Fig. 3: Increase in O₃ with a 1 °C increase in temperature.

Spatial distribution of sensitivity of ground-level ozone concentrations (MDA8) to daily average temperature changes at monitoring sites in China (a) and the United States (b) from April to October 2015–2022. Different colors represent the sensitivity of ozone concentration to temperature variations, with a gradient from blue to red indicating the range from a decrease in ozone concentration (blue) to an increase (red). Circles, squares, and triangles represent significant positive correlation, significant negative correlation, and no significant correlation, respectively. The significance level is typically set at p < 0.05.