Widespread surface water p CO2 undersaturation during ice-melt season in an Arctic continental shelf sea (Hudson Bay, Canada)
Estimating sea–air CO2 fluxes in coastal seas remains a source of uncertainty in global carbon budgets because processes like primary production, upwelling, water mixing, and freshwater inputs produce high spatial and temporal variability of CO2 partial pressure (pCO2). As a result, improving our pC...
Published in: | Elementa: Science of the Anthropocene |
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University of California Press
2021
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Online Access: | http://dx.doi.org/10.1525/elementa.2020.00130 http://online.ucpress.edu/elementa/article-pdf/doi/10.1525/elementa.2020.00130/463851/elementa.2020.00130.pdf |
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crunicaliforniap:10.1525/elementa.2020.00130 2023-11-12T04:11:25+01:00 Widespread surface water p CO2 undersaturation during ice-melt season in an Arctic continental shelf sea (Hudson Bay, Canada) Ahmed, Mohamed M. M. Else, Brent G. T. Butterworth, Brian Capelle, David W. Guéguen, Céline Miller, Lisa A. Meilleur, Claudie Papakyriakou, Tim 2021 http://dx.doi.org/10.1525/elementa.2020.00130 http://online.ucpress.edu/elementa/article-pdf/doi/10.1525/elementa.2020.00130/463851/elementa.2020.00130.pdf en eng University of California Press http://creativecommons.org/licenses/by/4.0/ Elementa: Science of the Anthropocene volume 9, issue 1 ISSN 2325-1026 Atmospheric Science Geology Geotechnical Engineering and Engineering Geology Ecology Environmental Engineering Oceanography journal-article 2021 crunicaliforniap https://doi.org/10.1525/elementa.2020.00130 2023-10-15T17:43:58Z Estimating sea–air CO2 fluxes in coastal seas remains a source of uncertainty in global carbon budgets because processes like primary production, upwelling, water mixing, and freshwater inputs produce high spatial and temporal variability of CO2 partial pressure (pCO2). As a result, improving our pCO2 baseline observations in these regions is important, especially in sub-Arctic and Arctic seas that are experiencing strong impacts of climate change. Here, we show the patterns and main processes controlling seawater pCO2 and sea–air CO2 fluxes in Hudson Bay during the 2018 spring and early summer seasons. We observed spatially limited pCO2 supersaturation (relative to the atmosphere) near river mouths and beneath sea ice and widespread undersaturated pCO2 in offshore and ice-melt-influenced waters. pCO2 was highly correlated with salinity and temperature, with a limited but statistically significant relationship with chlorophyll a and fluorescent dissolved organic matter. Hudson Bay on average was undersaturated with respect to atmospheric CO2, which we attribute mainly to the dominance of sea-ice meltwater. We calculated an average net CO2 flux of about –5mmol CO2 m–2 day–1 (–3.3 Tg C) during the spring and early summer seasons (92 days). Combining this result with extrapolated estimates for late summer and fall seasons, we estimate the annual CO2 flux of Hudson Bay during the open water season (184 days) to be –7.2 Tg C. Our findings indicate that the bay on average is a weaker CO2 sink than most other Arctic seas, emphasizing the importance of properly accounting for seasonal variability in the Arctic coastal shelves to obtain reliable sea–air CO2 exchange budgets. Article in Journal/Newspaper Arctic Climate change Hudson Bay Sea ice University of California Press (via Crossref) Arctic Canada Hudson Hudson Bay Elementa: Science of the Anthropocene 9 1 |
institution |
Open Polar |
collection |
University of California Press (via Crossref) |
op_collection_id |
crunicaliforniap |
language |
English |
topic |
Atmospheric Science Geology Geotechnical Engineering and Engineering Geology Ecology Environmental Engineering Oceanography |
spellingShingle |
