Abstract

This study attempted to evaluate evapotranspiration (ET) estimation algorithm at a lodgepole pine tree open forest in eastern Idaho, United States. The coordinate location of study area (Latitude is 44.5o N; Longitude is 111.4o W) and the Elevation is 1950 meter. By performing eddy covariance method for the data collected under 10:30 am in local solar time, clear-sky condition and 16-day period. Furthermore, the accuracy of ET model was evaluated by using sensible flux dataset measured by scintillometer. This experiment considers scintillometer-measured sensible flux data to evaluate the accuracy of ET model. In scintillometer, evapotranspiration computed using radiation measurement data. There were two sets of sensible and latent heat flux data. One was measured on the south tower, and the other was measured on the north tower. The dataset from the south tower was much more reliable in term of data availability. This study used sensible heat and latent heat flux data from the south tower. The dataset from north tower were used only as supplementary dataset when the dataset from south tower were not available. This study concluded that scintillometer was be able to provide ground truth ET dataset to improve the accuracy of ET estimation algorithm and it suggests that to obtain the accuracy measurement of ET estimation actual, a simple linear adjustment should be applied in the ET algorithm model.