Cold-water corals in the Subpolar North Atlantic Ocean exposed to aragonite undersaturation if the 2 °C global warming target is not met
The net uptake of carbon dioxide (CO2) from the atmosphere is changing the ocean’s chemical state. Such changes, commonly known as ocean acidification, include a reduction in pH and the carbonate ion concentration ([CO3 2− ]), which in turn lowers oceanic saturation states for calcium carbonate (CaC...
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ftunivalgarve:oai:sapientia.ualg.pt:10400.1/16785 2023-05-15T16:48:05+02:00 Cold-water corals in the Subpolar North Atlantic Ocean exposed to aragonite undersaturation if the 2 °C global warming target is not met García-Ibáñez, Maribel I. Bates, Nicholas R. Bakker, Dorothee C.E. Fontela, Marcos Velo, Antón 2021-06 http://hdl.handle.net/10400.1/16785 https://doi.org/10.1016/j.gloplacha.2021.103480 eng eng Elsevier info:eu-repo/grantAgreement/EC/H2020/820989/EU http://hdl.handle.net/10400.1/16785 doi:10.1016/j.gloplacha.2021.103480 1872-6364 openAccess http://creativecommons.org/licenses/by/4.0/ CC-BY Ocean acidification Aragonite saturation state Atlantic Meridional Overturning Circulation Eastern-Subpolar North Atlantic Ocean article 2021 ftunivalgarve https://doi.org/10.1016/j.gloplacha.2021.103480 2022-05-30T08:50:01Z The net uptake of carbon dioxide (CO2) from the atmosphere is changing the ocean’s chemical state. Such changes, commonly known as ocean acidification, include a reduction in pH and the carbonate ion concentration ([CO3 2− ]), which in turn lowers oceanic saturation states for calcium carbonate (CaCO3) minerals. The values for aragonite (aragonite; one of the main CaCO3 minerals formed by marine calcifying organisms) influence the calcification rate and geographic distribution of cold-water corals (CWCs), important for biodiversity. Here, high-quality measurements, collected on thirteen cruises along the same track during 1991–2018, are used to determine the long-term changes in Ωaragonite in the Irminger and Iceland Basins of the North Atlantic Ocean, providing the first trends of Ωaragonite in the deep waters of these basins. The entire water column of both basins showed significant negative aragonite trends between − 0.0014 ± 0.0002 and − 0.0052 ± 0.0007 per year. The decrease in aragonite in the intermediate waters, where nearly half of the CWC reefs of the study region are located, caused the aragonite isolines to rapidly migrate upwards at a rate between 6 and 34 m per year. The main driver of the decline in Ωaragonite in the Irminger and Iceland Basins was the increase in anthropogenic CO2. But this was partially offset by increases in salinity (in Subpolar Mode Water), enhanced ventilation (in upper Labrador Sea Water), and increases in alkalinity (in classical Labrador Sea Water, cLSW; and overflow waters). We also found that water mass aging reinforced the aragonite decrease in cLSW. Based on these aragonite trends over the last three decades, we project that the entire water column of the Irminger and Iceland Basins will likely be undersaturated for aragonite when in equilibrium with an atmospheric mole fraction of CO2 (xCO2) of ~880 ppmv, corresponding to climate model projections for the end of the century based on the highest CO2 emission scenarios. However, intermediate waters will likely be ... Article in Journal/Newspaper Iceland Labrador Sea North Atlantic Ocean acidification Universidade do Algarve: Sapienta Global and Planetary Change 201 103480 |
institution |
Open Polar |
collection |
Universidade do Algarve: Sapienta |
op_collection_id |
ftunivalgarve |
language |
English |
topic |
Ocean acidification Aragonite saturation state Atlantic Meridional Overturning Circulation Eastern-Subpolar North Atlantic Ocean |
spellingShingle |
Ocean acidification Aragonite saturation state Atlantic Meridional Overturning Circulation Eastern-Subpolar North Atlantic Ocean García-Ibáñez, Maribel I. Bates, Nicholas R. Bakker, Dorothee C.E. Fontela, Marcos Velo, Antón Cold-water corals in the Subpolar North Atlantic Ocean exposed to aragonite undersaturation if the 2 °C global warming target is not met |
