Extension of Penman's formulae to multi-layer models

In this paper, the well-established multi-layer model originally devised by Waggoner and Reifsnyder (1968) is used. This steady-state model based on an electrical analogue simulates the energy exchange between the vegetation and the atmosphere. A purely mathematical development of the basic equations of this model yields explicit expressions of the total fluxes of sensible and latent heat at the top of the canopy as a function of the net radiation absorbed in each layer, the soil heat flux, the water vapour pressure deficit at a reference height and the whole set of elementary conductances (stomatal, boundary-layer and aerodynamic). These new equations can be considered as a generalization of the familiar Penman's formulae to a multi-layer model.