长三角地区1-10 nm大气新粒子的成核与生长速率及关键性物理化学影响因素的的研究

新粒子生成初始阶段(1-10 nm)的成核速率J和分粒径段的生长速率GR(Dp)不仅表征了新粒子生成的强度，决定了其对大气气溶胶的贡献，更反映了不同挥发性前驱气体的浓度水平，测量J和GR(Dp)对于理解新粒子意义重大。我们将在长三角地区同步观测1-10 nm粒径分布、气态前驱物（硫酸、氨气、有机胺、多种VOC及其氧化产物）和环境因素（温度、湿度和气溶胶表面积浓度等）。利用气溶胶动态方程反演具有高度时间和粒径分辨率的J(t)和GR(Dp,t)，研究不同大气污染水平下1-10 nm新粒子J(t)和GR(Dp,t)的日变化特征，考察其与气态前驱物和环境因素的关系。辅之以流动管实验，模拟气态前驱物和环境因素对1-10 nm新粒子J和GR(Dp)的贡献和影响，测量气态物质在新粒子上的生长速率系数Kg(Dp)，揭示其中关键性物理化学过程，提出J和GR(Dp)的参数化方案，为完善气溶胶成核模型提供依据。

Nucleation rate J and size-dependent growth rate GR(Dp) in the initial formation steps (diameter: 1-10 nm ) determine the intensity and contribution of new particle formation to ambient aerosols, and reflect the concentrations of gaseous precursors with different volatility. Therefore, J and GR(Dp) measurement is important to understand new particle formation in the atmosphere. We propose to simultaneously measure size distribution of 1-10 nm new particles, gaseous precursors (sulfuric acid, ammonia, amines, VOCs and their oxidation products) and environmental variables (temperature, humidity, and aerosol surface area concentration) in the atmospheres of various pollution levels in the Yangtse River Delta region. Time and size-dependent J(t) and GR(Dp, t) will be inverted based on aerosol general dynamic equations. We will investigate the temporal characteristics of J(t) and GR(Dp, t) in 1-10 nm size range, as well as their connections to gaseous precursors and environmental variables. Laboratory flow tube experiments will be conducted to simulate the influences of gaseous precursors and environmental variables on J(t) and GR(Dp, t) of 1-10 nm new particles. Size resolved growth rate factor Kg(Dp) of gaseous precursors will be obtained. Based on atmospheric measurements and laboratory simulation, we will reveal the critical physical and chemical processes in the 1-10 nm new particle formation and provide aerosol nucleation rate and growth rate parameterizations. The result of this study will improve the nucleation module in air quality models.