Using Radiocarbon Measurements of Dissolved Inorganic Carbon to Determine a Revised Residence Time for Deep Baffin Bay
The Canadian Arctic is warming at three times the rate of the rest of the planet and the effects of climate change on the Arctic marine carbon cycle remains unconstrained. Baffin Bay is a semi-enclosed, Arctic basin that connects the Arctic Ocean to the north to the Labrador Sea to the south. While...
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2022
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Online Access: | https://doi.org/10.3389/fmars.2022.845536 https://doaj.org/article/ad5c99a5be6846e5be717ca1bc18475e |
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ftdoajarticles:oai:doaj.org/article:ad5c99a5be6846e5be717ca1bc18475e 2023-05-15T14:29:17+02:00 Using Radiocarbon Measurements of Dissolved Inorganic Carbon to Determine a Revised Residence Time for Deep Baffin Bay Sara Zeidan Jennifer Walker Brent G. T. Else Lisa A. Miller Kumiko Azetsu-Scott Brett D. Walker 2022-04-01T00:00:00Z https://doi.org/10.3389/fmars.2022.845536 https://doaj.org/article/ad5c99a5be6846e5be717ca1bc18475e EN eng Frontiers Media S.A. https://www.frontiersin.org/articles/10.3389/fmars.2022.845536/full https://doaj.org/toc/2296-7745 2296-7745 doi:10.3389/fmars.2022.845536 https://doaj.org/article/ad5c99a5be6846e5be717ca1bc18475e Frontiers in Marine Science, Vol 9 (2022) dissolved inorganic carbon DIC 13C 14C anthropogenic bomb Science Q General. Including nature conservation geographical distribution QH1-199.5 article 2022 ftdoajarticles https://doi.org/10.3389/fmars.2022.845536 2022-12-30T22:20:09Z The Canadian Arctic is warming at three times the rate of the rest of the planet and the effects of climate change on the Arctic marine carbon cycle remains unconstrained. Baffin Bay is a semi-enclosed, Arctic basin that connects the Arctic Ocean to the north to the Labrador Sea to the south. While the physical oceanography of surface Baffin Bay is well characterized, less is known about deep water formation mechanisms within the Basin. Only a few residence-time estimates for Baffin Bay Deep Water (BBDW) exist and range from 20 to 1450 years. Better residence time estimates are needed to understand the oceanographic significance of Baffin Bay. Here we report stable carbon (δ13C) and radiocarbon (Δ14C) values of dissolved inorganic carbon (DIC) collected aboard the CCGS Amundsen in 2019. DIC δ13C and Δ14C values between ranged between -0.7‰ to +1.9‰ and -90.0‰ to +29.8‰, respectively. Surface DIC δ13C values were between +0.7‰ to +1.9‰, while deep (>100m) values were 0.0 to -0.7‰. Surface DIC Δ14C values ranged between -5.4‰ to +22.9‰, while deep DIC (>1400m) DIC Δ14C averaged -82.2 ± 8.5‰ (n = 9). To constrain natural DIC Δ14C values, we quantified the amount of atmospheric “bomb” 14C in DIC (Δ14Cbomb; using the potential alkalinity method; Palk) and anthropogenic DIC (DICanth; using the ΔC* method). Both proxies indicate an absence of Δ14Cbomb and DICanth below 1000m. Using two previously proposed deep water formation mechanisms and our corrected DIC Δ14Cnatural values, we estimated a 14C-based residence time of 360-690 years for BBDW. Based on these residence times, we infer carbon is likely stored for centuries in deep Baffin Bay. Article in Journal/Newspaper Arctic Basin Arctic Arctic Ocean Baffin Bay Baffin Bay Baffin Climate change Labrador Sea Directory of Open Access Journals: DOAJ Articles Arctic Arctic Ocean Baffin Bay Frontiers in Marine Science 9 |
institution |
Open Polar |
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Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
dissolved inorganic carbon DIC 13C 14C anthropogenic bomb Science Q General. Including nature conservation geographical distribution QH1-199.5 |
spellingShingle |
dissolved inorganic carbon DIC 13C 14C anthropogenic bomb Science Q General. Including nature conservation geographical distribution QH1-199.5 Sara Zeidan Jennifer Walker Brent G. T. Else Lisa A. Miller Kumiko Azetsu-Scott Brett D. Walker Using Radiocarbon Measurements of Dissolved Inorganic Carbon to Determine a Revised Residence Time for Deep Baffin Bay |
