Abstract：
Based on ozone (O3) monitoring data for Xiangtan and meteorological observation data for 2020-2022, we examined ozone pollution characteristics and the effects of meteorological factors on daily maximum 8-h average ozone (O3-8h) concentrations in Xiangtan. Thus, we observed significant increases as well as notable seasonal variations in O3-8h concentrations in Xiangtan during the period considered. The ozone and temperature change response slope (KO3-T) indicated that local emissions had no significant effect on O3-8h generation. Further, average O3-8h concentration and maximum temperature (Tmax) values showed a polynomial distribution. Specifically, at Tmax < 27 °C, it increased almost linearly with increasing temperature, and at Tmax between 27 and 37 °C, it showed an upward curvilinear trend as temperature increased, but at a much lower rate. Then, at Tmax > 37 °C, it decreased with increasing temperature. With respect to relative humidity (RH), the average O3-8h concentration primarily exceeded the standard value when RH varied in the range of 45-65%, which is the key humidity range for O3 pollution, and the inflection point for the correlation curve between O3-8h concentration and RH appeared at ~55%. Furthermore, at wind speeds (WSs) below 1.5 m∙s-1, O3-8h concentration increased rapidly, and at WSs in the 1.5-2 m∙s-1 range, it increased at a much faster rate. However, at WSs > 2 m∙s-1, it decreased slowly with increasing WS. O3-8h concentration also showed the tendency to exceed the standard value when the dominant wind directions in Xiangtan were easterly or southeasterly.
摘要：
基于湘潭臭氧（O3）监测数据和2020-2022年的气象观测数据，我们研究了臭氧污染特征以及气象因素对湘潭日最大8-h平均臭氧（O3-8h）浓度的影响。因此，在所考虑的时期内，我们观察到湘潭的O3-8h浓度显着增加以及显着的季节性变化。臭氧和温度变化响应斜率(KO3-T)表明局部排放对O3-8h生成没有显著影响。Further,平均O3-8h浓度和最高温度(Tmax)值呈多项式分布。具体来说,在Tmax<27°C时，随着温度的升高，它几乎呈线性增加，Tmax在27和37°C之间，随着温度的升高，它显示出向上的曲线趋势，但速度要低得多。然后，在Tmax>37°C时，它随着温度的升高而降低。相对于相对湿度(RH),当RH在45-65%范围内变化时，平均O3-8h浓度主要超过标准值，这是O3污染的关键湿度范围，O3-8h浓度与RH之间的相关曲线拐点出现在〜55％。此外，在风速(WSs)低于1.5m·s-1时，O3-8h浓度迅速增加，而在WSs在1.5-2米·s-1范围内，它以更快的速度增长。然而,在WSs>2m·s-1时，随WS的增加缓慢下降。O3-8h浓度在湘潭主导风向偏东或偏东南时也有超过标准值的趋势。
