Favorable Conditions for Suspension Freezing in an Arctic Coastal Polynya
Arctic sea ice incorporates and transports sediment, releasing it back into the water column during the melting season. This process constitutes an important aspect of marine sediment transport and biogeochemical cycling. Sediment incorporation into sea ice is considered to occur mainly through unde...
Published in: | Journal of Geophysical Research: Oceans |
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Online Access: | http://hdl.handle.net/2115/78371 https://doi.org/10.1029/2019JC015536 |
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fthokunivhus:oai:eprints.lib.hokudai.ac.jp:2115/78371 2023-05-15T14:56:46+02:00 Favorable Conditions for Suspension Freezing in an Arctic Coastal Polynya Ito, Masato Ohshima, Kay I Fukamachi, Yasushi Hirano, Daisuke Mahoney, Andrew R. Jones, Joshua Takatsuka, Toru Eicken, Hajo http://hdl.handle.net/2115/78371 https://doi.org/10.1029/2019JC015536 eng eng American Geophysical Union http://hdl.handle.net/2115/78371 Journal of Geophysical Research Oceans, 124(12): 8701-8719 http://dx.doi.org/10.1029/2019JC015536 Copyright 2019 American Geophysical Union. https://creativecommons.org/licenses/by/4.0/ CC-BY frazil ice resuspended sediment suspension freezing coastal polynya Arctic Ocean 450 article fthokunivhus https://doi.org/10.1029/2019JC015536 2022-11-18T01:05:43Z Arctic sea ice incorporates and transports sediment, releasing it back into the water column during the melting season. This process constitutes an important aspect of marine sediment transport and biogeochemical cycling. Sediment incorporation into sea ice is considered to occur mainly through underwater interaction between frazil ice and resuspended sediment, referred to as suspension freezing. However, harsh environmental conditions have greatly limited field observations of this phenomenon. Analysis of mooring data from a coastal polynya in the northeastern Chukchi Sea, in conjunction with coastal ice radar and meteorological data, indicates that suspension freezing is a key mechanism for sediment entrainment into sea ice. During polynya episodes, acoustic backscatter data obtained by an Acoustic Doppler Current Profiler showed the presence of frazil ice from the surface down to 20- to 25-m depth, coinciding with in situ and potential supercooling. Underwater frazil ice persisted over 1 week under windy, turbulent water column conditions. A combination of the turbidity and Acoustic Doppler Current Profiler backscatter data revealed upward sediment dispersion associated with strong currents during the polynya episodes. The fact that frazil ice and resuspended sediment were detected at the same depth and time strongly suggests the interaction between ice crystals and sediment particles, that is, suspension freezing. Plain Language Summary Sea ice incorporates, transports, and releases particulate matter. These processes constitute an important aspect of the biology, biogeochemical cycling, and pollutant transport in polar oceans. Seafloor sediments serve as the most important source of such particulate matter; however, the process of sediment incorporation into sea ice remains poorly explored. We conducted a year-long study of sediment resuspension and entrainment processes, using underwater sensors deployed in the Chukchi Sea. During winter, wind-driven offshore transport of sea ice created area of open water ... Article in Journal/Newspaper Arctic Arctic Ocean Chukchi Chukchi Sea Sea ice Hokkaido University Collection of Scholarly and Academic Papers (HUSCAP) Arctic Arctic Ocean Chukchi Sea Journal of Geophysical Research: Oceans 124 12 8701 8719 |
institution |
Open Polar |
collection |
Hokkaido University Collection of Scholarly and Academic Papers (HUSCAP) |
op_collection_id |
fthokunivhus |
language |
English |
topic |
frazil ice resuspended sediment suspension freezing coastal polynya Arctic Ocean 450 |
spellingShingle |
