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

## Description

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

## Usage

 `1` ```.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_abs = α_s (1 + r) S_sw + α_l σ (T_sky ^ 4 + T_air ^ 4)

The incident longwave (aka thermal infrared) radiation is modeled from sky and air temperature σ (T_sky ^ 4 + T_air ^ 4) where T_sky is function of the air temperature and incoming solar shortwave radiation:

T_sky = T_air - 20 S_sw / 1000

 Symbol R Description Units Default α_s `abs_s` absorbtivity of shortwave radiation (0.3 - 4 μm) none 0.80 α_l `abs_l` absorbtivity of longwave radiation (4 - 80 μm) none 0.97 r `r` reflectance for shortwave irradiance (albedo) none 0.2 σ `s` Stefan-Boltzmann constant W / (m^2 K^4) 5.67e-08 S_sw `S_sw` incident short-wave (solar) radiation flux density W / m^2 1000 S_lw `S_lw` incident long-wave radiation flux density W / m^2 calculated T_air `T_air` air temperature K 298.15 T_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

 ```1 2 3 4 5 6 7 8``` ```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 June 21, 2020, 2:32 a.m.