The effect of (NH4)2SO4 on the freezing properties of non-mineral dust ice nucleating substances of atmospheric relevance
A wide range of materials including mineral dust, soil dust, and bioaerosols have been shown to act as ice nuclei in the atmosphere. During atmospheric transport, these materials can become coated with inorganic and organic solutes which may impact their ability to nucleate ice. While a number of st...
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ftcopernicus:oai:publications.copernicus.org:acpd93616 2023-05-15T18:18:55+02:00 The effect of (NH4)2SO4 on the freezing properties of non-mineral dust ice nucleating substances of atmospheric relevance Worthy, Soleil E. Kumar, Anand Xi, Yu Yun, Jingwei Chen, Jessie Xu, Cuishan Irish, Victoria E. Amato, Pierre Bertram, Allan K. 2021-03-25 application/pdf https://doi.org/10.5194/acp-2021-245 https://acp.copernicus.org/preprints/acp-2021-245/ eng eng doi:10.5194/acp-2021-245 https://acp.copernicus.org/preprints/acp-2021-245/ eISSN: 1680-7324 Text 2021 ftcopernicus https://doi.org/10.5194/acp-2021-245 2021-03-29T16:22:16Z A wide range of materials including mineral dust, soil dust, and bioaerosols have been shown to act as ice nuclei in the atmosphere. During atmospheric transport, these materials can become coated with inorganic and organic solutes which may impact their ability to nucleate ice. While a number of studies have investigated the impact of solutes at low concentrations on ice nucleation by mineral dusts, very few studies have examined their impact on non-mineral dust ice nuclei. We studied the effect of dilute (NH 4 ) 2 SO 4 solutions on immersion freezing of a variety of non-mineral dust ice nucleating substances including bacteria, fungi, sea ice diatom exudates, sea surface microlayer, and humic substances using the droplet freezing technique. We also studied the effect of (NH 4 ) 2 SO 4 on immersion freezing of mineral dust particles for comparison purposes. (NH 4 ) 2 SO 4 had no effect on the median freezing temperature of nine of the ten tested non-mineral dust materials. There was a small but statistically significant decrease in the median freezing temperature of the bacteria X. campestris (change in median freezing temperature ∆T_50 = -0.43 ± 0.19 °C) in the presence of (NH4)2SO4 compared to pure water. Conversely, (NH 4 ) 2 SO 4 increased the median freezing temperature of four different mineral dusts (Potassium-rich feldspar, Arizona Test Dust, Kaolinite, Montmorillonite) by 3 °C to 8 °C. This significant difference in the response of mineral dust and non-mineral dust ice nucleating substances when exposed to (NH 4 ) 2 SO 4 suggests that they nucleate ice and/or interact with (NH 4 ) 2 SO 4 via different mechanisms. This difference suggests that the relative importance of mineral dust to non-mineral dust particles for ice nucleation in mixed-phase clouds could increase as these particles become coated with ammonium sulfate in the atmosphere. This difference also suggests that the addition of (NH 4 ) 2 SO 4 to atmospheric samples of unknown composition could be used as an indicator or assay for the presence of mineral dust ice nuclei. Text Sea ice Copernicus Publications: E-Journals |
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English |
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A wide range of materials including mineral dust, soil dust, and bioaerosols have been shown to act as ice nuclei in the atmosphere. During atmospheric transport, these materials can become coated with inorganic and organic solutes which may impact their ability to nucleate ice. While a number of studies have investigated the impact of solutes at low concentrations on ice nucleation by mineral dusts, very few studies have examined their impact on non-mineral dust ice nuclei. We studied the effect of dilute (NH 4 ) 2 SO 4 solutions on immersion freezing of a variety of non-mineral dust ice nucleating substances including bacteria, fungi, sea ice diatom exudates, sea surface microlayer, and humic substances using the droplet freezing technique. We also studied the effect of (NH 4 ) 2 SO 4 on immersion freezing of mineral dust particles for comparison purposes. (NH 4 ) 2 SO 4 had no effect on the median freezing temperature of nine of the ten tested non-mineral dust materials. There was a small but statistically significant decrease in the median freezing temperature of the bacteria X. campestris (change in median freezing temperature ∆T_50 = -0.43 ± 0.19 °C) in the presence of (NH4)2SO4 compared to pure water. Conversely, (NH 4 ) 2 SO 4 increased the median freezing temperature of four different mineral dusts (Potassium-rich feldspar, Arizona Test Dust, Kaolinite, Montmorillonite) by 3 °C to 8 °C. This significant difference in the response of mineral dust and non-mineral dust ice nucleating substances when exposed to (NH 4 ) 2 SO 4 suggests that they nucleate ice and/or interact with (NH 4 ) 2 SO 4 via different mechanisms. This difference suggests that the relative importance of mineral dust to non-mineral dust particles for ice nucleation in mixed-phase clouds could increase as these particles become coated with ammonium sulfate in the atmosphere. This difference also suggests that the addition of (NH 4 ) 2 SO 4 to atmospheric samples of unknown composition could be used as an indicator or assay for the presence of mineral dust ice nuclei. |
format |
Text |
author |
Worthy, Soleil E. Kumar, Anand Xi, Yu Yun, Jingwei Chen, Jessie Xu, Cuishan Irish, Victoria E. Amato, Pierre Bertram, Allan K. |
spellingShingle |
Worthy, Soleil E. Kumar, Anand Xi, Yu Yun, Jingwei Chen, Jessie Xu, Cuishan Irish, Victoria E. Amato, Pierre Bertram, Allan K. The effect of (NH4)2SO4 on the freezing properties of non-mineral dust ice nucleating substances of atmospheric relevance |
author_facet |
Worthy, Soleil E. Kumar, Anand Xi, Yu Yun, Jingwei Chen, Jessie Xu, Cuishan Irish, Victoria E. Amato, Pierre Bertram, Allan K. |
author_sort |
Worthy, Soleil E. |
title |
The effect of (NH4)2SO4 on the freezing properties of non-mineral dust ice nucleating substances of atmospheric relevance |
title_short |
The effect of (NH4)2SO4 on the freezing properties of non-mineral dust ice nucleating substances of atmospheric relevance |
title_full |
The effect of (NH4)2SO4 on the freezing properties of non-mineral dust ice nucleating substances of atmospheric relevance |
title_fullStr |
The effect of (NH4)2SO4 on the freezing properties of non-mineral dust ice nucleating substances of atmospheric relevance |
title_full_unstemmed |
The effect of (NH4)2SO4 on the freezing properties of non-mineral dust ice nucleating substances of atmospheric relevance |
title_sort |
effect of (nh4)2so4 on the freezing properties of non-mineral dust ice nucleating substances of atmospheric relevance |
publishDate |
2021 |
url |
https://doi.org/10.5194/acp-2021-245 https://acp.copernicus.org/preprints/acp-2021-245/ |
genre |
Sea ice |
genre_facet |
Sea ice |
op_source |
eISSN: 1680-7324 |
op_relation |
doi:10.5194/acp-2021-245 https://acp.copernicus.org/preprints/acp-2021-245/ |
op_doi |
https://doi.org/10.5194/acp-2021-245 |
_version_ |
1766195674001440768 |