A comparison of bowen ratio and eddy correlation sensible and latent heat flux measurements above deciduous forest
Tóm tắt
Sensible and latent heat flux densities (H and ΛE) were measured above a mature, 18 m deciduous forest during July and August, 1988, using the Bowen ratio-energy balance (BREB) and eddy correlation (EC) methods. EC estimates ofH and ΛE underestimated day-time surface available energy by 11%. EC also partitioned available energy differently than BREB. forź/L<0.0, EC favouredH and BREB favoured ΛE.
Practical and theoretical limitations of the BREB and EC methods above forests are discussed. The most plausible causes for the failure of EC to close the surface energy balance are a low frequency loss of flux and the failure of a single point measurement to account for the spatial dispersive flux. The most plausible causes of the EC-BREB energy partitioning anomaly are the invalidity of the BREB similarity assumption and the violation of flux-gradient diffusion assumptions in the near-field diffusion region.
Tài liệu tham khảo
Anderson, Dean E., Verma, S. B., and Clement, R. J.: 1986, ‘Turbulence Spectra of CO2, Water Vapour, Temperature and Velocity over a Deciduous Forest’,Agric. For. Meteorol. 38, 81–99.
Barr, A. G.: 1991, ‘Local and Regional Estimates of Sensible and Latent Heat Flux Densities From a Pathch-Work Surface’, Ph.D. thesis, University of Guelph, 218 pp.
Bernhofer, C.: 1992, ‘Estimating Forest Evapotranspiration at a Non-Ideal Site’,Agric. For. Meteorol. 60, 17–32.
Coppin, P. A., Raupach, M. R. and Legg, B. J.: 1986, ‘Experiments on Scalar Dispersion within a Model Plant Canopy. Part II: An Elevated Plane Source’,Boundary-Layer Meteorol. 35, 167–91.
Denmead, O. T. and Bradley, E. F.: 1985, ‘Flux-Gradient Relationships in a Forest Canopy’, in B. A. Hutchinson and B. B. Hicks (eds.),The Forest-Atmosphere Interaction, D. Reidel Boston, pp. 421–442.
Dyer, A. J. and Hicks, B. B.: 1970, ‘Flux-Gradient Relationships in the Constant Flux Layer’,Q.J.R. Meteorol. Soc. 96, 715–721.
Environment Canada. 1989, ‘AES Guidelines For Cooperative Autostations’, Guide 89-1, Climate Adaptations Branch, Canadian Climate Centre, Downsview, ON. 59 pp.
Fritschen, L. and Gay, L.: 1979,Environmental Instrumentation, New York: Springer Verlag, 216 pp.
Gao, W., Shaw, R. H. and Paw U, K. T.: 1989, ‘Observations of Organized Structures in Turbulent Flow with and Without a Forest Canopy’,Boundary-Layer Meteorol. 47, 349–377.
Högström, U., Bergstrom, H., Sofi-Smedman, A., Halldin, S. and Lindroth, A.: 1989, ‘Turbulent Exchange Above a Pine Forest. I: Fluxes and Gradients’,Boundary-Layer Meteorol. 49, 197–217.
Kaimal, J. C., Wyngaard, J. C., Izumi, I. and Cote, O. R.: 1972, ‘Spectral Characteristics of Surface-Layer Turbulence’,Q.J.R. Meteorol. Soc. 98, 663–589.
Lee, Xuhui and Black, T. A.: 1993, ‘Atmospheric Turbulence Within and Above a Douglas-fir Stand. Part II. Eddy Fluxes of Sensible Heat and Water Vapour’,Boundary-Layer Meteorol. 64, 369–389.
Lindroth, A. and Halldin, S.: 1990, ‘Gradient Measurements with Fixed and Reversing Temperature and Humidity Sensors above a Thin Forest’,Agric. For. Meteorol. 53, 81–103.
Mahrt, L.: 1991, ‘Boundary-Layer Moisture Regimes’,Q.J.R. Meteorol. Soc. 117, 151–176.
Massman, W. J.: 1992, ‘Correcting Errors Associated with Soil Heat Flux Measurements and Estimating Soil Thermal Properties from Soil Temperature and Heat Flux Plate Data’,Agric. For. Meteorol. 59, 249–266.
McBean, Gordon A.: 1992, ‘Role of Active-Passive Scalar Relationships in Evaporation from Vegetated Gordon A.: 1992’, in J. P. O'Kane (ed.),Topics in Theoretical Hydrology, European Geophysical Union. pp. 47–58.
