What is the lifetime of ozone and precursors over the OTAG region?

The atmospheric lifetime of ozone influences the distance over which it is transported. The "lifetime" discussed here includes the initial formation time of ozone (6-12 hours), as well as the decay time due to removal processes (24-30 hours), yielding a total lifetime of about 1-2 days. There is evidence that the ozone formation time and removal time in urban plumes is shorter, with a resulting lifetime of about 20 hours while in elevated, NOx-rich point source plumes, the ozone lifetime can be twice as long. Temporal analysis of ozone data indicates that on average, ozone events tend to last longer in the southern portion of the OTAG domain than in the North.

(a)(b)
Figure 1. a) Urban ozone plume of St. Louis measured on July 18, 1975. The excess ozone concentration within the plume is about 20-30 ppb. b) Ozone flux (tons/hr) in the St. Louis urban plume. Note that most of the ozone is produced within the first 100 km from the city.