Tidally modified western boundary current drives interbasin exchange between the Sea of Okhotsk and the North Pacific

Abstract The interbasin exchange between the Sea of Okhotsk and the North Pacific governs the intermediate water ventilation and fertilization of the nutrient-rich subpolar Pacific, and thus has an enormous influence on the North Pacific. However, the mechanism of this exchange is puzzling; current...

Descripción completa

Guardado en:

Detalles Bibliográficos
Autores principales:	Hung-Wei Shu, Humio Mitsudera, Kaihe Yamazaki, Tomohiro Nakamura, Takao Kawasaki, Takuya Nakanowatari, Hatsumi Nishikawa, Hideharu Sasaki
Formato:	article
Lenguaje:	EN
Publicado:	Nature Portfolio 2021
Materias:	Medicine R Science Q
Acceso en línea:	https://doaj.org/article/234c67820dc84a83b6a4135ffa9b0295
Etiquetas:	Agregar Etiqueta Sin Etiquetas, Sea el primero en etiquetar este registro!

id	oai:doaj.org-article:234c67820dc84a83b6a4135ffa9b0295
record_format	dspace
spelling	oai:doaj.org-article:234c67820dc84a83b6a4135ffa9b02952021-12-02T17:34:30ZTidally modified western boundary current drives interbasin exchange between the Sea of Okhotsk and the North Pacific10.1038/s41598-021-91412-y2045-2322https://doaj.org/article/234c67820dc84a83b6a4135ffa9b02952021-06-01T00:00:00Zhttps://doi.org/10.1038/s41598-021-91412-yhttps://doaj.org/toc/2045-2322Abstract The interbasin exchange between the Sea of Okhotsk and the North Pacific governs the intermediate water ventilation and fertilization of the nutrient-rich subpolar Pacific, and thus has an enormous influence on the North Pacific. However, the mechanism of this exchange is puzzling; current studies have not explained how the western boundary current (WBC) of the subarctic North Pacific intrudes only partially into the Sea of Okhotsk. High-resolution models often exhibit unrealistically small exchanges, as the WBC overshoots passing by deep straits and does not induce exchange flows. Therefore, partial intrusion cannot be solely explained by large-scale, wind-driven circulation. Here, we demonstrate that tidal forcing is the missing mechanism that drives the exchange by steering the WBC pathway. Upstream of the deep straits, tidally-generated topographically trapped waves over a bank lead to cross-slope upwelling. This upwelling enhances bottom pressure, thereby steering the WBC pathway toward the deep straits. The upwelling is identified as the source of joint-effect-of-baroclinicity-and-relief (JEBAR) in the potential vorticity equation, which is caused by tidal oscillation instead of tidally-enhanced vertical mixing. The WBC then hits the island chain and induces exchange flows. This tidal control of WBC pathways is applicable on subpolar and polar regions globally.Hung-Wei ShuHumio MitsuderaKaihe YamazakiTomohiro NakamuraTakao KawasakiTakuya NakanowatariHatsumi NishikawaHideharu SasakiNature PortfolioarticleMedicineRScienceQENScientific Reports, Vol 11, Iss 1, Pp 1-16 (2021)
institution	DOAJ
collection	DOAJ
language	EN
topic	Medicine R Science Q
spellingShingle	Medicine R Science Q Hung-Wei Shu Humio Mitsudera Kaihe Yamazaki Tomohiro Nakamura Takao Kawasaki Takuya Nakanowatari Hatsumi Nishikawa Hideharu Sasaki Tidally modified western boundary current drives interbasin exchange between the Sea of Okhotsk and the North Pacific
description	Abstract The interbasin exchange between the Sea of Okhotsk and the North Pacific governs the intermediate water ventilation and fertilization of the nutrient-rich subpolar Pacific, and thus has an enormous influence on the North Pacific. However, the mechanism of this exchange is puzzling; current studies have not explained how the western boundary current (WBC) of the subarctic North Pacific intrudes only partially into the Sea of Okhotsk. High-resolution models often exhibit unrealistically small exchanges, as the WBC overshoots passing by deep straits and does not induce exchange flows. Therefore, partial intrusion cannot be solely explained by large-scale, wind-driven circulation. Here, we demonstrate that tidal forcing is the missing mechanism that drives the exchange by steering the WBC pathway. Upstream of the deep straits, tidally-generated topographically trapped waves over a bank lead to cross-slope upwelling. This upwelling enhances bottom pressure, thereby steering the WBC pathway toward the deep straits. The upwelling is identified as the source of joint-effect-of-baroclinicity-and-relief (JEBAR) in the potential vorticity equation, which is caused by tidal oscillation instead of tidally-enhanced vertical mixing. The WBC then hits the island chain and induces exchange flows. This tidal control of WBC pathways is applicable on subpolar and polar regions globally.
format	article
author	Hung-Wei Shu Humio Mitsudera Kaihe Yamazaki Tomohiro Nakamura Takao Kawasaki Takuya Nakanowatari Hatsumi Nishikawa Hideharu Sasaki
author_facet	Hung-Wei Shu Humio Mitsudera Kaihe Yamazaki Tomohiro Nakamura Takao Kawasaki Takuya Nakanowatari Hatsumi Nishikawa Hideharu Sasaki
author_sort	Hung-Wei Shu
title	Tidally modified western boundary current drives interbasin exchange between the Sea of Okhotsk and the North Pacific
title_short	Tidally modified western boundary current drives interbasin exchange between the Sea of Okhotsk and the North Pacific
title_full	Tidally modified western boundary current drives interbasin exchange between the Sea of Okhotsk and the North Pacific
title_fullStr	Tidally modified western boundary current drives interbasin exchange between the Sea of Okhotsk and the North Pacific
title_full_unstemmed	Tidally modified western boundary current drives interbasin exchange between the Sea of Okhotsk and the North Pacific
title_sort	tidally modified western boundary current drives interbasin exchange between the sea of okhotsk and the north pacific
publisher	Nature Portfolio
publishDate	2021
url	https://doaj.org/article/234c67820dc84a83b6a4135ffa9b0295
work_keys_str_mv	AT hungweishu tidallymodifiedwesternboundarycurrentdrivesinterbasinexchangebetweentheseaofokhotskandthenorthpacific AT humiomitsudera tidallymodifiedwesternboundarycurrentdrivesinterbasinexchangebetweentheseaofokhotskandthenorthpacific AT kaiheyamazaki tidallymodifiedwesternboundarycurrentdrivesinterbasinexchangebetweentheseaofokhotskandthenorthpacific AT tomohironakamura tidallymodifiedwesternboundarycurrentdrivesinterbasinexchangebetweentheseaofokhotskandthenorthpacific AT takaokawasaki tidallymodifiedwesternboundarycurrentdrivesinterbasinexchangebetweentheseaofokhotskandthenorthpacific AT takuyanakanowatari tidallymodifiedwesternboundarycurrentdrivesinterbasinexchangebetweentheseaofokhotskandthenorthpacific AT hatsuminishikawa tidallymodifiedwesternboundarycurrentdrivesinterbasinexchangebetweentheseaofokhotskandthenorthpacific AT hideharusasaki tidallymodifiedwesternboundarycurrentdrivesinterbasinexchangebetweentheseaofokhotskandthenorthpacific
_version_	1718379928607522816

Tidally modified western boundary current drives interbasin exchange between the Sea of Okhotsk and the North Pacific

Ejemplares similares