Geoscience Reference
In-Depth Information
Table 26.5
Values of (incoming) solar radiation, net solar radiation, longwave radiation, and net radiation calculated in 2(d)
assuming it is both an arid and a humid site.
Hour
(local)
Solar
(W m
−2
)
Net solar
(W m
−2
)
Net (arid)
(W m
−2
)
Net (humid)
(W m
−2
)
Hour
(local)
Solar
(W m
−2
)
Net solar
(W m
−2
)
Net (arid)
(W m
−2
)
Net (humid)
(W m
−2
)
0.5
0
0
−28
−41
12.5
517
398
369
357
1.5
0
0
−28
−41
13.5
489
376
348
335
2.5
0
0
−28
−41
14.5
435
335
306
294
3.5
0
0
−28
−41
15.5
358
276
248
235
4.5
0
0
−28
−41
16.5
265
204
176
163
5.5
53
41
12
0
17.5
161
124
95
83
6.5
161
124
95
83
18.5
53
41
12
0
7.5
265
204
176
163
19.5
0
0
−28
−41
8.5
358
276
248
235
20.5
0
0
−28
−41
9.5
435
335
306
294
21.5
0
0
−28
−41
10.5
489
376
348
335
22.5
0
0
−28
−41
11.5
517
398
369
357
23.5
0
0
−28
−41
600
Solar
Net (humid)
500
Net (arid)
400
300
200
Figure 26.5
The diurnal cycle
of (incoming) solar radiation, net
solar radiation, longwave
radiation, and net radiation
calculated in 2(d) assuming it is
an arid and a humid site.
100
0
0
6
12
Time (hrs)
18
24
−
100
(b) For saturated sandy soil the thermal conductivity,
k
s
, is 2.20 W m
−2
K
−1
and
the thermal diffusivity,
s
, is 0.74 × 10
−6
m
2
s
−1
. The damping depth,
D
, for
the daily time period
P
= (24 × 60 × 60) = 86,400 seconds is 0.143 m [from
Equation (6.13)]. The farmer used Equation (6.14) to estimate the instanta-
neous surface soil heat flux.
(c) The vapor pressure at the bottom level, vapor pressure at top level, Bowen
ratio, net radiation, soil heat flux, available energy, latent heat flux and sen-
sible heat flux are tabulated in Table 26.6.
(d) The net radiation, soil heat flux, available energy, latent heat flux and the sen-
sible heat flux are plotted as a function of time through the day in Fig. 26.8.
α
