报告题目：Modeling of gas-phase clusters and atmospheric new particle formation

报告人：Roope Halonen, Postdoctoral researcher (Tianjin University)     

报告时间： 2022年10月28日（周五）15：30-17：00

报告地点：腾讯会议 760-549-231

报告摘要：Nucleation, where nanoscale clusters are formed from atoms or molecules of a metastable phase, is a ubiquitous process. Despite being an active field of research for over a century, a rather significant gap still exists between experiment and theory. The main reasons for this are related to the peculiar physicochemical properties of the smallest clusters and the possible nonstandard growth pathways. Therefore, multi-level modeling combining quantum chemical data with a detailed representation of the growth dynamics is often required to accurately capture the observed clustering behavior from first principles.

My presentation focuses mainly on the theoretical inspection of clusters formed from gaseous precursors in Earth’s atmosphere. These “secondary aerosols” are not only responsible for adverse health effects through air pollution but affect the climate directly through light scattering and indirectly by acting as seed particles for clouds. Thus identifying the principal mechanisms and the key molecules behind atmospheric nucleation has its utmost importance especially since the main sources of uncertainty for understanding global warming are related to aerosols.

报告人简介：Roope Halonen received a master’s degree in computational physics from the University of Helsinki (2016) and his Ph.D. (2021) from the Institute for Atmospheric and Earth System Research at the University of Helsinki working with theoretical and computational modeling of gas-phase clusters and their formation. Presently, he is employed as a postdoctoral researcher at the Center of Joint Quantum Studies at Tianjin University. His work focuses mainly on developing accurate and applicable modeling approaches for atmospheric new particle formation, but also on unraveling the problems related to classical nucleation theory.

参考文献:

[1] R. Cai, R. Yin, C. Yan, D. Yang, C. Deng, L. Dada, J. Kangasluoma, J. Kontkanen, R. Halonen, Y. Ma, X. Zhang, P. Paasonen, T. Petäjä, V.-M. Kerminen, Y. Liu, F. Bianchi, J. Zheng, L. Wang, J. Hao, J. N. Smith, N. M. Donahue, M. Kulmala, D. R. Worsnop, J. Jiang, The missing base molecules in atmospheric acid–base nucleation, National Science Review, Volume 9, Issue 10, October 2022, https://doi.org/10.1093/nsr/nwac137.

[2] V. Tikkanen, B. Reischl, H. Vehkamäki, and R. Halonen, Nonisothermal nucleation in the gas phase is driven by cool subcritical clusters, Proceedings of the National Academy of Sciences, 119, 28, e2201955119, 2022, https://doi.org/10.1073/pnas.2201955119.