Canopy/Field

CANOPY/FIELD

CloudRoots focuses on how the available energy is partitioned on surface fluxes at the soil and by plants. Measuring the concentration and isofluxes of stable isotopologues of CO₂, H₂O enable us to quantify how much of the evaporation is driven by soil or by plants. Particular attention is paid on how to scale up the leaf processes to the canopy processes. To this end, the A-gs model (see LEAF) is upscaled to the canopy level. It is at the canopy level where the turbulent fluxes need to be accurately represented to adequately reproduce the dynamics of the clear and cloudy boundary-layers. In all the planned field campaigns, we attempt to measure these fluxes using eddy-covariance and scintillometer techniques (see INSTRUMENTS). With the later technique, we will measure 1-minute turbulent measurements of the carbon dioxide and water vapor stable isotopologues (isofluxes). Here, we expect to collect evidence on how the turbulent fluxes evolve under transition periods (clouds, diurnal and weather variability) and their partitioning. This research is connected to the explicit simulation of these turbulent fluxes. Here, we can make use of two sorts of canopy representations: multi-layer and bulk. Using the first approach, we can represent the transfer of radiation and the state meteorological and atmospheric composition variables within the canopy at the sub-meter scale. The bulk canopy approach enables us to determine the performance of more crude representations, like the ones used in weather and climate models, on the canopy turbulent fluxes.