Fig. 4 shows interesting patterns in CO concentration. The
upper subfigure shows regular patterns for all week days
except Friday and Saturday, where the concentration drops
significantly. These results are also confirmed by the lower
right subfigure. In fact, Friday and Saturday are the two
weekend days in Qatar, and consequently there is no much
traffic in Eduction City during those days. Since the main
source of CO is the exhaust gases of vehicles, it is expected
that the CO concentration would be significantly reduced
during weekends in the Education City campus.
The bottom left subfigure of Fig. 4 shows the CO concentration
versus the 24 hours of a day. As expected, these
concentrations are reduced during working hours, where the
number of moving vehicles is limited. In the morning and
afternoon hours, the concentration increases due to the increase
in the number of vehicles on the road.
Fig. 5 also shows interesting patterns for