| 珠江三角洲大气光化学氧化剂(Ox)与PM2.5复合超标污染特征及气象影响因素 |
| 摘要点击 3240 全文点击 1032 投稿时间：2020-07-29 修订日期：2020-09-17 |
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| 中文关键词 大气光化学氧化剂(Ox) PM2.5 复合污染 天气形势 珠江三角洲(PRD) |
| 英文关键词 atmospheric photochemical oxidant (Ox) PM2.5 complex pollution weather situation Pearl River Delta (PRD) |
| 作者 | 单位 | E-mail | | 颜丰华 | 暨南大学环境与气候研究院, 粤港澳环境质量协同创新联合实验室, 广州 510443 | 13557016413@163.com | | 陈伟华 | 暨南大学环境与气候研究院, 粤港澳环境质量协同创新联合实验室, 广州 510443 | | | 常鸣 | 暨南大学环境与气候研究院, 粤港澳环境质量协同创新联合实验室, 广州 510443 | | | 王伟文 | 暨南大学环境与气候研究院, 粤港澳环境质量协同创新联合实验室, 广州 510443 | | | 刘永林 | 暨南大学环境与气候研究院, 粤港澳环境质量协同创新联合实验室, 广州 510443 | | | 钟部卿 | 暨南大学环境与气候研究院, 粤港澳环境质量协同创新联合实验室, 广州 510443 | | | 毛敬英 | 暨南大学环境与气候研究院, 粤港澳环境质量协同创新联合实验室, 广州 510443 | | | 杨土士 | 暨南大学环境与气候研究院, 粤港澳环境质量协同创新联合实验室, 广州 510443 | | | 王雪梅 | 暨南大学环境与气候研究院, 粤港澳环境质量协同创新联合实验室, 广州 510443 | eciwxm@jnu.edu.cn | | 刘婵芳 | 深圳市环境监测中心站, 深圳 518049 | 99753846@qq.com |
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| 中文摘要 |
| 基于粤港澳珠江三角洲区域空气监测网络12个监测子站的大气污染物数据，梳理2013~2017年大气光化学氧化剂Ox（NO2+O3）与PM2.5质量浓度的变化趋势.Ox+PM2.5复合超标污染定义为NO2和PM2.5质量浓度日平均值以及O3浓度日最大8 h平均值（O3 MDA8）同时超过二级浓度限值，分析了不同类型站点复合超标污染的时空分布特征以及气象因素影响.结果表明，2013~2017年珠三角PM2.5年均质量浓度由（44±7）μg·m-3下降至（32±4）μg·m-3，实现PM2.5连续3 a达标.Ox年均质量浓度由2013年（127±14）μg·m-3下降至2016年（114±12）μg·m-3，2017年反弹至（129±13）μg·m-3，O3浓度上升明显（10 μg·m-3）.以O3为首要污染物的污染过程占比由2013年33%增多至2017年78%，多个城市同时发生污染的区域特征明显.研究时段内Ox+PM2.5复合超标污染事件共发生60次，主要在城区站点（78%）和郊区站点（22%）.秋季发生复合超标污染天数最多（52%），是因为强太阳辐射有利于臭氧生成，大气氧化性增加，进而促进了PM2.5二次生成.造成珠三角复合超标污染的天气形势主要为高压出海型（43%）、高压控制型（30%）和热带低压型（27%）.就具体气象因素而言，气温在20~25℃且相对湿度在60%~75%的范围内时，复合超标污染事件发生占比最高（22%）.在O3重污染过程中，夜间高湿和低风速使得NO2和PM2.5浓度显著上升，日间高温加剧了复合超标污染. |
| 英文摘要 |
| Based on the atmospheric pollutant data from twelve monitoring sites in the Guangdong-Hong Kong-Macao Pearl River Delta Regional Air Quality Monitoring Network, the mass concentration trends of atmospheric photochemical oxidants (Ox, NO2+O3) and PM2.5 during 2013-2017 were studied. The complex nonattainment pollution of Ox and PM2.5 is defined as the daily average mass concentration of NO2 and PM2.5 and daily maximum 8 h average (O3 MDA8) mass concentration of O3 simultaneously that exceeds the Chinese grade Ⅱ national air quality standard. The characteristics and meteorological factors that influence the complex nonattainment pollution of Ox and PM2.5 at different types of areas were analyzed. The results indicate that from 2013 to 2017, the annual average mass concentration of PM2.5 in the Pearl River Delta (PRD) region decreased from (44±7) μg·m-3 to (32±4) μg·m-3, which met the annual standard for three consecutive years. The annual average mass concentration of Ox decreased from (127±14) μg·m-3 in 2013 to (114±12) μg·m-3 in 2016 and then showed a general rebound trend to (129±13) μg·m-3 in 2017 when O3 concentrations increased significantly (10 μg·m-3). The proportion of pollution processes with O3 as the primary pollutant increased from 33% in 2013 to 78% in 2017, and the regional characteristics of simultaneous pollution in multiple cities have been highlighted. The complex nonattainment pollution of Ox and PM2.5 occurred 60 times during the study period, primarily in urban sites (78%) and suburban sites (22%). The largest number of days of complex nonattainment pollution occurred in autumn (52%) because of strong solar radiation that was conducive to ozone formation, and consequently, the high oxidization of the atmosphere promoted the secondary generation of PM2.5. The weather conditions that caused the complex nonattainment pollution in the PRD mainly include outflow-high-pressures (43%), subtropical-high-pressures(30%), and tropical-depressions (27%). In terms of specific meteorological conditions, when the temperature was in the range of 20-25℃ and relative humidity was in the range of 60%-75%, the proportion of complex nonattainment pollution was the highest (22%). When O3 pollution was substantial, the high relative humidity and low wind speed during the nighttime caused the concentration of NO2 and PM2.5 to rise significantly, and then the high temperatures during the day aggravated the complex nonattainment pollution. |
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