eTheses Repository - University of Birmingham

Air temperature ( o C)
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Time
SJP METRAS METRAS+BEP
Figure 5.8: Diurnal cycle of air temperature (ºC) at the SJP site from August 6 th to August 7 th 1998
according to the SJP measurements (blue), the traditional simulation (pink) and the simulation with
BEP (yellow).
Figure 5.9 shows the air temperature comparison for the BBP site. The implementation of
the urban canopy scheme should have no direct influence on a completely rural site located
upstream of the city (Otte et al. 2004), however as this site is located outside the domain
the measurements are compared with the closest grid cell, which has an urban fraction of
20% and is located close to the domain boundary. Differences between the measurements
and the model results might also be affected by advection from nearby urban areas.
Compared to LWC, LHR and SJP this is the grid cell with lowest urbanised fraction, and
for this reason the difference between the traditional and METRAS+BEP air temperatures
is much smaller as expected. For both simulations the comparison for the first 6 hours is
excellent which probably reflects the fact that out of the four stations used for the validation
the BBP station is closest to the Larkhill station whose surface data was used to initialise
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