1.Nanjing University;2.Nanjing Meterological Bureau
研究表明东亚地区严重的近地层空气污染与高空急流之间存在着一定的联系。本文利NCEP/NCAR逐日风场、垂直速度资料以及Science Data Bank的地面污染物和气象要素数据，运用统计分析法研究了冬季东亚高空急流与近地面空气污染物高浓度区的关系并初步探讨了两者之间的作用机制。结果表明：2013-2018年冬季我国华北平原是颗粒物的高值区。华北平原污染物PM2.5、PM10的平均浓度分别为80.65μg/m3、118.62μg/m3，超标天数分别共计459、489天。这段期间内颗粒物浓度均呈逐年缓慢下降趋势，PM2.5/PM10平均约为0.65，该比值保持多年稳定。其中该地区的空气污染物浓度与东亚高空温带急流的强度关系显著，两者可能通过地面温度以及经向风进而产生联系。当东亚温带急流强度减弱时，华北平原内地面温度降低、地面经向风减弱进而使得华北平原内中部的PM10、北部的PM2.5浓度均较低；当东亚温带急流强度增强时，华北平原内地面温度升高、地面经向风增强进而使得华北平原内中部的PM10、北部的PM2.5浓度均较高。
Studies have shown that there is a certain connection between the serious near-surface air pollution in East Asia and the Upper jet stream. Based on the NCEP/NCAR daily wind field, vertical velocity data, and ground pollutant and meteorological element data from Science Data Bank, this paper uses statistical analysis to preliminary explore the relationship and mechanism between the East Asian jet streams and the high-concentration air pollutants near the ground in the winter. The results show that the concentrations of particulate matter in the North China Plain is much higher in the winter of 2013-2018. The average concentrations of PM2.5 and PM10 in the North China Plain were 80.65μg/m3 and 118.62μg/m3 and the number of days exceeding the environmental standards reached 459 and 489 days in all, respectively. During this period, the concentration of particulate matter showed a slow downward trend year by year, and the average PM2.5/PM10 was about 0.65, and this ratio remained stable for many years. the concentration of air pollutants in the North China Plain has a significant relationship with the intensity of the East Asian polar front jet, and they may be related by ground temperature and meridional wind. When the strength of the polar front jet is weakened, the surface temperature decrease and the ground meridional wind weaken in the North China Plain, so that the PM10 concentration in the central part of the North China Plain and the PM2.5 concentration in the northern part of the North China Plain are both lower; when the strength of the polar front jet increases, the surface temperature rise and meridional wind strengthen, which possibly lead to higher concentration of PM10 in the middle part of the North China Plain and PM2.5 in the north part of the North China Plain .