Biological and Environmental Research - Earth and Environmental System Sciences
Earth and Environmental System Modeling

Ice nucleation by aerosols from anthropogenic pollution

TitleIce nucleation by aerosols from anthropogenic pollution
Publication TypeJournal Article
Year of Publication2019
AuthorsZhao, Bin, Wang Yuan, Gu Yu, Liou Kuo-Nan, Jiang Jonathan H., Fan Jiwen, Liu Xiaohong, Huang Lei, and Yung Yuk L.
JournalNature Geoscience
Volume12
Number8
Pages602-607
Abstract / Summary

The formation of ice particles in the atmosphere strongly affects cloud properties and the climate. While mineral dust is known to be an effective ice nucleating particle, the role of aerosols from anthropogenic pollution in ice nucleation is still under debate. Here we probe the ice nucleation ability of different aerosol types by combining 11-year observations from multiple satellites and cloud-resolving model simulations. We find that, for strong convective systems, the ice particle effective radius near cloud top decreases with increasing loading of polluted continental aerosols, because the ice formation is dominated by homogeneous freezing of cloud droplets, which are smaller under more polluted conditions. By contrast, an increase in ice particle effective radius with polluted continental aerosols is found for moderate convection. Our model simulations suggest that this positive correlation is explained by enhanced heterogeneous ice nucleation and prolonged ice particle growth at higher aerosol loading, indicating that polluted continental aerosols contain a considerable fraction of ice-nucleating particles. Similar aerosol–ice relationships are observed for dust aerosols, further corroborating the ice nucleation ability of polluted continental aerosols. By catalyzing ice formation, aerosols from anthropogenic pollution could have profound impacts on cloud lifetime and radiative effect as well as precipitation efficiency.

URLhttp://dx.doi.org/10.1038/s41561-019-0389-4
DOI10.1038/s41561-019-0389-4
Journal: Nature Geoscience
Year of Publication: 2019
Volume: 12
Number: 8
Pages: 602-607
Publication Date: 08/2019

The formation of ice particles in the atmosphere strongly affects cloud properties and the climate. While mineral dust is known to be an effective ice nucleating particle, the role of aerosols from anthropogenic pollution in ice nucleation is still under debate. Here we probe the ice nucleation ability of different aerosol types by combining 11-year observations from multiple satellites and cloud-resolving model simulations. We find that, for strong convective systems, the ice particle effective radius near cloud top decreases with increasing loading of polluted continental aerosols, because the ice formation is dominated by homogeneous freezing of cloud droplets, which are smaller under more polluted conditions. By contrast, an increase in ice particle effective radius with polluted continental aerosols is found for moderate convection. Our model simulations suggest that this positive correlation is explained by enhanced heterogeneous ice nucleation and prolonged ice particle growth at higher aerosol loading, indicating that polluted continental aerosols contain a considerable fraction of ice-nucleating particles. Similar aerosol–ice relationships are observed for dust aerosols, further corroborating the ice nucleation ability of polluted continental aerosols. By catalyzing ice formation, aerosols from anthropogenic pollution could have profound impacts on cloud lifetime and radiative effect as well as precipitation efficiency.

DOI: 10.1038/s41561-019-0389-4
Citation:
Zhao, B, Y Wang, Y Gu, K Liou, JH Jiang, J Fan, X Liu, L Huang, and YL Yung.  2019.  "Ice nucleation by aerosols from anthropogenic pollution."  Nature Geoscience 12(8): 602-607.  https://doi.org/10.1038/s41561-019-0389-4.