- Comparative analysis of three sudden heavy pollution processes in Suqian
- 1. 南京信息工程大学, 南京 210000;2. 宿迁市气象局, 宿迁 223800
- 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.