Influence of Salinity and Temperature Gradients on the Variability of the North Brazil Undercurrent
The North Brazil Undercurrent (NBUC) is a narrow (<1°) northward western boundary current in the tropical South Atlantic Ocean. It carries a large volume of water (>16 Sv) and plays an important role in the Atlantic Meridional Overturning Circulation and the South Atlantic Subtropical Cell. St...
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ftdoajarticles:oai:doaj.org/article:1635d9ccf6144c9f99b90626a0307fff 2023-05-15T18:21:13+02:00 Influence of Salinity and Temperature Gradients on the Variability of the North Brazil Undercurrent Hao Liu Zexun Wei Ingo Richter Xunwei Nie Chuanshun Li 2021-09-01T00:00:00Z https://doi.org/10.3389/fmars.2021.744833 https://doaj.org/article/1635d9ccf6144c9f99b90626a0307fff EN eng Frontiers Media S.A. https://www.frontiersin.org/articles/10.3389/fmars.2021.744833/full https://doaj.org/toc/2296-7745 2296-7745 doi:10.3389/fmars.2021.744833 https://doaj.org/article/1635d9ccf6144c9f99b90626a0307fff Frontiers in Marine Science, Vol 8 (2021) North Brazil Undercurrent salinity-based geostrophic velocity temperature-based geostrophic velocity temporal variability HYCOM OFES2 Science Q General. Including nature conservation geographical distribution QH1-199.5 article 2021 ftdoajarticles https://doi.org/10.3389/fmars.2021.744833 2022-12-31T07:02:11Z The North Brazil Undercurrent (NBUC) is a narrow (<1°) northward western boundary current in the tropical South Atlantic Ocean. It carries a large volume of water (>16 Sv) and plays an important role in the Atlantic Meridional Overturning Circulation and the South Atlantic Subtropical Cell. Strong salinity and temperature fronts occur over the NBUC region. The role of temperature and salinity gradients on the genesis of NBUC variability has never been explored. This study uses three high-resolution (≤0.1°) and one low-resolution (=0.25°) model outputs to explore the linear trend of NBUC transport and its variability on annual and interannual time scales. We find that the linear trend and interannual variability of the geostrophic NBUC transport show large discrepancies among the datasets. Thus, the linear trend and variability of the geostrophic NBUC are associated with model configuration. We also find that the relative contributions of salinity and temperature gradients to the geostrophic shear of the NBUC are not model dependent. Salinity-based and temperature-based geostrophic NBUC transports tend to be opposite-signed on all time scales. Despite the limited salinity and temperature profiles, the model results are consistent with the in-situ observations on the annual cycle and interannual time scales. This study shows the relationship of salinity-based and temperature-based geostrophic NBUC variations in the annual and interannual variability and trend among different models and highlights the equal important roles of temperature and salinity in driving the variability of NBUC transport. Article in Journal/Newspaper South Atlantic Ocean Directory of Open Access Journals: DOAJ Articles Frontiers in Marine Science 8 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
North Brazil Undercurrent salinity-based geostrophic velocity temperature-based geostrophic velocity temporal variability HYCOM OFES2 Science Q General. Including nature conservation geographical distribution QH1-199.5 |
spellingShingle |
North Brazil Undercurrent salinity-based geostrophic velocity temperature-based geostrophic velocity temporal variability HYCOM OFES2 Science Q General. Including nature conservation geographical distribution QH1-199.5 Hao Liu Zexun Wei Ingo Richter Xunwei Nie Chuanshun Li Influence of Salinity and Temperature Gradients on the Variability of the North Brazil Undercurrent |
topic_facet |
North Brazil Undercurrent salinity-based geostrophic velocity temperature-based geostrophic velocity temporal variability HYCOM OFES2 Science Q General. Including nature conservation geographical distribution QH1-199.5 |
description |
The North Brazil Undercurrent (NBUC) is a narrow (<1°) northward western boundary current in the tropical South Atlantic Ocean. It carries a large volume of water (>16 Sv) and plays an important role in the Atlantic Meridional Overturning Circulation and the South Atlantic Subtropical Cell. Strong salinity and temperature fronts occur over the NBUC region. The role of temperature and salinity gradients on the genesis of NBUC variability has never been explored. This study uses three high-resolution (≤0.1°) and one low-resolution (=0.25°) model outputs to explore the linear trend of NBUC transport and its variability on annual and interannual time scales. We find that the linear trend and interannual variability of the geostrophic NBUC transport show large discrepancies among the datasets. Thus, the linear trend and variability of the geostrophic NBUC are associated with model configuration. We also find that the relative contributions of salinity and temperature gradients to the geostrophic shear of the NBUC are not model dependent. Salinity-based and temperature-based geostrophic NBUC transports tend to be opposite-signed on all time scales. Despite the limited salinity and temperature profiles, the model results are consistent with the in-situ observations on the annual cycle and interannual time scales. This study shows the relationship of salinity-based and temperature-based geostrophic NBUC variations in the annual and interannual variability and trend among different models and highlights the equal important roles of temperature and salinity in driving the variability of NBUC transport. |
format |
Article in Journal/Newspaper |
author |
Hao Liu Zexun Wei Ingo Richter Xunwei Nie Chuanshun Li |
author_facet |
Hao Liu Zexun Wei Ingo Richter Xunwei Nie Chuanshun Li |
author_sort |
Hao Liu |
title |
Influence of Salinity and Temperature Gradients on the Variability of the North Brazil Undercurrent |
title_short |
Influence of Salinity and Temperature Gradients on the Variability of the North Brazil Undercurrent |
title_full |
Influence of Salinity and Temperature Gradients on the Variability of the North Brazil Undercurrent |
title_fullStr |
Influence of Salinity and Temperature Gradients on the Variability of the North Brazil Undercurrent |
title_full_unstemmed |
Influence of Salinity and Temperature Gradients on the Variability of the North Brazil Undercurrent |
title_sort |
influence of salinity and temperature gradients on the variability of the north brazil undercurrent |
publisher |
Frontiers Media S.A. |
publishDate |
2021 |
url |
https://doi.org/10.3389/fmars.2021.744833 https://doaj.org/article/1635d9ccf6144c9f99b90626a0307fff |
genre |
South Atlantic Ocean |
genre_facet |
South Atlantic Ocean |
op_source |
Frontiers in Marine Science, Vol 8 (2021) |
op_relation |
https://www.frontiersin.org/articles/10.3389/fmars.2021.744833/full https://doaj.org/toc/2296-7745 2296-7745 doi:10.3389/fmars.2021.744833 https://doaj.org/article/1635d9ccf6144c9f99b90626a0307fff |
op_doi |
https://doi.org/10.3389/fmars.2021.744833 |
container_title |
Frontiers in Marine Science |
container_volume |
8 |
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1766200369566711808 |