Nutrient distributions associated with snow and sediment-laden layers in sea ice of the southern Sea of Okhotsk
Samples of first-year sea ice, snow and under-ice water were collected in the southern Sea of Okhotsk in mid-February 2007 and 2008 to elucidate the processes controlling nutrient concentrations in sea ice. Temperature, salinity, oxygen isotopic ratio (δ18O) and inorganic nutrient concentrations (NO...
Published in: | Marine Chemistry |
---|---|
Main Authors: | , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Elsevier B.V.
|
Subjects: | |
Online Access: | http://hdl.handle.net/2115/43117 https://doi.org/10.1016/j.marchem.2009.11.005 |
id |
fthokunivhus:oai:eprints.lib.hokudai.ac.jp:2115/43117 |
---|---|
record_format |
openpolar |
spelling |
fthokunivhus:oai:eprints.lib.hokudai.ac.jp:2115/43117 2023-05-15T18:16:48+02:00 Nutrient distributions associated with snow and sediment-laden layers in sea ice of the southern Sea of Okhotsk Nomura, Daiki Nishioka, Jun Granskog, Mats A. Krell, Andreas Matoba, Sumito Toyota, Takenobu Hattori, Hiroshi Shirasawa, Kunio http://hdl.handle.net/2115/43117 https://doi.org/10.1016/j.marchem.2009.11.005 eng eng Elsevier B.V. http://hdl.handle.net/2115/43117 Marine Chemistry, 119(1-4): 1-8 http://dx.doi.org/10.1016/j.marchem.2009.11.005 Sea ice Snow Nutrient Remineralization Sediment Sea of Okhotsk 452 article (author version) fthokunivhus https://doi.org/10.1016/j.marchem.2009.11.005 2022-11-18T01:01:59Z Samples of first-year sea ice, snow and under-ice water were collected in the southern Sea of Okhotsk in mid-February 2007 and 2008 to elucidate the processes controlling nutrient concentrations in sea ice. Temperature, salinity, oxygen isotopic ratio (δ18O) and inorganic nutrient concentrations (NO3, NH4, NO2, PO4 and SiO2) were measured. Sea ice was categorized into four types; snow-ice, frazil ice, columnar ice and a mixture of granular and columnar ice, based on δ18O composition and ice texture. Frazil ice dominated the total ice thickness (52.8%), and columnar ice was sandwiched between frazil ice layers, indicating dynamic ice-growth processes such as rafting and ridging. Furthermore, the ice was banded by layers of particulate materials (sediment layers), which were frequently encountered during cruises. High NO3 and NH4 concentrations were found in snow and snow-ice implying that these were supplied from the atmosphere with snowfall and incorporated into the sea ice through snow-ice formation. In the sediment-laden layers, which were categorized as frazil ice, NO2, PO4 and SiO2 concentrations were highest of all the ice types and considerably enriched compared to parent seawater, suggesting the remineralization of the particulate organic matter. On the other hand, NO3 concentrations in sediment layers were low (depleted), leading to extremely low N (NO3 + NH4 + NO2): P ratios in sediment layers, from 0.2 to 0.8, with respect to that of under-ice water or Redfield ratio. These results suggest that in part of sediment-laden layers fixed-nitrogen was removed partially as molecular nitrogen (N2) from the sea ice environment by anaerobic nitrate reduction processes (denitrification) by denitrifying bacteria while adding phosphate from associated remineralization of organic phosphorus. The effect of melting of snow and sea ice is dilution for salinity, NO3 and SiO2, no change in NO2 and PO4, and a minor enrichment for NH4 in the mixed layer in spring and early summer. This suggests that snow/ice meltwater with ... Article in Journal/Newspaper Sea ice Hokkaido University Collection of Scholarly and Academic Papers (HUSCAP) Okhotsk Marine Chemistry 119 1-4 1 8 |
institution |
Open Polar |
collection |
Hokkaido University Collection of Scholarly and Academic Papers (HUSCAP) |
op_collection_id |
fthokunivhus |
language |
English |
topic |
Sea ice Snow Nutrient Remineralization Sediment Sea of Okhotsk 452 |
spellingShingle |
