.get_Sr {tealeaves}

S_r: longwave re-radiation (W / m^2)

Description

S_r: longwave re-radiation (W / m^2)

Usage

.get_Sr(T_leaf, pars)

Arguments

T_leaf

Leaf temperature in Kelvin

pars

Concatenated parameters (leaf_par, enviro_par, and constants)

Details

S_\mathrm{r} = 2 \sigma \alpha_\mathrm{l} T_\mathrm{air} ^ 4

The factor of 2 accounts for re-radiation from both leaf surfaces (Foster and Smith 1986).

Symbol	R	Description	Units	Default
\alpha_\mathrm{l}	abs_l	absorbtivity of longwave radiation (4 - 80 \mum)	none	0.97
T_\mathrm{air}	T_air	air temperature	K	298.15
\sigma	s	Stefan-Boltzmann constant	W / (m^2 K^4)	5.67e-08

Note that leaf absorbtivity is the same value as leaf emissivity

Value

Value in W / m^2 of class units

References

Foster JR, Smith WK. 1986. Influence of stomatal distribution on transpiration in low-wind environments. Plant, Cell & Environment 9: 751-9.

Examples

library(tealeaves)

cs <- make_constants()
ep <- make_enviropar()
lp <- make_leafpar()

T_leaf <- set_units(298.15, K)

tealeaves:::.get_Sr(T_leaf, c(cs, ep, lp))