Potential ozone loss in mid-latitude lowermost stratosphere during summer today and in future

Potential chemical ozone destruction in the mid-latitude lowermost stratosphere in summer is discussed as a side effect of sulphate solar radiation management (SRM) and in case of a stratospheric moistening due to convective overshooting or a climate change. Enhanced water vapor together with low temperatures may yield a heterogeneous chlorine activation, which drives catalytic ozone destruction. An additional increase of the Surface Aerosol Density by SRM would accelerate this ozone loss process. However, the likelihood of this chemical ozone loss process and its impact on ozone in the lowermost stratosphere in particular above North America for conditions today and in future is a matter of current debate. We present a study about the sensitivity of this chemical ozone loss process to the temperature, water vapor content, sulfate aerosols, and trace gases (as Cl_y and NO_y) performing box-model simulations with the Chemical Lagrangian Model of the Stratosphere (CLaMS). Using future scenarios from the Geoengineering Large Ensemble project (GLENS), which is based on several different WACCM simulations, we estimate the impact of climate change and the application of sulfate SRM on ozone in the mid-latitude lowermost stratosphere in summer.