Energy balance

options.calc_ebal

Definition

Net radiation (Rn):

>>> Rn = (SW_in - SW_out) + (LW_in - LW_out)

SW - shortwave radiation (400-2400 nm)

LW - longwave (thermal) radiation

Net radiation can be partitioned into 3 (4) heat fluxes:

>>> Rn = H + lE + G

H - sensible heat

lE - latent heat

G - ground heat flux

SCOPE

With options.calc_ebal energy balance loop is started until the energy balance is closed (net radiation become equal to heat fluxes).

To close energy balance leaf temperatures and Monin-Obukhov length L are iteratively adjusted.

This how it looks like:

Leaf temperatures are calculated by biochemical() or biochemical_MD12().

Initial values of soil and leaf temperatures are equal to ambient temperature (Ta).

Monin-Obukhov length influences on aerodynamic resistances values.

The results of energy balance calculations are the following:

variable	units	canopy	soil	total
H	W m-2	115.5	19.5	135.0
lE	W m-2	146.2	44.9	191.1
G	W m-2	-	35.0	35.0
Rn	W m-2	261.7	100.1	361.8

Also SCOPE calculates photosynthesis of canopy which in this case was 18.7 umol m-2 s-1

Radiation budget is also calculated by SCOPE:

variable	units	in	out	net
SW	W m-2	600	104.4	495.6
LW	W m-2	300	434.0	-134.0
Rn	W m-2	-	-	361.8