Mesoscale Eddy Effects on the Subduction of North Pacific Eastern Subtropical Mode Water

2020 ◽  
Vol 125 (5) ◽  
Author(s):  
Ran Wang ◽  
Xuhua Cheng ◽  
Lixiao Xu ◽  
Jiajia Chen
Keyword(s):  
North Pacific ◽  
Mesoscale Eddy ◽  
Mode Water ◽  
Subtropical Mode Water

Enhanced warming of the subtropical mode water in the North Pacific and North Atlantic

2017 ◽  
Vol 7 (9) ◽  
pp. 656-658 ◽  
Author(s):  
Shusaku Sugimoto ◽  
Kimio Hanawa ◽  
Tomowo Watanabe ◽  
Toshio Suga ◽  
Shang-Ping Xie
Keyword(s):  
North Atlantic ◽  
North Pacific ◽  
Mode Water ◽  
Subtropical Mode Water ◽  
The North ◽  
The North Pacific

Climatology and decadal variations in multicore structure of the North Pacific subtropical mode water

2017 ◽  
Vol 122 (9) ◽  
pp. 7506-7520 ◽  
Author(s):  
Cong Liu ◽  
Shang-Ping Xie ◽  
Peiliang Li ◽  
Lixiao Xu ◽  
Wendian Gao
Keyword(s):  
North Pacific ◽  
Mode Water ◽  
Subtropical Mode Water ◽  
The North ◽  
Decadal Variations ◽  
The North Pacific

scholarly journals Observations of the Subtropical Mode Water Evolution from the Kuroshio Extension System Study

2006 ◽  
Vol 36 (3) ◽  
pp. 457-473 ◽  
Author(s):  
Bo Qiu ◽  
Peter Hacker ◽  
Shuiming Chen ◽  
Kathleen A. Donohue ◽  
D. Randolph Watts ◽  
...  
Keyword(s):  
North Pacific Ocean ◽  
Kuroshio Extension ◽  
Mesoscale Eddy ◽  
Lower Boundary ◽  
Late Winter ◽  
Mode Water ◽  
Subtropical Mode Water ◽  
Budget Analysis ◽  
Recirculation Gyre ◽  
The Kuroshio

Abstract Properties and seasonal evolution of North Pacific Ocean subtropical mode water (STMW) within and south of the Kuroshio Extension recirculation gyre are analyzed from profiling float data and additional hydrographic and shipboard ADCP measurements taken during 2004. The presence of an enhanced recirculation gyre and relatively low mesoscale eddy variability rendered this year favorable for the formation of STMW. Within the recirculation gyre, STMW formed from late-winter convection that reached depths greater than 450 m near the center of the gyre. The lower boundary of STMW, corresponding to σθ ≃ 25.5 kg m−3, was set by the maximum depth of the late-winter mixed layer. Properties within the deep portions of the STMW layer remained largely unchanged as the season progressed. In contrast, the upper boundary of the STMW layer eroded steadily as the seasonal thermocline deepened from late April to August. Vertical eddy diffusivity responsible for this erosion was estimated from a budget analysis of potential vorticity to be in the range of ∼2–5 × 10−4 m2 s−1. The latitudinal extent of the STMW formation was narrow, extending from 30°N to the Kuroshio Extension jet near 35°N. South of 30°N, STMW did not form locally but was transported from the recirculation gyre by lateral induction.

“Eddy Resolving” Observation of the North Pacific Subtropical Mode Water

2011 ◽  
Vol 41 (4) ◽  
pp. 666-681 ◽  
Author(s):  
Eitarou Oka ◽  
Toshio Suga ◽  
Chiho Sukigara ◽  
Katsuya Toyama ◽  
Keishi Shimada ◽  
...  
Keyword(s):  
High Resolution ◽  
North Pacific ◽  
Kuroshio Extension ◽  
Uniform Structure ◽  
Mode Water ◽  
Subtropical Mode Water ◽  
The North ◽  
Late Fall ◽  
The Kuroshio ◽  
The North Pacific

