Maters, EC orcid.org/0000-0003-1032-9865, Cimarelli, C orcid.org/0000-0002-5707-5930, Casas, AS orcid.org/0000-0001-5013-1701 et al. (2 more authors) (2020) Volcanic ash ice-nucleating activity can be enhanced or depressed by ash-gas interaction in the eruption plume. Earth and Planetary Science Letters, 551. 116587. ISSN 0012-821X
Abstract
Volcanic ash can trigger ice nucleation when immersed in supercooled water. This will impact several processes (e.g., electrification, aggregation, precipitation) in the eruption plume and cloud and in the wider atmosphere upon ash dispersal. Previous studies show that ash bulk properties, reflecting the chemistry and phase state of the source magma, likely contribute to the ice-nucleating activity (INA) of ash. However, it remains unexplored how interaction with magmatic gases in the hot eruption plume, which inevitably leads to altered ash surface properties, affects the ash INA. Here we demonstrate that the INA of tephra is raised by exposure to H2O(g) mixed with SO2(g) at both 800 and 400 °C, but is substantially reduced by exposure to H2O(g) alone or mixed with HCl(g) at the same temperatures. In contrast, the INA of K-feldspar and quartz is reduced by all three eruption plume processing treatments. The decrease in INA of all silicates after heating with H2O(g) might relate to a loss of ice-active sites by surface dehydroxylation and/or oxidation. In the presence of HCl(g) or SO2(g), respectively, metal chloride or sulphate salts form on the tephra surfaces only. While NaCl and CaCl2 seem to have no effect on the tephra INA, CaSO4 is inferred to create ice-active sites, potentially through a particular combination of surface chemistry and topography. Overall, our findings suggest a complex interplay of bulk mineralogy and surface alteration in influencing ice nucleation by volcanic ash, and highlight the general sensitivity (enhancement or depression) of ash INA to interaction with magmatic gases in the eruption plume.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). |
Keywords: | volcanic ash; ice nucleation; eruption plume; heterogeneous |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Environment (Leeds) > School of Earth and Environment (Leeds) > Inst for Climate & Atmos Science (ICAS) (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 13 Oct 2020 15:48 |
Last Modified: | 06 Jan 2025 11:49 |
Status: | Published |
Publisher: | Elsevier |
Identification Number: | 10.1016/j.epsl.2020.116587 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:166535 |