Ocean thermodynamics behind the asymmetry of interannual variation of South China Sea winter cold tongue strength

2018 ◽  
Vol 52 (5-6) ◽  
pp. 3241-3253
Author(s):  
Marvin Xiang Ce Seow ◽  
Tomoki Tozuka
Keyword(s):  
South China Sea ◽  
South China ◽  
Interannual Variation ◽  
Cold Tongue ◽  
Tongue Strength ◽  
China Sea ◽  
Winter Cold ◽  
The Asymmetry

scholarly journals Dynamical and thermodynamical analysis of the South China Sea winter cold tongue

2015 ◽  
Vol 47 (5-6) ◽  
pp. 1629-1646 ◽  
Author(s):  
Bijoy Thompson ◽  
Pavel Tkalich ◽  
Paola Malanotte-Rizzoli ◽  
Bastien Fricot ◽  
Juliette Mas
Keyword(s):  
South China Sea ◽  
South China ◽  
The South China Sea ◽  
Cold Tongue ◽  
The South ◽  
China Sea ◽  
Winter Cold

scholarly journals Satellite observations of the small-scale cyclonic eddies in the western South China Sea

2014 ◽  
Vol 11 (9) ◽  
pp. 13515-13532
Author(s):  
F. Liu ◽  
S. Tang ◽  
C. Chen
Keyword(s):  
South China Sea ◽  
South China ◽  
Rotation Speed ◽  
Mesoscale Eddies ◽  
Small Scale ◽  
Western Boundary ◽  
Cold Tongue ◽  
China Sea ◽  
Western South China Sea ◽  
Offshore Transport

Abstract. High-resolution ocean color observation offers an opportunity to investigate the oceanic small-scale processes. In this study, The Medium Resolution Imaging Spectrometer (MERIS) daily 300 m data are used to study small-scale processes in the western South China Sea. It is indicated that the cyclonic eddies with horizontal scales of the order of 10 km are frequently observed during upwelling season of each year over 2004–2009. These small-scale eddies are generated in the vicinity of the southern front of the cold tongue, and then propagate eastward with a speed of approximately 12 cm s−1. This propagation speed is consistent with the velocity of the western boundary current. As a result, the small-scale eddies keep rotating high levels of the phytoplankton away from the coastal areas, resulting in the accumulation of phytoplankton in the interior of the eddies. The generation of the small-scale eddies may be associated with strengthening of the relative movement between the rotation speed of the anticylconic mesoscale eddies and the offshore transport. With the increases of the normalized rotation speed of the anticyclonic mesoscale eddies relative to the offshore transport, the offshore current become meander under the impacts of the anticyclonic mesoscale eddies. The meandered cold tongue and instability front may stimulate the generation of the small-scale eddies. Unidirectional uniform wind along cold tongue may also contribute to the formation of the small-scale eddies.

Interannual variation of the South China Sea circulation during winter: intensified in the southern basin

2018 ◽  
Vol 52 (3-4) ◽  
pp. 1917-1933 ◽  
Author(s):  
Tingting Zu ◽  
Huijie Xue ◽  
Dongxiao Wang ◽  
Bingxu Geng ◽  
Lili Zeng ◽  
...  
Keyword(s):  
South China Sea ◽  
South China ◽  
Interannual Variation ◽  
The South China Sea ◽  
The South ◽  
Southern Basin ◽  
China Sea ◽  
South China Sea Circulation

scholarly journals Interannual Variation of the Cold-Season Rainfall Center in the South China Sea

2017 ◽  
Vol 30 (2) ◽  
pp. 669-688 ◽  
Author(s):  
Tsing-Chang Chen ◽  
Jenq-Dar Tsay ◽  
Jun Matsumoto
Keyword(s):  
South China Sea ◽  
Shear Flow ◽  
South China ◽  
Interannual Variation ◽  
Cold Season ◽  
The Philippines ◽  
The South China Sea ◽  
Enso Cycle ◽  
Cold Surge ◽  
China Sea

