Nutrient and Silicon Isotope Dynamics in the Laptev Sea and Implications for Nutrient Availability in the Transpolar Drift
Realistic prediction of the near-future response of Arctic Ocean primary productivity to ongoing warming and sea ice loss requires a mechanistic understanding of the processes controlling nutrient bioavailability. To evaluate continental nutrient inputs, biological utilization and the influence of m...
Published in: | Global Biogeochemical Cycles |
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Main Authors: | , , , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
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AGU (American Geophysical Union)
2022
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Online Access: | https://oceanrep.geomar.de/id/eprint/57033/ https://oceanrep.geomar.de/id/eprint/57033/2/2022gb007316-sup-0001-supporting https://oceanrep.geomar.de/id/eprint/57033/3/2022gb007316-sup-0002-table https://oceanrep.geomar.de/id/eprint/57033/9/Global%20Biogeochemical%20Cycles%20-%202022%20-%20Laukert.pdf https://doi.org/10.1029/2022GB007316 |
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ftoceanrep:oai:oceanrep.geomar.de:57033 2024-02-11T10:01:39+01:00 Nutrient and Silicon Isotope Dynamics in the Laptev Sea and Implications for Nutrient Availability in the Transpolar Drift Laukert, Georgi Grasse, Patricia Novikhin, A. Povazhnyi, V. Doering, Kristin Hölemann, J. Janout, M. Bauch, Dorothea Kassens, Heidi Frank, Martin 2022-09 text https://oceanrep.geomar.de/id/eprint/57033/ https://oceanrep.geomar.de/id/eprint/57033/2/2022gb007316-sup-0001-supporting https://oceanrep.geomar.de/id/eprint/57033/3/2022gb007316-sup-0002-table https://oceanrep.geomar.de/id/eprint/57033/9/Global%20Biogeochemical%20Cycles%20-%202022%20-%20Laukert.pdf https://doi.org/10.1029/2022GB007316 en eng AGU (American Geophysical Union) Wiley https://oceanrep.geomar.de/id/eprint/57033/2/2022gb007316-sup-0001-supporting https://oceanrep.geomar.de/id/eprint/57033/3/2022gb007316-sup-0002-table https://oceanrep.geomar.de/id/eprint/57033/9/Global%20Biogeochemical%20Cycles%20-%202022%20-%20Laukert.pdf Laukert, G. , Grasse, P. , Novikhin, A., Povazhnyi, V., Doering, K. , Hölemann, J., Janout, M., Bauch, D. , Kassens, H. and Frank, M. (2022) Nutrient and Silicon Isotope Dynamics in the Laptev Sea and Implications for Nutrient Availability in the Transpolar Drift. Open Access Global Biogeochemical Cycles, 36 (9). Art.Nr. e2022GB007316. DOI 10.1029/2022GB007316 <https://doi.org/10.1029/2022GB007316>. doi:10.1029/2022GB007316 cc_by_nc_nd_4.0 info:eu-repo/semantics/openAccess Article PeerReviewed info:eu-repo/semantics/article 2022 ftoceanrep https://doi.org/10.1029/2022GB007316 2024-01-15T00:25:56Z Realistic prediction of the near-future response of Arctic Ocean primary productivity to ongoing warming and sea ice loss requires a mechanistic understanding of the processes controlling nutrient bioavailability. To evaluate continental nutrient inputs, biological utilization and the influence of mixing and winter processes in the Laptev Sea, the major source region of the Transpolar Drift, we compare observed with preformed concentrations of dissolved inorganic nitrogen (DIN), phosphorus (DIP), silicic acid (DSi) and silicon isotope compositions of DSi (δ30SiDSi) obtained for two summers (2013, 2014) and one winter (2012). In summer, preformed nutrient concentrations persisted in the surface layer of the southeastern Laptev Sea, while diatom-dominated utilization caused intense northward drawdown and a pronounced shift in δ30SiDSi from +0.91 to +3.82 ‰. The modeled Si isotope fractionation suggests that DSi in the northern Laptev Sea originated from the Lena River during the spring freshet, while in the southeastern Laptev Sea it was continuously supplied by it during the summer. Primary productivity fueled by river-borne nutrients was enhanced by admixture of DIN- and DIP-rich Atlantic-sourced waters to the surface, either by convective mixing during the previous winter or by occasional storm-induced stratification breakdowns in late summer. Substantial enrichments of DSi (+240 %) and DIP (+90 %) beneath the Lena River plume were caused by sea ice-driven redistribution and remineralization. Predicted weaker stratification on the outer Laptev shelf will enhance DSi utilization and removal through greater vertical DIN supply, which will limit DSi export and reduce diatom-dominated primary productivity in the Transpolar Drift. Key Points - Surface DIN, DIP, DSi and Si isotope dynamics are controlled by marine and riverine inputs and uptake by phytoplankton - Strong DIP and DSi enrichments beneath the Lena River plume are due to sea ice-driven nutrient redistribution and remineralization - Enhanced DSi ... Article in Journal/Newspaper Arctic Arctic Ocean laptev Laptev Sea lena river Phytoplankton Sea ice OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) Arctic Arctic Ocean Laptev Sea Global Biogeochemical Cycles 36 9 |
institution |
Open Polar |
collection |
OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) |
op_collection_id |
ftoceanrep |
language |
English |
description |
