昼夜不同氧化途径影响苯系物SOA吸湿参数差异的烟雾箱研究

二次有机气溶胶（SOA）在颗粒物中占比不断增加的趋势导致其对颗粒物吸湿性的影响愈加显著。SOA吸湿能力（即κSOA值）的参数化研究对于进一步了解其对大气辐射强迫、云凝结核活性的影响具有重要意义。目前对于苯系物SOA吸湿能力尚未有同时针对粒径、湿度以及老化程度的参数化系统研究，且对于SOA吸湿增长能力的微物理机制仍存在许多未知。本项目拟利用烟雾箱模拟系统和外场颗粒物吸湿性观测相结合的方式，通过多种吸湿性监测手段（HTDMA+加湿浊度计+配套仪器），研究典型苯系物SOA的吸湿特性，重点分析氧化机制和老化程度对SOA的κSOA值的影响。通过本研究有望厘清SOA昼夜吸湿能力存在差异的影响机制；利用烟雾箱模拟结果与环境颗粒物吸湿性的对比分析，对环境SOA的吸湿参数κE-SOA建立基于粒径、相对湿度以及老化等因子的参数化方程。本项目的实施可为提高环境模式模拟结果的准确性起到数据支撑作用。

More significant influences of secondary organic aerosol (SOA) on the hygroscopic characteristics of particulate matters have been occurred with the increasing proportion of SOA in PM2.5. Parameterized studies of SOA hygroscopicity (i.e. κSOA) are of great significance for further understanding its effects on atmospheric radiative forcing and cloud condensation nuclear activity, as well as improving the accuracy of model simulation. Up to now, there have been no systematic parameterized studies on the hygroscopicity of benzene SOA based on particle size, humidity and aging, and there are still many unknown microphysical mechanisms for the hygroscopic growth ability of SOA. This project intends to study the hygroscopicity of typical benzene SOA via various hygroscopic monitoring methods (HTDMA, humidified nephelometer system and supporting instruments) using chamber study and field research, and mainly focus on analyzing the influences of oxidation mechanisms and aging degree on κSOA value. This study is expected to further clarify the hygroscopicity of typical anthropogenic SOA; to understand the influences of different mechanisms in daytime and nighttime on hygroscopicity of SOA; to obtain κE-SOA based on particle size, relative humidity and aging. The implementation of this project would play a supporting role for the development of model simulation.