Variables

There are so many variables in PlantBiophysics that it can be difficult to remember what is their name, what are they describing or what is their unit.

Fortunately, PlantBiophysics implements a method for the variables function from PlantSimEngine, which helps us get all variables used in PlantBiophysics:

using PlantBiophysics, PlantSimEngine
variables(PlantBiophysics)

37×3 DataFrame

Row	Variable	Description	Unit
	String15	String	String31
1	A	carbon assimilation	μmol[CO₂] m⁻² s⁻¹
2	Cᵢ	Intercellular CO₂ concentration	mol[CO₂] m⁻² s⁻¹
3	Cₐ	Air CO₂ concentration	mol[CO₂] m⁻² s⁻¹
4	Cₛ	Air CO₂ concentration at the leaf surface	mol[CO₂] m⁻² s⁻¹
5	Dₗ	Vapour pressure difference between the surface and the saturated air vapour pressure	kPa
6	Gbc	Leaf boundary conductance for CO₂ (one-sided)	mol[CO₂] m⁻² s⁻¹
7	Gbₕ	Leaf boundary conductance for heat (one-sided)	m s⁻¹
8	Gₛ	stomatal conductance for CO₂	mol[CO₂] m⁻² s⁻¹
9	H	Sensible heat flux	W m⁻²
10	P	Air pressure	kPa
11	Ra_LW_f	Absorbed longwave radiation flux (TIR) also called net flux between the object and the atmosphere	W m⁻²
12	Ra_NIR_f	Absorned net NIR radiation flux	W m⁻²
13	Ra_PAR_f	Absorned net PAR radiation flux	W m⁻²
14	Ra_SW_f	Absorned net shortwave radiation (PAR + NIR). Often computed from a light interception model	W m⁻²
15	Rbₕ	Leaf boundary resistance for heat (one-sided)	m s⁻¹
16	Rh	Relative humidity	0-1
17	Ri_NIR_f	Incoming NIR flux	W m⁻²
18	Ri_PAR_f	Incoming PAR flux	W m⁻²
19	Ri_SW_f	Incoming short wave radiation flux	W m⁻²
20	Ri_TIR_f	Incoming TIR flux	W m⁻²
21	T	Air temperature	Celsius degree
22	Tₗ	Leaf temperature	Celsius degree
23	VPD	Vapor pressure deficit	kPa
24	Wind	wind speed	m s⁻¹
25	aPPFD	Absorbed Photosynthetic Photon Flux Density	μmol[photon] m⁻² s⁻¹
26	clearness	Sky clearness	0-1
27	d	Characteristic dimension e.g. leaf width	meter
28	duration	Time duration e.g. for a time-step	seconds
29	e	Vapor pressure	kPa
30	eₛ	Saturated vapor pressure	kPa
31	sky_fraction	View factor between the object and the sky for both faces (0-2)	-
32	Δ	Slope of the saturation vapor pressure at air temperature	-
33	γ	Psychrometer "constant"	kPa K⁻¹
34	ε	Atmosphere emissivity	0-1
35	λ	Latent heat of vaporization	J kg⁻¹
36	λE	Latent heat flux	W m⁻²
37	ρ	Air density	kg m⁻³