广东省森林地区异戊二烯生成的二次有机气溶胶的观测和模拟

The air pollution of fine particulates is the serious environmental and social problem in China. The sources and compositions of the fine particulates are extremely complicated, in which the organic aerosol produced by the biogenic volatile organic compounds (VOCs) is one of the most important compositions. Isoprene, the biogenic VOCs with the largest emission, is selected in this study, and isoprene and organic aerosols are observed in a forest area of Guangdong Province. SPIMS and EC/OC carbon aerosol analyzer are used to observe isoprene, EC and OC in-situ, and high volume sampler is applied to collect aerosol samples on quartz filters. The samples are analyzed by GC-MS to detect 2-methyltetrols produced by isoprene. The EC tracer method is employed to estimate the concentration of secondary rganic aerosol (SOA), and then to calculate the contribution of isoprene to SOA. According to the concentrations of isoprene and its products, parameterization method to simulation SOA by isoprene is established in box models of EASY-MADE. In this study, it may strengthen the understanding of the contribution of biogenic VOCs to the fine particulates, and it is supposed to support the improvement of the air quality model.

大气中的细颗粒物污染已经成为我国面临的严重的环境问题和社会问题。细颗粒物的来源和组成非常复杂，其中天然源挥发性有机物（VOCs）生成的有机颗粒物是一种重要的组分。本研究选取排放量最大的天然源VOCs异戊二烯为代表，在广东省的森林地区对异戊二烯和有机颗粒物进行测量。利用挥发性有机物质谱仪和EC/OC分析仪对异戊二烯，元素碳和有机碳进行在线观测，并利用大流量采样器在石英膜上采集颗粒物样品。石英膜样品用GC-MS分析其中异戊二烯的特征产物2-甲基丁四醇类物质（2-methyltetrols）。利用改进的EC示踪法估算二次有机气溶胶(SOA)的浓度，进而估算异戊二烯对SOA的贡献。在盒子模型EASY-MADE中，根据异戊二烯及其产物的浓度，建立模拟异戊二烯生成的SOA的参数化方法。该研究可以加强对天然源VOCs对细颗粒物贡献的认识，并可能对空气质量模型的改进提供支持。

大气中的细颗粒物污染已经成为我国面临的严重的环境问题和社会问题。细颗粒物的来源和组成非常复杂，其中天然源挥发性有机物（VOCs）生成的有机颗粒物是一种重要的组分。.本研究选取排放量最大的天然源VOCs异戊二烯为研究对象，在云南森林地区进行异戊二烯特征物种观测。分析结果表明各特征物种浓度差异较大，其中2-甲基丁四醇类示踪物的浓度水平最高，2-甲基赤藻醇（2-methylerythritol）的年均浓度为67.1 ng/m3，2-甲基苏阿醇（2-methylthreitol）浓度为27.5 ng/m3。.选取10-12月7个样品，利用盒子模型对异戊二烯生成二次有机气溶胶进行模拟。基准方案下，模拟平均误差为0.52。按照不同的温度组进行参数优化，优化后模拟平均误差降至0.38。.本项目结果验证对于森林地区，利用异戊二烯特征产物来模拟异戊二烯生成SOA具有一定可行性和类似森林地区条件下的应用价值。