Seasonal variability of the long-chain alkenone flux and the effect on the U37k'-index in the Norwegian Sea
A seasonally-varying sedimentation pattern was observed for the alkenone flux measured with sediment traps in the northern North Atlantic. In the Norwegian Sea (traps were set at 500, 1000 and 3000 m) the alkenone flux varied between 0.1 and 7.1 μg m−2 d−1 and followed the seasonal pattern of the bu...
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Language: | English |
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Elsevier
1998
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Online Access: | https://oceanrep.geomar.de/id/eprint/4329/ https://oceanrep.geomar.de/id/eprint/4329/1/Thomsen.pdf https://doi.org/10.1016/S0146-6380(98)00003-5 |
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ftoceanrep:oai:oceanrep.geomar.de:4329 2023-05-15T15:38:50+02:00 Seasonal variability of the long-chain alkenone flux and the effect on the U37k'-index in the Norwegian Sea Thomsen, Claudia Schulz-Bull, Detlef E. Petrick, Gert Duinker, Jan C. 1998 text https://oceanrep.geomar.de/id/eprint/4329/ https://oceanrep.geomar.de/id/eprint/4329/1/Thomsen.pdf https://doi.org/10.1016/S0146-6380(98)00003-5 en eng Elsevier https://oceanrep.geomar.de/id/eprint/4329/1/Thomsen.pdf Thomsen, C., Schulz-Bull, D. E., Petrick, G. and Duinker, J. C. (1998) Seasonal variability of the long-chain alkenone flux and the effect on the U37k'-index in the Norwegian Sea. Organic Geochemistry, 28 . pp. 311-323. DOI 10.1016/S0146-6380(98)00003-5 <https://doi.org/10.1016/S0146-6380%2898%2900003-5>. doi:10.1016/S0146-6380(98)00003-5 info:eu-repo/semantics/restrictedAccess Article PeerReviewed 1998 ftoceanrep https://doi.org/10.1016/S0146-6380(98)00003-5 2023-04-07T14:49:19Z A seasonally-varying sedimentation pattern was observed for the alkenone flux measured with sediment traps in the northern North Atlantic. In the Norwegian Sea (traps were set at 500, 1000 and 3000 m) the alkenone flux varied between 0.1 and 7.1 μg m−2 d−1 and followed the seasonal pattern of the bulk parameters. Maximum fluxes occurred from mid-October until mid-November and were also high in May. A surprising result was that considerably higher particle fluxes were observed at 3000 m. For the alkenone flux, the highest additional input of 250% was observed during the period when sediment resuspension was greatest in summer. At the Barents Sea continental margin (traps at 1840 and 1950 m) the alkenone fluxes follow the sedimentation pattern of the bulk parameters, with a less visible signal of distinct seasonality observed in the 1950 m trap. The sedimentation of total alkenones varied between 0.8 and 144 μg m−2 d−1 at 1840 m and between 0.5 and 31.0 μg m−2 d−1 at 1950 m. Resuspension and lateral advection contributed significantly to measured fluxes in the two near-bottom traps. Alkenone concentrations were determined in faecal pellets of Appendicularia, ostracods and euphausids from selected samples at the Barents Sea site. The alkenone flux in pellets (4% to 24% of total) was 5 to 6 times higher at 1950 m depth than at 1840 m and the major part (77–78%) of the total flux of C37:3 reaching the near-bottom trap at 1950 m was associated with faecal pellets of the meso-zooplankton. Spatial and temporal variations of the U37k′ signals were observed, indicating that the imprint in the alkenone signal depends on the origin and transport pathway of the organic material. Strong deviations occur in areas where nepheloid layers contribute particles of long residence times to the primary flux. Article in Journal/Newspaper Barents Sea North Atlantic Norwegian Sea OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) Barents Sea Norwegian Sea Organic Geochemistry 28 5 311 323 |
institution |
Open Polar |
collection |
OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) |
op_collection_id |
ftoceanrep |
language |
English |
description |
