京津冀地区大气NO2污染特征研究

京津冀都市圈作为全国主要的重化工业基地，区域性大气污染问题成为关注的焦点。NO2作为二次颗粒物及光化学污染物的重要前体物，了解其在时空尺度的污染特征对于保护公众康健及大气污染综合治理具有重要意义。本研究主要基于OMI遥感反演数据并结合部分地面监测数据，研究了2005—2013年京津冀NO2区域污染特征。结果表明：京津冀NO2柱浓度总体呈现逐年升高的趋势，年平均增长速率可达5.69%。在空间格局上呈东南平原区高、西北山区低的特征，平原的年均柱浓度是山区的3倍多；平原区存在两大NO2高值区域，分别为北京-天津-唐山区域和石家庄-邢台-邯郸区域；9年内， NO2高值范围不断扩大，且呈现明显的连片趋势。各城市大气 NO2在9年内的增长趋势也表现出明显的空间差异性。其中石家庄、唐山、邢台等 NO2重度污染区域的增长速率最大，衡水、沧州、秦皇岛、廊坊等中度污染区域的增长速率次之，承德、张家口等轻度污染区域的增长速率最小。京津冀NO2柱浓度具有显著的季节变化特征，总体表现为秋冬高、春夏低，但山区与平原区差异较大。人口密度、能源消耗、机动车排放等人为因素与京津冀 NO2污染密切相关，不同城市的首要影响因素却不同。北京 NO2柱浓度变化主要受机动车排放影响，天津、唐山、石家庄、邯郸、邢台地区主要受工业燃煤的影响，其次为机动车排放。人为因素对平原区NO2柱浓度的影响作用始终占据主导地位，对山区的主导作用从2006年开始突显。此外，京津冀平原区NO2重污染中心的形成还受到特殊地形和不利的气象条件影响。2008奥运年，京津冀空气质量得到迅速且有效的改善，说明北京及周边省市联合开展大气污染治理及监管工作的有效性及必要性。

Spatial and Temporal Characteristics of Atmospheric NO2 in the Beijing-Tianjin-Hebei Region

Beijing-Tianjin-Hebei（BTH） economic region is one of the major national heavy industrial area. Regional air contamination in this region becomes one of the focus problems for social public concern. NO2 as an important precursor of secondary particle and photochemical pollutants, having its detailed knowledge of spatial and temporal characteristics is great important for public health and atmospheric pollution management. Based on remote sensing data derived from OMI sensor and ground-based observation data, the temporal-spatial characteristics of NO2over the BTH area was analyzed from 2005 to 2013. The ground monitoring and remote sensing results have high consistency both in regional distribution and change trend. The result showed that the regional average value has an increasing trend and the high NO2 regions mainly distributed in plain areas. The annual increasing rate in whole region is 5.69% and the mean value in plain area is more than three times than mountain areas. There are two high NO2 areas in the plain, Beijing-Tianjin-Tangshan region and Shijiazhuang -Xingtai-Handan region, expanding and becoming continuous regions. NO2 growth trend also showed significant spatial differences in 9 years. The growth rates in Shijiazhuang, Tangshan and Xingtai are higher than Hengshui, Changzhou, Qinhuangdao and Langfang’s. The growth rates in Chengde and Zhangjiakou are minimized. BTH NO2 was also showed a significant seasonal variation, NO2 in autumn and winter were higher than spring and summer. However, it was different in mountain and plain areas. Anthropogenic resources, such as the density of population, energy consumption and vehicle emission, are closely related to NO2 pollution in BTH. And the main factor is distinct in different heavily polluted cities. The tropospheric column NO2in Beijing is mainly affected by vehicle, while the principle influence in Tianjin and Hebei is industrial consumption. Anthropogenic emissions dominate the NO2 column concentration over plain areas in 9 years and over mount