Urban Soil-Canopy-Atmosphere Exchanges at Submesoscales: Learning from Model Development, Evaluation, and Coupling with LES - Meteorological and Air Quality Models for Urban Areas - page 47

5m/s

5m/s

122500

122500

TP
303
302
301
300
299

120000

120000

117500

117500

298
297
296
295
294

115000

115000

112500

112500

110000

110000

107500

107500

845000 850000 855000

845000 850000 855000

X X

(a) (b)

Fig. 6.9 City influence on the low level fields: ( a ) potential temperature (colours) and wind
(vectors) at 1300 UTC (June 25, 2001) at 7.5 m above ground level (G2 domain), actual situa-
tion; ( b ) alternate simulation without the city (see text) - the white lines indicate the positions
of Fig. 6.10 vertical cross-sections and the numbers indicate those of Fig. 6.11 vertical profiles
(See also Colour Plate 10 on page 175)

actual situation, coupled with the thermal internal boundary layer development. At
the same location, the atmosphere is clearly convective with the city, but slightly sta-
ble without (Fig. 6.11), showing the importance of city characteristics in numerical
simulations.

5m/s

(u,w) y = 115030 m North

5m/s (u,w) y=115030mNorth

TP
301
300
299
298
297
296
295

500

500

400

400

300

300

200

200

100

100

0

0

845000 850000 855000

850000
X

855000

845000

East West East

X

West

5m/s

5m/s

(v,w) x = 846610 m East (v,w) x = 846610 m East

500 500

400

400

300

300

200

200

100

100

0 0

110000 115000 120000 110000 115000 120000

North

South South North

Y

Y

(a) (b)

Fig. 6.10 ( a ) Vertical W-E ( top )andS-N( bottom ) cross-sections of the atmospheric boundary
layer potential temperature and wind fields - same situation as Fig. 6.9, actual situation; ( b )alter-
nate simulation without the city. The white lines indicate the position of Fig. 6.11 city centre
vertical profiles (2 and 4) (See also Colour Plate 11 on page 175)