Surface Renewal analysis for sensible heat flux density using structure functions

Surface renewal (SR) analysis was used to estimate the sensible heat flux density (H) over different crop canopies (grass, wheat, and sorghum) and the results were compared with eddy covariance measurements. High-frequency temperature traces showed ramp-like structures, and structure functions were used to determine the mean amplitude and duration of these ramps. The ramp characteristics were used to estimate H. A wide range of sensible heat flux density conditions were observed. The accuracy was acceptable, but was dependent on the measurement height, the wind shear at the measurement level, and the time lags used in the structure functions. The use of surface renewal H values in energy balance determination of »E can give results nearly as accurate as those obtained using a sonic anemometer.