Primary and secondary organic aerosols in Fresno, California during wintertime: Results from high resolution aerosol mass spectrometry
Primary and secondary organic aerosols in Fresno, California during wintertime: Results from high resolution aerosol mass spectrometry
复制标题
DOI：
10.1029/2012jd018026
复制
发表时间：
2012-10-02
影响因子：
4.4
通讯作者：
Zhang, Qi
中科院分区：
文献类型：
--
作者：
Ge, Xinlei;Setyan, Ari;Zhang, Qi
2010 年冬季，在加利福尼亚州弗雷斯诺使用 Aerodyne 高分辨率飞行时间气溶胶质谱仪 (HR-ToF-AMS) 对有机气溶胶 (OA) 进行了研究。 OA在亚微米气溶胶质量中占主导地位（平均= 67%），平均浓度为7.9 μ g m(-3)，标称分子式为C1H1.59N0.014O0.27S0.00008，对应于平均有机质碳比为1.50。通过高分辨率质谱的正矩阵分解，鉴定了三种主要 OA (POA) 因子和一种代表继发性 OA (SOA) 的氧化 OA 因子 (OOA)。三个 POA 因素，包括与交通相关的碳氢化合物 OA (HOA)、烹饪 OA (COA) 和住宅供暖释放的生物质燃烧 OA (BBOA)，平均占 OA 质量的 57%，在下午 6 点至 9 点之间高达 80%，在此期间，晚高峰交通、晚餐烹饪和住宅木材燃烧造成的排放量因混合层高度较低而加剧。基于有机物尺寸分辨质谱的多线性分析，估计了 OA 因子的基于质量的尺寸分布。 HOA 和BBOA 的真空空气动力学直径(D-va) 峰值均在140 nm 处，而OOA 的峰值在460 nm 处的累积模式。 COA 表现出独特的尺寸分布，具有两种尺寸模式，分别以 200 nm 和 450 nm 为中心。这项研究强调了人为 POA 排放（主要来自交通、烹饪和住宅供暖）在弗雷斯诺冬季气溶胶污染中发挥的主导作用。
Organic aerosols (OA) were studied in Fresno, California, in winter 2010 with an Aerodyne High Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS). OA dominated the submicron aerosol mass (average = 67%) with an average concentration of 7.9 mu g m(-3) and a nominal formula of C1H1.59N0.014O0.27S0.00008, which corresponds to an average organic mass-to-carbon ratio of 1.50. Three primary OA (POA) factors and one oxygenated OA factor (OOA) representative of secondary OA (SOA) were identified via Positive Matrix Factorization of the high-resolution mass spectra. The three POA factors, which include a traffic-related hydrocarbon-like OA (HOA), a cooking OA (COA), and a biomass burning OA (BBOA) released from residential heating, accounted for an average 57% of the OA mass and up to 80% between 6 - 9 P.M., during which enhanced emissions from evening rush hour traffic, dinner cooking, and residential wood burning were exacerbated by low mixed layer height. The mass-based size distributions of the OA factors were estimated based on multilinear analysis of the size-resolved mass spectra of organics. Both HOA and BBOA peaked at similar to 140 nm in vacuum aerodynamic diameter (D-va) while OOA peaked at an accumulation mode of similar to 460 nm. COA exhibited a unique size distribution with two size modes centering at similar to 200 nm and 450 nm respectively. This study highlights the leading roles played by anthropogenic POA emissions, primarily from traffic, cooking and residential heating, in aerosol pollution in Fresno in wintertime.