【摘要】 采用2019年12月13日—2020年2月10日开封市空气质量监测站逐日PM_2.5质量浓度、郑州探空站数据及NCEP气象资料，分析了PM_2.5质量浓度和500 hPa以下逆温层、低层风的变化特征。结果表明，在PM_2.5质量浓度静稳积累期，500 hPa东亚中纬度环流平直，低层（925 hPa和1000 hPa）多偏南风，近地面相对湿度逐渐增加，对流层中下层多层逆温逐渐建立，此时受本地排放积累、吸湿增长和扩散能力下降的共同作用，再加上较长的持续时间，导致PM_2.5质量浓度不断增长。PM_2.5质量浓度的快速增长可分为两类：一是高空低槽携带冷空气由华北影响河南，对流层中下层逆温被破坏，京津冀的污染物经太行山东麓向南传输所致；二是高空环流平直，PM_2.5颗粒向地面均压场中的辐合线或弱低压中心附近的辐合区积聚，地面高湿弱风，近地逆温层建立或增强，扩散能力下降，共同作用而致。快速清除期，通常伴随着高空低槽携带冷空气影响河南，对流层下层逆温被破坏或减弱，低层多东北风、东风和西北风。另外，850 hPa与925 hPa的垂直风切变可表征大气垂直扩散能力，与12 h后的PM_2.5质量浓度（空气质量监测站位于探空站东约60 km处）的Pearson相关系数最大（-0.367）,可据此提前12 h预报开封市PM_2.5质量浓度变化。更多还原

【Abstract】 Based on the daily PM_2.5 mass concentration of the Kaifeng air quality monitoring station, Zhengzhou sounding station data, and NCEP meteorological data from 13 December 2019 to 10 February 2020, the variation characteristics of PM_2.5 mass concentration, temperature inversion layer below 500 hPa and low-level wind are analyzed. The results show that during the static accumulation period of PM_2.5 mass concentration, the 500 hPa mid-latitude circulation over East Asia was straight, winds were mostly southerly at 925 hPa and 1000 hPa, the relative humidity near the surface increased gradually, and the multilayer temperature inversion was gradually established in the middle and lower troposphere. PM_2.5 mass concentration kept growing during the relatively long period of static accumulation due to the combined effects of local emission accumulation, moisture absorption growth and diffusion capacity decline. The rapid growth of PM_2.5 mass concentration can be divided into two types: one is caused by the cold air carried by high-level trough from North China to Henan, the destroyed temperature inversion in the middle and lower troposphere, and the pollutants transported from the Beijing-Tianjin-Hebei region toward the south area through the eastern foot of the Taihang Mountains; and the other is because the high-level circulation is flat and straight, PM_2.5 particles accumulate towards the convergence line in the surface pressure field or the convergence zone near the weak low-pressure center, the surface has high humidity and weak wind, the near-surface inversion layer is established or strengthened, and the atmospheric diffusion condition is reduced. The rapid clearing period is usually accompanied by the high-level trough with cold air affecting Henan, the temperature inversion in the lower troposphere is destroyed or weakened, and the northeasterly, easterly and northwesterly winds blow frequently in the lower layer. In addition, the vertical wind shear at 850 hPa and 925 hPa can characterize the vertical diffusion capacity of the atmosphere, and it has the largest Pearson correlation coefficient（-0.367） with the 12 h PM_2.5 mass concentration（the air quality monitoring station is located about 60 km east of the sounding station）. This finding can be used in predicting the change of PM_2.5 mass concentration 12 h in advance in Kaifeng City.更多还原