Chen Xiyao, Ye Chunxiang, Wang Yuanyuan, Wu Zhijun, Zhu Tong, Zhang Fan, Ding Xiaokun, Shi Zongbo, Zheng Zhonghua, Li Weijun
Key Laboratory of Geoscience Big Data and Deep Resource of Zhejiang Province, Department of Atmospheric Sciences, School of Earth Sciences, Zhejiang University, Hangzhou 310027, China.
College Environmental Sciences and Engineering, Peking University, Beijing 100871, China.
iScience. 2023 Oct 4;26(11):108125. doi: 10.1016/j.isci.2023.108125. eCollection 2023 Nov 17.
Incomplete combustion of fossil fuels and biomass burning emit large amounts of soot particles into the troposphere. The condensation process is considered to influence the size (D) and mixing state of soot particles, which affects their solar absorption efficiency and lifetimes. However, quantifying aging evolution of soot remains hampered in the real world because of complicated sources and observation technologies. In the Himalayas, we isolated soot sourced from transboundary transport of biomass burning and revealed soot aging mechanisms through microscopic observations. Most of coated soot particles stabilized one soot core under D < 400 nm, but 34.8% of them contained multi-soot cores (n ≥ 2) and n increased 3-9 times with increasing D. We established the soot mixing models to quantify transformation from condensation- to coagulation-dominant regime at D ≈ 400 nm. Studies provide essential references for adopting mixing rules and quantifying the optical absorption of soot in atmospheric models.
化石燃料的不完全燃烧和生物质燃烧会向对流层排放大量烟尘颗粒。凝结过程被认为会影响烟尘颗粒的大小（D）和混合状态，进而影响其对太阳辐射的吸收效率和寿命。然而，由于来源复杂和观测技术的限制，在现实世界中量化烟尘的老化演变仍然存在困难。在喜马拉雅地区，我们分离出了源自生物质燃烧跨界传输的烟尘，并通过显微镜观测揭示了烟尘老化机制。在D < 400 nm时，大多数包覆烟尘颗粒稳定在一个烟尘核心，但其中34.8%含有多个烟尘核心（n≥2），且随着D的增加，n增加3 - 9倍。我们建立了烟尘混合模型，以量化在D≈400 nm时从以凝结为主到以凝聚为主的转变过程。这些研究为在大气模型中采用混合规则和量化烟尘的光吸收提供了重要参考。
