Sensible heat fluxes by scintillometer and eddy covariance in an irrigated vineyard

Representative evapotranspiration (ET) measurements over vineyards are today still challenging due to spatial variability of plants, soil conditions and surface topography. In this context, a suitable technique to measure turbulent fluxes is scintillometry, that can give measurement of sensible heat flux at large scale and over heterogeneous surface. ET can then be estimated as residual of the energy budget. In the present study, we present results from an intensive campaign carried out during summer 2016 in Southern Italy. We deployed a Large Aperture Scintillometer (LAS) in an extensive vineyard of 140 ha with a path length of 760 m, providing good fetch for the measurements. The site is characterized by gently slope with uniform vegetation, however spatial and temporal variability of soil water content was present due to irrigation shift rotation among different patches. In order to have some local reference measurements of sensible heat flux, we deployed three Eddy Covariance (EC) stations along the scintillometer path, representative of two different irrigation schedules. The relationship between sensible heat flux by EC and LAS showed to be very good. Scintillometer measurement showed to be mostly influenced by the central area of the path, whereas edge fluxes were not adequately represented.