Using 226Ra and 228Ra isotopes to distinguish water mass distribution in the Canadian Arctic Archipelago
As a shelf-dominated basin, the Arctic Ocean and its biogeochemistry are heavily influenced by continental and riverine sources. Radium isotopes (226Ra, 228Ra, 224Ra, and 223Ra), are transferred from the sediments to seawater, making them ideal tracers of sediment–water exchange processes and ocean...
Published in: | Biogeosciences |
---|---|
Main Authors: | , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Copernicus Publications
2020
|
Subjects: | |
Online Access: | https://doi.org/10.5194/bg-17-4937-2020 https://noa.gwlb.de/receive/cop_mods_00054335 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00053986/bg-17-4937-2020.pdf https://bg.copernicus.org/articles/17/4937/2020/bg-17-4937-2020.pdf |
id |
ftnonlinearchiv:oai:noa.gwlb.de:cop_mods_00054335 |
---|---|
record_format |
openpolar |
spelling |
ftnonlinearchiv:oai:noa.gwlb.de:cop_mods_00054335 2023-05-15T14:28:44+02:00 Using 226Ra and 228Ra isotopes to distinguish water mass distribution in the Canadian Arctic Archipelago Mears, Chantal Thomas, Helmuth Henderson, Paul B. Charette, Matthew A. MacIntyre, Hugh Dehairs, Frank Monnin, Christophe Mucci, Alfonso 2020-10 electronic https://doi.org/10.5194/bg-17-4937-2020 https://noa.gwlb.de/receive/cop_mods_00054335 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00053986/bg-17-4937-2020.pdf https://bg.copernicus.org/articles/17/4937/2020/bg-17-4937-2020.pdf eng eng Copernicus Publications Biogeosciences -- http://www.bibliothek.uni-regensburg.de/ezeit/?2158181 -- http://www.copernicus.org/EGU/bg/bg.html -- 1726-4189 https://doi.org/10.5194/bg-17-4937-2020 https://noa.gwlb.de/receive/cop_mods_00054335 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00053986/bg-17-4937-2020.pdf https://bg.copernicus.org/articles/17/4937/2020/bg-17-4937-2020.pdf https://creativecommons.org/licenses/by/4.0/ uneingeschränkt info:eu-repo/semantics/openAccess CC-BY article Verlagsveröffentlichung article Text doc-type:article 2020 ftnonlinearchiv https://doi.org/10.5194/bg-17-4937-2020 2022-02-08T22:35:02Z As a shelf-dominated basin, the Arctic Ocean and its biogeochemistry are heavily influenced by continental and riverine sources. Radium isotopes (226Ra, 228Ra, 224Ra, and 223Ra), are transferred from the sediments to seawater, making them ideal tracers of sediment–water exchange processes and ocean mixing. As the two long-lived isotopes of the radium quartet, 226Ra and 228Ra (226Ra with a t1∕2 of 1600 years and 228Ra with a t1∕2 of 5.8 years) can provide insight into the water mass compositions, distribution patterns, as well as mixing processes and their associated timescales throughout the Canadian Arctic Archipelago (CAA). The wide range of 226Ra and 228Ra activities, as well as of the 228Ra∕226Ra, measured in water samples collected during the 2015 GEOTRACES cruise, complemented by additional chemical tracers – dissolved inorganic carbon (DIC), total alkalinity (AT), barium (Ba), and the stable oxygen isotope composition of water (δ18O) – highlight the dominant biogeochemical, hydrographic, and bathymetric features of the CAA. Bathymetric features, such as the continental shelf and shallow coastal sills, are critical in modulating circulation patterns within the CAA, including the bulk flow of Pacific waters and the inhibited eastward flow of denser Atlantic waters through the CAA. Using a principal component analysis, we unravel the dominant mechanisms and apparent water mass end-members that shape the tracer distributions. We identify two distinct water masses located above and below the upper halocline layer throughout the CAA and distinctly differentiate surface waters in the eastern and western CAA. Furthermore, we highlight water exchange across 80∘ W, inferring a draw of Atlantic water (originating from Baffin Bay) into the CAA. This underscores the presence of an Atlantic water “U-turn” located at Barrow Strait, where the same water mass is seen along the northernmost edge at 80∘ W as well as along the southeasternmost confines of Lancaster Sound. Overall, this study provides a stepping stone for future research initiatives within the Canadian Arctic Archipelago, revealing how quantifying disparities in the distributions of radioactive tracers can provide valuable information on water mass distributions, flow patterns, and mixing within vulnerable areas such as the CAA. Article in Journal/Newspaper Arctic Archipelago Arctic Arctic Ocean Baffin Bay Baffin Bay Baffin Canadian Arctic Archipelago Lancaster Sound Niedersächsisches Online-Archiv NOA Arctic Arctic Ocean Baffin Bay Barrow Strait ENVELOPE(-94.168,-94.168,74.402,74.402) Canadian Arctic Archipelago Lancaster Sound ENVELOPE(-83.999,-83.999,74.218,74.218) Pacific Biogeosciences 17 20 4937 4959 |
institution |
Open Polar |
collection |
Niedersächsisches Online-Archiv NOA |
op_collection_id |
ftnonlinearchiv |
language |
English |
topic |
article Verlagsveröffentlichung |
spellingShingle |
article Verlagsveröffentlichung Mears, Chantal Thomas, Helmuth Henderson, Paul B. Charette, Matthew A. MacIntyre, Hugh Dehairs, Frank Monnin, Christophe Mucci, Alfonso Using 226Ra and 228Ra isotopes to distinguish water mass distribution in the Canadian Arctic Archipelago |
