Regional Energetics Over the North Pacific, South China Sea and the Indonesian Seas During Winter

1978 ◽  
pp. 1283-1301
Author(s):  
Takio Murakami
Keyword(s):  
South China Sea ◽  
South China ◽  
North Pacific ◽  
Indonesian Seas ◽  
China Sea ◽  
The North ◽  
The North Pacific

Upwelling velocity and ventilation in the western South China Sea deduced from CFC-12 and SF6 observations

2021 ◽  
Vol 79 (1) ◽  
pp. 1-25
Author(s):  
Weimin Wang ◽  
Peng Huang ◽  
Hengxiang Deng ◽  
Mian Chen ◽  
Minggang Cai ◽  
...  
Keyword(s):  
South China Sea ◽  
Transit Time ◽  
South China ◽  
North Pacific ◽  
Time Distribution ◽  
China Sea ◽  
The North ◽  
Western South China Sea ◽  
Transit Time Distribution ◽  
The North Pacific

This study presents observations of the transient tracers CFC-12 and SF6 in the western South China Sea during the fall of 2015. A CFC-12 maximum was discovered in the western South China Sea at the subsurface layer (150–200 m), which could be traced back to the North Pacific Tropical Water. The transit time distribution approach was used to estimate the ventilation time in this area. The constrained Δ /Γ ratio of 0.5 was obtained using CFC-12/SF6 tracer pair. This ratio is lower than the empirical unit ratio of one as used for previous estimates. Waters in the northern region of the western South China Sea appear younger than waters in the southern region. The water mass corresponding to the salinity minimum has a mean age of ∼67 ± 16 years along the 15º N line (marked by the red dashed rectangle in Fig. 1), which increases to ∼76 ± 18 years along the 10º N line (blue dashed rectangle, Fig. 1). The higher mean ages indicate that the intermediate water was ventilated from the North Pacific, which is far distant from the South China Sea. The column inventory of Cant is ∼31.3 mol C m–2. Upwelling velocities of up to ∼55 × 10–5 m s–1 was computed using the tracer data, indicating that tracer-free water as yet not influenced by human perturbation could be carried to the upper layer by upwelling. Using the transit time distribution derived mean age with transient tracers provides a possible way to determine the ventilation time scale for the study area.

scholarly journals Interannual Variation of the Late Spring–Early Summer Monsoon Rainfall in the Northern Part of the South China Sea

2011 ◽  
Vol 24 (16) ◽  
pp. 4295-4313 ◽  
Author(s):  
Tsing-Chang Chen ◽  
Wan-Ru Huang ◽  
Ming-Cheng Yen
Keyword(s):  
South China Sea ◽  
South China ◽  
North Pacific ◽  
Interannual Variation ◽  
The South China Sea ◽  
The South ◽  
China Sea ◽  
Northern Vietnam ◽  
The North ◽  
The North Pacific

Abstract Major rainfall (≥60%) in the northern part of the South China Sea (between North Vietnam and Taiwan) during May–June (the mei-yu season—the first phase of the Southeast–East Asian monsoon) is produced by rainstorms originating over the northern Vietnam–southwestern China region and the northern part of the South China Sea. As observed in this study, the occurrence frequency of rainstorms and rainfall contribution by these rainstorms undergoes a distinct interannual variation, in-phase with those of monsoon westerlies in northern Indochina and sea surface temperature (SST) anomalies over the NOAA Niño-3.4 region ΔSST (Niño-3.4). This in-phase relationship between monsoon westerlies and the ΔSST (Niño-3.4) anomalies is a result of the filling (deepening) of the subtropical Asian continental thermal low in response to the ΔSST (Niño-3.4) warm (cold) anomalies. Accompanied with this response is a slight southward (northward) shift of the North Pacific convergence zone (NPCZ), which extends from southern China to the North Pacific east of Japan. Thus, a favorable environment that meets the Charney–Stern instability criterion in initiating rainstorm genesis is enhanced (suppressed) by the intensification (weakening) of the monsoon shear flow formed by the midtropospheric northwesterly flow around the northeast periphery of the Tibetan Plateau and the monsoon westerlies. The meridional shift of the NPCZ established an elongated anomalous convergence (divergence) zone of water vapor flux along rainstorm tracks to increase (reduce) the rain-producing efficiency of rainstorms. Consequently, this interannual rainfall variation between northern Vietnam and Taiwan is primarily caused by rainstorm genesis and rain-producing efficiency.

scholarly journals Excess total organic carbon in the intermediate water of the South China Sea and its export to the North Pacific

2009 ◽  
Vol 10 (12) ◽  
pp. n/a-n/a ◽  
Author(s):  
Minhan Dai ◽  
Feifei Meng ◽  
Tiantian Tang ◽  
Shu-Ji Kao ◽  
Jianrong Lin ◽  
...  
Keyword(s):  
Organic Carbon ◽  
South China Sea ◽  
Total Organic Carbon ◽  
South China ◽  
North Pacific ◽  
The South China Sea ◽  
Intermediate Water ◽  
China Sea ◽  
The North ◽  
The North Pacific

scholarly journals Intrusion of the North Pacific waters into the South China Sea

2000 ◽  
Vol 105 (C3) ◽  
pp. 6415-6424 ◽  
Author(s):  
Tangdong Qu ◽  
Humio Mitsudera ◽  
Toshio Yamagata
Keyword(s):  
South China Sea ◽  
South China ◽  
North Pacific ◽  
The South China Sea ◽  
The South ◽  
China Sea ◽  
The North ◽  
Pacific Waters ◽  
The North Pacific

scholarly journals Isolation of the South China Sea from the North Pacific Subtropical Gyre since the latest Miocene due to formation of the Luzon Strait

