Brine flow through sea ice
Values provided in temporal and spatial coverage are approximate only. Metadata record for data from ASAC Project 1060 See the link below for public details on this project. Taken from the referenced publications: Sea ice exhibits a marked transition in its fluid transport properties at a critical b...
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Australian Ocean Data Network
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Online Access: | https://researchdata.ands.org.au/brine-flow-sea-ice/686061 https://data.aad.gov.au/metadata/records/ASAC_1060 https://secure3.aad.gov.au/proms/public/projects/report_project_public.cfm?project_no=1060 http://data.aad.gov.au/aadc/portal/download_file.cfm?file_id=3068 http://data.aad.gov.au/aadc/metadata/citation.cfm?entry_id=ASAC_1060 |
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ftands:oai:ands.org.au::686061 |
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record_format |
openpolar |
institution |
Open Polar |
collection |
Research Data Australia (Australian National Data Service - ANDS) |
op_collection_id |
ftands |
language |
unknown |
topic |
oceans PACK ICE EARTH SCIENCE CRYOSPHERE SEA ICE POLYNYAS SALINITY SALINITY/DENSITY HEAT FLUX ICE DEPTH/THICKNESS ICE TEMPERATURE SNOW MELT SNOW DEPTH sea-ice Nathaniel B. Palmer snow cover brine infiltrate drillhole snowpack insulation SHIPS R/V NBP > R/V Nathaniel B. Palmer AMD/AU CEOS AMD ACE/CRC OCEAN > SOUTHERN OCEAN CONTINENT > ANTARCTICA GEOGRAPHIC REGION > POLAR SOUTHERN OCEAN > WEDDELL SEA |
spellingShingle |
oceans PACK ICE EARTH SCIENCE CRYOSPHERE SEA ICE POLYNYAS SALINITY SALINITY/DENSITY HEAT FLUX ICE DEPTH/THICKNESS ICE TEMPERATURE SNOW MELT SNOW DEPTH sea-ice Nathaniel B. Palmer snow cover brine infiltrate drillhole snowpack insulation SHIPS R/V NBP > R/V Nathaniel B. Palmer AMD/AU CEOS AMD ACE/CRC OCEAN > SOUTHERN OCEAN CONTINENT > ANTARCTICA GEOGRAPHIC REGION > POLAR SOUTHERN OCEAN > WEDDELL SEA Brine flow through sea ice |
topic_facet |
oceans PACK ICE EARTH SCIENCE CRYOSPHERE SEA ICE POLYNYAS SALINITY SALINITY/DENSITY HEAT FLUX ICE DEPTH/THICKNESS ICE TEMPERATURE SNOW MELT SNOW DEPTH sea-ice Nathaniel B. Palmer snow cover brine infiltrate drillhole snowpack insulation SHIPS R/V NBP > R/V Nathaniel B. Palmer AMD/AU CEOS AMD ACE/CRC OCEAN > SOUTHERN OCEAN CONTINENT > ANTARCTICA GEOGRAPHIC REGION > POLAR SOUTHERN OCEAN > WEDDELL SEA |
description |
Values provided in temporal and spatial coverage are approximate only. Metadata record for data from ASAC Project 1060 See the link below for public details on this project. Taken from the referenced publications: Sea ice exhibits a marked transition in its fluid transport properties at a critical brine volume fraction Pc of about 5 percent, or temperature Tc of about -5 degrees Celsius for salinity of 5 parts per thousand. For temperatures warmer than Tc brine carrying heat and nutrients can move through the ice, whereas for colder temperatures the ice is impermeable. This transition plays a key role in the geophysics, biology, and remote sensing of sea ice. Percolation theory can be used to understand this critical behaviour or transport in sea ice. The similarity of sea ice microstructure to compressed powders is used to theoretically predict Pc of about 5 percent. The snow cover on Antarctic sea ice often depresses the ice below sea level, allowing brine or seawater to infiltrate, or flood the snowpack. This significantly reduces the thermal insulation properties of the snow cover, and increases the ocean/atmosphere heat flux. The subsequent refreezing of this saturated snow or slush layer, to form snow-ice, can account for a significant percentage of the total ice mass in some regions. The extent of saturated snow cannot presently be estimated from satellite remote-sensing data and, because it is often hidden by a layer of dry snow, cannot be estimated from visual observations. Here, we use non-parametric statistics to combine sea-ice and snow thickness data from drillhole measurements with routine visual observations of snow and ice characteristics to estimate the extent of brine-infiltrated snow. During a field