Geoscience Reference
In-Depth Information
According to the distribution of specific humidity near the surface, shown
in
Figure 2.31
:
• Speciic humidity levels throughout the tropics are about ive times larger
than at high latitudes.
• The air over land surfaces tends to be drier than the marine air in the winter
hemisphere. In the summer hemisphere, the continental air is more moist
than the marine air at the same latitude over the eastern portions of the
continents, and drier in the west.
(a) DJF
4
60°N
4
4
8
4
8
8
30°N
4
12
12
16
12
8
16
8
4
16
8
16
16
Equator
12
16
16
12
12
8
16
16
16
30°S
12
12
12
8
8
8
8
60°S
4
4
4
0°
30°E
60°E
90°E
120°E
150°E
180°
150°W 120°W
90°W
60°W
30°W
0°
(b) JJA
4
4
4
8
60°N
4
8
8
8
8
12
16
8
16
12
8
30°N
1
12
8
12
16
12
20
16
20
16
16
Equator
12
16
8
16
12
16
12
12
30°S
12
8
8
8
8
8
4
4
60°S
4
0°
30°E
60°E
90°E
120°E
150°E
180°
150°W 120°W
90°W
60°W
30°W
0°
Figure 2.31 Geographical distribution of specific humidity at 900 hPa for (a) December-
January-February (DJF) and (b) June-July-August (JJA). Units are 10
−3
kg
H
2
/kg
air
.
