Impacts of the fall 2007 California wildfires on surface ozone: Integrating local observations with global model simulations

The latter include a synthetic tracer providing information about the amount of ozone produced from the fires. It is shown that the global model is well suited for simulating the overall fire impact and a valuable tool for extracting information about the fire influence from the observations.

A clear increase in observed ozone is found when the model predicts a strong impact of pollution from the fires, where measured afternoon 8-hour concentrations increased, on average, by about 10 ppb. The findings demonstrate that intense wildfire periods can significantly increase the frequency of ozone concentrations exceeding current U.S. health standards, and might cause violations also during photochemically less active seasons.