The evolution of light and vertical mixing across a phytoplankton ice-edge bloom
During summer, phytoplankton can bloom in the Arctic Ocean, both in open water and under ice, often strongly linked to the retreating ice edge. There, the surface ocean responds to steep lateral gradients in ice melt, mixing, and light input, shaping the Arctic ecosystem in unique ways not found in...
Published in: | Elementa: Science of the Anthropocene |
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Online Access: | http://dx.doi.org/10.1525/elementa.357 https://online.ucpress.edu/elementa/article-pdf/doi/10.1525/elementa.357/434726/357-6139-1-pb.pdf |
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crunicaliforniap:10.1525/elementa.357 2024-09-30T14:29:55+00:00 The evolution of light and vertical mixing across a phytoplankton ice-edge bloom Randelhoff, Achim Oziel, Laurent Massicotte, Philippe Bécu, Guislain Galí, Martí Lacour, Léo Dumont, Dany Vladoiu, Anda Marec, Claudie Bruyant, Flavienne Houssais, Marie-Noëlle Tremblay, Jean-Éric Deslongchamps, Gabrièle Babin, Marcel Deming, Jody W. Arrigo, Kevin 2019 http://dx.doi.org/10.1525/elementa.357 https://online.ucpress.edu/elementa/article-pdf/doi/10.1525/elementa.357/434726/357-6139-1-pb.pdf en eng University of California Press http://creativecommons.org/licenses/by/4.0/ Elementa: Science of the Anthropocene volume 7 ISSN 2325-1026 journal-article 2019 crunicaliforniap https://doi.org/10.1525/elementa.357 2024-09-12T05:01:43Z During summer, phytoplankton can bloom in the Arctic Ocean, both in open water and under ice, often strongly linked to the retreating ice edge. There, the surface ocean responds to steep lateral gradients in ice melt, mixing, and light input, shaping the Arctic ecosystem in unique ways not found in other regions of the world ocean. In 2016, we sampled a high-resolution grid of 135 hydrographic stations in Baffin Bay as part of the Green Edge project to study the ice-edge bloom, including turbulent vertical mixing, the under-ice light field, concentrations of inorganic nutrients, and phytoplankton biomass. We found pronounced differences between an Atlantic sector dominated by the warm West Greenland Current and an Arctic sector with surface waters originating from the Canadian archipelago. Winter overturning and thus nutrient replenishment was hampered by strong haline stratification in the Arctic domain, whereas close to the West Greenland shelf, weak stratification permitted winter mixing with high-nitrate Atlantic-derived waters. Using a space-for-time approach, we linked upper ocean dynamics to the phytoplankton bloom trailing the retreating ice edge. In a band of 60 km (or 15 days) around the ice edge, the upper ocean was especially affected by a freshened surface layer. Light climate, as evidenced by deep 0.415 mol m–2 d–1 isolumes, and vertical mixing, as quantified by shallow mixing layer depths, should have permitted significant net phytoplankton growth more than 100 km into the pack ice at ice concentrations close to 100%. Yet, under-ice biomass was relatively low at 20 mg chlorophyll-a m–2 and depth-integrated total chlorophyll-a (0–80 m) peaked at an average value of 75 mg chlorophyll-a m–2 only around 10 days after ice retreat. This phenological peak may hence have been the delayed result of much earlier bloom initiation and demonstrates the importance of temporal dynamics for constraints of Arctic marine primary production. Article in Journal/Newspaper Arctic Arctic Ocean Baffin Bay Baffin Bay Baffin Canadian Archipelago Greenland Phytoplankton University of California Press Arctic Arctic Ocean Baffin Bay Greenland Elementa: Science of the Anthropocene 7 |
institution |
Open Polar |
collection |
University of California Press |
op_collection_id |
crunicaliforniap |
language |
English |
description |
