Global view of sea-ice production in polynyas and its linkage to dense/bottom water formation
Abstract Global overturning circulation is driven by density differences. Saline water rejected during sea-ice formation in polynyas is the main source of dense water, and thus sea-ice production is a key factor in the overturning circulation. Due to difficulties associated with in situ observation,...
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ftbiomed:oai:biomedcentral.com:s40562-016-0045-4 2023-05-15T13:39:16+02:00 Global view of sea-ice production in polynyas and its linkage to dense/bottom water formation Ohshima, Kay Nihashi, Sohey Iwamoto, Katsushi 2016-05-12 http://www.geoscienceletters.com/content/3/1/13 en eng BioMed Central Ltd. http://www.geoscienceletters.com/content/3/1/13 Copyright 2016 Ohshima et al. Sea-ice production Dense water Antarctic Bottom Water Okhotsk Sea Intermediate Water Coastal polynya Overturning Microwave radiometer AMSR-E Review 2016 ftbiomed 2016-05-14T23:59:59Z Abstract Global overturning circulation is driven by density differences. Saline water rejected during sea-ice formation in polynyas is the main source of dense water, and thus sea-ice production is a key factor in the overturning circulation. Due to difficulties associated with in situ observation, sea-ice production and its interannual variability have not been well understood until recently. Methods to estimate sea-ice production on large scales have been developed using heat flux calculations based on satellite microwave radiometer data. Using these methods, we present the mapping of sea-ice production with the same definition and scale globally, and review the polynya ice production and its relationship with dense/bottom water. The mapping demonstrates that ice production rate is high in Antarctic coastal polynyas, in contrast to Arctic coastal polynyas. This is consistent with the formation of Antarctic Bottom Water (AABW), the densest water mass which occupies the abyssal layer of the global ocean. The Ross Ice Shelf polynya has by far the highest ice production in the Southern Hemisphere. The Cape Darnley polynya (65°E–69°E) is found to be the second highest production area and recent observations revealed that this is the missing (fourth) source of AABW. In the region off the Mertz Glacier Tongue (MGT), the third source of AABW, sea-ice production decreased by as much as 40 %, due to the MGT calving in early 2010, resulting in a significant decrease in AABW production. The Okhotsk Northwestern polynya exhibits the highest ice production in the Northern Hemisphere, and the resultant dense water formation leads to overturning in the North Pacific, extending to the intermediate layer. Estimates of its ice production show a significant decrease over the past 30–50 years, likely causing the weakening of the North Pacific overturning. These regions demonstrate the strong linkage between variabilities of sea-ice production and bottom/intermediate water formation. The mapping has also provided surface boundary conditions and validation data of heat- and salt-flux associated with sea-ice formation/melting for various ocean and coupled models. Review Antarc* Antarctic Arctic Ice Shelf Mertz Glacier okhotsk sea Ross Ice Shelf Sea ice BioMed Central Arctic Antarctic Okhotsk Ross Ice Shelf Pacific Mertz Glacier ENVELOPE(144.500,144.500,-67.667,-67.667) Darnley ENVELOPE(69.717,69.717,-67.717,-67.717) Mertz Glacier Tongue ENVELOPE(145.500,145.500,-67.167,-67.167) Cape Darnley ENVELOPE(69.567,69.567,-67.738,-67.738) |
institution |
Open Polar |
collection |
BioMed Central |
op_collection_id |
ftbiomed |
language |
English |
topic |
Sea-ice production Dense water Antarctic Bottom Water Okhotsk Sea Intermediate Water Coastal polynya Overturning Microwave radiometer AMSR-E |
spellingShingle |
Sea-ice production Dense water Antarctic Bottom Water Okhotsk Sea Intermediate Water Coastal polynya Overturning Microwave radiometer AMSR-E Ohshima, Kay Nihashi, Sohey Iwamoto, Katsushi Global view of sea-ice production in polynyas and its linkage to dense/bottom water formation |
