Inorganic carbon fluxes on the Mackenzie Shelf of the Beaufort Sea
The Mackenzie Shelf in the southeastern Beaufort Sea is a region that has experienced large changes in the past several decades as warming, sea-ice loss, and increased river discharge have altered carbon cycling. Upwelling and downwelling events are common on the shelf, caused by strong, fluctuating...
Main Authors: | , , , , |
---|---|
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
2018
|
Subjects: | |
Online Access: | https://era.library.ualberta.ca/items/d9bca873-6633-4665-9be7-4b1d2fea3bf9 https://doi.org/10.7939/r3-n46c-yh63 |
id |
ftunivalberta:oai:era.library.ualberta.ca:d9bca873-6633-4665-9be7-4b1d2fea3bf9 |
---|---|
record_format |
openpolar |
spelling |
ftunivalberta:oai:era.library.ualberta.ca:d9bca873-6633-4665-9be7-4b1d2fea3bf9 2024-06-23T07:50:23+00:00 Inorganic carbon fluxes on the Mackenzie Shelf of the Beaufort Sea Mol, Jacoba Thomas, Helmuth Myers, Paul G. Hu, Xianmin Mucci, Alfonso 2018-01-01 https://era.library.ualberta.ca/items/d9bca873-6633-4665-9be7-4b1d2fea3bf9 https://doi.org/10.7939/r3-n46c-yh63 English eng https://era.library.ualberta.ca/items/d9bca873-6633-4665-9be7-4b1d2fea3bf9 doi:10.7939/r3-n46c-yh63 http://creativecommons.org/licenses/by/4.0/ Global warming Carbon cycle Sea ice Ocean circulation Marine ecology Article (Published) 2018 ftunivalberta https://doi.org/10.7939/r3-n46c-yh63 2024-06-03T03:09:00Z The Mackenzie Shelf in the southeastern Beaufort Sea is a region that has experienced large changes in the past several decades as warming, sea-ice loss, and increased river discharge have altered carbon cycling. Upwelling and downwelling events are common on the shelf, caused by strong, fluctuating along-shore winds, resulting in cross-shelf Ekman transport, and an alternating estuarine and anti-estuarine circulation. Downwelling carries dissolved inorganic carbon (DIC) and other remineralization products off the shelf and into the deep basin for possible long-term storage in the world's oceans. Upwelling carries DIC and nutrient-rich waters from the Pacific-origin upper halocline layer (UHL) onto the shelf. Profiles of DIC and total alkalinity (TA) taken in August and September of 2014 are used to investigate the cycling of carbon on the Mackenzie Shelf. The along-shore transport of water and the cross-shelf transport of DIC are quantified using velocity field output from a simulation of the Arctic and Northern Hemisphere Atlantic (ANHA4) configuration of the Nucleus of European Modelling of the Ocean (NEMO) framework. A strong upwelling event prior to sampling on the Mackenzie Shelf took place, bringing CO2-rich (elevated pCO2) water from the UHL onto the shelf bottom. The maximum on-shelf DIC flux was estimated at 16.9×10³ mol C d-1 m-2 during the event. The maximum on-shelf transport of DIC through the upwelling event was found to be 65±15×10-3 Tg C d-1. TA and the oxygen isotope ratio of water (δ18O-H2O) are used to examine water-mass distributions in the study area and to investigate the influence of Pacific Water, Mackenzie River freshwater, and sea-ice melt on carbon dynamics and air-sea fluxes of carbon dioxide (CO2) in the surface mixed layer. Understanding carbon transfer in this seasonally dynamic environment is key to quantify the importance of Arctic shelf regions to the global carbon cycle and provide a basis for understanding how it will respond to the aforementioned climate-induced changes. Article in Journal/Newspaper Arctic Beaufort Sea Global warming Mackenzie river Mackenzie Shelf Sea ice University of Alberta: Era - Education and Research Archive Arctic Mackenzie River Pacific |
institution |
Open Polar |
collection |
University of Alberta: Era - Education and Research Archive |
op_collection_id |
ftunivalberta |
language |
English |
topic |
