David I. Stannard 1993 <p><span>Eddy correlation measurements of sensible and latent heat flux are used with measurements of net radiation, soil heat flux, and other micrometeorological variables to develop the Penman-Monteith, Shuttleworth-Wallace, and modified Priestley-Taylor evapotranspiration models for use in a sparsely vegetated, semiarid rangeland. The Penman-Monteith model, a one-component model designed for use with dense crops, is not sufficiently accurate (</span><i>r</i>²<span><span>&nbsp;</span>= 0.56 for hourly data and<span>&nbsp;</span></span><i>r</i>²<span><span>&nbsp;</span>= 0.60 for daily data). The Shuttleworth-Wallace model, a two-component logical extension of the Penman-Monteith model for use with sparse crops, performs significantly better (</span><i>r</i>²<span><span>&nbsp;</span>= 0.78 for hourly data and<span>&nbsp;</span></span><i>r</i>²<span><span>&nbsp;</span>= 0.85 for daily data). The modified Priestley-Taylor model, a one-component simplified form of the Penman potential evapotranspiration model, surprisingly performs as well as the Shuttle worth-Wallace model. The rigorous Shuttleworth-Wallace model predicts that about one quarter of the vapor flux to the atmosphere is from bare-soil evaporation. Further, during daylight hours, the small leaves are sinks for sensible heat produced at the hot soil surface.</span></p> application/pdf 10.1029/93WR00333 en American Geophysical Union Comparison of Penman-Monteith, Shuttleworth-Wallace, and modified Priestley-Taylor evapotranspiration models for wildland vegetation in semiarid rangeland article