The impact of the annual solar eclipse, starting on 21st June 2020, attributable to surface ozone concentration (O₃) has been investigated in this study. To estimate the influence of the solar eclipse on O₃ better, the variations of one reaction precursor of ozone production [nitrogen dioxide (NO₂)], coupled with the meteorological factors (including Total Solar Irradiance (TSI), Temperature (T), and Relative Humidity (RH)), were analyzed in Yunnan Province, China. The results show observed O₃ decreases from the beginning of the eclipse, reaching its minimum value when the eclipse left Yunnan province. During the period of the solar eclipse, the O₃ decrease lasted for 20 h with a reduction ofmore than 40%. The reduction of TSI lasted for 5h with a maximum at -90%. Simultaneously, the temperature decreased but the relative humidity increased during the reduction in solar radiation.O₃ exhibits a significantly positive correlation with temperature and a negative correlation with relative humidity. However, NO₂ did not show a clear response with changes lasting for 4 h.O₃ and NO₂ show a negative correlation. The influence of CO on O₃ is minor except for Kunming. Thus, O₃ in seriously polluted cities is more sensitive to NO₂ and CO during the eclipse, such as in Kunming.

solar eclipse, surface ozone, total irradiance, CO, NO2