Kaolinite particles as ice nuclei: Learning from the use of different kaolinite samples and different coatings
Kaolinite particles from two different sources (Fluka and Clay Minerals Society (CMS)) were examined with respect to their ability to act as ice nuclei (IN). This was done in the water-subsaturated regime where often deposition ice nucleation is assumed to occur, and for water-supersaturated conditi...
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fttibhannoverren:oai:oa.tib.eu:123456789/5639 2024-09-15T18:12:04+00:00 Kaolinite particles as ice nuclei: Learning from the use of different kaolinite samples and different coatings Wex, H. Demott, P.J. Tobo, Y. Hartmann, S. Rösch, M. Clauss, T. Tomsche, L. Niedermeier, D. Stratmann, F. 2014 application/pdf https://oa.tib.eu/renate/handle/123456789/5639 https://doi.org/10.34657/4268 eng eng Göttingen : Copernicus ISSN:1680-7316 DOI:https://doi.org/10.5194/acp-14-5529-2014 https://doi.org/10.34657/4268 https://oa.tib.eu/renate/handle/123456789/5639 CC BY 3.0 Unported https://creativecommons.org/licenses/by/3.0/ frei zugänglich ddc:550 cloud microphysics feldspar freezing ice core kaolinite nucleation sulfuric acid supersaturation water vapor status-type:publishedVersion doc-type:Article doc-type:Text 2014 fttibhannoverren https://doi.org/10.34657/426810.5194/acp-14-5529-2014 2024-06-26T23:32:42Z Kaolinite particles from two different sources (Fluka and Clay Minerals Society (CMS)) were examined with respect to their ability to act as ice nuclei (IN). This was done in the water-subsaturated regime where often deposition ice nucleation is assumed to occur, and for water-supersaturated conditions, i.e., in the immersion freezing mode. Measurements were done using a flow tube (the Leipzig Aerosol Cloud Interaction Simulator, LACIS) and a continuous-flow diffusion chamber (CFDC). Pure and coated particles were used, with coating thicknesses of a few nanometers or less, where the coating consisted of levoglucosan, succinic acid or sulfuric acid. In general, it was found that the coatings strongly reduced deposition ice nucleation. Remaining ice formation in the water-subsaturated regime could be attributed to immersion freezing, with particles immersed in concentrated solutions formed by the coatings. In the immersion freezing mode, ice nucleation rate coefficients het from both instruments agreed well with each other, particularly when the residence times in the instruments were accounted for. Fluka kaolinite particles coated with either levoglucosan or succinic acid showed the same IN activity as pure Fluka kaolinite particles; i.e., it can be assumed that these two types of coating did not alter the ice-active surface chemically, and that the coatings were diluted enough in the droplets that were formed prior to the ice nucleation, so that freezing point depression was negligible. However, Fluka kaolinite particles, which were either coated with pure sulfuric acid or were first coated with the acid and then exposed to additional water vapor, both showed a reduced ability to nucleate ice compared to the pure particles. For the CMS kaolinite particles, the ability to nucleate ice in the immersion freezing mode was similar for all examined particles, i.e., for the pure ones and the ones with the different types of coating. Moreover, het derived for the CMS kaolinite particles was comparable to het derived for ... Article in Journal/Newspaper ice core Renate - Repositorium für Naturwissenschaften und Technik (TIB Hannover) |
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Open Polar |
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Renate - Repositorium für Naturwissenschaften und Technik (TIB Hannover) |
op_collection_id |
fttibhannoverren |
language |
English |
topic |
ddc:550 cloud microphysics feldspar freezing ice core kaolinite nucleation sulfuric acid supersaturation water vapor |
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ddc:550 cloud microphysics feldspar freezing ice core kaolinite nucleation sulfuric acid supersaturation water vapor Wex, H. Demott, P.J. Tobo, Y. Hartmann, S. Rösch, M. Clauss, T. Tomsche, L. Niedermeier, D. Stratmann, F. Kaolinite particles as ice nuclei: Learning from the use of different kaolinite samples and different coatings |
topic_facet |
ddc:550 cloud microphysics feldspar freezing ice core kaolinite nucleation sulfuric acid supersaturation water vapor |
description |
Kaolinite particles from two different sources (Fluka and Clay Minerals Society (CMS)) were examined with respect to their ability to act as ice nuclei (IN). This was done in the water-subsaturated regime where often deposition ice nucleation is assumed to occur, and for water-supersaturated conditions, i.e., in the immersion freezing mode. Measurements were done using a flow tube (the Leipzig Aerosol Cloud Interaction Simulator, LACIS) and a continuous-flow diffusion chamber (CFDC). Pure and coated particles were used, with coating thicknesses of a few nanometers or less, where the coating consisted of levoglucosan, succinic acid or sulfuric acid. In general, it was found that the coatings strongly reduced deposition ice nucleation. Remaining ice formation in the water-subsaturated regime could be attributed to immersion freezing, with particles immersed in concentrated solutions formed by the coatings. In the immersion freezing mode, ice nucleation rate coefficients het from both instruments agreed well with each other, particularly when the residence times in the instruments were accounted for. Fluka kaolinite particles coated with either levoglucosan or succinic acid showed the same IN activity as pure Fluka kaolinite particles; i.e., it can be assumed that these two types of coating did not alter the ice-active surface chemically, and that the coatings were diluted enough in the droplets that were formed prior to the ice nucleation, so that freezing point depression was negligible. However, Fluka kaolinite particles, which were either coated with pure sulfuric acid or were first coated with the acid and then exposed to additional water vapor, both showed a reduced ability to nucleate ice compared to the pure particles. For the CMS kaolinite particles, the ability to nucleate ice in the immersion freezing mode was similar for all examined particles, i.e., for the pure ones and the ones with the different types of coating. Moreover, het derived for the CMS kaolinite particles was comparable to het derived for ... |
format |
Article in Journal/Newspaper |
author |
Wex, H. Demott, P.J. Tobo, Y. Hartmann, S. Rösch, M. Clauss, T. Tomsche, L. Niedermeier, D. Stratmann, F. |
author_facet |
Wex, H. Demott, P.J. Tobo, Y. Hartmann, S. Rösch, M. Clauss, T. Tomsche, L. Niedermeier, D. Stratmann, F. |
author_sort |
Wex, H. |
title |
Kaolinite particles as ice nuclei: Learning from the use of different kaolinite samples and different coatings |
title_short |
Kaolinite particles as ice nuclei: Learning from the use of different kaolinite samples and different coatings |
title_full |
Kaolinite particles as ice nuclei: Learning from the use of different kaolinite samples and different coatings |
title_fullStr |
Kaolinite particles as ice nuclei: Learning from the use of different kaolinite samples and different coatings |
title_full_unstemmed |
Kaolinite particles as ice nuclei: Learning from the use of different kaolinite samples and different coatings |
title_sort |
kaolinite particles as ice nuclei: learning from the use of different kaolinite samples and different coatings |
publisher |
Göttingen : Copernicus |
publishDate |
2014 |
url |
https://oa.tib.eu/renate/handle/123456789/5639 https://doi.org/10.34657/4268 |
genre |
ice core |
genre_facet |
ice core |
op_relation |
ISSN:1680-7316 DOI:https://doi.org/10.5194/acp-14-5529-2014 https://doi.org/10.34657/4268 https://oa.tib.eu/renate/handle/123456789/5639 |
op_rights |
CC BY 3.0 Unported https://creativecommons.org/licenses/by/3.0/ frei zugänglich |
op_doi |
https://doi.org/10.34657/426810.5194/acp-14-5529-2014 |
_version_ |
1810449666524839936 |