dot-get_dwv: d_wv: water vapour gradient (mol / m ^ 3)

In muir-lab/tleavesMC: Schymanski Equation

Description

d_wv: water vapour gradient (mol / m ^ 3)

Usage

.get_dwv(T_leaf, pars, unitless)

Arguments

T_leaf	Leaf temperature in Kelvin
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

Water vapour gradient: The water vapour pressure differential from inside to outside of the leaf is the saturation water vapor pressure inside the leaf (p_leaf) minus the water vapor pressure of the air (p_air):

d_wv = p_leaf / (R T_leaf) - RH p_air / (R T_air)

Note that water vapor pressure is converted from kPa to mol / m^3 using ideal gas law.

Symbol	R	Description	Units	Default
p_air	p_air	saturation water vapour pressure of air	kPa	calculated
p_leaf	p_leaf	saturation water vapour pressure inside the leaf	kPa	calculated
R	R	ideal gas constant	J / (mol K)	8.3144598
RH	RH	relative humidity	%	0.50
T_air	T_air	air temperature	K	298.15
T_leaf	T_leaf	leaf temperature	K	input

Value

Value in mol / m^3 of class units

Examples

# Water vapour gradient: 

leaf_par <- make_leafpar()
enviro_par <- make_enviropar()
constants <- make_constants()
pars <- c(leaf_par, enviro_par, constants)
T_leaf <- set_units(300, K)
T_air <- set_units(298.15, K)
p_leaf <- set_units(35.31683, kPa)
p_air <- set_units(31.65367, kPa)

d_wv <- p_leaf / (pars$R * T_leaf) - pars$RH * p_air / (pars$R * T_air)

muir-lab/tleavesMC documentation built on July 5, 2020, 12:23 a.m.