Different photolysis kinetics at the surface of frozen freshwater vs. frozen salt solutions
Reactions at air-ice interfaces can proceed at very different rates than those in aqueous solution, due to the unique disordered region at the ice surface known as the quasi-liquid layer (QLL) . The physical and chemical nature of the surfacial region of ice is greatly affected by solutes such as so...
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Online Access: | https://doi.org/10.5194/acp-10-10917-2010 https://doaj.org/article/3d1c1faeaec1471d9c63625e5176a2a0 |
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ftdoajarticles:oai:doaj.org/article:3d1c1faeaec1471d9c63625e5176a2a0 2023-05-15T18:18:35+02:00 Different photolysis kinetics at the surface of frozen freshwater vs. frozen salt solutions T. F. Kahan N.-O. A. Kwamena D. J. Donaldson 2010-11-01T00:00:00Z https://doi.org/10.5194/acp-10-10917-2010 https://doaj.org/article/3d1c1faeaec1471d9c63625e5176a2a0 EN eng Copernicus Publications http://www.atmos-chem-phys.net/10/10917/2010/acp-10-10917-2010.pdf https://doaj.org/toc/1680-7316 https://doaj.org/toc/1680-7324 doi:10.5194/acp-10-10917-2010 1680-7316 1680-7324 https://doaj.org/article/3d1c1faeaec1471d9c63625e5176a2a0 Atmospheric Chemistry and Physics, Vol 10, Iss 22, Pp 10917-10922 (2010) Physics QC1-999 Chemistry QD1-999 article 2010 ftdoajarticles https://doi.org/10.5194/acp-10-10917-2010 2023-01-08T01:32:51Z Reactions at air-ice interfaces can proceed at very different rates than those in aqueous solution, due to the unique disordered region at the ice surface known as the quasi-liquid layer (QLL) . The physical and chemical nature of the surfacial region of ice is greatly affected by solutes such as sodium halide salts. In this work, we studied the effects of sodium chloride and sodium bromide on the photolysis kinetics of harmine, an aromatic organic compound, in aqueous solution and at the surface of frozen salt solutions above the eutectic temperature. In common with other aromatic organic compounds we have studied, harmine photolysis is much faster on ice surfaces than in aqueous solution, but the presence of NaCl or NaBr – which does not affect photolysis kinetics in solution – reduces the photolysis rate on ice. The rate decreases monotonically with increasing salt concentration; at the concentrations found in seawater, harmine photolysis at the surface of frozen salt solutions proceeds at the same rate as in aqueous solution. These results suggest that the brine excluded to the surfaces of frozen salt solutions is a true aqueous solution, and so it may be possible to use aqueous-phase kinetics to predict photolysis rates at sea ice surfaces. This is in marked contrast to the result at the surface of frozen freshwater samples, where reaction kinetics are often not well-described by aqueous-phase processes. Article in Journal/Newspaper Sea ice Directory of Open Access Journals: DOAJ Articles Atmospheric Chemistry and Physics 10 22 10917 10922 |
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Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Physics QC1-999 Chemistry QD1-999 |
spellingShingle |
Physics QC1-999 Chemistry QD1-999 T. F. Kahan N.-O. A. Kwamena D. J. Donaldson Different photolysis kinetics at the surface of frozen freshwater vs. frozen salt solutions |
topic_facet |
Physics QC1-999 Chemistry QD1-999 |
description |
Reactions at air-ice interfaces can proceed at very different rates than those in aqueous solution, due to the unique disordered region at the ice surface known as the quasi-liquid layer (QLL) . The physical and chemical nature of the surfacial region of ice is greatly affected by solutes such as sodium halide salts. In this work, we studied the effects of sodium chloride and sodium bromide on the photolysis kinetics of harmine, an aromatic organic compound, in aqueous solution and at the surface of frozen salt solutions above the eutectic temperature. In common with other aromatic organic compounds we have studied, harmine photolysis is much faster on ice surfaces than in aqueous solution, but the presence of NaCl or NaBr – which does not affect photolysis kinetics in solution – reduces the photolysis rate on ice. The rate decreases monotonically with increasing salt concentration; at the concentrations found in seawater, harmine photolysis at the surface of frozen salt solutions proceeds at the same rate as in aqueous solution. These results suggest that the brine excluded to the surfaces of frozen salt solutions is a true aqueous solution, and so it may be possible to use aqueous-phase kinetics to predict photolysis rates at sea ice surfaces. This is in marked contrast to the result at the surface of frozen freshwater samples, where reaction kinetics are often not well-described by aqueous-phase processes. |
format |
Article in Journal/Newspaper |
author |
T. F. Kahan N.-O. A. Kwamena D. J. Donaldson |
author_facet |
T. F. Kahan N.-O. A. Kwamena D. J. Donaldson |
author_sort |
T. F. Kahan |
title |
Different photolysis kinetics at the surface of frozen freshwater vs. frozen salt solutions |
title_short |
Different photolysis kinetics at the surface of frozen freshwater vs. frozen salt solutions |
title_full |
Different photolysis kinetics at the surface of frozen freshwater vs. frozen salt solutions |
title_fullStr |
Different photolysis kinetics at the surface of frozen freshwater vs. frozen salt solutions |
title_full_unstemmed |
Different photolysis kinetics at the surface of frozen freshwater vs. frozen salt solutions |
title_sort |
different photolysis kinetics at the surface of frozen freshwater vs. frozen salt solutions |
publisher |
Copernicus Publications |
publishDate |
2010 |
url |
https://doi.org/10.5194/acp-10-10917-2010 https://doaj.org/article/3d1c1faeaec1471d9c63625e5176a2a0 |
genre |
Sea ice |
genre_facet |
Sea ice |
op_source |
Atmospheric Chemistry and Physics, Vol 10, Iss 22, Pp 10917-10922 (2010) |
op_relation |
http://www.atmos-chem-phys.net/10/10917/2010/acp-10-10917-2010.pdf https://doaj.org/toc/1680-7316 https://doaj.org/toc/1680-7324 doi:10.5194/acp-10-10917-2010 1680-7316 1680-7324 https://doaj.org/article/3d1c1faeaec1471d9c63625e5176a2a0 |
op_doi |
https://doi.org/10.5194/acp-10-10917-2010 |
container_title |
Atmospheric Chemistry and Physics |
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10 |
container_issue |
22 |
container_start_page |
10917 |
op_container_end_page |
10922 |
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1766195221167603712 |