make_parameters {tealeaves}

Make lists of parameters of leaf, environmental, or constant parameters

Description

Make lists of parameters of leaf, environmental, or constant parameters

make_leafpar

make_enviropar

make_constants

Usage

make_leafpar(replace = NULL)

make_enviropar(replace = NULL)

make_constants(replace = NULL)

Arguments

replace

A named list of parameters to replace defaults. If NULL, defaults will be used.

Details

Leaf parameters:

Symbol	R	Description	Units	Default
d	leafsize	Leaf characteristic dimension	m	0.1
\alpha_\mathrm{l}	abs_l	absorbtivity of longwave radiation (4 - 80 \mum)	none	0.97
\alpha_\mathrm{s}	abs_s	absorbtivity of shortwave radiation (0.3 - 4 \mum)	none	0.50
g_\mathrm{sw}	g_sw	stomatal conductance to H2O	(\mumol H2O) / (m^2 s Pa)	5
g_\mathrm{uw}	g_uw	cuticular conductance to H2O	(\mumol H2O) / (m^2 s Pa)	0.1
\mathrm{logit}(sr)	logit_sr	stomatal ratio (logit transformed)	none	0 = logit(0.5)

Environment parameters:

Symbol	R	Description	Units	Default
P	P	atmospheric pressure	kPa	101.3246
r	r	reflectance for shortwave irradiance (albedo)	none	0.2
\mathrm{RH}	RH	relative humidity	none	0.50
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
u	wind	windspeed	m / s	2

Constants:

Symbol	R	Description	Units	Default
c_p	c_p	heat capacity of air	J / (g K)	1.01
D_{h,0}	D_h0	diffusion coefficient for heat in air at 0 °C	m^2 / s	19.0e-06
D_{m,0}	D_m0	diffusion coefficient for momentum in air at 0 °C	m^2 / s	13.3e-06
D_{w,0}	D_w0	diffusion coefficient for water vapour in air at 0 C	m^2 / s	21.2e-06
\epsilon	epsilon	ratio of water to air molar masses	none	0.622
eT	eT	exponent for temperature dependence of diffusion	none	1.75
G	G	gravitational acceleration	m / s^2	9.8
Nu	Nu	Nusselt number	none	calculated
R	R	ideal gas constant	J / (mol K)	8.3144598
R_\mathrm{air}	R_air	specific gas constant for dry air	J / (kg K)	287.058
\sigma	s	Stefan-Boltzmann constant	W / (m^2 K^4)	5.67e-08
Sh	Sh	Sherwood number	none	calculated

Value

make_leafpar: An object inheriting from class leaf_par
make_enviropar: An object inheriting from class enviro_par
make_constants: An object inheriting from class constants

Examples

library(tealeaves)

# Use defaults
cs <- make_constants()
ep <- make_enviropar()
lp <- make_leafpar()

# Replace defaults

ep <- make_enviropar(
  replace = list(
    T_air = set_units(300, K)
  )
)

lp <- make_leafpar(
  replace = list(
    leafsize = set_units(c(0.1, 0.2), m)
  )
)