Segregation of Atmospheric Oxidants in Turbulent Urban Environments

In the atmospheric boundary layer that is affected by turbulent motions and inhomogeneous surface chemical emissions, short-lived reactive species may not be completely mixed within any given airmass. Coarse models, which assume complete mixing each grid-box, overestimate rates at react. We used a large eddy simulation (LES) model embedded in Weather Research Forecasting (WRF) to assess influence of segregation on photochemistry convective layer. implemented our vicinity Hong Kong Island, subject strong flow spatially anthropogenic biogenic emissions. conclude under heavy pollution conditions, reduces rate reaction between hydrocarbons hydroxyl radical (OH) 25% near urban areas. Furthermore, polluted ozone production urbanized areas 50% about 100 m above surface. The reduction only equal 20% forested mountain area. This highlights need develop grid refinement approaches regional global models with high levels. Under clean simulations suggest role small can ignored modelling approaches.