Abstract:

With the in-depth implementation of air pollution prevention and control, pollutants concentration such as PM_2.5 has gradually decreased in Guangdong Province, but O₃ replaced PM_2.5 as the primary pollutant of air pollution in Guangdong Province. Understanding of the characteristics of O₃ pollution is of great significance for the scientific O₃ pollution management and prevention in Guangdong Province. Monitoring data of 102 national ambient air quality monitoring stations and weather type data of ozone pollution from 2016 to 2020 were used to analyze the characteristics of O₃ pollution and key time and key cities for O₃ prevention and control in Guangdong Province. The results showed that (1) O₃-8h annual evaluation concentration in Guangdong Province increased by 8.7% from 2016 to 2020, which was the only elevated pollutant among the six pollutants in air quality evaluation. The excessive concentration of O₃-8h reduced excellent days ratio in Guangdong Province by 2.8, 4.8, 5.2, 8.9 and 4.2 percentage points, respectively. (2) High daily average value of O₃-8h concentration mainly occurred in April-May and August-November. During these two periods, daily mean value of O₃-8h concentration in Guangdong Province exceeded the limit of Class II standard, accounted for more than 97.6% of the total number of days exceeding the standard, indicating that O₃ pollution control in these two periods should be strengthened. (3) Four weather types including weak cold air, typhoon periphery, subtropical anticyclone, and anticyclone circulation, were most closely related to O₃ pollution. Air quality forecasts and warnings should be strengthened so that pollution prevention and control can be deployed in advance when relevant weather types occur. (4) Sensitive period for ozone compliance in Pearl River Delta region was from August to November, when Guangzhou, Dongguan, Foshan, Zhaoqing, Shenzhen, Zhuhai, Zhongshan and Jiangmen need to be controlled; Sensitive period for ozone compliance in Eastern and Western Guangdong was from September to November, when Shanwei, Shantou, Chaozhou, Maoming, Yangjiang, and Zhanjiang need to be controlled; Sensitive period for ozone compliance in Northern Guangdong was from September to October, when Shaoguan and Qingyuan need to be controlled. Ozone Pollution Prevention and Control in key cities should be strengthened during the relevant time period, to reduce O₃ pollution days and increase excellent days ratio of air quality.

Key words: ozone, sensitive period for compliance, pollution control, weather type, excellent days ratio, Guangdong Province

摘要：

随着大气污染防治工作的深入实施，广东省PM_2.5等大气污染物浓度逐步降低，O₃取代PM_2.5成为广东省空气污染的首要污染物。深入了解广东省O₃污染特征对O₃污染科学治理与防控具有非常重要的意义。利用2016—2020年广东省102个国家环境空气质量监测站监测数据以及臭氧污染天气型数据，分析O₃污染特征，解析O₃污染重点防控时间与重点城市。结果表明，（1）2016—2020年期间，广东省O₃-8h年评价质量浓度上升8.7%，是空气质量评价的6项污染物中唯一升高的污染物。O₃-8h质量浓度超标使广东省各年度空气质量优良天数比例分别减少了2.8、4.8、5.2、8.9、4.2个百分点。（2）广东省O₃-8h质量浓度日均值高值主要分布在4—5月、8—11月，在这两个时段，广东省O₃-8h质量浓度日均值超过二级标准限值的天数占全年超标天数的97.6%以上，说明应加强对这两个时段O₃污染管控。（3）弱冷空气、台风外围、副高、反气旋环流等4种天气型，与O₃污染关系最为密切，应加强气象与空气质量联合预报预警，在污染天气型到来前部署污染防控工作。（4）珠三角区域臭氧达标敏感期为8—11月，需重点管控广州市、东莞市、佛山市、肇庆市、深圳市、珠海市、中山市、江门市；粤东、粤西区域臭氧达标敏感期为9—11月，需重点管控汕尾市、汕头市、潮州市、茂名市、阳江市、湛江市；粤北区域臭氧达标敏感期为9—10月，需重点管控韶关市、清远市。在上述时间段加强对应城市的O₃污染管控，减少O₃污染天数，有助于提升空气质量优良天数比例。

关键词: 臭氧, 达标敏感期, 污染管控, 天气型, 优良天数比例, 广东省