Geoscience Reference
In-Depth Information
Now we examine the vertical temperature
gradient in the lower troposphere.
Vertical temperature gradients are determined
in part by energy transfers and in part by vertical
motion of the air. The various factors interact
in a highly complex manner. The energy terms
are the release of latent heat by condensation,
radiative cooling of the air and sensible heat
transfer from the ground. Horizontal temperature
advection, by the motion of cold and warm air
masses, may also be important. Vertical motion is
10
30
20
10
10
0
0
1000
1100 1200
Energy flux density (Wm
-2
)
1300
1400
Figure 3.19
Direct solar radiation as a function
of altitude observed in the European Alps. The
absorbing effects of water vapor and dust,
particularly below about 3000m, are shown by
comparison with a theoretical curve for an ideal
atmosphere without water vapor or aerosols.
Source: After Albetti, Kastrov, Kimball and Pope; from Barry
(2008).
Figure 3.20
Average direct beam solar radiation
(W m
-2
) incident at the surface under cloudless
skies at Trier, West Germany, and Tucson, Arizona,
as a function of slope, aspect, time of day and
season of year.
Source: After Geiger (1965) and Sellers (1965).
TRIER, WEST GERMANY
(50°N)
TUCSON, ARIZONA
(32°N)
North-facing
South-facing
North-facing
South-facing
04
06
08
10
12
21 June
0
800
0
800
14
16
18
400
200
20
04
06
08
10
12
22 Dec
14
16
18
20
0
20
40
60
80
0
20
40
60
80
0
20
40
60
80
0
20
40
60
80
Angle of slope (degrees)
