A New Index Developed for Fast Diagnosis of Meteorological Roles in Ground-Level Ozone Variations

China experienced worsening ground-level ozone (O(3)) pollution from 2013 to 2019. In this study, meteorological parameters, including surface temperature (T(2)), solar radiation (SW), and wind speed (WS), were classified into two aspects, (1) Photochemical Reaction Condition (PRC = T(2) × SW) and (2) Physical Dispersion Capacity (PDC = WS). In this way, a Meteorology Synthetic Index (MSI = PRC/PDC) was developed for the quantification of meteorology-induced ground-level O(3) pollution. The positive linear relationship between the 90th percentile of MDA8 (maximum daily 8-h average) O(3) concentration and MSI determined that the contribution of meteorological changes to ground-level O(−3) varied on a latitudinal gradient, decreasing from ∼40% in southern China to 10%–20% in northern China. Favorable photochemical reaction conditions were more important for ground-level O(3) pollution. This study proposes a universally applicable index for fast diagnosis of meteorological roles in ground-level O(3) variability, which enables the assessment of the observed effects of precursor emissions reductions that can be used for designing future control policies. ELECTRONIC SUPPLEMENTARY MATERIAL: Supplementary material is available in the online version of this article at 10.1007/s00376-021-1257-x.