Aerosol Background Concentrations Influence Aerosol‐Cloud Interactions as Much as the Choice of Aerosol‐Cloud Parameterization
Abstract We use an independent observational estimate of aerosol‐cloud interactions (ACI) during the 2014 Holuhraun volcanic eruption in Iceland to evaluate four ACI parameterizations in a regional model. All parameterizations reproduce the observed pattern of liquid cloud droplet size reduction dur...
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| Format: | Article |
| Language: | English |
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Wiley
2025-04-01
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| Series: | Geophysical Research Letters |
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| Online Access: | https://doi.org/10.1029/2024GL111780 |
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| author | Louis Marelle Gunnar Myhre Jennie L. Thomas Jean‐Christophe Raut |
| author_facet | Louis Marelle Gunnar Myhre Jennie L. Thomas Jean‐Christophe Raut |
| author_sort | Louis Marelle |
| collection | DOAJ |
| description | Abstract We use an independent observational estimate of aerosol‐cloud interactions (ACI) during the 2014 Holuhraun volcanic eruption in Iceland to evaluate four ACI parameterizations in a regional model. All parameterizations reproduce the observed pattern of liquid cloud droplet size reduction during the eruption, but strongly differ on its magnitude and on the resulting effective radiative forcing (ERF). Our results contradict earlier findings that this eruption could be used to constrain liquid water path (LWP) adjustments in models, except to exclude extremely high LWP adjustments of more than 20 gm−2. The modeled ERF is very sensitive to the non‐volcanic background aerosol concentration: doubling the non‐volcanic aerosol background weakens the ACI ERF by ∼30%. Since aerosol biases in climate models can be an order of magnitude or more, these results suggest that aerosol background concentrations could be a major and under‐examined source of uncertainty for modeling ACI. |
| format | Article |
| id | doaj-art-8164a1806cab4a26b9a69bbd6e1000db |
| institution | DOAJ |
| issn | 0094-8276 1944-8007 |
| language | English |
| publishDate | 2025-04-01 |
| publisher | Wiley |
| record_format | Article |
| series | Geophysical Research Letters |
| spelling | doaj-art-8164a1806cab4a26b9a69bbd6e1000db2025-08-20T02:56:34ZengWileyGeophysical Research Letters0094-82761944-80072025-04-01528n/an/a10.1029/2024GL111780Aerosol Background Concentrations Influence Aerosol‐Cloud Interactions as Much as the Choice of Aerosol‐Cloud ParameterizationLouis Marelle0Gunnar Myhre1Jennie L. Thomas2Jean‐Christophe Raut3Sorbonne Université UVSQ CNRS LATMOS Paris FranceCenter for International Climate Research Oslo NorwayUniversité Grenoble Alpes CNRS IRD Grenoble INP IGE Grenoble FranceSorbonne Université UVSQ CNRS LATMOS Paris FranceAbstract We use an independent observational estimate of aerosol‐cloud interactions (ACI) during the 2014 Holuhraun volcanic eruption in Iceland to evaluate four ACI parameterizations in a regional model. All parameterizations reproduce the observed pattern of liquid cloud droplet size reduction during the eruption, but strongly differ on its magnitude and on the resulting effective radiative forcing (ERF). Our results contradict earlier findings that this eruption could be used to constrain liquid water path (LWP) adjustments in models, except to exclude extremely high LWP adjustments of more than 20 gm−2. The modeled ERF is very sensitive to the non‐volcanic background aerosol concentration: doubling the non‐volcanic aerosol background weakens the ACI ERF by ∼30%. Since aerosol biases in climate models can be an order of magnitude or more, these results suggest that aerosol background concentrations could be a major and under‐examined source of uncertainty for modeling ACI.https://doi.org/10.1029/2024GL111780aerosol‐cloud interactionsclimate modelingclimate sciencecloudsaerosolsradiative forcing |
| spellingShingle | Louis Marelle Gunnar Myhre Jennie L. Thomas Jean‐Christophe Raut Aerosol Background Concentrations Influence Aerosol‐Cloud Interactions as Much as the Choice of Aerosol‐Cloud Parameterization Geophysical Research Letters aerosol‐cloud interactions climate modeling climate science clouds aerosols radiative forcing |
| title | Aerosol Background Concentrations Influence Aerosol‐Cloud Interactions as Much as the Choice of Aerosol‐Cloud Parameterization |
| title_full | Aerosol Background Concentrations Influence Aerosol‐Cloud Interactions as Much as the Choice of Aerosol‐Cloud Parameterization |
| title_fullStr | Aerosol Background Concentrations Influence Aerosol‐Cloud Interactions as Much as the Choice of Aerosol‐Cloud Parameterization |
| title_full_unstemmed | Aerosol Background Concentrations Influence Aerosol‐Cloud Interactions as Much as the Choice of Aerosol‐Cloud Parameterization |
| title_short | Aerosol Background Concentrations Influence Aerosol‐Cloud Interactions as Much as the Choice of Aerosol‐Cloud Parameterization |
| title_sort | aerosol background concentrations influence aerosol cloud interactions as much as the choice of aerosol cloud parameterization |
| topic | aerosol‐cloud interactions climate modeling climate science clouds aerosols radiative forcing |
| url | https://doi.org/10.1029/2024GL111780 |
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