研究报告
庞礴,郑有飞,殷华,王锦杰,颜雅琼.宿迁3次突发性空气重污染过程对比分析[J].环境科学学报,2020,40(11):4122-4132
宿迁3次突发性空气重污染过程对比分析
- Comparative analysis of three sudden heavy pollution processes in Suqian
- 基金项目:江苏省气象局青年基金(No.KQ201916,KQ202016);宿迁市科技支撑计划项目(No.S201607)
- 庞礴
- 1. 南京信息工程大学, 南京 210000;2. 宿迁市气象局, 宿迁 223800
- 摘要:利用空气质量资料、常规观测资料、NCEP1.0°×1.0°再分析资料,应用数理统计、天气学等方法对宿迁市3次突发性重污染天气进行对比分析.结果表明:①宿迁"突发"空气重污染时,AQI级别由前一日的一、二级至第2日转为五级以上,AQI值迅速上升.②3次空气重污染过程天气背景相似,高层为宽广平直的偏西气流,地面受高压控制,中低层风向和温度平流突然转变,且都有深厚的逆温层结;持续变化较小的气压梯度、较低风速、温度日较差及相对湿度的增大(150328过程(即2015年3月28日—4月1日污染过程)除外)为颗粒物浓度迅速增长提供了条件.③大气稳定度级别迅速变高和混合层高度迅速降低并维持,对污染物快速聚集有显著影响.④物理量诊断表明,污染发生前期上空为弱上升运动,随后迅速转为下沉运动,或气流下沉运动区域迅速扩大、升高,是空气质量迅速转差的重要动力因素.⑤内蒙古地区的沙尘远距离输送形成的污染,是造成150328过程与另外两次过程明显不同的主要原因.
- Abstract:Based on the air quality data, conventional observation data and NCEP 1.0°×1.0° reanalysis data, a comparison among three sudden severe air pollution events in Suqian was carried out by employing the mathematical statistics and synoptic meteorology analysis. The results show that: ①When the sudden heavy air pollution events occurred in Suqian, the AQI changed from level 1 or 2 on the previous day to above level 5 on the next day. ②All events had similar weather backgrounds, which manifested broad and straight westerlies at the high-level, high pressures at the surface, and an abrupt reverse of wind direction and temperature advection, as well as a deep inversion layer, at the low-middle level. In addition, continuous changes of slight pressure gradient, low wind speed, diurnal temperature range and relative humidity increase (except for 150328 event) were beneficial to the rapid raising of particle concentration; ③The atmospheric stability strengthened and the mixed layer lowered, exerting a significant impact on the pollutant accumulation.④Physical diagnosis shows that, at the early stage of pollution occurrence, the most important dynamic factor contributing to the air pollution was the rapid changing from weak ascending motion to descending motion, or the expansion of descending motion. ⑤The 150328 event had distinct process from the other two events, mainly attributed to the long-distance sand dust transportation from Inner Mongolia.