McCaughey, J. H. and Saxton, W. L.: 1988, ‘Energy Balance Storage Terms in a Mixed Forest’,Agric. For. Meteorol. 44, 1–18.
McGinn, S. M.: 1988, ‘Heat, Water Vapour and CO2 Exchange above Alfalfa and Maize’, Ph.D. Thesis, University of Guelph, 205 pp.
McNeill, D. D. and Shuttleworth, W. J.: 1975, ‘Comparative Measurements of the Energy Fluxes over a Pine Forest’,Boundary-Layer Meteorol. 9, 297–313.
Monteith, J. L.: 1973,Principles of Environmental Physics, London: Edwin Arnold, 241 pp.
Neumann, H. H., Hartog, G. den and Shaw, R. H.: 1989, ‘Leaf Area Measurements Based on Hemispheric Photographs and Leaf-Litter Collection in a Deciduous Forest during Autumn Leaf-fall’,Agric. For. Meteorol.,45, 325–345.
Nobel, P. S.: 1983,Biophysical Plant Physiology and Ecology, San Fransisco: W.H. Freeman, 608 pp.
Oke, T. R.: 1978,Boundary Layer Climates, London: Methuen and Co. 372 pp.
Raupach, M. R.: 1979, ‘Anomalies in Flux-Gradient Relationships over Forest’,Boundary-Layer Meteorol. 16, 467–486.
Raupach, M. R.: 1987, ‘A Lagrangian Analysis of Scalar Transfer in Vegetation Canopies’,Q.J.R. Meteorol. Soc. 113, 107–120.
Raupach, M. R.: 1989, ‘A Practical Lagrangian Method for Relating Scalar Concentration to Source Distribution in Vegetation Canopies’,Q.J.R. Meteorol. Soc. 115, 609–632.
Roth, M. and Oke, T. R.: 1993, ‘Turbulent Transfer Characteristics over an Urban Surface. I: Spectral Characteristics’,Q.J.R. Meteorol. Soc. 119, 1071–1104.
Schotanus, P., Nieuwstadt, F. T. M. and de Bruin, H. A. R.: 1983, ‘Temperature Measurement with a Sonic Anemometer and its Application to Heat and Moisture Fluxes’,Boundary-Layer Meteorol. 26, 81–93.
Shaw, R.: 1985, ‘On Diffusive and Dispersive Fluxes in Forest Canopies’, in B. A. Hutchinson and B. B. Hicks (eds.),The Forest-Atmosphere Interaction D. Reidel: Boston, pp. 407–419.
Sinclair, T. R., Allen, L. H. and Lemon, E. R.: 1975, ‘An Analysis of Errors in the Calculation of Energy Flux Densities above Vegetation by a Bowen Ration Profile Method’,Boundary-Layer Meteorol. 8, 129–139.
Spittlehouse, D. L. and Black, T. A.: 1980, ‘Evaluation of the Bowen Ratio/Energy Balance Method for Determining Forest Evapotranspiration’,Atmos.-Ocean 18, 98–116.
Tanner, C. B. and Thurtell, G. W.: 1969, ‘Anemoclinometer Measurements of Reynolds Stress and Heat Transport in the Atmospheric Surface Layer’, Report to Atmospheric Sciences Laboratory, Fort Huachuca, Arizona.
Verma, S. B., Baldocchi, D. B., Anderson, D. E., Matt, D. R. and Clement, R. J.: 1986, ‘Eddy Fluxes of CO2 Water Vapour, and Sensible Heat over a Deciduous Forest’,Boundary-Layer Meteorol. 36, 71–91.
Webb, E. K., Pearman, G. I. and Leuning, R.: 1980, ‘Correction of Flux Measurements for Density Effects Due to Heat and Water Vapour Transfer’,Q.J. R. Meteorol. Soc. 106, 85–100.
Wyngaard, J. C.: 1973, ‘On Surface Layer Turbulence’, in Duane A. Haugen (ed.),Workshop on Micrometeorology, American Meteorological Society.
Wyngaard, J. C., Coté O. R. and Izumi, Y.: 1971, ‘Local Free Convection, similarity, and the Budgets of Shear Stress and Heat Flux’,J. Atm. Sci. 28, 1171–1182.
Zar, J. H.: 1974,Biostatistical Analysis. Englewood Cliffs, NJ: Prentice-Hall, 620 pp.