Activation and Growth of Newly Formed Atmospheric Particles

该项目的重点是研究大气中新粒子的形成和生长。它涉及一项国际合作，使美国科学家能够在瑞士的欧洲核子研究中心（CERN）的云室（COsmics Leaving Outdoor Droplets）工作。这项研究的结果预期将对大气科学以外的许多工业和其他自然过程产生影响。这项研究的目标是：（1）先进的测量方法，使测量新成核团簇的尺寸分布成为可能;粒子作为时间的函数，因为它们存在于形成它们的大气中，以便映射它们通过开尔文状态的通道，即，（2）当低挥发性有机化合物和极低挥发性有机化合物在Kelvin尺寸范围内凝聚在惰性和硫酸簇上时，测量和模拟多组分活化动力学，改变大气的温度和组成以探测潜在的机制;（3）在仔细控制的室实验中测量和模拟新颗粒的形成、二次活化和生长，以便在大范围的大气条件下和对于关键的气溶胶前体约束和参数化新颗粒的形成。

This project is focused on the study of the formation and growth of new particles in the atmosphere. It involves an international collaboration that enables U.S. scientists to work at CERN, the European Organization for Nuclear Research in Switzerland, at the CLOUD (COsmics Leaving Outdoor Droplets) chamber there. The results of this research are expected to have implications that go beyond the atmospheric sciences, to numerous industrial and other natural processes.The objectives of this research are to: (1) advance measurement methods to make it possible to measure the size distribution of freshly nucleated clusters/particles as a function of time as they exist in the atmosphere in which they are formed in order to map their passage through the Kelvin regime, i.e., from near critical, or even sub-critical cluster sizes through to stable particles; (2) measure and model the multicomponent activation kinetics as low volatility organic compounds and extremely low volatility organic compounds condense on inert and sulfuric acid clusters in the Kelvin size regime, varying the temperature and composition of the atmosphere to probe the underlying mechanisms; (3) measure and model new particle formation, secondary activation, and growth in carefully controlled chamber experiments in order to constrain and parameterize new particle formation under a wide range of atmospheric conditions and for key aerosol precursors.