eTheses Repository - University of Birmingham

Figure 4.6: Vertical section at y=0 of potential temperature (K) as computed by the urban_BEP
simulation at 12:00 noon of the second day of the simulation.......................................... 96
Figure 4.7: Vertical section at y=0 of the horizontal speed (ms -1 ) as computed by the
urban_BEP simulation at 12:00 noon of the second day of simulation............................ 97
Figure 4.8: Vertical sections at y=0 of (a) potential temperature (K) and (b) horizontal wind
speed (ms -1 ) (b) as computed by the Orig simulation at 12:00 noon of the second day of
simulation..................................................................................................................................... 98
Figure 4.9: Vertical section at y=0 of the TKE (m 2 s -2 ) as computed by (a) the urban_BEP
simulation and (b) the Orig simulation at 12:00 noon of the second day of simulation.99
Figure 4.10: Vertical section at y=0 of potential temperature (K) as computed by the
urban_BEP simulation at 04:00 of the second day of simulation. ...................................101
Figure 4.11: Vertical section at y=0 of horizontal wind speed (ms -1 ) as computed by the
urban_BEP simulation at 04:00 of second day of simulation. ..........................................102
Figure 4.12: Vertical sections at y=0 of (a) the potential temperature (K) and (b) the horizontal
wind speed (ms -1 ) as computed by the Orig simulation at 04:00 of the second day of
simulation...................................................................................................................................102
Figure 4.13: Diurnal variation of the UHI intensity (K) for the second day of simulation,
calculated as the maximum difference in potential temperature at the first grid level
between the urban area and a rural point upwind of the city. The pink line represents
the urban_BEP simulation, and the blue line the Orig simulation. Sunrise and sunset are
around 04:00 and 20:00 respectively.....................................................................................103
Figure 4.14: Potential temperature (K) along the line y=0, z=10m as computed by the three
simulations bh2 (black line), a01 (green) and bh3 (yellow) at 04:00 on the second day of
simulation. The simulations represent a mean building height of 7 m (bh2), 15 m (a01)
and 29.5 m (bh3) respectively. ................................................................................................108
Figure 4.15: Vertical profiles of (a) wind speed (ms -1 ) and (b) TKE (m 2 s -2 ) at x=0, y=0 as
computed by the three simulations bh2 (black line), a01 (green) and bh3 (yellow) at
04:00 of the second day of simulations. The simulations represent a mean building
height of 7 m (bh2), 15 m (a01) and 29.5 m (bh3) respectively.........................................109
Figure 4.16: Potential temperature (K) along the line y=0, z=10 m, as computed by the three
simulations with the internal temperatures behind urban walls and roofs (‘twini’ and
‘trini’) both set to 293 K (black line), 295 K (green) and 297 K (yellow) at 04:00 for the
second day of simulation. .......................................................................................................111
Figure 4.17: Diurnal variation of the difference in potential temperature (K) between the
simulations alb1 and the control simulation a01 (blue line) and between the simulations
alb2 and a01 (pink line) at x=0, y=0, z=10 m for the second day of simulation. The
alb1 simulation represents an urban albedo of 0.30 and the alb2 simulation represents
an urban albedo of 0.15...........................................................................................................115
Figure 4.18: Diurnal variation of the difference in potential temperature (K) between the
control simulation a01 and the vegetated simulations veg1 (blue) and veg2 (pink) at x=0,
y=0, z=10 m for the second day of simulation. The veg1 simulation represents an urban
area with 10% vegetated fraction, and the veg2 simulation represents an urban area with
30% vegetated fraction............................................................................................................118
Figure 4.19: Correlation between the fraction of vegetation in the urban area and the potential
temperature (K) at x=y=0, z=10, at 12:00 noon for the second day of simulations ..119
Figure 4.20: Potential temperature (K) along the line y=0, z=10 m as computed by the three
simulations with the urban area measuring 6 km, 10 km and 20 km respectively
(yellow, green and black), at 04:00 for the second day of simulation.............................122
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