Geoscience Reference
In-Depth Information
(a)
600
500
W m
−
2
400
R
n
L
e
E (EBBR)
300
L
e
E (Lysimeter)
200
100
H
G
0
−
100
0
6
12
18
24
Time (h)
(b)
600
R
n
500
L
e
E (Lysimeter)
W m
−
2
400
300
L
e
E (EBBR)
200
H
100
G
0
−
100
0
6
12
18
24
Time (h)
Fig. 2.20 Example of the daily cycle of the energy balance for a young (a) and a mature (b) maize canopy near
Versailles, France. EBBR indicates the latent heat flux obtained by the Bowen ratio method (after
Perrier
et al
., 1976).
these measurements are not available, the components can be obtained by theoretical
methods or simpler empirical formulae.
Short-wave radiation
R
s
is the radiant flux resulting directly from the solar radiation. This incoming solar
radiation has most of its energy contained in the wavelength range from 0.1 to 4
m.
At the outside of the atmosphere this flux, i.e. the solar constant, has been measured on
μ
