Conditions favorable for secondary ice production in Arctic mixed-phase clouds
<p>The Arctic is very susceptible to climate change and thus is warming much faster than the rest of the world. Clouds influence terrestrial and solar radiative fluxes and thereby impact the amplified Arctic warming. The partitioning of thermodynamic phases (i.e., ice crystals and water drople...
| Main Authors: | , , , , , , , , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2022-12-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | https://acp.copernicus.org/articles/22/15579/2022/acp-22-15579-2022.pdf |
| _version_ | 1811188085077049344 |
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| author | J. T. Pasquier J. Henneberger F. Ramelli A. Lauber A. Lauber R. O. David J. Wieder J. Wieder T. Carlsen R. Gierens M. Maturilli U. Lohmann |
| author_facet | J. T. Pasquier J. Henneberger F. Ramelli A. Lauber A. Lauber R. O. David J. Wieder J. Wieder T. Carlsen R. Gierens M. Maturilli U. Lohmann |
| author_sort | J. T. Pasquier |
| collection | DOAJ |
| description | <p>The Arctic is very susceptible to climate change and thus is warming much faster than the rest of the world. Clouds influence terrestrial and solar radiative fluxes and thereby impact the amplified Arctic warming. The partitioning of thermodynamic phases (i.e., ice crystals and water droplets) within mixed-phase clouds (MPCs) especially influences their radiative properties. However, the processes responsible for ice crystal formation remain only partially characterized. In particular, so-called secondary ice production (SIP) processes, which create supplementary ice crystals from primary ice crystals and the environmental conditions that they occur in, are poorly understood. The microphysical properties of Arctic MPCs were measured during the Ny-Ålesund AeroSol Cloud ExperimENT (NASCENT) campaign to obtain a better understanding of the atmospheric conditions favorable for the occurrence of SIP processes. To this aim, the in situ cloud microphysical properties retrieved by a holographic cloud imager mounted on a tethered balloon system were complemented by ground-based remote sensing and ice-nucleating particle measurements. During the 6 d investigated in this study, SIP occurred during about 40 % of the in-cloud measurements, and high SIP events with number concentrations larger than 10 L<span class="inline-formula"><sup>−1</sup></span> of small pristine ice crystals occurred in 4 % of the in-cloud measurements. This demonstrates the role of SIP for Arctic MPCs. The highest concentrations of small pristine ice crystals were produced at temperatures between <span class="inline-formula">−5</span> and <span class="inline-formula">−3</span> <span class="inline-formula"><sup>∘</sup></span>C and were related to the occurrence of supercooled large droplets freezing upon collision with ice crystals. This suggests that a large fraction of ice crystals in Arctic MPCs are produced via the droplet-shattering mechanism. From evaluating the ice crystal images, we could identify ice–ice collision as a second SIP mechanism that dominated when fragile ice crystals were observed. Moreover, SIP occurred over a large temperature range and was observed in up to 80 % of the measurements down to <span class="inline-formula">−24</span> <span class="inline-formula"><sup>∘</sup></span>C due to the occurrence of ice–ice collisions. This emphasizes the importance of SIP at temperatures below <span class="inline-formula">−8</span> <span class="inline-formula"><sup>∘</sup></span>C, which are currently not accounted for in most numerical weather models. Although ice-nucleating particles may be necessary for the initial freezing of water droplets, the ice crystal number concentration is frequently determined by secondary production mechanisms.</p> |
| first_indexed | 2024-04-11T14:14:25Z |
| format | Article |
| id | doaj.art-40946c6ede2d4fa4a74dec20a5778b33 |
| institution | Directory Open Access Journal |
| issn | 1680-7316 1680-7324 |
| language | English |
| last_indexed | 2024-04-11T14:14:25Z |
| publishDate | 2022-12-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Atmospheric Chemistry and Physics |
