Year: 2026
Type: article
Abstract: Fogs over polluted regions often exhibit extremely low supersaturation, yet the controlling mechanisms remain poorly constrained. Existing frameworks attribute supersaturation adjustment mainly to competition among activated droplets, while the role of interstitial aerosol water has been largely overlooked due to observational limitations. Here, we develop a new approach based on an advanced optical instrument to achieve online, size‐resolved quantification of interstitial aerosol water uptake. By combining optical measurements with a machine learning–constrained framework, we retrieve dry aerosol volume and hygroscopic growth at saturation of interstitial aerosols, enabling fog water budget analysis. Observations on the North China Plain show that interstitial aerosol water contributes >50% of total fog water during formation and remains comparable (>25%) to droplet water throughout evolution. This competition helps suppress the supersaturation to <0.03%, limiting aerosol activation and droplet growth. These results identify interstitial aerosol water as a key regulator of fog supersaturation in polluted atmospheres.
Source: Geophysical Research Letters
DOI: 10.1029/2026gl123841
Authors: Qi Liu, Ye Kuang, Weihong Huang, Hanbing Xu, Wanyun Xu, Nan Ma, Mengxiang Hou, Qingpeng Meng, Yujing Pan, Fengling Yuan, Miaomiao Zhai, Tianxu Chen, Mingwei Li, Qiqi Mo, Xingyu Liu, Jiangchuan Tao, Li Liu, Weiqi Xu, Qingwei Zeng, Gang Zhao, Yuxuan Bian, Defeng Zhao, Ru‐Jin Huang, Lei Liu, Yele Sun
Institutions: Jinan University, Sun Yat-sen University, Chinese Academy of Sciences, Chinese Academy of Meteorological Sciences, Institute of Atmospheric Physics, State Key Laboratory of Severe Weather, Fudan University, Minzu University of China, Institute of Earth Environment, China Meteorological Administration, National University of Defense Technology, Institute of Tropical and Marine Meteorology, China Meteorological Administration
Language: English
Subfield: Global and Planetary Change
Field: Environmental Science
Domain: Physical Sciences
SDG: Climate action
Open Access status: gold
Estimated APC paid: $3,190
Awards: G1589541087, G5966680067, G6269446975
OpenAlex ID: W7225561021