Nutrient conditions in the subpolar North Atlantic during the last glacial period reconstructed from foraminifera-bound nitrogen isotopes
Surface nitrate concentration is a potentially useful diagnostic in reconstructing the past circulation of high-latitude North Atlantic waters. Moreover, nutrient consumption in the North Atlantic surface impacts the atmospheric concentration of carbon dioxide. To reconstruct nutrient conditions in...
Published in: | Paleoceanography |
---|---|
Main Authors: | , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | unknown |
Published: |
AGU
2013
|
Subjects: | |
Online Access: | https://edoc.unibas.ch/73044/ https://doi.org/10.1002/palo.20013 |
id |
ftunivbasel:oai:edoc.unibas.ch:73044 |
---|---|
record_format |
openpolar |
spelling |
ftunivbasel:oai:edoc.unibas.ch:73044 2023-05-15T14:01:28+02:00 Nutrient conditions in the subpolar North Atlantic during the last glacial period reconstructed from foraminifera-bound nitrogen isotopes Straub, M. Tremblay, M. M. Sigman, D. M. Studer, A. S. Ren, H. Toggweiler, J. R. Haug, G. H. 2013 https://edoc.unibas.ch/73044/ https://doi.org/10.1002/palo.20013 unknown AGU Straub, M. and Tremblay, M. M. and Sigman, D. M. and Studer, A. S. and Ren, H. and Toggweiler, J. R. and Haug, G. H. (2013) Nutrient conditions in the subpolar North Atlantic during the last glacial period reconstructed from foraminifera-bound nitrogen isotopes. Paleoceanography, 28 (1). pp. 79-90. doi:10.1002/palo.20013 info:isi/000317838200008 urn:ISSN:0883-8305 info:eu-repo/semantics/closedAccess Article PeerReviewed 2013 ftunivbasel https://doi.org/10.1002/palo.20013 2023-03-05T07:23:32Z Surface nitrate concentration is a potentially useful diagnostic in reconstructing the past circulation of high-latitude North Atlantic waters. Moreover, nutrient consumption in the North Atlantic surface impacts the atmospheric concentration of carbon dioxide. To reconstruct nutrient conditions in the subpolar North Atlantic region during the last ice age, a record of foraminifera-bound delta N-15 was measured in Neogloboquadrina pachyderma (sin.) from core V28-73 south of Iceland (57.2 degrees N, 20.9 degrees W). Foraminifera-bound delta N-15 is up to 2 parts per thousand lower during the last ice age than during the Holocene, suggesting as much as similar to 25% less complete nitrate consumption during the former. This is consistent with stronger light limitation associated with a deeper summer surface mixed layer, perhaps related to the formation of Glacial North Atlantic Intermediate Water previously suggested to have occurred near the core site. However, three single-point maxima in delta N-15 in the glacial section and the sharp deglacial delta N-15 rise coincide with Heinrich event layers. This suggests that increased water column stratification during Heinrich events, presumably due to surface freshening, reduced the nutrient supply from below and led to nearly complete nitrate consumption in the summertime mixed layer. The Heinrich layers in V28-73 are not accompanied by delta O-18 minima in either N. pachyderma (sin.) or Globigerinoides bulloides, which we tentatively attribute to extreme mixed-layer shoaling. The reconstructed subpolar North Atlantic upper water column changes-both glacial/interglacial and millennial-are inverse to those inferred for the Antarctic. Citation: Straub, M., M. M. Tremblay, D. M. Sigman, A. S. Studer, H. Ren, J. R. Toggweiler, and G. H. Haug (2013), Nutrient conditions in the subpolar North Atlantic during the last glacial period reconstructed from foraminifera-bound nitrogen isotopes, Paleoceanography, 28, 79-90, doi:10.1002/palo.20013. Article in Journal/Newspaper Antarc* Antarctic Iceland Neogloboquadrina pachyderma North Atlantic ren University of Basel: edoc Antarctic Haug ENVELOPE(15.188,15.188,67.918,67.918) The Antarctic Tremblay ENVELOPE(-120.853,-120.853,55.783,55.783) Paleoceanography 28 1 79 90 |
institution |
Open Polar |
collection |
University of Basel: edoc |
op_collection_id |
ftunivbasel |
language |
unknown |
description |
