Spatial Variability of the Flow and Turbulence Within a Model Canopy

• Published in: Boundary-layer meteorology Vol. 160; no. 3; pp. 375 - 396
• Main Authors: Harman, Ian N., Böhm, Margi, Finnigan, John J., Hughes, Dale
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01-09-2016; Springer; Springer Nature B.V
• Subjects: Analysis; Atmospheric Protection/Air Quality Control/Air Pollution; Atmospheric Sciences; Canopies; Computational fluid dynamics; Earth and Environmental Science; Earth Sciences; Field tests; Flow; Flow velocity; Fluid flow; Fluxes; Mathematical models; Meteorology; Research Article; Spatial analysis; Statistics; Turbulence; Turbulence models; Turbulent flow; Spatial variability; Turbulence; Wind tunnel; Canopy flow; Dispersive
• ISSN: 0006-8314; 1573-1472
• DOI: 10.1007/s10546-016-0150-0

The spatial variability of the mean flow and turbulence in and above a model canopy is investigated using three-dimensional laser Doppler velocimetry. The mean flow and turbulence are shown to be highly variable in space within the canopy but rapidly converge above the canopy. The coherent variations in the mean flow generate dispersive fluxes contributing almost a fifth to the total flux of momentum, and a greater contribution to the divergence of the flux, within the canopy. The higher-order turbulent statistics are more variable than the mean flow and often strongly correlated in space to variations in the mean flow. The implications of this microscale spatial variability for both field experiments and other laboratory experiments into canopy flow are discussed.