The study compared two models used to predict air quality in the eastern United States. One model used data from the MM5 meteorological model, while the other used data from the WRF model. The results showed that the WRF model predicted higher ozone levels in certain regions, leading to slightly less accurate predictions compared to the MM5 model. Differences in how the models calculate factors like vegetation and cloud cover affected the accuracy of the predictions. Overall, the WRF model performed better for some pollutants like sulfate, but worse for others like carbon and fine particulate matter. The primary reason for the differences in predictions between the two models was how they calculated the friction velocity, which affects the deposition of certain pollutants.