Radium Isotopes across the Arctic Ocean show Time Scales of Water Mass Ventilation and Increasing Shelf Inputs
The first full transarctic section of 228Ra in surface waters measured during GEOTRACES cruises PS94 and HLY1502 (2015) shows a consistent distribution with maximum activities in the Transpolar Drift. Activities in the central Arctic have increased from 2007 through 2011 to 2015. The increased 228Ra...
Published in: | Journal of Geophysical Research: Oceans |
---|---|
Main Authors: | , , , , , , , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
AGU (American Geophysical Union)
2018
|
Subjects: | |
Online Access: | https://oceanrep.geomar.de/id/eprint/43252/ https://oceanrep.geomar.de/id/eprint/43252/1/Loeff_Bauch_2018.pdf https://doi.org/10.1029/2018JC013888 |
id |
ftoceanrep:oai:oceanrep.geomar.de:43252 |
---|---|
record_format |
openpolar |
spelling |
ftoceanrep:oai:oceanrep.geomar.de:43252 2023-06-11T04:03:31+02:00 Radium Isotopes across the Arctic Ocean show Time Scales of Water Mass Ventilation and Increasing Shelf Inputs Rutgers van der Loeff, Michiel Kipp, Lauren Charette, Matthew A. Moore, Willard S. Black, Erin Stimac, Ingrid Charkin, Alexander Bauch, Dorothea Valk, Ole Karcher, Michael Krumpen, Thomas Casacuberta, Núria Smethie, William Rember, Robert 2018-07 text https://oceanrep.geomar.de/id/eprint/43252/ https://oceanrep.geomar.de/id/eprint/43252/1/Loeff_Bauch_2018.pdf https://doi.org/10.1029/2018JC013888 en eng AGU (American Geophysical Union) Wiley https://oceanrep.geomar.de/id/eprint/43252/1/Loeff_Bauch_2018.pdf Rutgers van der Loeff, M., Kipp, L., Charette, M. A., Moore, W. S., Black, E., Stimac, I., Charkin, A., Bauch, D. , Valk, O., Karcher, M., Krumpen, T., Casacuberta, N., Smethie, W. and Rember, R. (2018) Radium Isotopes across the Arctic Ocean show Time Scales of Water Mass Ventilation and Increasing Shelf Inputs. Open Access Journal of Geophysical Research: Oceans, 123 (7). pp. 4853-4873. DOI 10.1029/2018JC013888 <https://doi.org/10.1029/2018JC013888>. doi:10.1029/2018JC013888 cc_by_4.0 info:eu-repo/semantics/openAccess Article PeerReviewed 2018 ftoceanrep https://doi.org/10.1029/2018JC013888 2023-05-07T23:17:52Z The first full transarctic section of 228Ra in surface waters measured during GEOTRACES cruises PS94 and HLY1502 (2015) shows a consistent distribution with maximum activities in the Transpolar Drift. Activities in the central Arctic have increased from 2007 through 2011 to 2015. The increased 228Ra input is attributed to stronger wave action on shelves resulting from a longer ice‐free season. A concomitant decrease in the 228Th/228Ra ratio likely results from more rapid transit of surface waters depleted in 228Th by scavenging over the shelf. The 228Ra activities observed in intermediate waters (< 1500m) in the Amundsen Basin are explained by ventilation with shelf water on a time scale of about 15‐18 years, in good agreement with estimates based on SF6 and 129I/236U. The 228Th excess below the mixed layer up to 1500m depth can complement 234Th and 210Po as tracers of export production, after correction for the inherent excess resulting from the similarity of 228Ra and 228Th decay times. We show with a Th/Ra profile model that the 228Th/228Ra ratio below 1500m is inappropriate for this purpose because it is a delicate balance between horizontal supply of 228Ra and vertical flux of particulate 228Th. The accumulation of 226Ra in the deep Makarov Basin is not associated with an accumulation of Ba and can therefore be attributed to supply from decay of 230Th in the bottom sediment. We estimate a ventilation time of 480 years for the deep Makarov‐Canada Basin, in good agreement with previous estimates using other tracers. Article in Journal/Newspaper amundsen basin Arctic Arctic Arctic Ocean canada basin Central Arctic makarov basin OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) Arctic Arctic Ocean Canada Makarov Basin ENVELOPE(170.000,170.000,87.000,87.000) Amundsen Basin ENVELOPE(74.000,74.000,87.000,87.000) Journal of Geophysical Research: Oceans 123 7 4853 4873 |
institution |
Open Polar |
collection |
OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) |
op_collection_id |
ftoceanrep |
language |
English |
description |