topic_facet |
Sea-ice production Dense water Antarctic Bottom Water Okhotsk Sea Intermediate Water Coastal polynya Overturning Microwave radiometer AMSR-E |
description |
Abstract Global overturning circulation is driven by density differences. Saline water rejected during sea-ice formation in polynyas is the main source of dense water, and thus sea-ice production is a key factor in the overturning circulation. Due to difficulties associated with in situ observation, sea-ice production and its interannual variability have not been well understood until recently. Methods to estimate sea-ice production on large scales have been developed using heat flux calculations based on satellite microwave radiometer data. Using these methods, we present the mapping of sea-ice production with the same definition and scale globally, and review the polynya ice production and its relationship with dense/bottom water. The mapping demonstrates that ice production rate is high in Antarctic coastal polynyas, in contrast to Arctic coastal polynyas. This is consistent with the formation of Antarctic Bottom Water (AABW), the densest water mass which occupies the abyssal layer of the global ocean. The Ross Ice Shelf polynya has by far the highest ice production in the Southern Hemisphere. The Cape Darnley polynya (65°E–69°E) is found to be the second highest production area and recent observations revealed that this is the missing (fourth) source of AABW. In the region off the Mertz Glacier Tongue (MGT), the third source of AABW, sea-ice production decreased by as much as 40 %, due to the MGT calving in early 2010, resulting in a significant decrease in AABW production. The Okhotsk Northwestern polynya exhibits the highest ice production in the Northern Hemisphere, and the resultant dense water formation leads to overturning in the North Pacific, extending to the intermediate layer. Estimates of its ice production show a significant decrease over the past 30–50 years, likely causing the weakening of the North Pacific overturning. These regions demonstrate the strong linkage between variabilities of sea-ice production and bottom/intermediate water formation. The mapping has also provided surface boundary conditions and validation data of heat- and salt-flux associated with sea-ice formation/melting for various ocean and coupled models. |
format |
Review |
author |
Ohshima, Kay Nihashi, Sohey Iwamoto, Katsushi |
author_facet |
Ohshima, Kay Nihashi, Sohey Iwamoto, Katsushi |
author_sort |
Ohshima, Kay |
title |
Global view of sea-ice production in polynyas and its linkage to dense/bottom water formation |
title_short |
Global view of sea-ice production in polynyas and its linkage to dense/bottom water formation |
title_full |
Global view of sea-ice production in polynyas and its linkage to dense/bottom water formation |
title_fullStr |
Global view of sea-ice production in polynyas and its linkage to dense/bottom water formation |
title_full_unstemmed |
Global view of sea-ice production in polynyas and its linkage to dense/bottom water formation |
title_sort |
global view of sea-ice production in polynyas and its linkage to dense/bottom water formation |
publisher |
BioMed Central Ltd. |
publishDate |
2016 |
url |
http://www.geoscienceletters.com/content/3/1/13 |
long_lat |
ENVELOPE(144.500,144.500,-67.667,-67.667) ENVELOPE(69.717,69.717,-67.717,-67.717) ENVELOPE(145.500,145.500,-67.167,-67.167) ENVELOPE(69.567,69.567,-67.738,-67.738) |
geographic |
Arctic Antarctic Okhotsk Ross Ice Shelf Pacific Mertz Glacier Darnley Mertz Glacier Tongue Cape Darnley |
geographic_facet |
Arctic Antarctic Okhotsk Ross Ice Shelf Pacific Mertz Glacier Darnley Mertz Glacier Tongue Cape Darnley |
genre |
Antarc* Antarctic Arctic Ice Shelf Mertz Glacier okhotsk sea Ross Ice Shelf Sea ice |
genre_facet |
Antarc* Antarctic Arctic Ice Shelf Mertz Glacier okhotsk sea Ross Ice Shelf Sea ice |
op_relation |
http://www.geoscienceletters.com/content/3/1/13 |
op_rights |
Copyright 2016 Ohshima et al. |
_version_ |
1766116624045178880 |