新粒子形成对于区域空气污染和全球气候变化意义重大。申请人前期研究发现沙尘气团会促进新粒子形成事件的发生，但其内在机制尚不清楚。针对新粒子形成相关参数的全面连续观测，尤其是硫酸、超低挥发性有机物和 3 nm以下分子簇的观测是理解其内在机理的关键。本项目拟在前期青年项目的基础上，选择典型沙尘及扬尘季节（3-5月）继续在南京大学SORPES观测站针对新粒子形成相关间接前体物、直接前体物、颗粒物粒径全谱以及其它气体气溶胶参数进行三期强化观测。研究沙尘（或扬尘）气团影响下的新粒子形成及增长的特征。针对典型新粒子形成事件的前体物转化、分子簇凝聚及增长过程进行数值模拟，以野外观测和数值模拟的对比结果为指导，设计实验室控制试验，评估不同状态下的沙尘颗粒物对新粒子形成和增长关键过程的定量影响。本项目将有助于揭示我国高污染环境下新粒子形成和增长机制，为认识我国灰霾形成机制提供支撑。

Atmospheric new particle formation (NPF) plays important roles in regional air quality and global climate change. Our previous work found dust plumes can promote new particle formation and growth. But it’s inside mechanism was not clear. A continuous observation on NPF related parameters, especially sulfuric acid, extremely low volatility organic compounds (ELVOCs) and sub-3 nm clusters, is critical to understand these processes. On the basis of last NSFC project, we propose 3 3-month intensive campaigns at SORPES station during the dust seasons (March to May) from 2017 to 2019. Comprehensive NPF related parameters including the indirect precursors, direct precursors, particle size distributions from 1 nm to 20 µm and other gaseous and aerosol species will be measured with a set of state-of-the-art instruments (including CI-APi-TOF, AIS，PSM，DMPS, APS). Based on the measured values, the NPF events occurred in dust plumes will be analyzed. A photochemical box model (MCM) and new particle formation model (MALTE-BOX) will be used to simulate the key processes of the selected NPF events, which includes the transformation of sulfuric acid and ELVOCs, particle nucleation and growth. Based on the comparison between the measurements and simulation, some chamber work will be designed to evaluate the influence of dust particles on the key processes of NPF. This project will be helpful to understand the mechanism of NPF in heavy polluted environment from a more detailed perspective.