During summer, phytoplankton can bloom in the Arctic Ocean, both in open water and under ice, often strongly linked to the retreating ice edge. There, the surface ocean responds to steep lateral gradients in ice melt, mixing, and light input, shaping the Arctic ecosystem in unique ways not found in other regions of the world ocean. In 2016, we sampled a high-resolution grid of 135 hydrographic stations in Baffin Bay as part of the Green Edge project to study the ice-edge bloom, including turbulent vertical mixing, the under-ice light field, concentrations of inorganic nutrients, and phytoplankton biomass. We found pronounced differences between an Atlantic sector dominated by the warm West Greenland Current and an Arctic sector with surface waters originating from the Canadian archipelago. Winter overturning and thus nutrient replenishment was hampered by strong haline stratification in the Arctic domain, whereas close to the West Greenland shelf, weak stratification permitted winter mixing with high-nitrate Atlantic-derived waters. Using a space-for-time approach, we linked upper ocean dynamics to the phytoplankton bloom trailing the retreating ice edge. In a band of 60 km (or 15 days) around the ice edge, the upper ocean was especially affected by a freshened surface layer. Light climate, as evidenced by deep 0.415 mol m–2 d–1 isolumes, and vertical mixing, as quantified by shallow mixing layer depths, should have permitted significant net phytoplankton growth more than 100 km into the pack ice at ice concentrations close to 100%. Yet, under-ice biomass was relatively low at 20 mg chlorophyll-a m–2 and depth-integrated total chlorophyll-a (0–80 m) peaked at an average value of 75 mg chlorophyll-a m–2 only around 10 days after ice retreat. This phenological peak may hence have been the delayed result of much earlier bloom initiation and demonstrates the importance of temporal dynamics for constraints of Arctic marine primary production. |
author2 |
Deming, Jody W. Arrigo, Kevin |
format |
Article in Journal/Newspaper |
author |
Randelhoff, Achim Oziel, Laurent Massicotte, Philippe Bécu, Guislain Galí, Martí Lacour, Léo Dumont, Dany Vladoiu, Anda Marec, Claudie Bruyant, Flavienne Houssais, Marie-Noëlle Tremblay, Jean-Éric Deslongchamps, Gabrièle Babin, Marcel |
spellingShingle |
Randelhoff, Achim Oziel, Laurent Massicotte, Philippe Bécu, Guislain Galí, Martí Lacour, Léo Dumont, Dany Vladoiu, Anda Marec, Claudie Bruyant, Flavienne Houssais, Marie-Noëlle Tremblay, Jean-Éric Deslongchamps, Gabrièle Babin, Marcel The evolution of light and vertical mixing across a phytoplankton ice-edge bloom |
author_facet |
Randelhoff, Achim Oziel, Laurent Massicotte, Philippe Bécu, Guislain Galí, Martí Lacour, Léo Dumont, Dany Vladoiu, Anda Marec, Claudie Bruyant, Flavienne Houssais, Marie-Noëlle Tremblay, Jean-Éric Deslongchamps, Gabrièle Babin, Marcel |
author_sort |
Randelhoff, Achim |
title |
The evolution of light and vertical mixing across a phytoplankton ice-edge bloom |
title_short |
The evolution of light and vertical mixing across a phytoplankton ice-edge bloom |
title_full |
The evolution of light and vertical mixing across a phytoplankton ice-edge bloom |
title_fullStr |
The evolution of light and vertical mixing across a phytoplankton ice-edge bloom |
title_full_unstemmed |
The evolution of light and vertical mixing across a phytoplankton ice-edge bloom |
title_sort |
evolution of light and vertical mixing across a phytoplankton ice-edge bloom |
publisher |
University of California Press |
publishDate |
2019 |
url |
http://dx.doi.org/10.1525/elementa.357 https://online.ucpress.edu/elementa/article-pdf/doi/10.1525/elementa.357/434726/357-6139-1-pb.pdf |
geographic |
Arctic Arctic Ocean Baffin Bay Greenland |
geographic_facet |
Arctic Arctic Ocean Baffin Bay Greenland |
genre |
Arctic Arctic Ocean Baffin Bay Baffin Bay Baffin Canadian Archipelago Greenland Phytoplankton |
genre_facet |
Arctic Arctic Ocean Baffin Bay Baffin Bay Baffin Canadian Archipelago Greenland Phytoplankton |
op_source |
Elementa: Science of the Anthropocene volume 7 ISSN 2325-1026 |
op_rights |
http://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.1525/elementa.357 |
container_title |
Elementa: Science of the Anthropocene |
container_volume |
7 |
_version_ |
1811635072100466688 |