Brine Drainage and Initial Salt Entrapment in Sodium Chloride Ice.
To obtain a better understanding of the desalination of natural sea ice, an experimental technique was developed to measure sequential salinity profiles of a growing sodium chloride ice sheet. Using radioactive Na22 as a tracer, it was possible to determine both the concentration and movement of the...
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ftdtic:ADA021765 2023-05-15T16:37:24+02:00 Brine Drainage and Initial Salt Entrapment in Sodium Chloride Ice. Cox,G. F. N. Weeks,W. F. COLD REGIONS RESEARCH AND ENGINEERING LAB HANOVER N H 1975-12 text/html http://www.dtic.mil/docs/citations/ADA021765 http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA021765 en eng http://www.dtic.mil/docs/citations/ADA021765 APPROVED FOR PUBLIC RELEASE DTIC AND NTIS Snow Ice and Permafrost *SEA ICE *DESALINATION COMPUTER PROGRAMS MATHEMATICAL MODELS SPATIAL DISTRIBUTION THICKNESS EXPERIMENTAL DATA LABORATORY TESTS GROWTH(GENERAL) SOLIDIFICATION DRAINAGE TEMPERATURE GRADIENTS ICE TABLES(DATA) GRAVITY SODIUM CHLORIDE SALINITY CONCENTRATION(CHEMISTRY) RADIOACTIVE ISOTOPES BRINES EXPULSION TRACER STUDIES Isotopic labeling Text 1975 ftdtic 2016-02-20T10:38:13Z To obtain a better understanding of the desalination of natural sea ice, an experimental technique was developed to measure sequential salinity profiles of a growing sodium chloride ice sheet. Using radioactive Na22 as a tracer, it was possible to determine both the concentration and movement of the brine within the ice without destroying the sample. A detailed temperature and growth history of the ice was maintained so that the variation of the salinity profiles could be properly interpreted. Since the experimental salinity profile represented a smoothed, rather than a true salinity distribution, a deconvolution method was devised to restore the true salinity profile. In all respects, the salinity profiles are similar to those of natural sea ice. They have a characteristic C-shape, and clearly exhibit the effects of brine drainage. To determine the relative importance of the desalination mechanisms, a theoretical brine expulsion model was derived and compared to the experimental data. As input for the model, equations describing the variation of some properties of NaCl brine with temperature were derived. A simplified form of the model, when compared to the experimental results, indicated that brine expulsion was only important during the first several hours of ice growth, and later became a minor desalination process relative to gravity drainage which continued to be the dominant mechanism for the remainder of the study period (up to 6 weeks). The rate of gravity drainage was found to be dependent on the brine volume and the temperature gradient of the ice. As either the brine volume or temperature gradient was increased, the rate of change of salinity due to gravity drainage increased. Text Ice Ice Sheet permafrost Sea ice Defense Technical Information Center: DTIC Technical Reports database |
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Open Polar |
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Defense Technical Information Center: DTIC Technical Reports database |
op_collection_id |
ftdtic |
language |
English |
topic |
Snow Ice and Permafrost *SEA ICE *DESALINATION COMPUTER PROGRAMS MATHEMATICAL MODELS SPATIAL DISTRIBUTION THICKNESS EXPERIMENTAL DATA LABORATORY TESTS GROWTH(GENERAL) SOLIDIFICATION DRAINAGE TEMPERATURE GRADIENTS ICE TABLES(DATA) GRAVITY SODIUM CHLORIDE SALINITY CONCENTRATION(CHEMISTRY) RADIOACTIVE ISOTOPES BRINES EXPULSION TRACER STUDIES Isotopic labeling |
spellingShingle |
Snow Ice and Permafrost *SEA ICE *DESALINATION COMPUTER PROGRAMS MATHEMATICAL MODELS SPATIAL DISTRIBUTION THICKNESS EXPERIMENTAL DATA LABORATORY TESTS GROWTH(GENERAL) SOLIDIFICATION DRAINAGE TEMPERATURE GRADIENTS ICE TABLES(DATA) GRAVITY SODIUM CHLORIDE SALINITY CONCENTRATION(CHEMISTRY) RADIOACTIVE ISOTOPES BRINES EXPULSION TRACER STUDIES Isotopic labeling Cox,G. F. N. Weeks,W. F. Brine Drainage and Initial Salt Entrapment in Sodium Chloride Ice. |
topic_facet |
Snow Ice and Permafrost *SEA ICE *DESALINATION COMPUTER PROGRAMS MATHEMATICAL MODELS SPATIAL DISTRIBUTION THICKNESS EXPERIMENTAL DATA LABORATORY TESTS GROWTH(GENERAL) SOLIDIFICATION DRAINAGE TEMPERATURE GRADIENTS ICE TABLES(DATA) GRAVITY SODIUM CHLORIDE SALINITY CONCENTRATION(CHEMISTRY) RADIOACTIVE ISOTOPES BRINES EXPULSION TRACER STUDIES Isotopic labeling |
description |
To obtain a better understanding of the desalination of natural sea ice, an experimental technique was developed to measure sequential salinity profiles of a growing sodium chloride ice sheet. Using radioactive Na22 as a tracer, it was possible to determine both the concentration and movement of the brine within the ice without destroying the sample. A detailed temperature and growth history of the ice was maintained so that the variation of the salinity profiles could be properly interpreted. Since the experimental salinity profile represented a smoothed, rather than a true salinity distribution, a deconvolution method was devised to restore the true salinity profile. In all respects, the salinity profiles are similar to those of natural sea ice. They have a characteristic C-shape, and clearly exhibit the effects of brine drainage. To determine the relative importance of the desalination mechanisms, a theoretical brine expulsion model was derived and compared to the experimental data. As input for the model, equations describing the variation of some properties of NaCl brine with temperature were derived. A simplified form of the model, when compared to the experimental results, indicated that brine expulsion was only important during the first several hours of ice growth, and later became a minor desalination process relative to gravity drainage which continued to be the dominant mechanism for the remainder of the study period (up to 6 weeks). The rate of gravity drainage was found to be dependent on the brine volume and the temperature gradient of the ice. As either the brine volume or temperature gradient was increased, the rate of change of salinity due to gravity drainage increased. |
author2 |
COLD REGIONS RESEARCH AND ENGINEERING LAB HANOVER N H |
format |
Text |
author |
Cox,G. F. N. Weeks,W. F. |
author_facet |
Cox,G. F. N. Weeks,W. F. |
author_sort |
Cox,G. F. N. |
title |
Brine Drainage and Initial Salt Entrapment in Sodium Chloride Ice. |
title_short |
Brine Drainage and Initial Salt Entrapment in Sodium Chloride Ice. |
title_full |
Brine Drainage and Initial Salt Entrapment in Sodium Chloride Ice. |
title_fullStr |
Brine Drainage and Initial Salt Entrapment in Sodium Chloride Ice. |
title_full_unstemmed |
Brine Drainage and Initial Salt Entrapment in Sodium Chloride Ice. |
title_sort |
brine drainage and initial salt entrapment in sodium chloride ice. |
publishDate |
1975 |
url |
http://www.dtic.mil/docs/citations/ADA021765 http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA021765 |
genre |
Ice Ice Sheet permafrost Sea ice |
genre_facet |
Ice Ice Sheet permafrost Sea ice |
op_source |
DTIC AND NTIS |
op_relation |
http://www.dtic.mil/docs/citations/ADA021765 |
op_rights |
APPROVED FOR PUBLIC RELEASE |
_version_ |
1766027697486561280 |