Abstract Hydrographic data obtained by high-resolution shipboard observations and Argo profiling floats have been analyzed to study the mesoscale structure and circulation of the North Pacific Subtropical Mode Water (STMW). The float data show that in the late winter of 2008, STMW having a temperature of approximately 18.8°, 17.7°, and 16.6°C formed west of 140°E, at 140°–150°E, and east of 150°E, respectively, in the recirculation gyre south of the Kuroshio Extension. After spring, the newly formed STMW gradually shift southward, decreasing in thickness. Simultaneously, the STMWs of 16.6° and 17.7°C are gradually stirred and then mixed in terms of properties. In late fall, they seem to be integrated to form a single group of STMWs having a temperature centered at 17.2°C. Such STMW circulation in 2008 is much more turbulent than that in 2006, which was investigated in a previous study. The difference between the two years is attributed to the more variable state of the Kuroshio Extension in 2008, associated with stronger eddy activities in the STMW formation region, which enhance the eddy transport of STMW. High-resolution shipboard observations were carried out southeast of Japan at 141°–147°E in the early fall of 2008. To the south of the Kuroshio Extension, STMW exists as a sequence of patches with a horizontal scale of 100–200 km, whose thick portions correspond well to the mesoscale deepening of the permanent pycnocline. The western (eastern) hydrographic sections are occupied mostly by the 17.7°C (16.6°C) STMW, within which the 16.6°C (17.7°C) STMW exists locally, mostly at locations where both the permanent pycnocline depth and the STMW thickness are maximum. This structure implies that the STMW patches are transported away from their respective formation sites, corresponding to a shift in the mesoscale anticyclonic circulations south of the Kuroshio Extension. Furthermore, 20%–30% of the observed STMW pycnostads have two or three potential vorticity minima, mostly near temperatures of 16.6° and 17.7°C. The authors presume that such a structure formed as a result of the interleaving of the 16.6° and 17.7°C STMWs after they are stirred by mesoscale circulations, following which they are vertically mixed to form the 17.2°C STMW observed in late fall. These results indicate the importance of horizontal processes in destroying the vertically uniform structure of STMW after spring, particularly when the Kuroshio Extension is in a variable state.

scholarly journals Decadal-scale variability of the North Pacific subtropical mode water and its influence on the pycnocline observed along 137°E

2020 ◽  
Author(s):  
Fumiaki Kobashi ◽  
Toshiya Nakano ◽  
Naoto Iwasaka ◽  
Tomomichi Ogata
Keyword(s):  
North Pacific ◽  
Numerical Models ◽  
Kuroshio Extension ◽  
Japan Meteorological Agency ◽  
Mode Water ◽  
Substantial Impact ◽  
Subtropical Mode Water ◽  
The North ◽  
Decadal Scale ◽  
The North Pacific

AbstractDecadal-scale variability of the North Pacific subtropical mode water (STMW) and its influence on the pycnocline are examined by analyzing Japan Meteorological Agency (JMA) repeat hydrographic observations along the 137°E meridian from 1972 to 2019, with a particular focus on the summer season when the seasonal upper pycnocline develops above the STMW. The STMW appears between 20° and 32°N at 137°E, with the thickness varying on decadal timescales of approximately 9–15 years. Argo float observations suggest that the observed change in the STMW thickness originates in the wintertime mixed layer south of the Kuroshio Extension in the preceding year. The STMW has a substantial impact on the pycnocline. The presence of thick STMW shoals the upper pycnocline, occasionally concurrent with the deepening of the lower main pycnocline. The change is robust in the upper pycnocline, where the heaving of isopycnal surfaces occurs with density anomalies up near the surface. The subtropical front (STF) at subsurface depths, which is associated with a northward shoaling of the upper pycnocline and is maintained by the STMW in the climatology, also changes on decadal timescales. A thick STMW increases the northward shoaling of the upper pycnocline and intensifies the STF. On decadal timescales, the STF variations are accounted for by the STMW-induced change in the upper pycnocline slope. The change in the STF due to mode waters is consistent with previous findings from numerical models.

North Pacific Eastern Subtropical Mode Water simulation and future projection

2015 ◽  
Vol 34 (3) ◽  
pp. 25-30 ◽  
Author(s):  
Ruibin Xia ◽  
Qinyu Liu ◽  
Lixiao Xu ◽  
Yiqun Lu
Keyword(s):  
North Pacific ◽  
Future Projection ◽  
Mode Water ◽  
Subtropical Mode Water ◽  
Water Simulation
Sign in / Sign up

Export Citation Format

Share Document