Vertical Profiles of 226Ra and 228Ra Activity Concentrations in the Western Subarctic Gyre of the Pacific Ocean
The vertical activity concentration distributions of the radium isotopes, 226Ra and 228Ra, which are useful as radiotracers, were obtained for the first time in the western Subarctic Pacific Gyre (WSAG). It was possible to detect short-lived 228Ra present from the surface to 400 m depth by analyzing...
Published in: | Frontiers in Marine Science |
---|---|
Main Authors: | , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Frontiers Media S.A.
2022
|
Subjects: | |
Online Access: | https://doi.org/10.3389/fmars.2022.824862 https://doaj.org/article/24a828643fe34210b323fad2c1845990 |
id |
ftdoajarticles:oai:doaj.org/article:24a828643fe34210b323fad2c1845990 |
---|---|
record_format |
openpolar |
spelling |
ftdoajarticles:oai:doaj.org/article:24a828643fe34210b323fad2c1845990 2023-05-15T18:28:08+02:00 Vertical Profiles of 226Ra and 228Ra Activity Concentrations in the Western Subarctic Gyre of the Pacific Ocean Hirofumi Tazoe Hajime Obata Takuya Hara Mutsuo Inoue Takahiro Tanaka Jun Nishioka 2022-05-01T00:00:00Z https://doi.org/10.3389/fmars.2022.824862 https://doaj.org/article/24a828643fe34210b323fad2c1845990 EN eng Frontiers Media S.A. https://www.frontiersin.org/articles/10.3389/fmars.2022.824862/full https://doaj.org/toc/2296-7745 2296-7745 doi:10.3389/fmars.2022.824862 https://doaj.org/article/24a828643fe34210b323fad2c1845990 Frontiers in Marine Science, Vol 9 (2022) radium-228 radium-226 Subarctic Gyre of the Pacific Ocean vertical flux lateral transport Science Q General. Including nature conservation geographical distribution QH1-199.5 article 2022 ftdoajarticles https://doi.org/10.3389/fmars.2022.824862 2022-12-31T03:05:39Z The vertical activity concentration distributions of the radium isotopes, 226Ra and 228Ra, which are useful as radiotracers, were obtained for the first time in the western Subarctic Pacific Gyre (WSAG). It was possible to detect short-lived 228Ra present from the surface to 400 m depth by analyzing large seawater samples. Low 228Ra and high 226Ra activity concentrations in the surface layer in the WSAG were strongly influenced by upwelled deeper water with nutrients. The activity concentration distribution of 226Ra especially was in good agreement with the silicate concentration distribution, which was consistent with previous reported findings. These distributions were uniform from the surface to 100 m of the dichothermal layer due to vertical mixing in winter. 228Ra activity concentration decreased with water depth below the pycnocline and reached the undetectable level at 600 m which was within the oxygen minimum layer. Estimations of vertical fluxes of 228Ra and nitrate according to 228Ra decay indicated that the vertical transport by eddy diffusion was a minor process for the 228Ra and nitrate fluxes, and lateral transport mainly affected 228Ra in the intermediate warm water, that is, the mesothermal layer below the main pycnocline. Vertical mixing or submarine underground water and lateral transport to the WSAG could yield this 228Ra in the intermediate depth. Article in Journal/Newspaper Subarctic Directory of Open Access Journals: DOAJ Articles Pacific Frontiers in Marine Science 9 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
radium-228 radium-226 Subarctic Gyre of the Pacific Ocean vertical flux lateral transport Science Q General. Including nature conservation geographical distribution QH1-199.5 |
spellingShingle |
radium-228 radium-226 Subarctic Gyre of the Pacific Ocean vertical flux lateral transport Science Q General. Including nature conservation geographical distribution QH1-199.5 Hirofumi Tazoe Hajime Obata Takuya Hara Mutsuo Inoue Takahiro Tanaka Jun Nishioka Vertical Profiles of 226Ra and 228Ra Activity Concentrations in the Western Subarctic Gyre of the Pacific Ocean |
topic_facet |
radium-228 radium-226 Subarctic Gyre of the Pacific Ocean vertical flux lateral transport Science Q General. Including nature conservation geographical distribution QH1-199.5 |
description |
The vertical activity concentration distributions of the radium isotopes, 226Ra and 228Ra, which are useful as radiotracers, were obtained for the first time in the western Subarctic Pacific Gyre (WSAG). It was possible to detect short-lived 228Ra present from the surface to 400 m depth by analyzing large seawater samples. Low 228Ra and high 226Ra activity concentrations in the surface layer in the WSAG were strongly influenced by upwelled deeper water with nutrients. The activity concentration distribution of 226Ra especially was in good agreement with the silicate concentration distribution, which was consistent with previous reported findings. These distributions were uniform from the surface to 100 m of the dichothermal layer due to vertical mixing in winter. 228Ra activity concentration decreased with water depth below the pycnocline and reached the undetectable level at 600 m which was within the oxygen minimum layer. Estimations of vertical fluxes of 228Ra and nitrate according to 228Ra decay indicated that the vertical transport by eddy diffusion was a minor process for the 228Ra and nitrate fluxes, and lateral transport mainly affected 228Ra in the intermediate warm water, that is, the mesothermal layer below the main pycnocline. Vertical mixing or submarine underground water and lateral transport to the WSAG could yield this 228Ra in the intermediate depth. |
format |
Article in Journal/Newspaper |
author |
Hirofumi Tazoe Hajime Obata Takuya Hara Mutsuo Inoue Takahiro Tanaka Jun Nishioka |
author_facet |
Hirofumi Tazoe Hajime Obata Takuya Hara Mutsuo Inoue Takahiro Tanaka Jun Nishioka |
author_sort |
Hirofumi Tazoe |
title |
Vertical Profiles of 226Ra and 228Ra Activity Concentrations in the Western Subarctic Gyre of the Pacific Ocean |
title_short |
Vertical Profiles of 226Ra and 228Ra Activity Concentrations in the Western Subarctic Gyre of the Pacific Ocean |
title_full |
Vertical Profiles of 226Ra and 228Ra Activity Concentrations in the Western Subarctic Gyre of the Pacific Ocean |
title_fullStr |
Vertical Profiles of 226Ra and 228Ra Activity Concentrations in the Western Subarctic Gyre of the Pacific Ocean |
title_full_unstemmed |
Vertical Profiles of 226Ra and 228Ra Activity Concentrations in the Western Subarctic Gyre of the Pacific Ocean |
title_sort |
vertical profiles of 226ra and 228ra activity concentrations in the western subarctic gyre of the pacific ocean |
publisher |
Frontiers Media S.A. |
publishDate |
2022 |
url |
https://doi.org/10.3389/fmars.2022.824862 https://doaj.org/article/24a828643fe34210b323fad2c1845990 |
geographic |
Pacific |
geographic_facet |
Pacific |
genre |
Subarctic |
genre_facet |
Subarctic |
op_source |
Frontiers in Marine Science, Vol 9 (2022) |
op_relation |
https://www.frontiersin.org/articles/10.3389/fmars.2022.824862/full https://doaj.org/toc/2296-7745 2296-7745 doi:10.3389/fmars.2022.824862 https://doaj.org/article/24a828643fe34210b323fad2c1845990 |
op_doi |
https://doi.org/10.3389/fmars.2022.824862 |
container_title |
Frontiers in Marine Science |
container_volume |
9 |
_version_ |
1766210493342547968 |