surface Layer', J. Atmos. Sci. 28, 181–189.
Coulter, R. L.: 1990, 'A Case Study of Turbulence in the Stable Nocturnal Boundary Layer', Boundary-Layer Meteorol. 52, 75–91.
Derbyshire, H.: 1990, 'Nieuwstadt Stable Boundary Layer Revisited', Quart. J. Roy. Meteorol. Soc. 116, 127–158.
Dias, N. L., Brutsaert, W., and Wesely, M. L.: 1995, 'Z-less Stratification under Stable Conditions', Boundary-Layer Meteorol. 75, 175–187.
Dyer, A. J.: 1974, 'A Review of Flux-Profile Relationships', Boundary-Layer Meteorol. 7, 363–372.
Founda, D., Trombou, D., Lalas, D. P., and Asimakopoulos, D. N.: 1987, 'Some Measurements of Turbulence Characteristics over Complex, Terrain', Boundary-Layer Meteorol. 83, 221–245.
Goulden, M. L., Munger, J. W., Fan, S-W, Daube, B.C., and Wofsy, S. C.: 1996, 'Measurements of Carbon Storage by Long Term Eddy Correlation: Methods and a Critical Evaluation of Accuracy', Global Change Biol. 2, 169–182.
Hicks, B. B.: 1981, 'An Examination of Turbulence Statistics in the Surface Layer', Boundary-Layer Meteorol. 21, 389–402.
HÖgstrÖm, U.: 1988, 'Non-Dimensional Wind and Temperature Profiles in the Atmospheric Surface Layer: A Re-Evaluation', Boundary-Layer Meteorol. 42, 55–78.
Holt, S. E., Koseff, J. R., and Ferzinger, J. H.: 1992, 'A Numerical Study of the Evolution and Structure of Homogeneous Stably Stratified Sheared Turbulence', J. Fluid Mech. 237, 499–539.
Howell, J. F. and Sun, J.: 1999, 'Surface-Layer Fluxes in Stable Conditions', Boundary-Layer Meteorol. 90, 495–520.
Kaimal, J. C. and Finnigan, J. J.: 1994, Atmospheric Boundary Layer Flows, Oxford University Press, Oxford, 289 pp.
Kaltenbach, H.-J., Gerz, T., and Schumann, U.: 1994, 'Large-Eddy Simulation of Homogeneous Turbulence and Diffusion in Stably Stratified Shear Flow', J. Fluid Mech. 280, 1–40.
Kondo, J., Kanechika, O., and Yasuda, N.: 1978, 'Heat and Momentum Transfers under Strong Stability in the Atmospheric Surface Layer', J. Atmos. Sci. 35, 1012–1021.
Lienhard, J. H. and Van Atta, C. W.: 1990, 'The Decay of Turbulence in Thermally Stratified Flow', J. Fluid Mech. 210, 57–112.
Mahli, Y. S.: 1995: 'The Significance of the Dual Solutions for Heat Fluxes Measured by the Temperature Fluctuation Method in Stable Conditions', Boundary-Layer Meteorol. 74, 389–396.
Mahrt, L.: 1985, 'Vertical Structure and Turbulence in the Very Stable Boundary Layer', J. Atmos. Sci. 42, 2333–2349.
Mahrt, L.: 1999, 'Stratified Atmospheric Boundary Layers', Boundary-Layer Meteorol. 90, 375–396.
Mahrt, L., Sun, J., Blumen, W., Delany, T., and Oncley, S.: 1998, 'Nocturnal Boundary-Layer Regimes', Boundary-Layer Meteorol. 88, 255–278.
Mason, P. J. and King, J. C.: 1985, 'Measurements and Predictions of Flow and Turbulence over an Isolated Hill of Moderate Slope', Quart. J. Roy. Meteorol. Soc. 111, 617–640.
Mickle, R. E., Cook, N. J., Hoff, A. M., Jensen, N. O., Salmon, J. R., Taylor, P. A., Tetzlaff, G., and Teunissen, H. W.: 1988, 'The Askervein Hill Project: Vertical Profiles of Wind and Turbulence', Boundary-Layer Meteorol. 43, 143–169.
Moraes, O. L. L.: 2000, 'Turbulence Characteristics in the Surface Boundary Layer over the South America Pampa', Boundary-Layer Meteorol. 96, 317–335.
Nappo, C. J.: 1991, 'Sporadic Breakdown of Stability in the PBL over Simple and Complex Terrain', Boundary-Layer Meteorol. 54, 69–87.
Nieuwstadt, F. T. M.: 1984, 'The Turbulent Structure of the Stable, Nocturnal Boundary Layer', J. Atmos. Sci. 41, 2202–2216.
Pahlow, M., Parlange, M. B., and PortÉ-Agel, F.: 2001, 'On Monin-Obukhov Similarity in the Stable Atmospheric Boundary Layer', Boundary-Layer Meteorol. 99, 225–248.
Panofsky, H. A. and Dutton, J. A.: 1984, Atmospheric Turbulence Models for Engineering Applications, John Wiley and Sons, New York, 397 pp.
Smedman, A.-S.: 1988, 'Observations of a Multi-Level Turbulence Structure in a Very Stable Atmospheric Boundary Layer', Boundary-Layer Meteorol. 44, 247–264.
Soler, M. R., Infante, C., Buenestado, P., and Mahrt, L.: 2002, 'Observations of Nocturnal Drainage Flow in a Shallow Gully', Boundary-Layer Meteorol. 105, 253–273.
Stull, R. B.: 1988, An Introduction to Boundary Layer Meteorology, Kluwer Academic Publishers, Dordrecht, 666 pp.
Van de Wiel, B. J. H., Ronda, R. J., Moene, A. F., De Bruin, H. A. R., and Holtslag, A. A. M.: 2002, 'Intermittent Turbulence and Oscillations in the Stable Boundary Layer over Land. Part I: A Bulk Model', J. Atmos. Sci. 59, 942–958.
Von Misses, R.: 1964, Mathematical Theory of Probability and Statistics, Academic Press, 694 pp.
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, 190–211.
Yamada, T.: 1979, 'PBL Similarity Profiles Determined from a Level-2 Turbulence-Closure Model', Boundary-Layer Meteorol. 17, 333–351.
Rights and permissions
About this article
Cite this article
Moraes, O.L.L., Acevedo, O.C., Da Silva, R. et al. Nocturnal Surface-Layer Characteristics at the Bottom of a Valley. Boundary-Layer Meteorology 112, 159–177 (2004). https://doi.org/10.1023/B:BOUN.0000020163.36907.f9
Issue Date:
DOI: https://doi.org/10.1023/B:BOUN.0000020163.36907.f9