Accuracy of turbulent flux measurements through the use of high frequency data by eddy covariance tower: The case study of Landriano (PV), Italy

High frequency data measured by eddy covariance stations can be used for different applications, especially to obtain reliable turbulent flux estimations and to find the reason for possible errors into flux measurements. Generally, the quality of flux measurements is correlated with atmospheric turbulent characteristics and evaluated through the use of stationary or well-developed turbulence tests. However, a quantitative analysis of the error connected with each turbulent flux is not yet present in literature. In this work, starting from high frequency data of the three wind components and scalar passives, spectral analysis is used to quantify relative errors for each half-hourly flux of latent and sensible heat, momentum and carbon dioxide. The experimental dataset was obtained by a micrometeorological station located over a maize field at Landriano (PV) in Padana plain. Two different experimental time period are considered: one when the vegetation height is about 2.80 meters and second after harvesting time. The results have mainly shown a sinusoidal trend of the errors characterized by minimum peaks during daytimes, while in nighttime the measurements can be affected by imprecisions that could reach values up to 65-70%.