| spelling | doaj.art-40946c6ede2d4fa4a74dec20a5778b332022-12-22T04:19:36ZengCopernicus PublicationsAtmospheric Chemistry and Physics1680-73161680-73242022-12-0122155791560110.5194/acp-22-15579-2022Conditions favorable for secondary ice production in Arctic mixed-phase cloudsJ. T. Pasquier0J. Henneberger1F. Ramelli2A. Lauber3A. Lauber4R. O. David5J. Wieder6J. Wieder7T. Carlsen8R. Gierens9M. Maturilli10U. Lohmann11Institute for Atmospheric and Climate Science, ETH Zürich, Zurich, SwitzerlandInstitute for Atmospheric and Climate Science, ETH Zürich, Zurich, SwitzerlandInstitute for Atmospheric and Climate Science, ETH Zürich, Zurich, SwitzerlandInstitute for Atmospheric and Climate Science, ETH Zürich, Zurich, Switzerlandnow at: Center for Climate Systems Modelling (C2SM), ETH Zürich, Zurich, SwitzerlandDepartment of Geosciences, University of Oslo, Oslo, NorwayInstitute for Atmospheric and Climate Science, ETH Zürich, Zurich, Switzerlandnow at: femtoG AG, Zurich, SwitzerlandDepartment of Geosciences, University of Oslo, Oslo, NorwayInstitute for Geophysics and Meteorology, University of Cologne, Cologne, GermanyAlfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI), Potsdam, GermanyInstitute for Atmospheric and Climate Science, ETH Zürich, Zurich, Switzerland<p>The Arctic is very susceptible to climate change and thus is warming much faster than the rest of the world. Clouds influence terrestrial and solar radiative fluxes and thereby impact the amplified Arctic warming. The partitioning of thermodynamic phases (i.e., ice crystals and water droplets) within mixed-phase clouds (MPCs) especially influences their radiative properties. However, the processes responsible for ice crystal formation remain only partially characterized. In particular, so-called secondary ice production (SIP) processes, which create supplementary ice crystals from primary ice crystals and the environmental conditions that they occur in, are poorly understood. The microphysical properties of Arctic MPCs were measured during the Ny-Ålesund AeroSol Cloud ExperimENT (NASCENT) campaign to obtain a better understanding of the atmospheric conditions favorable for the occurrence of SIP processes. To this aim, the in situ cloud microphysical properties retrieved by a holographic cloud imager mounted on a tethered balloon system were complemented by ground-based remote sensing and ice-nucleating particle measurements. During the 6 d investigated in this study, SIP occurred during about 40 % of the in-cloud measurements, and high SIP events with number concentrations larger than 10 L<span class="inline-formula"><sup>−1</sup></span> of small pristine ice crystals occurred in 4 % of the in-cloud measurements. This demonstrates the role of SIP for Arctic MPCs. The highest concentrations of small pristine ice crystals were produced at temperatures between <span class="inline-formula">−5</span> and <span class="inline-formula">−3</span> <span class="inline-formula"><sup>∘</sup></span>C and were related to the occurrence of supercooled large droplets freezing upon collision with ice crystals. This suggests that a large fraction of ice crystals in Arctic MPCs are produced via the droplet-shattering mechanism. From evaluating the ice crystal images, we could identify ice–ice collision as a second SIP mechanism that dominated when fragile ice crystals were observed. Moreover, SIP occurred over a large temperature range and was observed in up to 80 % of the measurements down to <span class="inline-formula">−24</span> <span class="inline-formula"><sup>∘</sup></span>C due to the occurrence of ice–ice collisions. This emphasizes the importance of SIP at temperatures below <span class="inline-formula">−8</span> <span class="inline-formula"><sup>∘</sup></span>C, which are currently not accounted for in most numerical weather models. Although ice-nucleating particles may be necessary for the initial freezing of water droplets, the ice crystal number concentration is frequently determined by secondary production mechanisms.</p>https://acp.copernicus.org/articles/22/15579/2022/acp-22-15579-2022.pdf |
| spellingShingle | J. T. Pasquier J. Henneberger F. Ramelli A. Lauber A. Lauber R. O. David J. Wieder J. Wieder T. Carlsen R. Gierens M. Maturilli U. Lohmann Conditions favorable for secondary ice production in Arctic mixed-phase clouds Atmospheric Chemistry and Physics |
| title | Conditions favorable for secondary ice production in Arctic mixed-phase clouds |
| title_full | Conditions favorable for secondary ice production in Arctic mixed-phase clouds |
| title_fullStr | Conditions favorable for secondary ice production in Arctic mixed-phase clouds |
| title_full_unstemmed | Conditions favorable for secondary ice production in Arctic mixed-phase clouds |
| title_short | Conditions favorable for secondary ice production in Arctic mixed-phase clouds |
| title_sort | conditions favorable for secondary ice production in arctic mixed phase clouds |
| url | https://acp.copernicus.org/articles/22/15579/2022/acp-22-15579-2022.pdf |
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