scholarly journals Overturning circulation that ventilates the intermediate layer of the Sea of Okhotsk and the North Pacific: The role of salinity advection

2015 ◽  
Vol 120 (3) ◽  
pp. 1462-1489 ◽  
Author(s):  
Junji Matsuda ◽  
Humio Mitsudera ◽  
Tomohiro Nakamura ◽  
Yuichiro Sasajima ◽  
Hiroyasu Hasumi ◽  
...  
Keyword(s):  
North Pacific ◽  
Intermediate Layer ◽  
Sea Of Okhotsk ◽  
Overturning Circulation ◽  
The Sea Of Okhotsk ◽  
The North ◽  
The North Pacific

scholarly journals Evidence of change in the sea of okhotsk: Implications for the north pacific

2003 ◽  
Vol 41 (1) ◽  
pp. 49-63 ◽  
Author(s):  
Katherine L. Hill ◽  
Andrew J. Weaver ◽  
Howard J. Freeland ◽  
Alexander Bychkov
Keyword(s):  
North Pacific ◽  
Sea Of Okhotsk ◽  
The Sea Of Okhotsk ◽  
The North ◽  
The North Pacific

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

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hung-Wei Shu ◽  
Humio Mitsudera ◽  
Kaihe Yamazaki ◽  
Tomohiro Nakamura ◽  
Takao Kawasaki ◽  
...  
Keyword(s):  
North Pacific ◽  
Sea Of Okhotsk ◽  
Western Boundary Current ◽  
Western Boundary ◽  
Boundary Current ◽  
Exchange Flows ◽  
The Sea Of Okhotsk ◽  
The North ◽  
Interbasin Exchange ◽  
The North Pacific

AbstractThe 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.

3D Structure of Striations in the North Pacific

2021 ◽  
Author(s):  
YU ZHANG ◽  
YU PING GUAN ◽  
RUI XIN HUANG
Keyword(s):  
North Pacific ◽  
3D Structure ◽  
Three Dimensional ◽  
Vertical Plane ◽  
Dimensional Structure ◽  
The North ◽  
Layer Analysis ◽  
Fluid Potential ◽  
The North Pacific

AbstractOcean striations are composed of alternating quasi-zonal band-like flows; this kind of organized structure of currents be found in all world’s oceans and seas. Previous studies have mainly been focused on the mechanisms of their generation and propagation. This study uses the spatial high-pass filtering to obtain the three-dimensional structure of ocean striations in the North Pacific in both the z-coordinate and σ-coordinate based on 10-yr averaged SODA3 data. First, we identify an ideal-fluid potential density domain where the striations are undisturbed by the surface forcing and boundary effects. Second, using the isopycnal layer analysis, we show that on isopycnal surfaces the orientations of striations nearly follow the potential vorticity (PV) contours, while in the meridional-vertical plane the central positions of striations are generally aligned with the latitude of zero gradient of the relative PV. Our analysis provides a simple dynamical interpretation and better understanding for the role of ocean striations.

The North Pacific Pacemaker Effect on Historical ENSO and Its Mechanisms

2019 ◽  
Vol 32 (22) ◽  
pp. 7643-7661 ◽  
Author(s):  
Dillon J. Amaya ◽  
Yu Kosaka ◽  
Wenyu Zhou ◽  
Yu Zhang ◽  
Shang-Ping Xie ◽  
...  
Keyword(s):  
El Niño ◽  
North Pacific ◽  
El Nino ◽  
Southern Oscillation ◽  
Deep Convection ◽  
Boreal Summer ◽  
Enso Events ◽  
The North ◽  
The North Pacific

Abstract Studies have indicated that North Pacific sea surface temperature (SST) variability can significantly modulate El Niño–Southern Oscillation (ENSO), but there has been little effort to put extratropical–tropical interactions into the context of historical events. To quantify the role of the North Pacific in pacing the timing and magnitude of observed ENSO, we use a fully coupled climate model to produce an ensemble of North Pacific Ocean–Global Atmosphere (nPOGA) SST pacemaker simulations. In nPOGA, SST anomalies are restored back to observations in the North Pacific (>15°N) but are free to evolve throughout the rest of the globe. We find that the North Pacific SST has significantly influenced observed ENSO variability, accounting for approximately 15% of the total variance in boreal fall and winter. The connection between the North and tropical Pacific arises from two physical pathways: 1) a wind–evaporation–SST (WES) propagating mechanism, and 2) a Gill-like atmospheric response associated with anomalous deep convection in boreal summer and fall, which we refer to as the summer deep convection (SDC) response. The SDC response accounts for 25% of the observed zonal wind variability around the equatorial date line. On an event-by-event basis, nPOGA most closely reproduces the 2014/15 and the 2015/16 El Niños. In particular, we show that the 2015 Pacific meridional mode event increased wind forcing along the equator by 20%, potentially contributing to the extreme nature of the 2015/16 El Niño. Our results illustrate the significant role of extratropical noise in pacing the initiation and magnitude of ENSO events and may improve the predictability of ENSO on seasonal time scales.

scholarly journals Eastward salinity anomaly propagation in the intermediate layer of the North Pacific

2017 ◽  
Vol 122 (2) ◽  
pp. 1590-1607 ◽  
Author(s):  
Shinya Kouketsu ◽  
Satoshi Osafune ◽  
Yuichiro Kumamoto ◽  
Hiroshi Uchida
Keyword(s):  
North Pacific ◽  
Intermediate Layer ◽  
The North ◽  
Salinity Anomaly ◽  
The North Pacific

scholarly journals The Role of Tropical Mean-State Biases in Modeled Winter Northern Hemisphere El Niño Teleconnections

2020 ◽  
Vol 33 (11) ◽  
pp. 4751-4768 ◽  
Author(s):  
Samantha Ferrett ◽  
Matthew Collins ◽  
Hong-Li Ren ◽  
Bo Wu ◽  
Tianjun Zhou
Keyword(s):  
Northern Hemisphere ◽  
El Niño ◽  
North Pacific ◽  
El Nino ◽  
Teleconnection Pattern ◽  
The North ◽  
Precipitation Response ◽  
The North Pacific ◽  
Mean State

AbstractThe role of tropical mean-state biases in El Niño–Southern Oscillation teleconnections in the winter Northern Hemisphere is examined in coupled general circulation models from phase 5 of the Coupled Model Intercomparison Project (CMIP5). The main North Pacific teleconnection pattern, defined here by the strengths of the anomalous Kuroshio anticyclone and North Pacific cyclone, is linked to two anomalous Rossby wave sources that occur during El Niño: a negative source over East Asia and a positive source to the west of the North Pacific. Errors in the teleconnection pattern in models are associated with spatial biases in mean atmospheric ascent and descent and the strength of the corresponding forcing of Rossby waves via suppressed or enhanced El Niño precipitation responses in the tropical western North Pacific (WNP) and the equatorial central Pacific (CP). The WNP El Niño precipitation response is most strongly linked to the strength of the Kuroshio anticyclone and the CP El Niño precipitation response is most strongly linked to the strength of the North Pacific cyclone. The mean state and corresponding El Niño precipitation response can have seemingly distinct biases. A bias in the WNP does not necessarily correspond to a bias in the CP, suggesting that improvement of biases in both tropical WNP and equatorial CP regions should be considered for an accurate teleconnection pattern.

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