河南省北部区域霾污染过程中城市和农村点位PM2.5组分差异

近年来，我国京津冀及其周边地区暴发了多次霾污染过程，受观测仪器等因素的限制，尚未有对河南省北部城市和农村霾污染的对比研究.利用一系列在线高时间分辨率的观测仪器在河南省2个城市点位和3个农村点位对一次区域重污染过程(2018年1月12～25日)进行综合观测.结果表明SO₄^2-、 NO^-₃和NH⁺₄(SNA)是此次区域污染过程中5个点位PM_2.5中占比最高的组分，位于53%～63%之间，以NO^-₃为主24%～32%,其次为SO₄^2-(13%～17%).相较于城市点位，农村点位PM_2.5中有机物的占比更高，尤其是夜间.随着污染的加重，SNA的占比上升，重污染时段可达67%.此外，当区域受南部气团的传输影响时，5个点位PM_2.5中NO^-₃的占比增大；受北和东北部气团的传...

Differences in PM2.5 Components Between Urban and Rural Sites During Heavy Haze Event in Northern Henan Province

In recent years, the Beijing-Tianjin-Hebei region and its surrounding areas have experienced multiple haze pollution processes. Owing to the limitation of observational instruments, there has not been a comparative study of haze pollution between urban and rural areas in northern Henan province. A series of high-time-resolution instruments were used during a regional heavy pollution process (January 12-25, 2018) at two urban sites and three rural sites. The results showed that SO₄^2-, NO^-₃, and NH⁺₄ (SNA) were the components with the highest proportion in PM_2.5 at the five sites during the haze event with a range of 53%-63%, of which nitrate was the most important, accounting for 24%-32%, followed by sulfate, ranging from 13%-17%. Compared with urban sites, rural sites were more affected by organic matter, especially at night. With the aggravation of pollution, the proportion of SNA increased, reaching 67% during periods of heavy pollution. When the area was affected by the air mass transported from the south, the proportion of NO^-₃ in PM_2.5 increased, and when the area was affected by the air transport in the north, the proportions of SO₄^2- and organic matter increased. Ammonium nitrate was the most important component that led to the decrease in atmospheric visibility during the haze process. Moreover, the contributions of ammonium nitrate and ammonium sulfate at the urban sites were higher than those at the rural sites. To summarize, there were significant differences in PM_2.5 components between the urban and rural sites. Urban areas need to continue to strengthen the reduction in gaseous precursors, and rural areas need to pay attention to the sources of carbonaceous aerosol.