experiment in July 1994, while the R.V. Nathaniel B. Palmer was moored to a drifting ice floe in the Weddell Sea, Antarctica, data were collected on the sea-ice and snow characteristics. We report on the evolution of ice which grew in a newly opened lead. As expected with the cold atmospheric conditions, congelation ice initially formed in the lead. Subsequent snow accumulation and large ocean heat fluxes resulted in melt at the base of the ice, and enhanced flooding of the snow on ice surface. This flooded snow subsequently froze, and, five days after the lead opened, all the congelation ice had melted and twenty-six centimetres of snow ice had formed. We use measured sea-ice and snow salinities, thickness and oxygen isotope values of the newly formed lead ice to calculate the salt flux to the ocean. Although there was a salt flux to the ocean as the ice initially grew, we calculate a small net fresh-water input to the upper ocean by the end of the 5 day period. Similar processes of basal melt and surface snow-ice formation also occurred on the surrounding, thicker sea ice. Oceanographic studies in this region of the Weddell Sea have shown that salt rejection by sea-ice formation may enhance the ocean vertical thermohaline circulation and release heat from the deeper ocean to melt the ice cover. This type of deep convection is thought to initiate the Weddell polynya, which was observed only during the 1970s. Our results, which show than an ice cover can form with no salt input to the ocean, provide a mechanism which may help explain the more recent absence of the Weddell polynya. |
author2 |
AADC (originator) AU/AADC > Australian Antarctic Data Centre, Australia (resourceProvider) |
format |
Dataset |
title |
Brine flow through sea ice |
title_short |
Brine flow through sea ice |
title_full |
Brine flow through sea ice |
title_fullStr |
Brine flow through sea ice |
title_full_unstemmed |
Brine flow through sea ice |
title_sort |
brine flow through sea ice |
publisher |
Australian Ocean Data Network |
url |
https://researchdata.ands.org.au/brine-flow-sea-ice/686061 https://data.aad.gov.au/metadata/records/ASAC_1060 https://secure3.aad.gov.au/proms/public/projects/report_project_public.cfm?project_no=1060 http://data.aad.gov.au/aadc/portal/download_file.cfm?file_id=3068 http://data.aad.gov.au/aadc/metadata/citation.cfm?entry_id=ASAC_1060 |
op_coverage |
Spatial: northlimit=-60.0; southlimit=-68.0; westlimit=-20.0; eastLimit=5.0 Temporal: From 1994-07-01 to 1994-08-31 |
long_lat |
ENVELOPE(-20.0,5.0,-60.0,-68.0) |
geographic |
Antarctic Southern Ocean Weddell Weddell Sea |
geographic_facet |
Antarctic Southern Ocean Weddell Weddell Sea |
genre |
Antarc* Antarctic Antarctica Sea ice Southern Ocean Weddell Sea |
genre_facet |
Antarc* Antarctic Antarctica Sea ice Southern Ocean Weddell Sea |
op_source |
https://data.aad.gov.au |
op_relation |
https://researchdata.ands.org.au/brine-flow-sea-ice/686061 43cef222-466f-4793-8cbd-f87db8a62820 https://data.aad.gov.au/metadata/records/ASAC_1060 https://secure3.aad.gov.au/proms/public/projects/report_project_public.cfm?project_no=1060 http://data.aad.gov.au/aadc/portal/download_file.cfm?file_id=3068 http://data.aad.gov.au/aadc/metadata/citation.cfm?entry_id=ASAC_1060 |
_version_ |
1766245654405840896 |
spelling |
ftands:oai:ands.org.au::686061 2023-05-15T13:46:55+02:00 Brine flow through sea ice AADC (originator) AU/AADC > Australian Antarctic Data Centre, Australia (resourceProvider) Spatial: northlimit=-60.0; southlimit=-68.0; westlimit=-20.0; eastLimit=5.0 Temporal: From 1994-07-01 to 1994-08-31 https://researchdata.ands.org.au/brine-flow-sea-ice/686061 https://data.aad.gov.au/metadata/records/ASAC_1060 https://secure3.aad.gov.au/proms/public/projects/report_project_public.cfm?project_no=1060 http://data.aad.gov.au/aadc/portal/download_file.cfm?file_id=3068 http://data.aad.gov.au/aadc/metadata/citation.cfm?entry_id=ASAC_1060 unknown Australian Ocean Data Network https://researchdata.ands.org.au/brine-flow-sea-ice/686061 43cef222-466f-4793-8cbd-f87db8a62820 https://data.aad.gov.au/metadata/records/ASAC_1060 https://secure3.aad.gov.au/proms/public/projects/report_project_public.cfm?project_no=1060 