Observed and predicted sensitivities of extreme surface ozone to meteorological drivers in three US cities

Abstract We conduct a case study of observed and simulated maximum daily 8-h average (MDA8) ozone (O 3 ) in three US cities for summers during 1996–2005. The purpose of this study is to evaluate the ability of a high resolution atmospheric chemistry model to reproduce observed relationships between meteorology and high or extreme O 3 . We employ regional coupled chemistry-transport model simulations to make three types of comparisons between simulated and observational data, comparing (1) tails of the O 3 response variable, (2) distributions of meteorological predictor variables, and (3) sensitivities of high and extreme O 3 to meteorological predictors. This last comparison is made using two methods: quantile regression, for the 0.95 quantile of O 3 , and tail dependence optimization, which is used to investigate even higher O 3 extremes. Across all three locations, we find substantial differences between simulations and observational data in both meteorology and meteorological sensitivities of high and extreme O 3 .