The fraction of ozone near the surface in urban areas tends to be overestimated in atmospheric models. New observations at the IAO reveal a possible explanation, which is presented in the following paper https://www.science.org/doi/10.1126/sciadv.add2365
Short summary: Long-term eddy covariance measurements of O3, NO and NO2, combined with models and remote sensing observations over an urban area, allowed disentangling important physical and chemical processes. When generalized our findings suggest that the depositional ozone flux near the surface in urban environments is negligible compared to the flux caused by chemical conversion of ozone. This leads to an underestimation of the Leighton ratio, and is a key process for modulating urban NO2 mixing ratios.