Atmospheric Science Geology Geotechnical Engineering and Engineering Geology Ecology Environmental Engineering Oceanography Ahmed, Mohamed M. M. Else, Brent G. T. Butterworth, Brian Capelle, David W. Guéguen, Céline Miller, Lisa A. Meilleur, Claudie Papakyriakou, Tim Widespread surface water p CO2 undersaturation during ice-melt season in an Arctic continental shelf sea (Hudson Bay, Canada) |
topic_facet |
Atmospheric Science Geology Geotechnical Engineering and Engineering Geology Ecology Environmental Engineering Oceanography |
description |
Estimating sea–air CO2 fluxes in coastal seas remains a source of uncertainty in global carbon budgets because processes like primary production, upwelling, water mixing, and freshwater inputs produce high spatial and temporal variability of CO2 partial pressure (pCO2). As a result, improving our pCO2 baseline observations in these regions is important, especially in sub-Arctic and Arctic seas that are experiencing strong impacts of climate change. Here, we show the patterns and main processes controlling seawater pCO2 and sea–air CO2 fluxes in Hudson Bay during the 2018 spring and early summer seasons. We observed spatially limited pCO2 supersaturation (relative to the atmosphere) near river mouths and beneath sea ice and widespread undersaturated pCO2 in offshore and ice-melt-influenced waters. pCO2 was highly correlated with salinity and temperature, with a limited but statistically significant relationship with chlorophyll a and fluorescent dissolved organic matter. Hudson Bay on average was undersaturated with respect to atmospheric CO2, which we attribute mainly to the dominance of sea-ice meltwater. We calculated an average net CO2 flux of about –5mmol CO2 m–2 day–1 (–3.3 Tg C) during the spring and early summer seasons (92 days). Combining this result with extrapolated estimates for late summer and fall seasons, we estimate the annual CO2 flux of Hudson Bay during the open water season (184 days) to be –7.2 Tg C. Our findings indicate that the bay on average is a weaker CO2 sink than most other Arctic seas, emphasizing the importance of properly accounting for seasonal variability in the Arctic coastal shelves to obtain reliable sea–air CO2 exchange budgets. |
format |
Article in Journal/Newspaper |
author |
Ahmed, Mohamed M. M. Else, Brent G. T. Butterworth, Brian Capelle, David W. Guéguen, Céline Miller, Lisa A. Meilleur, Claudie Papakyriakou, Tim |
author_facet |
Ahmed, Mohamed M. M. Else, Brent G. T. Butterworth, Brian Capelle, David W. Guéguen, Céline Miller, Lisa A. Meilleur, Claudie Papakyriakou, Tim |
author_sort |
Ahmed, Mohamed M. M. |
title |
Widespread surface water p CO2 undersaturation during ice-melt season in an Arctic continental shelf sea (Hudson Bay, Canada) |
title_short |
Widespread surface water p CO2 undersaturation during ice-melt season in an Arctic continental shelf sea (Hudson Bay, Canada) |
title_full |
Widespread surface water p CO2 undersaturation during ice-melt season in an Arctic continental shelf sea (Hudson Bay, Canada) |
title_fullStr |
Widespread surface water p CO2 undersaturation during ice-melt season in an Arctic continental shelf sea (Hudson Bay, Canada) |
title_full_unstemmed |
Widespread surface water p CO2 undersaturation during ice-melt season in an Arctic continental shelf sea (Hudson Bay, Canada) |
title_sort |
widespread surface water p co2 undersaturation during ice-melt season in an arctic continental shelf sea (hudson bay, canada) |
publisher |
University of California Press |
publishDate |
2021 |
url |
http://dx.doi.org/10.1525/elementa.2020.00130 http://online.ucpress.edu/elementa/article-pdf/doi/10.1525/elementa.2020.00130/463851/elementa.2020.00130.pdf |
geographic |
Arctic Canada Hudson Hudson Bay |
geographic_facet |
Arctic Canada Hudson Hudson Bay |
genre |
Arctic Climate change Hudson Bay Sea ice |
genre_facet |
Arctic Climate change Hudson Bay Sea ice |
op_source |
Elementa: Science of the Anthropocene volume 9, issue 1 ISSN 2325-1026 |
op_rights |
http://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.1525/elementa.2020.00130 |
container_title |
Elementa: Science of the Anthropocene |
container_volume |
9 |
container_issue |
1 |
_version_ |
1782330534579404800 |