The first full transarctic section of 228Ra in surface waters measured during GEOTRACES cruises PS94 and HLY1502 (2015) shows a consistent distribution with maximum activities in the Transpolar Drift. Activities in the central Arctic have increased from 2007 through 2011 to 2015. The increased 228Ra input is attributed to stronger wave action on shelves resulting from a longer ice‐free season. A concomitant decrease in the 228Th/228Ra ratio likely results from more rapid transit of surface waters depleted in 228Th by scavenging over the shelf. The 228Ra activities observed in intermediate waters (< 1500m) in the Amundsen Basin are explained by ventilation with shelf water on a time scale of about 15‐18 years, in good agreement with estimates based on SF6 and 129I/236U. The 228Th excess below the mixed layer up to 1500m depth can complement 234Th and 210Po as tracers of export production, after correction for the inherent excess resulting from the similarity of 228Ra and 228Th decay times. We show with a Th/Ra profile model that the 228Th/228Ra ratio below 1500m is inappropriate for this purpose because it is a delicate balance between horizontal supply of 228Ra and vertical flux of particulate 228Th. The accumulation of 226Ra in the deep Makarov Basin is not associated with an accumulation of Ba and can therefore be attributed to supply from decay of 230Th in the bottom sediment. We estimate a ventilation time of 480 years for the deep Makarov‐Canada Basin, in good agreement with previous estimates using other tracers. |
format |
Article in Journal/Newspaper |
author |
Rutgers van der Loeff, Michiel Kipp, Lauren Charette, Matthew A. Moore, Willard S. Black, Erin Stimac, Ingrid Charkin, Alexander Bauch, Dorothea Valk, Ole Karcher, Michael Krumpen, Thomas Casacuberta, Núria Smethie, William Rember, Robert |
spellingShingle |
Rutgers van der Loeff, Michiel Kipp, Lauren Charette, Matthew A. Moore, Willard S. Black, Erin Stimac, Ingrid Charkin, Alexander Bauch, Dorothea Valk, Ole Karcher, Michael Krumpen, Thomas Casacuberta, Núria Smethie, William Rember, Robert Radium Isotopes across the Arctic Ocean show Time Scales of Water Mass Ventilation and Increasing Shelf Inputs |
author_facet |
Rutgers van der Loeff, Michiel Kipp, Lauren Charette, Matthew A. Moore, Willard S. Black, Erin Stimac, Ingrid Charkin, Alexander Bauch, Dorothea Valk, Ole Karcher, Michael Krumpen, Thomas Casacuberta, Núria Smethie, William Rember, Robert |
author_sort |
Rutgers van der Loeff, Michiel |
title |
Radium Isotopes across the Arctic Ocean show Time Scales of Water Mass Ventilation and Increasing Shelf Inputs |
title_short |
Radium Isotopes across the Arctic Ocean show Time Scales of Water Mass Ventilation and Increasing Shelf Inputs |
title_full |
Radium Isotopes across the Arctic Ocean show Time Scales of Water Mass Ventilation and Increasing Shelf Inputs |
title_fullStr |
Radium Isotopes across the Arctic Ocean show Time Scales of Water Mass Ventilation and Increasing Shelf Inputs |
title_full_unstemmed |
Radium Isotopes across the Arctic Ocean show Time Scales of Water Mass Ventilation and Increasing Shelf Inputs |
title_sort |
radium isotopes across the arctic ocean show time scales of water mass ventilation and increasing shelf inputs |
publisher |
AGU (American Geophysical Union) |
publishDate |
2018 |
url |
https://oceanrep.geomar.de/id/eprint/43252/ https://oceanrep.geomar.de/id/eprint/43252/1/Loeff_Bauch_2018.pdf https://doi.org/10.1029/2018JC013888 |
long_lat |
ENVELOPE(170.000,170.000,87.000,87.000) ENVELOPE(74.000,74.000,87.000,87.000) |
geographic |
Arctic Arctic Ocean Canada Makarov Basin Amundsen Basin |
geographic_facet |
Arctic Arctic Ocean Canada Makarov Basin Amundsen Basin |
genre |
amundsen basin Arctic Arctic Arctic Ocean canada basin Central Arctic makarov basin |
genre_facet |
amundsen basin Arctic Arctic Arctic Ocean canada basin Central Arctic makarov basin |
op_relation |
https://oceanrep.geomar.de/id/eprint/43252/1/Loeff_Bauch_2018.pdf Rutgers van der Loeff, M., Kipp, L., Charette, M. A., Moore, W. S., Black, E., Stimac, I., Charkin, A., Bauch, D. , Valk, O., Karcher, M., Krumpen, T., Casacuberta, N., Smethie, W. and Rember, R. (2018) Radium Isotopes across the Arctic Ocean show Time Scales of Water Mass Ventilation and Increasing Shelf Inputs. Open Access Journal of Geophysical Research: Oceans, 123 (7). pp. 4853-4873. DOI 10.1029/2018JC013888 <https://doi.org/10.1029/2018JC013888>. doi:10.1029/2018JC013888 |
op_rights |
cc_by_4.0 info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1029/2018JC013888 |
container_title |
Journal of Geophysical Research: Oceans |
container_volume |
123 |
container_issue |
7 |
container_start_page |
4853 |
op_container_end_page |
4873 |
_version_ |
1768380135650623488 |