Figure 1: Changes in atmospheric ozone concentration in Los Angeles (California, USA) over a 24-hour period.

Figure 1
State the two primary air pollutants from fossil fuels which contribute to the formation of photochemical smog.
Identify two effects of tropospheric ozone.
With reference to Figure 1:
explain why ozone concentration changes over this 24-hour period.
explain why ozone levels are highest within the valley.













