Articles | Volume 23, issue 14
https://doi.org/10.5194/acp-23-8259-2023
https://doi.org/10.5194/acp-23-8259-2023
ACP Letters
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25 Jul 2023
ACP Letters | Highlight paper |  | 25 Jul 2023

Detection of large-scale cloud microphysical changes within a major shipping corridor after implementation of the International Maritime Organization 2020 fuel sulfur regulations

Michael S. Diamond

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Cited articles

Albrecht, B. A.: Aerosols, Cloud Microphysics, and Fractional Cloudiness, Science, 245, 1227–1230, https://doi.org/10.1126/science.245.4923.1227, 1989. 
Ault, A. P., Gaston, C. J., Wang, Y., Dominguez, G., Thiemens, M. H., and Prather, K. A.: Characterization of the Single Particle Mixing State of Individual Ship Plume Events Measured at the Port of Los Angeles, Environ. Sci. Technol., 44, 1954–1961, https://doi.org/10.1021/es902985h, 2010. 
Benjamini, Y. and Hochberg, Y.: Controlling the False Discovery Rate: A Practical and Powerful Approach to Multiple Testing, J. R. Stat. Soc. B Met., 57, 289–300, 1995. 
Capaldo, K., Corbett, J. J., Kasibhatla, P., Fischbeck, P., and Pandis, S. N.: Effects of ship emissions on sulphur cycling and radiative climate forcing over the ocean, Nature, 400, 743–746, https://doi.org/10.1038/23438, 1999. 
CERES Science Team: CERES_SSF_Terra-Aqua_Edition4A Data Quality Summary, NASA Langley Research Center, Langley, VA, https://ceres.larc.nasa.gov/documents/DQ_summaries/CER_SSF_Terra-Aqua_Edition4A.pdf (last access: 19 July 2023), 2016. 
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Executive editor
In 2020, a new international law was imposed that placed strong restrictions on sulfur emissions from the international shipping industry. In addition to reducing air pollution, an anticipated side effect was reduction of the climate cooling effect that is often associated with "ship-tracks". Aerosol pollutant emissions from ships, when they rise into overlying clouds, lead to higher cloud droplet number concentrations, smaller cloud droplet sizes, and clouds that are more reflective to incoming sunlight, easily seen in satellite imagery as long bright lines downwind of ships. Past studies into whether the new law has led to darker clouds have been equivocal. For this study, the authors used sophisticated statistical techniques to compare cloud droplet size and reflectivity before and after the law was implemented focusing on a shipping corridor in the southeast Atlantic. They found strong evidence that droplet sizes have indeed increased, and that clouds have darkened with a significant local climate warming. Globally, the impact is much smaller, but may still represent an important consideration for assessments of the total summed effect of aerosols on climate.
Short summary
Fuel sulfur regulations were implemented for ships in 2020 to improve air quality but may also accelerate global warming. We use spatial statistics and satellite retrievals to detect changes in the size of cloud droplets and find evidence for a resulting decrease in cloud brightness within a major shipping corridor after the sulfur limits went into effect. Our results confirm both that the regulations are being followed and that they are having a warming influence via their effect on clouds.
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