[Effect of Meteorological Elements and Air Pollutants on Ozone in Yinchuan City Park]

To examine the underlying determinants of ozone （O₃） in Yinchuan's urban park during varying seasons and to ascertain the role played by meteorological events and air contaminants in influencing O₃ concentrations at high altitudes, data on O₃, meteorological factors, and air pollutants were collected through prolonged positional observations carried out at the Ningxia Yinchuan National Urban Ecosystem Research Station. Pearson correlation analysis and a structural equation model were utilized to investigate the spatio-temporal distribution patterns, trends, and the primary factors influencing O₃. The findings demonstrated a notable seasonal variability in O₃ levels in Yinchuan's urban park, displaying an "unimodal type" with the O₃ concentration peaking in summer （131.18 μg·m^-3） and bottoming out in winter （71.45 μg·m^-3）. Among the meteorological factors, the highest impact on O₃ was attributed to temperature and wind speed （temperature mainly through direct effects and wind speed mainly through indirect effects）. Conversely, air pollutants such as NO and SO₂ greatly affected O₃ primarily through direct effects. Wind speed was identified as the primary influencing factor on O₃ during spring and summer, potentially contributing 29% and 24.7%, respectively. Conversely, NO₂ was implicated as the primary factor during autumn and winter, with an estimated contribution of 26.6% and 29.7%, respectively. Thus, a structural equation model can efficiently reveal the primary determinants behind O₃ variations throughout various seasons, which could furnish a scientifically rigorous foundation and technical aid for mitigating and managing O₃ levels in high-altitude regions.