topic_facet |
dissolved inorganic carbon DIC 13C 14C anthropogenic bomb Science Q General. Including nature conservation geographical distribution QH1-199.5 |
description |
The Canadian Arctic is warming at three times the rate of the rest of the planet and the effects of climate change on the Arctic marine carbon cycle remains unconstrained. Baffin Bay is a semi-enclosed, Arctic basin that connects the Arctic Ocean to the north to the Labrador Sea to the south. While the physical oceanography of surface Baffin Bay is well characterized, less is known about deep water formation mechanisms within the Basin. Only a few residence-time estimates for Baffin Bay Deep Water (BBDW) exist and range from 20 to 1450 years. Better residence time estimates are needed to understand the oceanographic significance of Baffin Bay. Here we report stable carbon (δ13C) and radiocarbon (Δ14C) values of dissolved inorganic carbon (DIC) collected aboard the CCGS Amundsen in 2019. DIC δ13C and Δ14C values between ranged between -0.7‰ to +1.9‰ and -90.0‰ to +29.8‰, respectively. Surface DIC δ13C values were between +0.7‰ to +1.9‰, while deep (>100m) values were 0.0 to -0.7‰. Surface DIC Δ14C values ranged between -5.4‰ to +22.9‰, while deep DIC (>1400m) DIC Δ14C averaged -82.2 ± 8.5‰ (n = 9). To constrain natural DIC Δ14C values, we quantified the amount of atmospheric “bomb” 14C in DIC (Δ14Cbomb; using the potential alkalinity method; Palk) and anthropogenic DIC (DICanth; using the ΔC* method). Both proxies indicate an absence of Δ14Cbomb and DICanth below 1000m. Using two previously proposed deep water formation mechanisms and our corrected DIC Δ14Cnatural values, we estimated a 14C-based residence time of 360-690 years for BBDW. Based on these residence times, we infer carbon is likely stored for centuries in deep Baffin Bay. |
format |
Article in Journal/Newspaper |
author |
Sara Zeidan Jennifer Walker Brent G. T. Else Lisa A. Miller Kumiko Azetsu-Scott Brett D. Walker |
author_facet |
Sara Zeidan Jennifer Walker Brent G. T. Else Lisa A. Miller Kumiko Azetsu-Scott Brett D. Walker |
author_sort |
Sara Zeidan |
title |
Using Radiocarbon Measurements of Dissolved Inorganic Carbon to Determine a Revised Residence Time for Deep Baffin Bay |
title_short |
Using Radiocarbon Measurements of Dissolved Inorganic Carbon to Determine a Revised Residence Time for Deep Baffin Bay |
title_full |
Using Radiocarbon Measurements of Dissolved Inorganic Carbon to Determine a Revised Residence Time for Deep Baffin Bay |
title_fullStr |
Using Radiocarbon Measurements of Dissolved Inorganic Carbon to Determine a Revised Residence Time for Deep Baffin Bay |
title_full_unstemmed |
Using Radiocarbon Measurements of Dissolved Inorganic Carbon to Determine a Revised Residence Time for Deep Baffin Bay |
title_sort |
using radiocarbon measurements of dissolved inorganic carbon to determine a revised residence time for deep baffin bay |
publisher |
Frontiers Media S.A. |
publishDate |
2022 |
url |
https://doi.org/10.3389/fmars.2022.845536 https://doaj.org/article/ad5c99a5be6846e5be717ca1bc18475e |
geographic |
Arctic Arctic Ocean Baffin Bay |
geographic_facet |
Arctic Arctic Ocean Baffin Bay |
genre |
Arctic Basin Arctic Arctic Ocean Baffin Bay Baffin Bay Baffin Climate change Labrador Sea |
genre_facet |
Arctic Basin Arctic Arctic Ocean Baffin Bay Baffin Bay Baffin Climate change Labrador Sea |
op_source |
Frontiers in Marine Science, Vol 9 (2022) |
op_relation |
https://www.frontiersin.org/articles/10.3389/fmars.2022.845536/full https://doaj.org/toc/2296-7745 2296-7745 doi:10.3389/fmars.2022.845536 https://doaj.org/article/ad5c99a5be6846e5be717ca1bc18475e |
op_doi |
https://doi.org/10.3389/fmars.2022.845536 |
container_title |
Frontiers in Marine Science |
container_volume |
9 |
_version_ |
1766303334837256192 |