Ning An, Shen Jiewen, Zhao Bin, Wang Shuxiao, Cai Runlong, Jiang Jingkun, Yan Chao, Fu Xiao, Zhang Yunhong, Li Jing, Ouyang Daiwei, Sun Yisheng, Saiz-Lopez Alfonso, Francisco Joseph S, Zhang Xiuhui
Key Laboratory of Cluster Science, Ministry of Education of China, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, China.
State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China.
Proc Natl Acad Sci U S A. 2024 Jul 30;121(31):e2404595121. doi: 10.1073/pnas.2404595121. Epub 2024 Jul 24.
New particle formation (NPF) substantially affects the global radiation balance and climate. Iodic acid (IA) is a key marine NPF driver that recently has also been detected inland. However, its impact on continental particle nucleation remains unclear. Here, we provide molecular-level evidence that IA greatly facilitates clustering of two typical land-based nucleating precursors: dimethylamine (DMA) and sulfuric acid (SA), thereby enhancing particle nucleation. Incorporating this mechanism into an atmospheric chemical transport model, we show that IA-induced enhancement could realize an increase of over 20% in the SA-DMA nucleation rate in iodine-rich regions of China. With declining anthropogenic pollution driven by carbon neutrality and clean air policies in China, IA could enhance nucleation rates by 1.5 to 50 times by 2060. Our results demonstrate the overlooked key role of IA in continental NPF nucleation and highlight the necessity for considering synergistic SA-IA-DMA nucleation in atmospheric modeling for correct representation of the climatic impacts of aerosols.
新粒子形成（NPF）对全球辐射平衡和气候有重大影响。碘酸（IA）是海洋中NPF的关键驱动因素，最近在陆地上也被检测到。然而，其对大陆粒子成核的影响仍不明确。在此，我们提供了分子层面的证据，表明碘酸极大地促进了两种典型的陆地成核前体物质：二甲胺（DMA）和硫酸（SA）的聚集，从而增强了粒子成核。将这一机制纳入大气化学传输模型后，我们发现，在中国富碘地区，碘酸诱导的增强作用可使SA-DMA成核率提高20%以上。随着中国碳中和和清洁空气政策推动人为污染减少，到2060年，碘酸可使成核率提高1.5至50倍。我们的研究结果证明了碘酸在大陆NPF成核中被忽视的关键作用，并强调了在大气建模中考虑SA-IA-DMA协同成核以正确呈现气溶胶气候影响的必要性。
