Analysis of Priestley-Taylor method in different environments and coverages

Evapotranspiration is one of the most important variables in the hydrological cycle. In this sense, its precise quantification is necessary in the field of climatology, meteorology, hydrology, ecology, environmental sciences and agronomy. In this work, the potential and actual evapotranspiration are calculate with Priestley-Taylor equation by satellite data, used in differents world zones with diverse climates and coverages. Respect to potential evapotranspiration, better results are obtained in humid/subhumid areas (R-RMSE around 0.4 mm d
⁻¹
) than arid/semiarid areas (R-RMSE is 1.0 mm d
⁻¹
). On the other hand, respect to actual evapotranspiration, the errors are smaller in humid/subhumid areas (between 0.6 to 1.1 mm d
⁻¹
) than equatorial areas (between 1.2 to 3.4 mm d
⁻¹
). As well as, a systematic underestimation is observed by calculate method.