Surface nitrate concentration is a potentially useful diagnostic in reconstructing the past circulation of high-latitude North Atlantic waters. Moreover, nutrient consumption in the North Atlantic surface impacts the atmospheric concentration of carbon dioxide. To reconstruct nutrient conditions in the subpolar North Atlantic region during the last ice age, a record of foraminifera-bound delta N-15 was measured in Neogloboquadrina pachyderma (sin.) from core V28-73 south of Iceland (57.2 degrees N, 20.9 degrees W). Foraminifera-bound delta N-15 is up to 2 parts per thousand lower during the last ice age than during the Holocene, suggesting as much as similar to 25% less complete nitrate consumption during the former. This is consistent with stronger light limitation associated with a deeper summer surface mixed layer, perhaps related to the formation of Glacial North Atlantic Intermediate Water previously suggested to have occurred near the core site. However, three single-point maxima in delta N-15 in the glacial section and the sharp deglacial delta N-15 rise coincide with Heinrich event layers. This suggests that increased water column stratification during Heinrich events, presumably due to surface freshening, reduced the nutrient supply from below and led to nearly complete nitrate consumption in the summertime mixed layer. The Heinrich layers in V28-73 are not accompanied by delta O-18 minima in either N. pachyderma (sin.) or Globigerinoides bulloides, which we tentatively attribute to extreme mixed-layer shoaling. The reconstructed subpolar North Atlantic upper water column changes-both glacial/interglacial and millennial-are inverse to those inferred for the Antarctic. Citation: Straub, M., M. M. Tremblay, D. M. Sigman, A. S. Studer, H. Ren, J. R. Toggweiler, and G. H. Haug (2013), Nutrient conditions in the subpolar North Atlantic during the last glacial period reconstructed from foraminifera-bound nitrogen isotopes, Paleoceanography, 28, 79-90, doi:10.1002/palo.20013. |
format |
Article in Journal/Newspaper |
author |
Straub, M. Tremblay, M. M. Sigman, D. M. Studer, A. S. Ren, H. Toggweiler, J. R. Haug, G. H. |
spellingShingle |
Straub, M. Tremblay, M. M. Sigman, D. M. Studer, A. S. Ren, H. Toggweiler, J. R. Haug, G. H. Nutrient conditions in the subpolar North Atlantic during the last glacial period reconstructed from foraminifera-bound nitrogen isotopes |
author_facet |
Straub, M. Tremblay, M. M. Sigman, D. M. Studer, A. S. Ren, H. Toggweiler, J. R. Haug, G. H. |
author_sort |
Straub, M. |
title |
Nutrient conditions in the subpolar North Atlantic during the last glacial period reconstructed from foraminifera-bound nitrogen isotopes |
title_short |
Nutrient conditions in the subpolar North Atlantic during the last glacial period reconstructed from foraminifera-bound nitrogen isotopes |
title_full |
Nutrient conditions in the subpolar North Atlantic during the last glacial period reconstructed from foraminifera-bound nitrogen isotopes |
title_fullStr |
Nutrient conditions in the subpolar North Atlantic during the last glacial period reconstructed from foraminifera-bound nitrogen isotopes |
title_full_unstemmed |
Nutrient conditions in the subpolar North Atlantic during the last glacial period reconstructed from foraminifera-bound nitrogen isotopes |
title_sort |
nutrient conditions in the subpolar north atlantic during the last glacial period reconstructed from foraminifera-bound nitrogen isotopes |
publisher |
AGU |
publishDate |
2013 |
url |
https://edoc.unibas.ch/73044/ https://doi.org/10.1002/palo.20013 |
long_lat |
ENVELOPE(15.188,15.188,67.918,67.918) ENVELOPE(-120.853,-120.853,55.783,55.783) |
geographic |
Antarctic Haug The Antarctic Tremblay |
geographic_facet |
Antarctic Haug The Antarctic Tremblay |
genre |
Antarc* Antarctic Iceland Neogloboquadrina pachyderma North Atlantic ren |
genre_facet |
Antarc* Antarctic Iceland Neogloboquadrina pachyderma North Atlantic ren |
op_relation |
Straub, M. and Tremblay, M. M. and Sigman, D. M. and Studer, A. S. and Ren, H. and Toggweiler, J. R. and Haug, G. H. (2013) Nutrient conditions in the subpolar North Atlantic during the last glacial period reconstructed from foraminifera-bound nitrogen isotopes. Paleoceanography, 28 (1). pp. 79-90. doi:10.1002/palo.20013 info:isi/000317838200008 urn:ISSN:0883-8305 |
op_rights |
info:eu-repo/semantics/closedAccess |
op_doi |
https://doi.org/10.1002/palo.20013 |
container_title |
Paleoceanography |
container_volume |
28 |
container_issue |
1 |
container_start_page |
79 |
op_container_end_page |
90 |
_version_ |
1766271311906078720 |