春节前后华北平原农村地区黑碳浓度及来源

在河南某农村站点利用黑碳仪（AE33）对春节前后（2018年2月12日~3月12日）黑碳气溶胶（eBC）进行在线连续监测，获得其质量浓度、昼夜变化及来源.结果表明：春节期间的eBC浓度最高，（8.22±4.17）μg/m³，该时期人为活动对eBC影响最为明显.春节前，生物质燃烧产生的eBC占其总浓度百分比最大，为（41.1±5.3）%，并随时间推移逐渐减小，降至（26.8±12.0）%.AAE（1.40±0.16）说明，该地区春节前后eBC的化石燃料排放和生物质燃烧贡献程度接近.与城市点位相比，本研究的AAE值较高.春节前后，观测地区的eBC昼夜变化存在2个明显高值时段，分别在7：00~9：00和20：00左右.春节期间的eBC昼夜变化无明显波动.根据浓度权重轨迹分析显示，春节期间eBC的潜在源区有山西、陕西、安徽和江苏等省份，其他时期集中在河南、湖北境内.本研究对于识别冬季农村燃烧源排放黑碳演化特征及其对区域重霾形成和发展的影响具有重要意义，也可为黑碳气溶胶气候、环境和健康模拟提供基础数据.

Levels and sources of black carbon around the spring festival at a rural site of the North China Plain

To obtain the mass concentrations, diurnal variations and sources of black carbon (eBC) aerosol around the Chinese spring festival (SF) in rural regions of the North China Plain, one-month (2018-2-12~2018-3-12) online continuous measurement of black carbon was conducted at a rural site in Henan province. During the SF, the eBC concentration was highest, (8.22±4.17)μg/m³, suggesting intensive emissions from anthropogenic activities. Before the SF, the contribution of biomass burning was the largest (41.1±5.3)%, and then gradually decreased down to (26.8±12.0)%. During the study period, the calculated AAE value (1.40±0.16) indicated that the contribution of biomass burning to eBC was close to that of fossil fuel in this area. Compared with some urban sites, the AAE value in this study was higher. Before and after the SF, the eBC mass concentrations show significant diurnal variations, with 2 peak values occurring at 07:00~09:00 and around 20:00 (local time). During the SF, the diurnal variation of eBC mass concentration did not fluctuate obviously. According to the concentration-weighted trajectories analysis, the main potential source regions of eBC were Shanxi, Shaanxi, Anhui, and Jiangsu provinces during the SF. In other two periods, Henan and Hubei provinces could be the main impact regions. This study is meaningful to identify the impact of BC emitted from rural combustion sources on regional haze formation and evolution, and it can also supply the dataset for corresponding modeling of BC's impacts on climate, air quality and human health.