During 15 November–31 December, a cold-season rainfall center appears in the southern part of the South China Sea (SCS) north of northwestern Borneo and juxtaposed along the southwest–northeast direction with rainfall centers for the Malay Peninsula and the Philippines. This SCS rainfall center also coincides geographically with the SCS surface trough. An effort is made to explore the formation mechanism of this rainfall center. It is primarily formed by the second intensification of heavy rainfall/flood cold surge vortex [CSV(HRF)] through its interaction with a cold surge flow over the SCS trough. Both the SCS rainfall center and the SCS surface trough are located at the easterly flow north of the near-equator trough. Modulated by the interannual variation of the cyclonic shear flow along the near-equator trough in concert with the El Niño–Southern Oscillation (ENSO) cycle, the SCS rainfall center undergoes an interannual variation. The impact of this ENSO cycle is accomplished through the regulation of CSV(HRF) trajectories originating from the Philippines vicinity and Borneo and propagating to different destinations. Rain-producing efficiency determined by the interannual variation of the divergent circulation accompanies the cyclonic shear flow around the near-equator trough in response to this ENSO cycle.

scholarly journals Interannual 14C Variations During 1977–1998 Recorded in Coral from Daya Bay, South China Sea

Radiocarbon ◽  
2004 ◽  
Vol 46 (2) ◽  
pp. 595-601 ◽  
Author(s):  
C D Shen ◽  
W X Yi ◽  
K F Yu ◽  
Y M Sun ◽  
Y Yang ◽  
...  
Keyword(s):  
South China Sea ◽  
Correlation Coefficient ◽  
South China ◽  
Interannual Variation ◽  
Southern Oscillation ◽  
Thermal Structure ◽  
The South China Sea ◽  
Daya Bay ◽  
The South ◽  
China Sea

Twenty-two annually banded samples of coral from 1977 to 1998 were collected from Daya Bay, South China Sea, and bomb 14C concentrations were determined. The interannual variation of coral Δ14C is controlled mainly by oceanic factors. In ENSO years, the coastwise upwelling current of the South China Sea has been intensified; hence, the coral Δ14C displays its minimum value. The interannual variation curve of Δ14C in coral bears a relationship with the Southern Oscillation Index (SOI) curves: the correlation coefficient between Δ14C and (SOI)w is 0.43 and the correlation coefficient between Δ14C and (SOI)y is 0.27. The coral Δ14C has no remarkable response to the variation of solar radiation energy. In the past 20 yr or so, the general situation and oceanic thermal structure of the South China Sea are still stable even though interannual variations in atmosphere-sea interaction and upwelling current driven by the tropical energy have occurred.

Roles of tropical remote forcings on the South China Sea winter atmospheric and cold tongue variabilities

2021 ◽  
pp. 1-51
Author(s):  
Marvin Xiang Ce Seow ◽  
Yushi Morioka ◽  
Tomoki Tozuka
Keyword(s):  
Indian Ocean ◽  
South China Sea ◽  
South China ◽  
Tropical Indian Ocean ◽  
Internal Variability ◽  
Tropical Pacific ◽  
The South China Sea ◽  
Cold Tongue ◽  
China Sea ◽  
The Tropical Pacific

AbstractInfluences from the tropical Pacific and Indian Oceans, and atmospheric internal variability on the South China Sea (SCS) atmospheric circulation and cold tongue (CT) variability in boreal winter and the relative roles of remote forcings at interannual time scales are studied using observational data, reanalysis products, and coupled model experiments. In the observation, strong CT years are accompanied by local cyclonic wind anomalies, which are an equatorial Rossby wave response to enhanced convection over the warmer-than-normal western equatorial Pacific associated with La Niña. Also, the cyclonic wind anomalies are an atmospheric Kelvin wave response to diabatic cooling anomalies linked to both the decaying late fall negative Indian Ocean Dipole (IOD) and winter atmospheric internal variability. Partially coupled experiments reveal that both the tropical Pacific air-sea coupling and atmospheric internal variability positively contribute to the coupled variability of the SCS CT, while the air-sea coupling over the tropical Indian Ocean weakens such variabilities. The northwest Pacific anticyclonic wind anomalies that usually precede El Niño–Southern Oscillation-independent negative IOD generated under the tropical Indian Ocean air-sea coupling undermine such variabilities.

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.

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