gw2gc {gunit}

Convert g_c (\mumol CO2/m^2/s/Pa) to g_w (\mumol H2O /m^2/s/Pa)

Description

Convert g_c (\mumol CO2/m^2/s/Pa) to g_w (\mumol H2O /m^2/s/Pa)

Convert g_c (umol CO2/m^2/s/Pa) to g_w (umol H2O /m^2/s/Pa)

Usage

gw2gc(g_w, D_c, D_w, unitless, a)

gc2gw(g_c, D_c, D_w, unitless, a)

Arguments

g_w

conductance to water vapor in units (\mumol H2O / (m^2 s Pa)) of class units.

D_c

diffusion coefficient for CO2 in air in units of m^2/s of class units

D_w

diffusion coefficient for H2O in air in units of m^2/s of class units

unitless

Logical. Should scientific units of arguments be checked and set? TRUE is safer, but slower. If FALSE, values provided are assumed to be in correct units.

units

a

exponent used for conversion. Use 1 for still air; 0.67 for laminar flow (Jones 2014). Should be unitless.

g_c

conductance to CO2 in units (\mumol H2O / (m^2 s Pa)) of class units.

Details

Diffusive conductance to CO2 is greater than that of H2O because of the higher molecular weight. To convert:

g_\mathrm{c} = g_\mathrm{w} (D_\mathrm{c} / D_\mathrm{w}) ^ a

g_\mathrm{w} = g_\mathrm{c} (D_\mathrm{w} / D_\mathrm{c}) ^ a

Value

Value with units \mumol / (m^2 s Pa) of class units.

Note

This function will soon be moving to the standalone gunit package.

References

Jones H. 2014. Plants and Microclimate (3rd edition). Cambridge University Press.

Examples

library(units)
D_c = set_units(1.29e-05, "m^2/s")
D_w = set_units(2.12e-05, "m^2/s")
g_c = set_units(3, "umol/m^2/s/Pa")
a = 1
g_w = gc2gw(g_c, D_c, D_w, a, unitless = FALSE)
g_w

gw2gc(g_w, D_c, D_w, a, unitless = FALSE)