The Effect of Basal Melting of the Shirase Glacier Tongue on the CO2 System in Lutzow-Holm Bay, East Antarctica
To clarify the effect of basal melting of ice tongues/ice shelf on the CO2 system in the Antarctic continental margin, seawater samples were collected for analysis of dissolved inorganic carbon (DIC), total alkalinity (TA), nutrients, chlorophyll a (chl.a), and oxygen isotopic ratios at the ice fron...
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Online Access: | http://hdl.handle.net/2115/83115 https://doi.org/10.1029/2020JG005762 |
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fthokunivhus:oai:eprints.lib.hokudai.ac.jp:2115/83115 2023-05-15T13:51:33+02:00 The Effect of Basal Melting of the Shirase Glacier Tongue on the CO2 System in Lutzow-Holm Bay, East Antarctica Kiuchi, Masaaki Nomura, Daiki Hirano, Daisuke Tamura, Takeshi Hashida, Gen Ushio, Shuki Simizu, Daisuke Ono, Kazuya Aoki, Shigeru http://hdl.handle.net/2115/83115 https://doi.org/10.1029/2020JG005762 eng eng American Geophysical Union http://hdl.handle.net/2115/83115 Journal of geophysical research biogeosciences, 126(5): e2020JG005762 http://dx.doi.org/10.1029/2020JG005762 Antarctica biogeochemistry CO2 ocean sea ice Southern Ocean 452 article fthokunivhus https://doi.org/10.1029/2020JG005762 2022-11-18T01:06:31Z To clarify the effect of basal melting of ice tongues/ice shelf on the CO2 system in the Antarctic continental margin, seawater samples were collected for analysis of dissolved inorganic carbon (DIC), total alkalinity (TA), nutrients, chlorophyll a (chl.a), and oxygen isotopic ratios at the ice front of the Shirase Glacier Tongue (SGT) in Lutzow-Holm Bay (LHB), East Antarctica during the summers of 2017 and 2018. At depths greater than similar to 20 dbar in LHB, CO2 system parameters were strongly influenced by the dilution effect of SGT basal melting and the inflow of modified Circumpolar Deep Water (mCDW). The distributions of DIC and TA agreed well with an offshore origin of mCDW that flowed beneath the SGT and mixing of basal meltwater and mCDW beneath the SGT. The fraction of SGT meltwater was highest at the station near the ice front. Dilution by SGT basal meltwater reduced the partial pressure of CO2 in the mCDW from 431 to 387 mu atm. The water then became a sink rather than source of atmospheric CO2. In the sea surface, DIC and TA were strongly influenced by biological processes. Salinity-normalized DIC decreased with the increase of salinity-normalized TA in accord with 106:16 C:N molar stoichiometry; the chl.a concentration at the sea surface was as high as 31 mu g L-1. Article in Journal/Newspaper Antarc* Antarctic Antarctica East Antarctica Ice Shelf Sea ice Shirase Glacier Southern Ocean Hokkaido University Collection of Scholarly and Academic Papers (HUSCAP) Antarctic East Antarctica Shirase Glacier ENVELOPE(39.000,39.000,-70.333,-70.333) Southern Ocean The Antarctic Journal of Geophysical Research: Biogeosciences 126 5 |
institution |
Open Polar |
collection |
Hokkaido University Collection of Scholarly and Academic Papers (HUSCAP) |
op_collection_id |
fthokunivhus |
language |
English |
topic |
Antarctica biogeochemistry CO2 ocean sea ice Southern Ocean 452 |
spellingShingle |
Antarctica biogeochemistry CO2 ocean sea ice Southern Ocean 452 Kiuchi, Masaaki Nomura, Daiki Hirano, Daisuke Tamura, Takeshi Hashida, Gen Ushio, Shuki Simizu, Daisuke Ono, Kazuya Aoki, Shigeru The Effect of Basal Melting of the Shirase Glacier Tongue on the CO2 System in Lutzow-Holm Bay, East Antarctica |
