清华大学赵斌团队实验室报道了大气新粒子形成机制的全球变化。相关论文发表在2024年6月12日出版的《自然》杂志上。

据介绍，气溶胶污染的研究和气候变化评估的一个关键挑战，是了解大气气溶胶颗粒最初是如何形成的。虽然新粒子形成(NPF)的机制已经在特定的地点得到描述，但在大多数地区，这种机制在很大程度上仍然不确定，因为大气模型模拟关键NPF过程的能力有限。

研究人员综合了分子水平的实验，在一个完全耦合的全球气候模式中建立了11种NPF机制和前体气体复杂化学转化的综合表征。综合模拟和观测结果表明，主要的NPF机制在全球范围内是不同的，并随区域和高度而变化。以前被忽视或代表性不足的涉及有机物、胺类、碘氧酸和HNO₃的机制，在大多数气溶胶浓度高或气溶胶辐射作用力大的地区可能占主导地位；这些区域包括海洋和人为污染的大陆边界层，以及热带雨林和亚洲季风区上空的对流层上层。

这些代表性不足的机制在其他地区也发挥着显著作用，例如太平洋和大西洋对流层上层。因此，在对流层下层不同区域，NPF占形成0.5%过饱和云的原子核的不同比例(10-80%)。全球NPF机制的综合模拟有助于改进气溶胶气候效应的估计和归因。

附：英文原文

Title: Global variability in atmospheric new particle formation mechanisms

Author: Zhao, Bin, Donahue, Neil M., Zhang, Kai, Mao, Lizhuo, Shrivastava, Manish, Ma, Po-Lun, Shen, Jiewen, Wang, Shuxiao, Sun, Jian, Gordon, Hamish, Tang, Shuaiqi, Fast, Jerome, Wang, Mingyi, Gao, Yang, Yan, Chao, Singh, Balwinder, Li, Zeqi, Huang, Lyuyin, Lou, Sijia, Lin, Guangxing, Wang, Hailong, Jiang, Jingkun, Ding, Aijun, Nie, Wei, Qi, Ximeng, Chi, Xuguang, Wang, Lin

Issue&Volume: 2024-06-12

Abstract: A key challenge in aerosol pollution studies and climate change assessment is to understand how atmospheric aerosol particles are initially formed. Although new particle formation (NPF) mechanisms have been described at specific sites, in most regions, such mechanisms remain uncertain to a large extent because of the limited ability of atmospheric models to simulate critical NPF processes. Here we synthesize molecular-level experiments to develop comprehensive representations of 11 NPF mechanisms and the complex chemical transformation of precursor gases in a fully coupled global climate model. Combined simulations and observations show that the dominant NPF mechanisms are distinct worldwide and vary with region and altitude. Previously neglected or underrepresented mechanisms involving organics, amines, iodine oxoacids and HNO₃ probably dominate NPF in most regions with high concentrations of aerosols or large aerosol radiative forcing; such regions include oceanic and human-polluted continental boundary layers, as well as the upper troposphere over rainforests and Asian monsoon regions. These underrepresented mechanisms also play notable roles in other areas, such as the upper troposphere of the Pacific and Atlantic oceans. Accordingly, NPF accounts for different fractions (10–80%) of the nuclei on which cloud forms at 0.5% supersaturation over various regions in the lower troposphere. The comprehensive simulation of global NPF mechanisms can help improve estimation and source attribution of the climate effects of aerosols.

DOI: 10.1038/s41586-024-07547-1

Source: https://www.nature.com/articles/s41586-024-07547-1