昆明市近地层臭氧特征分析及对策研究

Analysis of Ozone Concentration Characteristics in the Near Surface Layer and Countermeasures in Kunming

2015年以来昆明市空气质量持续改善,但O_(3)浓度逆势上升,已超越颗粒物成为昆明空气质量优良率的主要影响因素。利用国家地面空气质量监测点的逐小时O_(3)浓度数据,对O_(3)的年变化、季节变化和日变化特征进行了分析。得出结论:①近地层O_(3)浓度呈逐年缓慢上升趋势;②春季O_(3)小时浓度最高,夏、秋、冬季较低,其中秋季最低,春季白天O_(3)峰值持续时间长,且夜间O_(3)浓度也相对较高;③近地面O_(3)浓度每日午后14—17时达到最高,8时左右最低,日变化呈现“单峰型”。讨论了昆明地形地貌和气象因素对昆明近地层O_(3)浓度的影响,发现可能存在水平方向的远距离外源输入和大气垂直方向传输通道。提出了昆明市近地层O_(3)浓度控制的对策建议和未来科研展望。

With the continuous improvement of air quality in Kunming since 2015,however,the near-surface concentration of O_(3) is on the rise. O_(3) has exceeded PM to become the main negative factor affecting the excellent rate of air quality. Based on the hourly concentrations of near-surface O_(3) over the past 5 years,the annual,diurnal and seasonal changes were examined. The results discovered that the near-surface O_(3) has been increasing slowly and continuously year by year. The hourly O_(3) was highest in spring,and lowest in autumn. Peak interval of O_(3) was longer in spring daytime than other seasons,and nighttime concentration was also higher. The near-surface O_(3) in Kunming reached a maximum value at approximately 2∶ 00 to 5∶ 00 p. m. daily and a minimum value at approximately 8∶ 00 a. m. This paper explained the impact of the topographic factor and the meteorological factor on the near-surface O_(3). There might be a long distance external input in the horizontal direction and vertical transmission channels in the atmosphere. Finally,a series of control countermeasures with O_(3) for Kunming was proposed.