Direct observations of the turbulence kinetic energy budget within an orchard canopy

We describe direct observations of all of the terms of the turbulence kinetic energy budget equation within a walnut orchard canopy. These were made during the Canopy Horizontal Array of Turbulence Study (CHATS) in 2007. Sonic anemometers are used to determine the shear production, turbulence transport, and wake production terms. Fast-response pressure fluctuations were measured at three heights within and just above the canopy to determine pressure transport. Hot-film anemometers also were deployed within the canopy to determine dissipation. The results generally agree both with large eddy simulations and with residuals computed from previous observational studies.