Due to the complex terrain of Nevada

Hastie et al. (1996) reported for a rural site in Canada photochemical production of O3 characterized by a slow increase in O3 between the hours of 1100 to 1800 h. In contrast, assessment of the mean hourly rate of O3 change at NVROI sites showed a rapid hourly increase in O3 (~ 4 to 8 ppbv/h — spring/summer and ~ 2 to 6 ppbv/h — fall/winter) between 0800 and 1000 h in the spring and summer (Fig. 6).