The study focuses on the impact of soil moisture on stomatal uptake of O3 and related CTM-predicted O3 concentrations. It should be noted that non-stomatal uptake of O3 (by cuticles and underlying soils) typically contributes 50% of the overall uptake. It is not clear if the non-stomatal uptake was treated or not in the model simulations. If it is, this should be made clear and the relative contributions of stomatal and non-stomatal uptake can be briefly discussed. If it is not, then model simulation results may have serious questions.