The atmosphere in action - Fundamentals of the Physical Environment - page 125

(a)

Figure 6.18
Mean zonal wind for
(a) December-February
and (b) June-August
(m s -1 ). Positive values
denote a westerly
wind. Negative values
indicate easterly wind.
Source: www.
ecmwf.int/research/era

100

200

300

400

500

600

m s -1
100
80
60
50
40
35
30
25
20
15
10
5
2
-2
-5
-10
-15
-20
-25
-30
-35
-40
-50
-60
-80
-100

700

800

900

1000

10° 20° 30° 40° 50° 60° 70° 80° 90°S

90°N 80° 70° 60° 50° 40° 30° 20° 10° 0°

Latitude

(b)

100

200

300

400

500

600

700

800

900

1000

90°N 80°

10° 20° 30° 40° 50° 60° 70° 80° 90°S

70° 60° 50° 40° 30° 20° 10° 0°

Latitude

150° 30°W 0° 30°E

150° 180°

120° 120°

60° 60°

90° 90°

90° 90°

5 440

60°

60°

120° 120°

30°W 0° 30°E 150° 180° 150°

Figure 6.19 Mean 500 hPa contours in December-February for the northern and southern hemispheres.
Source: www.ecmwf.int/research/era