Interactions between atmospheric aerosols and ozone have a significant
impact on air pollution and the climate. However, the relative
importance of the response of surface ozone to aerosol scattering and
absorption has been poorly quantified from in situ observations. Results
derived from a one-year in situ observational study conducted in a
semi-arid region showed that the response of ozone to aerosol absorption
was more sensitive than to scattering. Specifically, the change in
surface ozone from low to high absorption coefficients was approximately
five times that from low to high scattering coefficients. The mass
scattering and absorption efficiencies, rather than the
single-scattering albedo, which are commonly applied in numerical
simulations, were able to clearly distinguish surface ozone. The
positive correlation between aerosol and ozone in summer showed the
promotion of secondary aerosols by ozone. This study provides robust
observational evidence of the response of surface ozone to aerosol
scattering and absorption.