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.

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 The Changing Influences of ENSO and the Pacific Meridional Mode on Mesoscale Eddies in the South China Sea

2019 ◽  
Vol 32 (3) ◽  
pp. 685-700 ◽  
Author(s):  
Pengfei Tuo ◽  
Jin-Yi Yu ◽  
Jianyu Hu
Keyword(s):  
South China Sea ◽  
Wind Stress ◽  
South China ◽  
Southern Oscillation ◽  
The South China Sea ◽  
Eddy Correlation ◽  
The South ◽  
Vector Method ◽  
China Sea ◽  
The Pacific

This study finds that the correlation between El Niño–Southern Oscillation (ENSO) and the activity of mesoscale oceanic eddies in the South China Sea (SCS) changed around 2004. The mesoscale eddy number determined from satellite altimetry observations using a geometry of the velocity vector method was significantly and negatively correlated with the Niño-3.4 index before 2004, but the correlation weakened and became insignificant afterward. Further analyses reveal that the ENSO–eddy relation is controlled by two major wind stress forcing mechanisms: one directly related to ENSO and the other indirectly related to ENSO through its subtropical precursor—the Pacific meridional modes (PMMs). Both mechanisms induce wind stress curl variations over the SCS that link ENSO to SCS eddy activities. While the direct ENSO mechanism always induces a negative ENSO–eddy correlation through the Walker circulation, the indirect mechanism is dominated by the northern PMM (nPMM), resulting in a negative ENSO–eddy correlation before 2004, and by the southern PMM (sPMM) after 2004, resulting in a positive ENSO–eddy correlation. As a result, the direct and indirect mechanisms enhance each other to produce a significant ENSO–eddy relation before 2004, but they cancel each other out, resulting in a weak ENSO–eddy relation afterward. The relative strengths of the northern and southern PMMs are the key to determining the ENSO–eddy relation and may be related to a phase change of the interdecadal Pacific oscillation.

Taxonomic diversity of fish species in the Daya Bay, the South China Sea

2012 ◽  
Vol 35 (6) ◽  
pp. 863-870 ◽  
Author(s):  
Na-na LI ◽  
Li-na DONG ◽  
Yong-zhen LI ◽  
Hong AI ◽  
Xia LI ◽  
...  
Keyword(s):  
South China Sea ◽  
Fish Species ◽  
South China ◽  
Taxonomic Diversity ◽  
The South China Sea ◽  
Daya Bay ◽  
The South ◽  
China Sea

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 Influence of the Size of Supertyphoon Megi (2010) on SST Cooling

2018 ◽  
Vol 146 (3) ◽  
pp. 661-677 ◽  
Author(s):  
Iam-Fei Pun ◽  
I.-I. Lin ◽  
Chun-Chi Lien ◽  
Chun-Chieh Wu
Keyword(s):  
South China Sea ◽  
Size Effect ◽  
South China ◽  
Thermal Structure ◽  
The South China Sea ◽  
The South ◽  
Translation Speed ◽  
China Sea ◽  
Philippine Sea ◽  
Sst Cooling

Supertyphoon Megi (2010) left behind two very contrasting SST cold-wake cooling patterns between the Philippine Sea (1.5°C) and the South China Sea (7°C). Based on various radii of radial winds, the authors found that the size of Megi doubles over the South China Sea when it curves northward. On average, the radius of maximum wind (RMW) increased from 18.8 km over the Philippine Sea to 43.1 km over the South China Sea; the radius of 64-kt (33 m s−1) typhoon-force wind (R64) increased from 52.6 to 119.7 km; the radius of 50-kt (25.7 m s−1) damaging-force wind (R50) increased from 91.8 to 210 km; and the radius of 34-kt (17.5 m s−1) gale-force wind (R34) increased from 162.3 to 358.5 km. To investigate the typhoon size effect, the authors conduct a series of numerical experiments on Megi-induced SST cooling by keeping other factors unchanged, that is, typhoon translation speed and ocean subsurface thermal structure. The results show that if it were not for Megi’s size increase over the South China Sea, the during-Megi SST cooling magnitude would have been 52% less (reduced from 4° to 1.9°C), the right bias in cooling would have been 60% (or 30 km) less, and the width of the cooling would have been 61% (or 52 km) less, suggesting that typhoon size is as important as other well-known factors on SST cooling. Aside from the size effect, the authors also conduct a straight-track experiment and find that the curvature of Megi contributes up to 30% (or 1.2°C) of cooling over the South China Sea.

Coral δ18O records as an indicator of winter monsoon intensity in the South China Sea

2003 ◽  
Vol 59 (3) ◽  
pp. 285-292 ◽  
Author(s):  
Zicheng Peng ◽  
Tegu Chen ◽  
Baofu Nie ◽  
M. John Head ◽  
Xuexian He ◽  
...  
Keyword(s):  
South China Sea ◽  
South China ◽  
Southern Oscillation ◽  
Winter Monsoon ◽  
The South China Sea ◽  
The South ◽  
Porites Lutea ◽  
China Sea ◽  
Meteorological Observatory ◽  
Monsoon Intensity

AbstractWe have used correlative analysis between mean December–January–February winter wind velocities, measured at the Xisha Meteorological Observatory (16°50′N, 112°20′E) in the middle of the South China Sea, and mean δ18O data for the corresponding month from Porites lutea coral, collected in Longwan waters (19°20′N, 110°39′E), to obtain a linear equation relating the two datasets. This winter wind velocity for the South China Sea (WMIIscs) can then be correlated to the coral δ18O by the equation WMIIscs = −1.213–1.351 δ18O (‰ PDB), r = −0.60, n = 40, P = 0.01. From this, the calculated WMIIscs-δ18O series from 1944 to 1997 tends to decrease during the 1940s to the 1960s; it increases slightly during the 1970s and then decreases again in the 1980s and 1990s. The calculated decadal mean WMIIscs-δ18O series had a obvious decrease from 5.92 to 4.63 m/s during the period of 1944–1997. The calculated yearly mean WMIIscs-δ18O value is 5.58 m/s from 1944 to 1976 and this decreases to 4.85 m/s from 1977 to 1998. That is the opposite trend to the observed yearly mean SST variation. The yearly mean SST anomaly is −0.27° from 1943 to 1976 and this increases to +0.16° from 1977 to 1998. Spectral analysis used on a 54-year-long calculated WMIIscs-δ18O series produces spectral peaks at 2.4–7 yr, which can be closely correlated with the quasibiennial oscillation band (QBO band, 2–2.4 yr) and the El Ñino southern oscillation band (ENSO band, 3–8 yr). Hence most of the variability of the winter monsoon intensity in the middle of the South China Sea is mainly constrained by changes in the thermal difference between the land and the adjoining sea area, perhaps due to global warming.

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