青藏高原高海拔背景大气环境下大气新粒子生成机制的观测与量子化学研究

Knowledge of the formation mechanism of atmospheric new particles is of importance in atmospheric chemistry and aerosol science. However, none of current nucleation theories can interpret well the mechanism of new particle formation (NPF). This project will integrate the field measurements including gaseous precursors, aerosol particle composition, and size distribution of number concentrations in the National Air Background Station of Qing-Tibet Plateau, and quantum chemistry computation from molecular level to study the key physical and chemical processes that play major roles in new particle formation. The Pseudo steady state chemical model will be used to investigate the mechanisms of sources and condensation sink of precursors, and the nucleation and growth rate of aerosol particles during NPF. We will also quantify the potential contributions of key chemical species and precursors vapor to NPF in typical region of Qing-Tebet plateau. Finally, we will develop a non-linear relationship between atmospheric NPF/Nucleation and multi-component gaseous species based on field observations and theoretical prediction. The results and findings in this project will provide new evidence for the burst of new particles and the formation mechanism of ultrafine particles, which is scientifically important to control the primary pollutants in China.

大气新粒子生成机制是目前大气化学和气溶胶研究领域的一个热点问题，到目前为止，没有一种完善的核化理论能够解释大气新粒子生成机制。本项目拟以青藏高原国家空气背景值站的实际观测数据为基础，对形成大气气溶胶前体物各项组分、颗粒物数谱分布进行观测并结合量子化学计算方法，从分子水平上研究控制新粒子生成的物理和化学过程；利用稳态化学模型研究青藏高原典型区域新粒子生成过程的源-汇机制，考察颗粒物核化和生长速率，确定影响核化的关键化学成分和敏感前体蒸气对新粒子生成的潜在贡献率，期望确立大气新粒子生成/核化与大气多组分之间的非线性关系。本项目的研究为典型区域新粒子爆发过程及超细粒子形成机制提供理论和技术支持，对国家大气环境基准优控污染物的确定和补充提供科学依据。

大气新粒子生成和生长机制是目前大气化学和气溶胶研究领域的一个热点问题，然而，到目前为止，没有一种完善的核化理论能够解释大气新粒子生成机制。本项目通过在青海磨石达坂国家空气背景值站的实际观测数据为基础，对形成大气气溶胶前体物各项组分（VOCs,SO2,NOx,O3,NMHC,CO, CO2,CH4等）、气象条件(气象5参数、能见度、UVB)、颗粒物数谱分布(3-500nm)和在线/离线颗粒物（PM10, PM2.5, PM1.0）进行综合观测和分析，并结合量子化学计算方法，从分子水平上研究洁净大气条件下控制新粒子生成和生长的物理和化学过程，计算颗粒物核化和生长速率，确定影响核化的关键化学成分和敏感前体蒸气对新粒子生成的潜在贡献。目前，高海拔区域的大气新粒子生成现象，国际上研究较少，本项目的研究为典型区域新粒子爆发过程及细粒子（PM2.5）和超细颗粒物（小于100nm）形成机制提供理论和技术支持，通过与特大城市新粒子生成现象比对可为复合污染条件下国家大气环境基准优控污染物的确定和补充提供科学依据。