PhotosynEB: Coupled leaf gas exchange model with energy balance

Description

As Photosyn, but calculates the leaf temperature based on the leaf's energy balance. Including sensible and long-wave heat loss, latent heat loss from evaporation, and solar radiation input. Calculate Tleaf from energy balance, given that we know gs

Usage

PhotosynEB(Tair = 25, VPD = 1.5, Wind = 2, Wleaf = 0.02,
  StomatalRatio = 1, LeafAbs = 0.86, RH = NULL, ...)

FindTleaf(gs, Tair, ...)

Arguments

Tair

Air temperature (C)

VPD

The vapour pressure deficit of the air (i.e. not the leaf-to-air VPD) (kPa).

Wind

Wind speed (m s-1)

Wleaf

Leaf width (m)

StomatalRatio

The stomatal ratio (cf. Licor6400 terminology), if it is 1, leaves have stomata only on one side (hypostomatous), 2 for leaves with stomata on both sides (amphistomatous).

LeafAbs

Leaf absorptance of solar radiation (0-1).

The relative humidity of the air (i.e. not calculated with leaf temperature) (in percent).

For FindTleaf, the stomatal conductance (mol m-2 s-1).

...

Further parameters passed to Photosyn. Note that Tleaf is not allowed as an input, since that is calculated by PhotosynEB from energy balance.

Details

Uses the Penman-Monteith equation to calculate the leaf transpiration rate, and finds Tleaf by solving the leaf energy balance iteratively. In the solution, it is accounted for that stomatal conductance and net radiation depend on Tleaf. There are no simplifications or approximations made to find the solution. Also included is the function FindTleaf, which calculates the leaf temperature if the stomatal conductance is known.