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shaoru Yin ◽  
F. Javier Hernández-Molina ◽  
Lin Lin ◽  
Jiangxin Chen ◽  
Weifeng Ding ◽  
...  
Keyword(s):  
South China Sea ◽  
South China ◽  
North Pacific ◽  
The South China Sea ◽  
Global Ocean ◽  
North Pacific Subtropical Gyre ◽  
The South ◽  
China Sea ◽  
The North ◽  
The North Pacific

AbstractThe North Pacific subtropical gyre (NPSG) plays a major role in present global ocean circulation. At times, the gyre has coursed through the South China Sea, but its role in the evolutionary development of that Sea remains uncertain. This work systematically describes a major shift in NPSG paleo-circulation evident from sedimentary features observed in seismic and bathymetric data. These data outline two contourite depositional systems—a buried one formed in the late Miocene, and a latest Miocene to present-day system. The two are divided by a prominent regional discontinuity that represents a major shift in paleo-circulation during the latest Miocene (~ 6.5 Ma). The shift coincides with the further restriction of the South China Sea with respect to the North Pacific due to the formation of the Luzon Strait as a consequence of further northwest movement of the Philippine Sea plate. Before that restriction, data indicate vigorous NPSG circulation in the South China Sea. Semi-closure, however, established a new oceanographic circulation regime in the latest Miocene. This work demonstrates the significant role of recent plate tectonics, gateway development, and marginal seas in the establishment of modern global ocean circulation.

scholarly journals Enhanced Diapycnal Mixing in the South China Sea

2009 ◽  
Vol 39 (12) ◽  
pp. 3191-3203 ◽  
Author(s):  
Jiwei Tian ◽  
Qingxuan Yang ◽  
Wei Zhao
Keyword(s):  
South China Sea ◽  
South China ◽  
North Pacific ◽  
Luzon Strait ◽  
The South China Sea ◽  
Diapycnal Mixing ◽  
China Sea ◽  
The North ◽  
Diapycnal Diffusivity ◽  
The North Pacific

Abstract Profiles of current velocity, temperature, and salinity were obtained in the Internal Wave and Mixing Experiment in the South China Sea (SCS), the Luzon Strait, and the North Pacific. The observations are examined for evidence of enhanced diapycnal mixing in the SCS, which reaches O(10−3 m2 s−1) in magnitude. Results from independent casts reveal that diapycnal diffusivity in the SCS and the Luzon Strait is elevated by two orders of magnitude over that of the smooth bathymetry in the North Pacific, which are typical of background values in an open ocean. The vertical distribution of diapycnal diffusivity is nonuniform in the SCS, exhibiting higher values at depths greater than about 1000 m. This result compares favorably with the direct microstructure measurements at four stations in the SCS. Velocity and density profiles are combined to estimate the internal tide energy flux generated in the Luzon Strait and directed into the SCS. The energy amounts to 10 GW, most of which is rationalized to be the potential energy source for enhanced mixing in the SCS.

scholarly journals Role of the South China Sea in Regulating the North Pacific Double-Gyre System

2017 ◽  
Vol 47 (7) ◽  
pp. 1617-1635 ◽  
Author(s):  
Haiyuan Yang ◽  
Lixin Wu ◽  
Shantong Sun ◽  
Zhaohui Chen
Keyword(s):  
South China Sea ◽  
South China ◽  
North Pacific ◽  
The South China Sea ◽  
China Sea ◽  
The North ◽  
The Kuroshio ◽  
The North Pacific ◽  
Double Gyre

AbstractThe role of the South China Sea (SCS) in regulating the North Pacific circulation is investigated using a two-layer quasigeostrophic (QG) model. The double-gyre circulations in the North Pacific with and without the SCS are compared and analyzed. It is found that the SCS acts as a sink of both potential vorticity (PV) and energy in the Pacific–SCS system for the mean state. Consequently, the Kuroshio and the upstream Kuroshio Extension (KE) are weaker in the presence of the SCS. Moreover, the eddy activity is also lower in the North Pacific Ocean because the barotropic instability is suppressed for a weaker circulation. In terms of low-frequency variations at interannual to decadal time scale, the presence of the SCS is found to enhance the variability of the latitudinal position and intensity of the KE jet. This is explained by a positive feedback process that is associated with the negative correlation between the inertia of the Kuroshio and its intrusion into the SCS.

Light Aircraft Navigation

1951 ◽  
Vol 4 (02) ◽  
pp. 167-177
Author(s):  
Michael Townsend
Keyword(s):  
South China Sea ◽  
South China ◽  
North Atlantic ◽  
North Pacific ◽  
Aleutian Islands ◽  
The North ◽  
Aircraft Navigation ◽  
The World ◽  
The North Atlantic ◽  
The North Pacific

This paper is an appreciation of the navigational problems encountered during a flight round the world in 1948, in a single-engined light aircraft. The route chosen (Fig. 2) covered nearly every type of flying weather in the world, from the perfect conditions of the Mediterranean in the summer to the severe climate of the Aleutian islands; navigation tests were provided by the overwater flights across the South China Sea (Hong Kong—Okinawa = 900 miles), the North Pacific (Chitose—Shemya = 1730 miles) and the North Atlantic.

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