Realistic prediction of the near-future response of Arctic Ocean primary productivity to ongoing warming and sea ice loss requires a mechanistic understanding of the processes controlling nutrient bioavailability. To evaluate continental nutrient inputs, biological utilization and the influence of mixing and winter processes in the Laptev Sea, the major source region of the Transpolar Drift, we compare observed with preformed concentrations of dissolved inorganic nitrogen (DIN), phosphorus (DIP), silicic acid (DSi) and silicon isotope compositions of DSi (δ30SiDSi) obtained for two summers (2013, 2014) and one winter (2012). In summer, preformed nutrient concentrations persisted in the surface layer of the southeastern Laptev Sea, while diatom-dominated utilization caused intense northward drawdown and a pronounced shift in δ30SiDSi from +0.91 to +3.82 ‰. The modeled Si isotope fractionation suggests that DSi in the northern Laptev Sea originated from the Lena River during the spring freshet, while in the southeastern Laptev Sea it was continuously supplied by it during the summer. Primary productivity fueled by river-borne nutrients was enhanced by admixture of DIN- and DIP-rich Atlantic-sourced waters to the surface, either by convective mixing during the previous winter or by occasional storm-induced stratification breakdowns in late summer. Substantial enrichments of DSi (+240 %) and DIP (+90 %) beneath the Lena River plume were caused by sea ice-driven redistribution and remineralization. Predicted weaker stratification on the outer Laptev shelf will enhance DSi utilization and removal through greater vertical DIN supply, which will limit DSi export and reduce diatom-dominated primary productivity in the Transpolar Drift. Key Points - Surface DIN, DIP, DSi and Si isotope dynamics are controlled by marine and riverine inputs and uptake by phytoplankton - Strong DIP and DSi enrichments beneath the Lena River plume are due to sea ice-driven nutrient redistribution and remineralization - Enhanced DSi ... |
format |
Article in Journal/Newspaper |
author |
Laukert, Georgi Grasse, Patricia Novikhin, A. Povazhnyi, V. Doering, Kristin Hölemann, J. Janout, M. Bauch, Dorothea Kassens, Heidi Frank, Martin |
spellingShingle |
Laukert, Georgi Grasse, Patricia Novikhin, A. Povazhnyi, V. Doering, Kristin Hölemann, J. Janout, M. Bauch, Dorothea Kassens, Heidi Frank, Martin Nutrient and Silicon Isotope Dynamics in the Laptev Sea and Implications for Nutrient Availability in the Transpolar Drift |
author_facet |
Laukert, Georgi Grasse, Patricia Novikhin, A. Povazhnyi, V. Doering, Kristin Hölemann, J. Janout, M. Bauch, Dorothea Kassens, Heidi Frank, Martin |
author_sort |
Laukert, Georgi |
title |
Nutrient and Silicon Isotope Dynamics in the Laptev Sea and Implications for Nutrient Availability in the Transpolar Drift |
title_short |
Nutrient and Silicon Isotope Dynamics in the Laptev Sea and Implications for Nutrient Availability in the Transpolar Drift |
title_full |
Nutrient and Silicon Isotope Dynamics in the Laptev Sea and Implications for Nutrient Availability in the Transpolar Drift |
title_fullStr |
Nutrient and Silicon Isotope Dynamics in the Laptev Sea and Implications for Nutrient Availability in the Transpolar Drift |
title_full_unstemmed |
Nutrient and Silicon Isotope Dynamics in the Laptev Sea and Implications for Nutrient Availability in the Transpolar Drift |
title_sort |
nutrient and silicon isotope dynamics in the laptev sea and implications for nutrient availability in the transpolar drift |
publisher |
AGU (American Geophysical Union) |
publishDate |
2022 |
url |
https://oceanrep.geomar.de/id/eprint/57033/ https://oceanrep.geomar.de/id/eprint/57033/2/2022gb007316-sup-0001-supporting https://oceanrep.geomar.de/id/eprint/57033/3/2022gb007316-sup-0002-table https://oceanrep.geomar.de/id/eprint/57033/9/Global%20Biogeochemical%20Cycles%20-%202022%20-%20Laukert.pdf https://doi.org/10.1029/2022GB007316 |
geographic |
Arctic Arctic Ocean Laptev Sea |
geographic_facet |
Arctic Arctic Ocean Laptev Sea |
genre |
Arctic Arctic Ocean laptev Laptev Sea lena river Phytoplankton Sea ice |
genre_facet |
Arctic Arctic Ocean laptev Laptev Sea lena river Phytoplankton Sea ice |
op_relation |
https://oceanrep.geomar.de/id/eprint/57033/2/2022gb007316-sup-0001-supporting https://oceanrep.geomar.de/id/eprint/57033/3/2022gb007316-sup-0002-table https://oceanrep.geomar.de/id/eprint/57033/9/Global%20Biogeochemical%20Cycles%20-%202022%20-%20Laukert.pdf Laukert, G. , Grasse, P. , Novikhin, A., Povazhnyi, V., Doering, K. , Hölemann, J., Janout, M., Bauch, D. , Kassens, H. and Frank, M. (2022) Nutrient and Silicon Isotope Dynamics in the Laptev Sea and Implications for Nutrient Availability in the Transpolar Drift. Open Access Global Biogeochemical Cycles, 36 (9). Art.Nr. e2022GB007316. DOI 10.1029/2022GB007316 <https://doi.org/10.1029/2022GB007316>. doi:10.1029/2022GB007316 |
op_rights |
cc_by_nc_nd_4.0 info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1029/2022GB007316 |
container_title |
Global Biogeochemical Cycles |
container_volume |
36 |
container_issue |
9 |
_version_ |
1790597457381425152 |