Global warming Carbon cycle Sea ice Ocean circulation Marine ecology |
spellingShingle |
Global warming Carbon cycle Sea ice Ocean circulation Marine ecology Mol, Jacoba Thomas, Helmuth Myers, Paul G. Hu, Xianmin Mucci, Alfonso Inorganic carbon fluxes on the Mackenzie Shelf of the Beaufort Sea |
topic_facet |
Global warming Carbon cycle Sea ice Ocean circulation Marine ecology |
description |
The Mackenzie Shelf in the southeastern Beaufort Sea is a region that has experienced large changes in the past several decades as warming, sea-ice loss, and increased river discharge have altered carbon cycling. Upwelling and downwelling events are common on the shelf, caused by strong, fluctuating along-shore winds, resulting in cross-shelf Ekman transport, and an alternating estuarine and anti-estuarine circulation. Downwelling carries dissolved inorganic carbon (DIC) and other remineralization products off the shelf and into the deep basin for possible long-term storage in the world's oceans. Upwelling carries DIC and nutrient-rich waters from the Pacific-origin upper halocline layer (UHL) onto the shelf. Profiles of DIC and total alkalinity (TA) taken in August and September of 2014 are used to investigate the cycling of carbon on the Mackenzie Shelf. The along-shore transport of water and the cross-shelf transport of DIC are quantified using velocity field output from a simulation of the Arctic and Northern Hemisphere Atlantic (ANHA4) configuration of the Nucleus of European Modelling of the Ocean (NEMO) framework. A strong upwelling event prior to sampling on the Mackenzie Shelf took place, bringing CO2-rich (elevated pCO2) water from the UHL onto the shelf bottom. The maximum on-shelf DIC flux was estimated at 16.9×10³ mol C d-1 m-2 during the event. The maximum on-shelf transport of DIC through the upwelling event was found to be 65±15×10-3 Tg C d-1. TA and the oxygen isotope ratio of water (δ18O-H2O) are used to examine water-mass distributions in the study area and to investigate the influence of Pacific Water, Mackenzie River freshwater, and sea-ice melt on carbon dynamics and air-sea fluxes of carbon dioxide (CO2) in the surface mixed layer. Understanding carbon transfer in this seasonally dynamic environment is key to quantify the importance of Arctic shelf regions to the global carbon cycle and provide a basis for understanding how it will respond to the aforementioned climate-induced changes. |
format |
Article in Journal/Newspaper |
author |
Mol, Jacoba Thomas, Helmuth Myers, Paul G. Hu, Xianmin Mucci, Alfonso |
author_facet |
Mol, Jacoba Thomas, Helmuth Myers, Paul G. Hu, Xianmin Mucci, Alfonso |
author_sort |
Mol, Jacoba |
title |
Inorganic carbon fluxes on the Mackenzie Shelf of the Beaufort Sea |
title_short |
Inorganic carbon fluxes on the Mackenzie Shelf of the Beaufort Sea |
title_full |
Inorganic carbon fluxes on the Mackenzie Shelf of the Beaufort Sea |
title_fullStr |
Inorganic carbon fluxes on the Mackenzie Shelf of the Beaufort Sea |
title_full_unstemmed |
Inorganic carbon fluxes on the Mackenzie Shelf of the Beaufort Sea |
title_sort |
inorganic carbon fluxes on the mackenzie shelf of the beaufort sea |
publishDate |
2018 |
url |
https://era.library.ualberta.ca/items/d9bca873-6633-4665-9be7-4b1d2fea3bf9 https://doi.org/10.7939/r3-n46c-yh63 |
geographic |
Arctic Mackenzie River Pacific |
geographic_facet |
Arctic Mackenzie River Pacific |
genre |
Arctic Beaufort Sea Global warming Mackenzie river Mackenzie Shelf Sea ice |
genre_facet |
Arctic Beaufort Sea Global warming Mackenzie river Mackenzie Shelf Sea ice |
op_relation |
https://era.library.ualberta.ca/items/d9bca873-6633-4665-9be7-4b1d2fea3bf9 doi:10.7939/r3-n46c-yh63 |
op_rights |
http://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.7939/r3-n46c-yh63 |
_version_ |
1802641264759275520 |