Spatially averaged sensible heat fluxes measured over barley

Measurements made with a large aperture scintillometer were compared to those made using an eddy correlation system over a uniform barley field. In spite of wind profile measurements indicating that conditions were not ideal for the application of Monin–Obukhov theory, good agreement was found between the instruments for measuring sensible heat fluxes as long as an effective value for the displacement height was used in the equations. This effective value was calculated from measurements made using sonic anemometers, although these data indicated a value well outside the normally accepted range. It is suggested that this is a consequence of the changes in atmospheric turbulence produced by a hill upwind of the experimental site.