Observation of gravity waves in a boreal forest
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In this paper we report the results of the analysis of two 60-min wave events that occurred in a boreal aspen forest during the 1994 BOREAS (Boreal Ecosystems-Atmosphere Study) field experiment. High frequency wind and temperature data were provided by three 3-D sonic anemometer/thermometers and fourteen fine-wire thermocouples positioned within and above the forest. Wave phase speeds, estimated from information revealed by spectral analysis and linear plane wave equations, are 2.2 and 1.3 m s-1 for the two events. The wavelengths are 130 m and 65 m respectively and are much larger than the vertical wave displacements. There is strong evidence from the present analysis and from the literature supporting our postulate that these waves are generated by shear instability. We propose that wind shear near the top of the stand is often large enough to reduce the gradient Richardson number below the critical value of 0.25 and thus is able to trigger the instability. When external conditions are favorable, the instability will grow into waves.
- Black, T. A., den Hartog, G., Neumann, H. H., Blanken, P. D., Yang, P. C., Russell, C., Nesic, Z., Lee, X., Chen, S. G., Staebler, R., and Novak, M. D.: 1996, ‘Annual Cycles of Water Vapor and Carbon Dioxide Fluxes in and above a Boreal Aspen Forest’, Global Change Biology 2, 219–229.
- Busack, B. and Br¨ ummer, B.: 1988, ‘A Case Study of Kelvin-Helmholtz Waves within an Off-shore Stable Boundary Layer: Observations and Linear Model’, Boundary-Layer Meteorol. 44, 105–135.
- Chimonas, G. and Hines, C. O.: 1986, ‘Doppler Ducting of Atmospheric Gravity Waves’, J. Geophys. Res. 91d, 1219–1230.
- de Baas, A. F. and Driedonks, G. M.: 1985, ‘Internal Gravity Waves in a Stably Stratified Boundary Layer’, Boundary-Layer Meteorol. 31, 303–323.
- Einaudi, F. and Finnigan, J. J.: 1993, ‘Wave-Turbulence Dynamics in the Stably Stratified Boundary Layer’, J. Atmos. Sci. 50, 1841–1864.
- Einaudi, F. and Finnigan, J. J.: 1981, ‘The Interaction between an Internal Gravity Wave and the Planetary Boundary Layer. Part I: the Linear Analysis’, Quart. J. Roy. Meteorol. Soc. 107, 793–806.
- Finnigan, J. J.: 1988, ‘Kinetic Energy Transfer between Internal Gravity Waves and Turbulence’, J. Atmos. Sci., 45, 486–505.
- Finnigan, J. J., Euinaudi, F., and Fua, D.: 1984, ‘The Interaction between an Internal Gravity Wave and Turbulence in the Stably-Stratified Nocturnal Boundary Layer’, J. Atmos. Sci. 41, 2409–2436.
- Fitzjarrald, D. R. and Moore, K. E.: 1990, ‘Mechanisms of Nocturnal Exchange between the Rain Forest and the Atmosphere’, J. Geophys. Res. 95d, 16,839–16,850.
- Gossard, E. E. and Hooke, W. H.: 1975, Waves in the Atmosphere, Elsevier Scientific Publishing Company, Amsterdam, 456 pp.
- Gossard, E. E. and Munk, W. H.: 1954, ‘On Gravity Waves in The Atmosphere’, J. Meteorol. 11, 259–269.
- Hooke, W. H., Hall, F. F., and Gossard, E. E.: 1973, ‘Observed Generation of an Atmospheric Gravity Wave by Shear Instability in the Mean Flow of the Planetary Boundary Layer’, Boundary-Layer Meteorol. 5, 29–41.
- Howard, L. N.: 1961, ‘Note on a Paper of J. W. Miles’, J. Fluid Mech. 10, 509–512.
- Kaimal, J. C., Wyngaard, J. C., Izumi, Y., and Coté, O. R.: 1972, ‘Spectral Characteristics of Surface Layer Turbulence’, Quart. J. Roy. Meteorol. Soc. 98, 563–589.
- King, J. C., Mobbs, S. D., Darby, M. S., and Rees, J. M.: 1987, ‘Observations of an Internal Gravity Wave in the Lower Troposphere at Halley, Antarctica’, Boundary-Layer Meteorol. 39, 1–13.
- Lee, X.: 1996, ‘Turbulence Spectra and Eddy Diffusivity over Forests’, J. Appl. Meteorol. 35, 1307–1318.
- Lee, X., Black, T. A., den Hartog, G., Neumann, H. H., Nesic, Z., and Olejnik, J.: 1996, ‘Carbon Diox-ide Exchange and Nocturnal Processes over a Mixed Deciduous Forest’, Agric. For. Meteorol., in press.
- Maitani, T.: 1989, ‘Wave-like Wind Fluctuations Observed in the Stable Surface Layer Over a Plant Canopy’, Boundary-Layer Meteorol. 48, 19–31.
- Miles, J. W.: 1961, ‘On the Stability of Heterogeneous Shear Flow’, J. Fluid Mech. 10, 496–508.
- Nappo, C. J. and Chimonas, G. C.: 1992, ‘Wave Exchange between the Ground Surface and a Boundary-Layer Critical Level’, J. Atmos. Sci. 49, 1075–1091.
- Paw U, K. T., Brunet, Y., Collineau, S., Shaw, R. H., Maitani, T., Qiu, J., and Hipps, L.: 1992, ‘On Coherent Structures in Turbulence above and within Agricultural Plant Canopies’, Agric. For. Meteorol. 61, 55–68.
- Paw U, K. T., Shaw, R. H., Maitani, T., and Cionco, R. M.: 1989, ‘Gravity Waves in an Almond Orchard’, in 19th AMS Conf. Agric. For. Meteorol. pp. 184–185 (preprint).
- Raupach, M. R., Finnigan, J. J., and Brunet, Y.: 1989, ‘Coherent Eddies in Vegetation Canopies’, in 4th Australasian Conf. on Heat and Mass Transfer, Christchurch, New Zealand, pp. 75–90.
- Observation of gravity waves in a boreal forest
Volume 84, Issue 3 , pp 383-398
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- Kluwer Academic Publishers
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- Canopy waves
- Shear instability
- Phase speed
- Industry Sectors
- Author Affiliations
- 1. School of Forestry and Environmental Studies, Yale University, New Haven, Connecticut, CT, 06511, U.S.A
- 2. Atmospheric Environment Service, Environment Canada, Toronto, Ontario, Canada
- 3. Department of Environmental Science, University of Virginia, Charlotteville, Virginia, U.S.A
- 4. Department of Soil Science, University of British Columbia, Vancouver, British Columbia, Canada