A seasonally-varying sedimentation pattern was observed for the alkenone flux measured with sediment traps in the northern North Atlantic. In the Norwegian Sea (traps were set at 500, 1000 and 3000 m) the alkenone flux varied between 0.1 and 7.1 μg m−2 d−1 and followed the seasonal pattern of the bulk parameters. Maximum fluxes occurred from mid-October until mid-November and were also high in May. A surprising result was that considerably higher particle fluxes were observed at 3000 m. For the alkenone flux, the highest additional input of 250% was observed during the period when sediment resuspension was greatest in summer. At the Barents Sea continental margin (traps at 1840 and 1950 m) the alkenone fluxes follow the sedimentation pattern of the bulk parameters, with a less visible signal of distinct seasonality observed in the 1950 m trap. The sedimentation of total alkenones varied between 0.8 and 144 μg m−2 d−1 at 1840 m and between 0.5 and 31.0 μg m−2 d−1 at 1950 m. Resuspension and lateral advection contributed significantly to measured fluxes in the two near-bottom traps. Alkenone concentrations were determined in faecal pellets of Appendicularia, ostracods and euphausids from selected samples at the Barents Sea site. The alkenone flux in pellets (4% to 24% of total) was 5 to 6 times higher at 1950 m depth than at 1840 m and the major part (77–78%) of the total flux of C37:3 reaching the near-bottom trap at 1950 m was associated with faecal pellets of the meso-zooplankton. Spatial and temporal variations of the U37k′ signals were observed, indicating that the imprint in the alkenone signal depends on the origin and transport pathway of the organic material. Strong deviations occur in areas where nepheloid layers contribute particles of long residence times to the primary flux. |
format |
Article in Journal/Newspaper |
author |
Thomsen, Claudia Schulz-Bull, Detlef E. Petrick, Gert Duinker, Jan C. |
spellingShingle |
Thomsen, Claudia Schulz-Bull, Detlef E. Petrick, Gert Duinker, Jan C. Seasonal variability of the long-chain alkenone flux and the effect on the U37k'-index in the Norwegian Sea |
author_facet |
Thomsen, Claudia Schulz-Bull, Detlef E. Petrick, Gert Duinker, Jan C. |
author_sort |
Thomsen, Claudia |
title |
Seasonal variability of the long-chain alkenone flux and the effect on the U37k'-index in the Norwegian Sea |
title_short |
Seasonal variability of the long-chain alkenone flux and the effect on the U37k'-index in the Norwegian Sea |
title_full |
Seasonal variability of the long-chain alkenone flux and the effect on the U37k'-index in the Norwegian Sea |
title_fullStr |
Seasonal variability of the long-chain alkenone flux and the effect on the U37k'-index in the Norwegian Sea |
title_full_unstemmed |
Seasonal variability of the long-chain alkenone flux and the effect on the U37k'-index in the Norwegian Sea |
title_sort |
seasonal variability of the long-chain alkenone flux and the effect on the u37k'-index in the norwegian sea |
publisher |
Elsevier |
publishDate |
1998 |
url |
https://oceanrep.geomar.de/id/eprint/4329/ https://oceanrep.geomar.de/id/eprint/4329/1/Thomsen.pdf https://doi.org/10.1016/S0146-6380(98)00003-5 |
geographic |
Barents Sea Norwegian Sea |
geographic_facet |
Barents Sea Norwegian Sea |
genre |
Barents Sea North Atlantic Norwegian Sea |
genre_facet |
Barents Sea North Atlantic Norwegian Sea |
op_relation |
https://oceanrep.geomar.de/id/eprint/4329/1/Thomsen.pdf Thomsen, C., Schulz-Bull, D. E., Petrick, G. and Duinker, J. C. (1998) Seasonal variability of the long-chain alkenone flux and the effect on the U37k'-index in the Norwegian Sea. Organic Geochemistry, 28 . pp. 311-323. DOI 10.1016/S0146-6380(98)00003-5 <https://doi.org/10.1016/S0146-6380%2898%2900003-5>. doi:10.1016/S0146-6380(98)00003-5 |
op_rights |
info:eu-repo/semantics/restrictedAccess |
op_doi |
https://doi.org/10.1016/S0146-6380(98)00003-5 |
container_title |
Organic Geochemistry |
container_volume |
28 |
container_issue |
5 |
container_start_page |
311 |
op_container_end_page |
323 |
_version_ |
1766370198533701632 |