http://data.aad.gov.au/aadc/portal/download_file.cfm?file_id=3068 http://data.aad.gov.au/aadc/metadata/citation.cfm?entry_id=ASAC_1060 https://data.aad.gov.au oceans PACK ICE EARTH SCIENCE CRYOSPHERE SEA ICE POLYNYAS SALINITY SALINITY/DENSITY HEAT FLUX ICE DEPTH/THICKNESS ICE TEMPERATURE SNOW MELT SNOW DEPTH sea-ice Nathaniel B. Palmer snow cover brine infiltrate drillhole snowpack insulation SHIPS R/V NBP > R/V Nathaniel B. Palmer AMD/AU CEOS AMD ACE/CRC OCEAN > SOUTHERN OCEAN CONTINENT > ANTARCTICA GEOGRAPHIC REGION > POLAR SOUTHERN OCEAN > WEDDELL SEA dataset ftands 2020-01-05T21:06:52Z Values provided in temporal and spatial coverage are approximate only. Metadata record for data from ASAC Project 1060 See the link below for public details on this project. Taken from the referenced publications: Sea ice exhibits a marked transition in its fluid transport properties at a critical brine volume fraction Pc of about 5 percent, or temperature Tc of about -5 degrees Celsius for salinity of 5 parts per thousand. For temperatures warmer than Tc brine carrying heat and nutrients can move through the ice, whereas for colder temperatures the ice is impermeable. This transition plays a key role in the geophysics, biology, and remote sensing of sea ice. Percolation theory can be used to understand this critical behaviour or transport in sea ice. The similarity of sea ice microstructure to compressed powders is used to theoretically predict Pc of about 5 percent. The snow cover on Antarctic sea ice often depresses the ice below sea level, allowing brine or seawater to infiltrate, or flood the snowpack. This significantly reduces the thermal insulation properties of the snow cover, and increases the ocean/atmosphere heat flux. The subsequent refreezing of this saturated snow or slush layer, to form snow-ice, can account for a significant percentage of the total ice mass in some regions. The extent of saturated snow cannot presently be estimated from satellite remote-sensing data and, because it is often hidden by a layer of dry snow, cannot be estimated from visual observations. Here, we use non-parametric statistics to combine sea-ice and snow thickness data from drillhole measurements with routine visual observations of snow and ice characteristics to estimate the extent of brine-infiltrated snow. During a field experiment in July 1994, while the R.V. Nathaniel B. Palmer was moored to a drifting ice floe in the Weddell Sea, Antarctica, data were collected on the sea-ice and snow characteristics. We report on the evolution of ice which grew in a newly opened lead. As expected with the cold atmospheric conditions, congelation ice initially formed in the lead. Subsequent snow accumulation and large ocean heat fluxes resulted in melt at the base of the ice, and enhanced flooding of the snow on ice surface. This flooded snow subsequently froze, and, five days after the lead opened, all the congelation ice had melted and twenty-six centimetres of snow ice had formed. We use measured sea-ice and snow salinities, thickness and oxygen isotope values of the newly formed lead ice to calculate the salt flux to the ocean. Although there was a salt flux to the ocean as the ice initially grew, we calculate a small net fresh-water input to the upper ocean by the end of the 5 day period. Similar processes of basal melt and surface snow-ice formation also occurred on the surrounding, thicker sea ice. Oceanographic studies in this region of the Weddell Sea have shown that salt rejection by sea-ice formation may enhance the ocean vertical thermohaline circulation and release heat from the deeper ocean to melt the ice cover. This type of deep convection is thought to initiate the Weddell polynya, which was observed only during the 1970s. Our results, which show than an ice cover can form with no salt input to the ocean, provide a mechanism which may help explain the more recent absence of the Weddell polynya. Dataset Antarc* Antarctic Antarctica Sea ice Southern Ocean Weddell Sea Research Data Australia (Australian National Data Service - ANDS) Antarctic Southern Ocean Weddell Weddell Sea ENVELOPE(-20.0,5.0,-60.0,-68.0) |