topic_facet |
Antarctica biogeochemistry CO2 ocean sea ice Southern Ocean 452 |
description |
To clarify the effect of basal melting of ice tongues/ice shelf on the CO2 system in the Antarctic continental margin, seawater samples were collected for analysis of dissolved inorganic carbon (DIC), total alkalinity (TA), nutrients, chlorophyll a (chl.a), and oxygen isotopic ratios at the ice front of the Shirase Glacier Tongue (SGT) in Lutzow-Holm Bay (LHB), East Antarctica during the summers of 2017 and 2018. At depths greater than similar to 20 dbar in LHB, CO2 system parameters were strongly influenced by the dilution effect of SGT basal melting and the inflow of modified Circumpolar Deep Water (mCDW). The distributions of DIC and TA agreed well with an offshore origin of mCDW that flowed beneath the SGT and mixing of basal meltwater and mCDW beneath the SGT. The fraction of SGT meltwater was highest at the station near the ice front. Dilution by SGT basal meltwater reduced the partial pressure of CO2 in the mCDW from 431 to 387 mu atm. The water then became a sink rather than source of atmospheric CO2. In the sea surface, DIC and TA were strongly influenced by biological processes. Salinity-normalized DIC decreased with the increase of salinity-normalized TA in accord with 106:16 C:N molar stoichiometry; the chl.a concentration at the sea surface was as high as 31 mu g L-1. |
format |
Article in Journal/Newspaper |
author |
Kiuchi, Masaaki Nomura, Daiki Hirano, Daisuke Tamura, Takeshi Hashida, Gen Ushio, Shuki Simizu, Daisuke Ono, Kazuya Aoki, Shigeru |
author_facet |
Kiuchi, Masaaki Nomura, Daiki Hirano, Daisuke Tamura, Takeshi Hashida, Gen Ushio, Shuki Simizu, Daisuke Ono, Kazuya Aoki, Shigeru |
author_sort |
Kiuchi, Masaaki |
title |
The Effect of Basal Melting of the Shirase Glacier Tongue on the CO2 System in Lutzow-Holm Bay, East Antarctica |
title_short |
The Effect of Basal Melting of the Shirase Glacier Tongue on the CO2 System in Lutzow-Holm Bay, East Antarctica |
title_full |
The Effect of Basal Melting of the Shirase Glacier Tongue on the CO2 System in Lutzow-Holm Bay, East Antarctica |
title_fullStr |
The Effect of Basal Melting of the Shirase Glacier Tongue on the CO2 System in Lutzow-Holm Bay, East Antarctica |
title_full_unstemmed |
The Effect of Basal Melting of the Shirase Glacier Tongue on the CO2 System in Lutzow-Holm Bay, East Antarctica |
title_sort |
effect of basal melting of the shirase glacier tongue on the co2 system in lutzow-holm bay, east antarctica |
publisher |
American Geophysical Union |
url |
http://hdl.handle.net/2115/83115 https://doi.org/10.1029/2020JG005762 |
long_lat |
ENVELOPE(39.000,39.000,-70.333,-70.333) |
geographic |
Antarctic East Antarctica Shirase Glacier Southern Ocean The Antarctic |
geographic_facet |
Antarctic East Antarctica Shirase Glacier Southern Ocean The Antarctic |
genre |
Antarc* Antarctic Antarctica East Antarctica Ice Shelf Sea ice Shirase Glacier Southern Ocean |
genre_facet |
Antarc* Antarctic Antarctica East Antarctica Ice Shelf Sea ice Shirase Glacier Southern Ocean |
op_relation |
http://hdl.handle.net/2115/83115 Journal of geophysical research biogeosciences, 126(5): e2020JG005762 http://dx.doi.org/10.1029/2020JG005762 |
op_doi |
https://doi.org/10.1029/2020JG005762 |
container_title |
Journal of Geophysical Research: Biogeosciences |
container_volume |
126 |
container_issue |
5 |
_version_ |
1766255458639675392 |