Geoscience Reference
In-Depth Information
°C
15
6
10
5
5
British
Muse
u
m
4
0
3
-5
m
2
-10
1
-15
0
-20
-1
-25
-20
-15
-10
-5
0
5
10
15
20
25
Eastings (km)
Figure 8.9
The pattern of air temperature differences between a rural reference climate station and a number of urban climate
stations located across London under calm and dry conditions at 0200-0300 hr for six urban heat island events during the period
1 July-30 September 2000.
Source: Greater London Authority, London's Urban Heat Island: A Summary for Decision Makers,(2006)
600
8UEDQ$UHD
6XEXUEV
/HYHO&RXQWU\
Gradient wind
500
-94
Gradient wind
400
-90
-98
-85
300
-80
-95
Gradient wind
-90
-75
-95
200
-84
-68
-91
-61
-77
-86
100
-51
-68
-78
-40
-5
6
-
40
-65
-30
0
0
5
10
0
5
10
0
5
10
Wind speed (m/sec)
Figure 8.10
The effect of terrain roughness on the wind speed profile. With decreasing roughness the depth of the modified
layer becomes shallower and the profile steeper. The figures are percentages of the gradient wind speed.
Source: After Davenport (1965)
