Abstract
Eddy-covariance data have been analyzed to investigate the influence of local stability on heat transfer within open canopies. The flux–gradient relationship for heat is derived from the temperature variance equation, and the stability dependence of the flux–gradient relationship is examined and discussed. The results indicate that the strong stability dependence of the nondimensional standard deviation of temperature, and the small contributions of turbulent transport to the temperature variance, lead to a strong stability dependence of the nondimensional temperature gradient within open canopies. Quadrant analysis and hole size analysis were performed for momentum and heat fluxes in the subcanopy, and the results indicate that the contribution of each quadrant to the total flux depends on both the local stability and canopy depth. The intermittency of the turbulent flux does not show a clear dependence on local stability. As the contribution of ejections to the heat flux increases, the vertical flux of the temperature variance changes sign from negative to positive, leading to small temperature variance transport in unstable conditions. Multi-resolution analysis indicates that heat and momentum are transported with different dominant time scales in very unstable conditions, suggesting a different role of local buoyancy in heat and momentum transfer.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Antonia RA (1981) Conditional sampling in turbulence measurement. Annu Rev Fluid Mech 13: 131–156
Blanken PD, Black TA, Neumann HH, Den Hartog G, Yang PC, Nesic Z, Staebler R, Chen W, Novak MD (1998) Turbulent flux measurements above and below the overstory of boreal aspen forest. Boundary-Layer Meteorol 89: 109–140
Brunet Y, Irvine MR (2000) The control of coherent eddies in vegetation canopies: streamwise structure spacing, canopy shear scale and atmospheric stability. Boundary-Layer Meteorol 94: 139–163
Cava D, Katul GG, Scrimieri A, Poggi D, Cescatti A, Giostra U (2006) Buoyancy and the sensible heat flux budget within dense canopies. Boundary-Layer Meteorol 118: 217–240
Coantic M, Simonin O (1984) Radiative effects on turbulent temperature spectra and budgets in the planetary boundary layer. J Atmos Sci 41: 2629–2951
Finnigan J (2000) Turbulence in plant canopies. Annu Rev Fluid Mech 32: 519–571
Garratt JR (1992) The atmospheric boundary layers. Cambridge University Press, UK, p 316
Howell JF, Mahrt L (1997) Multiresolution flux decomposition. Boundary-Layer Meteorol 83: 495–520
Juang JY, Katul GG, Siqueira MB, Stoy PC, McCarthy HR (2008) Investigating a hierarchy of Eulerian closure models for scalar transfer inside forested canopies. Boundary-Layer Meteorol 128: 1–32
Katul GG, Hsieh CI, Kuhn G, Ellsworth D, Nie D (1997) Turbulent eddy motion at the forest–atmosphere interface. J Geophys Res 102(D12): 13409–13421
Kim JH (1999) Spurious correlation between ratios with a common divisor. Stat Probab Lett 44: 383–386
Klipp C, Mahrt L (2004) Flux–gradient relationship, self-correlation and intermittency in the stable boundary layer. Q J Roy Meteorol Soc 130(601): 2087–2103
Leclerc MY, Beissner KC, Shwa RH, Den Hartog G (1990) The influence of atmospheric stability on the budgets of the Reynolds stress and turbulent kinetic-energy within and above a deciduous forest. J Appl Meteorol 29(9): 916–933
Leclerc MY, Bessner KC, Shaw RH, Den Hartog G, Neumann HH (1991) The influence of buoyancy on third-order turbulent velocity statistics within a deciduous forest. Boundary-Layer Meteorol 55: 109–123
Lee YH (2009) The spectral features of heat and momentum transfer within open canopies. Asian Pac J Atmos Sci (in revision)
Lee YH, Mahrt L (2005) Effect of stability on mixing in open canopies. Agric For Meteorol 135: 169–179
Nakagawa H, Nezu I (1977) Prediction of the contributions to the Reynolds stress from bursting events in open channel flow. J Fluid Mech 80: 99–128
Poggi D, Katul GG (2008) The effect of canopy roughness density on the constitutive components of the dispersive stress. Exp Fluids 45: 111–121
Poggi D, Katul GG, Albertson JD (2004) A note on the contribution of dispersive fluxes to momentum transfer within canopies. Boundary-Layer Meteorol 111: 615–621
Raupach MR (1981) Conditional statistics of Reynolds stress in rough-wall and smooth-wall turbulent boun- dary layers. J Fluid Mech 108: 363–382
Schwarz P, Law B, Williams M, Irvine J, Kurpius M, Moore D (2004) Climatic versus biotic constraints on carbon and water fluxes in seasonally drought-affected ponderosa pine ecosystems. Glob Biogeochem Cycle 18: GB4007. doi:10.1029/2004GB002234
Stull RB (1988) An introduction to boundary layer meteorology. Kluwer, Dordrecht, p 670
Su H-B, Shaw RH, Paw UKT, Moeng C-H, Sullivan PP (1998) Turbulent statistics of neutrally stratified flow within and above a sparse forest from large-eddy simulation and field observations. Boundary-Layer Meteorol 88: 363–397
Author information
Authors and Affiliations
Corresponding author
Additional information
An erratum to this article can be found at http://dx.doi.org/10.1007/s10546-010-9472-5
Rights and permissions
About this article
Cite this article
Lee, YH. The Influence of Local Stability on Heat and Momentum Transfer within Open Canopies. Boundary-Layer Meteorol 132, 383–399 (2009). https://doi.org/10.1007/s10546-009-9405-3
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10546-009-9405-3