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

Description Usage Arguments Details Value References Examples

Description

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

Usage

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.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

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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.