Sea ice Snow Nutrient Remineralization Sediment Sea of Okhotsk 452 Nomura, Daiki Nishioka, Jun Granskog, Mats A. Krell, Andreas Matoba, Sumito Toyota, Takenobu Hattori, Hiroshi Shirasawa, Kunio Nutrient distributions associated with snow and sediment-laden layers in sea ice of the southern Sea of Okhotsk |
topic_facet |
Sea ice Snow Nutrient Remineralization Sediment Sea of Okhotsk 452 |
description |
Samples of first-year sea ice, snow and under-ice water were collected in the southern Sea of Okhotsk in mid-February 2007 and 2008 to elucidate the processes controlling nutrient concentrations in sea ice. Temperature, salinity, oxygen isotopic ratio (δ18O) and inorganic nutrient concentrations (NO3, NH4, NO2, PO4 and SiO2) were measured. Sea ice was categorized into four types; snow-ice, frazil ice, columnar ice and a mixture of granular and columnar ice, based on δ18O composition and ice texture. Frazil ice dominated the total ice thickness (52.8%), and columnar ice was sandwiched between frazil ice layers, indicating dynamic ice-growth processes such as rafting and ridging. Furthermore, the ice was banded by layers of particulate materials (sediment layers), which were frequently encountered during cruises. High NO3 and NH4 concentrations were found in snow and snow-ice implying that these were supplied from the atmosphere with snowfall and incorporated into the sea ice through snow-ice formation. In the sediment-laden layers, which were categorized as frazil ice, NO2, PO4 and SiO2 concentrations were highest of all the ice types and considerably enriched compared to parent seawater, suggesting the remineralization of the particulate organic matter. On the other hand, NO3 concentrations in sediment layers were low (depleted), leading to extremely low N (NO3 + NH4 + NO2): P ratios in sediment layers, from 0.2 to 0.8, with respect to that of under-ice water or Redfield ratio. These results suggest that in part of sediment-laden layers fixed-nitrogen was removed partially as molecular nitrogen (N2) from the sea ice environment by anaerobic nitrate reduction processes (denitrification) by denitrifying bacteria while adding phosphate from associated remineralization of organic phosphorus. The effect of melting of snow and sea ice is dilution for salinity, NO3 and SiO2, no change in NO2 and PO4, and a minor enrichment for NH4 in the mixed layer in spring and early summer. This suggests that snow/ice meltwater with ... |
format |
Article in Journal/Newspaper |
author |
Nomura, Daiki Nishioka, Jun Granskog, Mats A. Krell, Andreas Matoba, Sumito Toyota, Takenobu Hattori, Hiroshi Shirasawa, Kunio |
author_facet |
Nomura, Daiki Nishioka, Jun Granskog, Mats A. Krell, Andreas Matoba, Sumito Toyota, Takenobu Hattori, Hiroshi Shirasawa, Kunio |
author_sort |
Nomura, Daiki |
title |
Nutrient distributions associated with snow and sediment-laden layers in sea ice of the southern Sea of Okhotsk |
title_short |
Nutrient distributions associated with snow and sediment-laden layers in sea ice of the southern Sea of Okhotsk |
title_full |
Nutrient distributions associated with snow and sediment-laden layers in sea ice of the southern Sea of Okhotsk |
title_fullStr |
Nutrient distributions associated with snow and sediment-laden layers in sea ice of the southern Sea of Okhotsk |
title_full_unstemmed |
Nutrient distributions associated with snow and sediment-laden layers in sea ice of the southern Sea of Okhotsk |
title_sort |
nutrient distributions associated with snow and sediment-laden layers in sea ice of the southern sea of okhotsk |
publisher |
Elsevier B.V. |
url |
http://hdl.handle.net/2115/43117 https://doi.org/10.1016/j.marchem.2009.11.005 |
geographic |
Okhotsk |
geographic_facet |
Okhotsk |
genre |
Sea ice |
genre_facet |
Sea ice |
op_relation |
http://hdl.handle.net/2115/43117 Marine Chemistry, 119(1-4): 1-8 http://dx.doi.org/10.1016/j.marchem.2009.11.005 |
op_doi |
https://doi.org/10.1016/j.marchem.2009.11.005 |
container_title |
Marine Chemistry |
container_volume |
119 |
container_issue |
1-4 |
container_start_page |
1 |
op_container_end_page |
8 |
_version_ |
1766190688786972672 |