Rapid saturation of cloud water adjustments to shipping emissions
<p>Human aerosol emissions change cloud properties by providing additional cloud condensation nuclei. This increases cloud droplet numbers, which in turn affects other cloud properties like liquid-water content and ultimately cloud albedo. These adjustments are poorly constrained, making aeros...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2023-10-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | https://acp.copernicus.org/articles/23/12545/2023/acp-23-12545-2023.pdf |
| _version_ | 1797663247825895424 |
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| author | P. Manshausen D. Watson-Parris D. Watson-Parris M. W. Christensen J.-P. Jalkanen P. Stier |
| author_facet | P. Manshausen D. Watson-Parris D. Watson-Parris M. W. Christensen J.-P. Jalkanen P. Stier |
| author_sort | P. Manshausen |
| collection | DOAJ |
| description | <p>Human aerosol emissions change cloud properties by providing additional cloud condensation nuclei. This increases cloud droplet numbers, which in turn affects other cloud properties like liquid-water content and ultimately cloud albedo. These adjustments are poorly constrained, making aerosol effects the most uncertain part of anthropogenic climate forcing. Here we show that cloud droplet number and water content react differently to changing emission amounts in shipping exhausts. We use information about ship positions and modeled emission amounts together with reanalysis winds and satellite retrievals of cloud properties. The analysis reveals that cloud droplet numbers respond linearly to emission amount over a large range (1–10 kg h<span class="inline-formula"><sup>−1</sup></span>) before the response saturates. Liquid water increases in raining clouds, and the anomalies are constant over the emission ranges observed. There is evidence that this independence of emissions is due to compensating effects under drier and more humid conditions, consistent with suppression of rain by enhanced aerosol. This has implications for our understanding of cloud processes and may improve the way clouds are represented in climate models, in particular by changing parameterizations of liquid-water responses to aerosol.</p> |
| first_indexed | 2024-03-11T19:11:47Z |
| format | Article |
| id | doaj.art-18080a47e08244949316d205961a13f5 |
| institution | Directory Open Access Journal |
| issn | 1680-7316 1680-7324 |
| language | English |
| last_indexed | 2024-03-11T19:11:47Z |
| publishDate | 2023-10-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Atmospheric Chemistry and Physics |
| spelling | doaj.art-18080a47e08244949316d205961a13f52023-10-09T11:41:10ZengCopernicus PublicationsAtmospheric Chemistry and Physics1680-73161680-73242023-10-0123125451255510.5194/acp-23-12545-2023Rapid saturation of cloud water adjustments to shipping emissionsP. Manshausen0D. Watson-Parris1D. Watson-Parris2M. W. Christensen3J.-P. Jalkanen4P. Stier5Atmospheric, Oceanic and Planetary Physics, Department of Physics, University of Oxford, Oxford, OX1 3PU, UKScripps Institution of Oceanography, University of California San Diego, La Jolla, CA 92093, USAHalıcıoğlu Data Science Institute, University of California San Diego, La Jolla, CA 92093, USAAtmospheric and Global Change Division, Pacific Northwest National Laboratory, Richland, WA, USAAtmospheric Composition Research, Finnish Meteorological Institute, Helsinki, FinlandAtmospheric, Oceanic and Planetary Physics, Department of Physics, University of Oxford, Oxford, OX1 3PU, UK<p>Human aerosol emissions change cloud properties by providing additional cloud condensation nuclei. This increases cloud droplet numbers, which in turn affects other cloud properties like liquid-water content and ultimately cloud albedo. These adjustments are poorly constrained, making aerosol effects the most uncertain part of anthropogenic climate forcing. Here we show that cloud droplet number and water content react differently to changing emission amounts in shipping exhausts. We use information about ship positions and modeled emission amounts together with reanalysis winds and satellite retrievals of cloud properties. The analysis reveals that cloud droplet numbers respond linearly to emission amount over a large range (1–10 kg h<span class="inline-formula"><sup>−1</sup></span>) before the response saturates. Liquid water increases in raining clouds, and the anomalies are constant over the emission ranges observed. There is evidence that this independence of emissions is due to compensating effects under drier and more humid conditions, consistent with suppression of rain by enhanced aerosol. This has implications for our understanding of cloud processes and may improve the way clouds are represented in climate models, in particular by changing parameterizations of liquid-water responses to aerosol.</p>https://acp.copernicus.org/articles/23/12545/2023/acp-23-12545-2023.pdf |
| spellingShingle | P. Manshausen D. Watson-Parris D. Watson-Parris M. W. Christensen J.-P. Jalkanen P. Stier Rapid saturation of cloud water adjustments to shipping emissions Atmospheric Chemistry and Physics |
| title | Rapid saturation of cloud water adjustments to shipping emissions |
| title_full | Rapid saturation of cloud water adjustments to shipping emissions |
| title_fullStr | Rapid saturation of cloud water adjustments to shipping emissions |
| title_full_unstemmed | Rapid saturation of cloud water adjustments to shipping emissions |
| title_short | Rapid saturation of cloud water adjustments to shipping emissions |
| title_sort | rapid saturation of cloud water adjustments to shipping emissions |
| url | https://acp.copernicus.org/articles/23/12545/2023/acp-23-12545-2023.pdf |
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