Long-Distance Atmospheric Transport of Microplastic Fibres Depends on Their Shapes
Document Type
Conference Paper
Publisher
European Geophysical Union
Publication Date
4-23-2023
Keywords
microplastic, microplastic fibers, long-range transport
Abstract
Recent studies have highlighted the importance of the atmosphere in the long-range transport of microplastic fibers (MPFs). However, both dry deposition processes and sources of MPFs are poorly understood due to their complexity in size and shape, which can be 100s $\mu m$ long, possessing round or flat cross-sections with dimensions of $O(1)\,\mu m$ thickness, and $O(10)\,\mu m$ width. Here, we develop a theory-based settling velocity model for MPFs in the atmosphere, predicting a much smaller aerodynamic size than a volumetrically equivalent spherical particle. Incorrect identification of flat fibers as cylindrical ones due to uncertainty in the thickness of sampled MPFs overestimates their dry deposition rate. Accounting for fiber thickness in sampled MPFs leads to a mean residence-time enhancement above $450\%$ compared to spherical-shaped particles, suggesting a much more efficient long-range transport of flat fibers than previously thought and that the ocean might be a major source of atmospheric plastics.
Recommended Citation
Li, Qi; Xiao, Shuolin; Cui, Yuanfeng; Brahney, Janice; and Mahowald, Natalie, "Long-Distance Atmospheric Transport of Microplastic Fibres Depends on Their Shapes" (2023). Watershed Sciences Faculty Publications. Paper 1222.
https://digitalcommons.usu.edu/wats_facpub/1222