Low ocean-floor rises regulate subpolar sea surface temperature by forming baroclinic jets
Mitsudera, H.; Miyama, T.; Nishigaki, H.; Nakanowatari, T.; Nishikawa, T.; Nakamura, T.; Wagawa, T.; Furue, R.; Fujii, Y.; Ito, S. (2018). Low ocean-floor rises regulate subpolar sea surface temperature by forming baroclinic jets. Nature Comm. 9(1): 11 pp. https://dx.doi.org/10.1038/s41467-018-03526-z
In: Nature Communications. Nature Publishing Group: London. ISSN 2041-1723; e-ISSN 2041-1723, more
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| Authors | | Top |
- Mitsudera, H.
- Miyama, T.
- Nishigaki, H.
- Nakanowatari, T.
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- Nishikawa, T.
- Nakamura, T.
- Wagawa, T.
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- Furue, R.
- Fujii, Y.
- Ito, S.
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| Abstract |
Sea surface temperature (SST) fronts in mid- to high-latitude oceans have significant impacts on extratropical atmospheric circulations and climate. In the western subarctic Pacific, sharp SST fronts form between the cold subarctic water and the recently found quasi-stationary jets that advect warm waters originating in the Kuroshio northeastward. Here we present a new mechanism of the jet formation paying attention to the propagation of baroclinic Rossby waves that is deflected by eddy-driven barotropic flows over bottom rises, although their height is low (~500 m) compared with the depth of the North Pacific Ocean (~6000 m). Steered by the barotropic flows, Rossby waves bring a thicker upper layer from the subtropical gyre and a thinner upper layer from the subarctic gyre, thereby creating a thickness jump, hence a surface jet, where they converge. This study reveals an overlooked role of low-rise bottom topography in regulating SST anomalies in subpolar oceans. |
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