topic_facet |
article Verlagsveröffentlichung |
description |
As a shelf-dominated basin, the Arctic Ocean and its biogeochemistry are heavily influenced by continental and riverine sources. Radium isotopes (226Ra, 228Ra, 224Ra, and 223Ra), are transferred from the sediments to seawater, making them ideal tracers of sediment–water exchange processes and ocean mixing. As the two long-lived isotopes of the radium quartet, 226Ra and 228Ra (226Ra with a t1∕2 of 1600 years and 228Ra with a t1∕2 of 5.8 years) can provide insight into the water mass compositions, distribution patterns, as well as mixing processes and their associated timescales throughout the Canadian Arctic Archipelago (CAA). The wide range of 226Ra and 228Ra activities, as well as of the 228Ra∕226Ra, measured in water samples collected during the 2015 GEOTRACES cruise, complemented by additional chemical tracers – dissolved inorganic carbon (DIC), total alkalinity (AT), barium (Ba), and the stable oxygen isotope composition of water (δ18O) – highlight the dominant biogeochemical, hydrographic, and bathymetric features of the CAA. Bathymetric features, such as the continental shelf and shallow coastal sills, are critical in modulating circulation patterns within the CAA, including the bulk flow of Pacific waters and the inhibited eastward flow of denser Atlantic waters through the CAA. Using a principal component analysis, we unravel the dominant mechanisms and apparent water mass end-members that shape the tracer distributions. We identify two distinct water masses located above and below the upper halocline layer throughout the CAA and distinctly differentiate surface waters in the eastern and western CAA. Furthermore, we highlight water exchange across 80∘ W, inferring a draw of Atlantic water (originating from Baffin Bay) into the CAA. This underscores the presence of an Atlantic water “U-turn” located at Barrow Strait, where the same water mass is seen along the northernmost edge at 80∘ W as well as along the southeasternmost confines of Lancaster Sound. Overall, this study provides a stepping stone for future research initiatives within the Canadian Arctic Archipelago, revealing how quantifying disparities in the distributions of radioactive tracers can provide valuable information on water mass distributions, flow patterns, and mixing within vulnerable areas such as the CAA. |
format |
Article in Journal/Newspaper |
author |
Mears, Chantal Thomas, Helmuth Henderson, Paul B. Charette, Matthew A. MacIntyre, Hugh Dehairs, Frank Monnin, Christophe Mucci, Alfonso |
author_facet |
Mears, Chantal Thomas, Helmuth Henderson, Paul B. Charette, Matthew A. MacIntyre, Hugh Dehairs, Frank Monnin, Christophe Mucci, Alfonso |
author_sort |
Mears, Chantal |
title |
Using 226Ra and 228Ra isotopes to distinguish water mass distribution in the Canadian Arctic Archipelago |
title_short |
Using 226Ra and 228Ra isotopes to distinguish water mass distribution in the Canadian Arctic Archipelago |
title_full |
Using 226Ra and 228Ra isotopes to distinguish water mass distribution in the Canadian Arctic Archipelago |
title_fullStr |
Using 226Ra and 228Ra isotopes to distinguish water mass distribution in the Canadian Arctic Archipelago |
title_full_unstemmed |
Using 226Ra and 228Ra isotopes to distinguish water mass distribution in the Canadian Arctic Archipelago |
title_sort |
using 226ra and 228ra isotopes to distinguish water mass distribution in the canadian arctic archipelago |
publisher |
Copernicus Publications |
publishDate |
2020 |
url |
https://doi.org/10.5194/bg-17-4937-2020 https://noa.gwlb.de/receive/cop_mods_00054335 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00053986/bg-17-4937-2020.pdf https://bg.copernicus.org/articles/17/4937/2020/bg-17-4937-2020.pdf |
long_lat |
ENVELOPE(-94.168,-94.168,74.402,74.402) ENVELOPE(-83.999,-83.999,74.218,74.218) |
geographic |
Arctic Arctic Ocean Baffin Bay Barrow Strait Canadian Arctic Archipelago Lancaster Sound Pacific |
geographic_facet |
Arctic Arctic Ocean Baffin Bay Barrow Strait Canadian Arctic Archipelago Lancaster Sound Pacific |
genre |
Arctic Archipelago Arctic Arctic Ocean Baffin Bay Baffin Bay Baffin Canadian Arctic Archipelago Lancaster Sound |
genre_facet |
Arctic Archipelago Arctic Arctic Ocean Baffin Bay Baffin Bay Baffin Canadian Arctic Archipelago Lancaster Sound |
op_relation |
Biogeosciences -- http://www.bibliothek.uni-regensburg.de/ezeit/?2158181 -- http://www.copernicus.org/EGU/bg/bg.html -- 1726-4189 https://doi.org/10.5194/bg-17-4937-2020 https://noa.gwlb.de/receive/cop_mods_00054335 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00053986/bg-17-4937-2020.pdf https://bg.copernicus.org/articles/17/4937/2020/bg-17-4937-2020.pdf |
op_rights |
https://creativecommons.org/licenses/by/4.0/ uneingeschränkt info:eu-repo/semantics/openAccess |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.5194/bg-17-4937-2020 |
container_title |
Biogeosciences |
container_volume |
17 |
container_issue |
20 |
container_start_page |
4937 |
op_container_end_page |
4959 |
_version_ |
1766302883600400384 |