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

.get_RabsR Documentation

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


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


.get_Rabs(pars, unitless)



Concatenated parameters (leaf_par, enviro_par, and constants)


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.


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 in W / m^2 of class units


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.



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.