[Sensitivity Analysis of Ozone Generation in Guangdong Province Based on OMI Satellite and Ground Observation Data].

Based on Ozone （O） Monitoring Instrument satellite remoting sensing data and reanalysis meteorological data, an analysis was conducted on the spatiotemporal distribution and trends of tropospheric nitrogen dioxide （NO） and formaldehyde （HCHO） in Guangdong Province from 2015 to 2020. The study also examined the changing characteristics of O generation sensitivity in relation to meteorological parameters. The results indicated that during 2015-2020, the tropospheric NO column concentration in Guangdong Province exhibited a distribution pattern with the Pearl River Delta （PRD） Region as the high-value center gradually decreasing towards the surrounding areas, with the most substantial decline observed in the Pearl River Delta. The HCHO column concentration showed a pattern of higher values in the PRD and lower values in the other regions. While most areas exhibited a decreasing trend in HCHO column concentration, the spatial distribution was more dispersed compared to that of NO. In most regions, the ratio of HCHO to NO （FNR） showed an increasing trend. The area under VOCs-NO synergistic control decreased, whereas the area under NO control increased. By 2020, the proportions of VOCs control area, VOCs-NO synergistic control area, and NO control area in Guangdong Province were 0.5%, 13.1%, and 86.4%, respectively. The FNR value showed an increasing trend； a positive correlation with 2 m temperature, relative humidity, downward surface shortwave radiation, and boundary layer height； and a negative correlation with 10 m wind speed and sea level pressure. The three most influential meteorological factors were downward surface shortwave radiation（DSSR）, relative humidity, and 2 m temperature, impacting the FNR value the most.