# dot-get_Rabs: R_abs: total absorbed radiation (W / m^2) In cdmuir/tealeaves: Solve for Leaf Temperature Using Energy Balance

 .get_Rabs R Documentation

## R_abs: total absorbed radiation (W / m^2)

### Description

R_abs: total absorbed radiation (W / m^2)

### Usage

.get_Rabs(pars, unitless)


### Arguments

 pars Concatenated parameters (leaf_par, enviro_par, and constants) unitless Logical. Should function use parameters with units? The function is faster when FALSE, but input must be in correct units or else results will be incorrect without any warning.

### Details

The following treatment follows Okajima et al. (2012):

R_\mathrm{abs} = \alpha_\mathrm{s} (1 + r) S_\mathrm{sw} + \alpha_\mathrm{l} \sigma (T_\mathrm{sky} ^ 4 + T_\mathrm{air} ^ 4)

The incident longwave (aka thermal infrared) radiation is modeled from sky and air temperature \sigma (T_\mathrm{sky} ^ 4 + T_\mathrm{air} ^ 4) where T_\mathrm{sky} is function of the air temperature and incoming solar shortwave radiation:

T_\mathrm{sky} = T_\mathrm{air} - 20 S_\mathrm{sw} / 1000

 Symbol R Description Units Default \alpha_\mathrm{s} abs_s absorbtivity of shortwave radiation (0.3 - 4 \mum) none 0.80 \alpha_\mathrm{l} abs_l absorbtivity of longwave radiation (4 - 80 \mum) none 0.97 r r reflectance for shortwave irradiance (albedo) none 0.2 \sigma s Stefan-Boltzmann constant W / (m^2 K^4) 5.67e-08 S_\mathrm{sw} S_sw incident short-wave (solar) radiation flux density W / m^2 1000 S_\mathrm{lw} S_lw incident long-wave radiation flux density W / m^2 calculated T_\mathrm{air} T_air air temperature K 298.15 T_\mathrm{sky} T_sky sky temperature K calculated

### Value

Value in W / m^2 of class units

### References

Okajima Y, H Taneda, K Noguchi, I Terashima. 2012. Optimum leaf size predicted by a novel leaf energy balance model incorporating dependencies of photosynthesis on light and temperature. Ecological Research 27: 333-46.

### Examples


library(tealeaves)

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

tealeaves:::.get_Rabs(c(cs, ep, lp), FALSE)



cdmuir/tealeaves documentation built on Feb. 28, 2024, 8:21 a.m.