frazil ice resuspended sediment suspension freezing coastal polynya Arctic Ocean 450 Ito, Masato Ohshima, Kay I Fukamachi, Yasushi Hirano, Daisuke Mahoney, Andrew R. Jones, Joshua Takatsuka, Toru Eicken, Hajo Favorable Conditions for Suspension Freezing in an Arctic Coastal Polynya |
topic_facet |
frazil ice resuspended sediment suspension freezing coastal polynya Arctic Ocean 450 |
description |
Arctic sea ice incorporates and transports sediment, releasing it back into the water column during the melting season. This process constitutes an important aspect of marine sediment transport and biogeochemical cycling. Sediment incorporation into sea ice is considered to occur mainly through underwater interaction between frazil ice and resuspended sediment, referred to as suspension freezing. However, harsh environmental conditions have greatly limited field observations of this phenomenon. Analysis of mooring data from a coastal polynya in the northeastern Chukchi Sea, in conjunction with coastal ice radar and meteorological data, indicates that suspension freezing is a key mechanism for sediment entrainment into sea ice. During polynya episodes, acoustic backscatter data obtained by an Acoustic Doppler Current Profiler showed the presence of frazil ice from the surface down to 20- to 25-m depth, coinciding with in situ and potential supercooling. Underwater frazil ice persisted over 1 week under windy, turbulent water column conditions. A combination of the turbidity and Acoustic Doppler Current Profiler backscatter data revealed upward sediment dispersion associated with strong currents during the polynya episodes. The fact that frazil ice and resuspended sediment were detected at the same depth and time strongly suggests the interaction between ice crystals and sediment particles, that is, suspension freezing. Plain Language Summary Sea ice incorporates, transports, and releases particulate matter. These processes constitute an important aspect of the biology, biogeochemical cycling, and pollutant transport in polar oceans. Seafloor sediments serve as the most important source of such particulate matter; however, the process of sediment incorporation into sea ice remains poorly explored. We conducted a year-long study of sediment resuspension and entrainment processes, using underwater sensors deployed in the Chukchi Sea. During winter, wind-driven offshore transport of sea ice created area of open water ... |
format |
Article in Journal/Newspaper |
author |
Ito, Masato Ohshima, Kay I Fukamachi, Yasushi Hirano, Daisuke Mahoney, Andrew R. Jones, Joshua Takatsuka, Toru Eicken, Hajo |
author_facet |
Ito, Masato Ohshima, Kay I Fukamachi, Yasushi Hirano, Daisuke Mahoney, Andrew R. Jones, Joshua Takatsuka, Toru Eicken, Hajo |
author_sort |
Ito, Masato |
title |
Favorable Conditions for Suspension Freezing in an Arctic Coastal Polynya |
title_short |
Favorable Conditions for Suspension Freezing in an Arctic Coastal Polynya |
title_full |
Favorable Conditions for Suspension Freezing in an Arctic Coastal Polynya |
title_fullStr |
Favorable Conditions for Suspension Freezing in an Arctic Coastal Polynya |
title_full_unstemmed |
Favorable Conditions for Suspension Freezing in an Arctic Coastal Polynya |
title_sort |
favorable conditions for suspension freezing in an arctic coastal polynya |
publisher |
American Geophysical Union |
url |
http://hdl.handle.net/2115/78371 https://doi.org/10.1029/2019JC015536 |
geographic |
Arctic Arctic Ocean Chukchi Sea |
geographic_facet |
Arctic Arctic Ocean Chukchi Sea |
genre |
Arctic Arctic Ocean Chukchi Chukchi Sea Sea ice |
genre_facet |
Arctic Arctic Ocean Chukchi Chukchi Sea Sea ice |
op_relation |
http://hdl.handle.net/2115/78371 Journal of Geophysical Research Oceans, 124(12): 8701-8719 http://dx.doi.org/10.1029/2019JC015536 |
op_rights |
Copyright 2019 American Geophysical Union. https://creativecommons.org/licenses/by/4.0/ |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1029/2019JC015536 |
container_title |
Journal of Geophysical Research: Oceans |
container_volume |
124 |
container_issue |
12 |
container_start_page |
8701 |
op_container_end_page |
8719 |
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1766328849548705792 |