topic_facet |
Ocean acidification Aragonite saturation state Atlantic Meridional Overturning Circulation Eastern-Subpolar North Atlantic Ocean |
description |
The net uptake of carbon dioxide (CO2) from the atmosphere is changing the ocean’s chemical state. Such changes, commonly known as ocean acidification, include a reduction in pH and the carbonate ion concentration ([CO3 2− ]), which in turn lowers oceanic saturation states for calcium carbonate (CaCO3) minerals. The values for aragonite (aragonite; one of the main CaCO3 minerals formed by marine calcifying organisms) influence the calcification rate and geographic distribution of cold-water corals (CWCs), important for biodiversity. Here, high-quality measurements, collected on thirteen cruises along the same track during 1991–2018, are used to determine the long-term changes in Ωaragonite in the Irminger and Iceland Basins of the North Atlantic Ocean, providing the first trends of Ωaragonite in the deep waters of these basins. The entire water column of both basins showed significant negative aragonite trends between − 0.0014 ± 0.0002 and − 0.0052 ± 0.0007 per year. The decrease in aragonite in the intermediate waters, where nearly half of the CWC reefs of the study region are located, caused the aragonite isolines to rapidly migrate upwards at a rate between 6 and 34 m per year. The main driver of the decline in Ωaragonite in the Irminger and Iceland Basins was the increase in anthropogenic CO2. But this was partially offset by increases in salinity (in Subpolar Mode Water), enhanced ventilation (in upper Labrador Sea Water), and increases in alkalinity (in classical Labrador Sea Water, cLSW; and overflow waters). We also found that water mass aging reinforced the aragonite decrease in cLSW. Based on these aragonite trends over the last three decades, we project that the entire water column of the Irminger and Iceland Basins will likely be undersaturated for aragonite when in equilibrium with an atmospheric mole fraction of CO2 (xCO2) of ~880 ppmv, corresponding to climate model projections for the end of the century based on the highest CO2 emission scenarios. However, intermediate waters will likely be ... |
format |
Article in Journal/Newspaper |
author |
García-Ibáñez, Maribel I. Bates, Nicholas R. Bakker, Dorothee C.E. Fontela, Marcos Velo, Antón |
author_facet |
García-Ibáñez, Maribel I. Bates, Nicholas R. Bakker, Dorothee C.E. Fontela, Marcos Velo, Antón |
author_sort |
García-Ibáñez, Maribel I. |
title |
Cold-water corals in the Subpolar North Atlantic Ocean exposed to aragonite undersaturation if the 2 °C global warming target is not met |
title_short |
Cold-water corals in the Subpolar North Atlantic Ocean exposed to aragonite undersaturation if the 2 °C global warming target is not met |
title_full |
Cold-water corals in the Subpolar North Atlantic Ocean exposed to aragonite undersaturation if the 2 °C global warming target is not met |
title_fullStr |
Cold-water corals in the Subpolar North Atlantic Ocean exposed to aragonite undersaturation if the 2 °C global warming target is not met |
title_full_unstemmed |
Cold-water corals in the Subpolar North Atlantic Ocean exposed to aragonite undersaturation if the 2 °C global warming target is not met |
title_sort |
cold-water corals in the subpolar north atlantic ocean exposed to aragonite undersaturation if the 2 °c global warming target is not met |
publisher |
Elsevier |
publishDate |
2021 |
url |
http://hdl.handle.net/10400.1/16785 https://doi.org/10.1016/j.gloplacha.2021.103480 |
genre |
Iceland Labrador Sea North Atlantic Ocean acidification |
genre_facet |
Iceland Labrador Sea North Atlantic Ocean acidification |
op_relation |
info:eu-repo/grantAgreement/EC/H2020/820989/EU http://hdl.handle.net/10400.1/16785 doi:10.1016/j.gloplacha.2021.103480 1872-6364 |
op_rights |
openAccess http://creativecommons.org/licenses/by/4.0/ |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1016/j.gloplacha.2021.103480 |
container_title |
Global and Planetary Change |
container_volume |
201 |
container_start_page |
103480 |
_version_ |
1766038198916481024 |