Difference in the Priestley–Taylor coefficients at two different heights of a tall micrometeorological tower

The eddy covariance method is highly recommended for measuring in situ water vapor flux. In this study, eddy covariance systems were installed at two heights (30 m and 100 m) on a micrometeorological tower located in a tropical mixed forest. We have identified a difference in the Priestley–Taylor coefficients (α), calculated at 30 m and 100 m, with vertical variation of water vapor flux, and this height-dependent difference is smaller when the vertical difference in wind speeds is higher. It will be useful to consider this result in the analysis of measurement data for model validation.