Water use by irrigated vineyards is a critical issue at present. The GRAPEX project recently has examined eddy covariance measurements and remote sensing models for ET in irrigated vineyards.
The microclimate in the canopy represents the environment in which the grapes grow. Also, the complex interactions between the microclimate and air above the canopy are key mechanisms of the ET process. Modern technology offers the ability to examine episodic variations in microclimate and its connections with turbulence transport.
Eddy covariance systems installed above and within irrigated vineyards, measured at the same time three components of wind, temperature, and the water vapor density. This allows examination of the coherence between variations in microclimate with transient turbulence exchanges within and above the vines.
Results show large differences in humidity exist between the above, inter-row and within row locations. The mean values of temperature and humidity above and within the canopy do not reflect the episodic nature of air temperature and humidity. We examine the probability distribution of contiguous periods exceeding various humidity thresholds; intermittency of temperature and humidity; and the scales and intensities of turbulence above the vines that couple with changes within the canopy. This will demonstrate the nature of vine microclimate and its interactions with the regional hot and dry air.