Effect of stratospheric ozone depletion on the net production of ozone in polluted rural areas

A one-dimensional model is used to study the effect of stratospheric ozone depletion (SOD) on the net production of ozone in the troposphere over various chemical coherent regions. It is found that in addition to the concentration of NO_x, the response of the net ozone production to SOD is also determined by the concentrations of non-methane hydrocarbons (NMHCs), ozone and water vapor. The threshold NO_x concentration, at which the response to SOD of the net ozone production changes from negative to positive, depends on the chemical regime and varies during a day, but it is typically about 1 ppb in a 24-hour average. The net ozone production in the boundary layer over polluted rural areas is most likely decreased due to SOD over a NO_x-limited region and increased over an NMHCs-limited region. In an NO_x-limited region the decrease in the net ozone production is the largest at high relative humidity. In cases with an increase in the net ozone production due to SOD, the increase is most favored at low relative humidity for the same NO_x and NMHCs conditions.