Data for "Heatwaves amplify MDA8 ozone pollution and offset exceedance-risk reductions across China"

This dataset supports the manuscript entitled “Heatwaves amplify MDA8 ozone pollution and offset exceedance-risk reductions across China”, submitted to Atmospheric Chemistry and Physics.The dataset contains processed station-level ozone, meteorological, and satellite-derived precursor data used to quantify heatwave-related MDA8 O3 enhancement and O3 exceedance risk across China from 2015 to 2024. The analysis was conducted for 1199 air-quality monitoring sites in China. Heatwaves were identified using a site-specific TX90pct threshold based on daily maximum temperature derived from ERA5 2 m temperature. MDA8 O3 was calculated from hourly surface O3 observations, and heatwave-related O3 enhancement was estimated relative to historical same-calendar non-heatwave days.