Large-scale seaweed cultivation diverges water and sediment microbial communities in the coast of Nan'ao Island, South China Sea

AbstractTopographic Rossby waves (TRWs) in the abyssal South China Sea (SCS) are investigated using observations and high-resolution numerical simulations. These energetic waves can account for over 40% of the kinetic energy (KE) variability in the deep western boundary current and seamount region in the central SCS. This proportion can even reach 70% over slopes in the northern and southern SCS. The TRW-induced currents exhibit columnar (i.e., in-phase) structure in which the speed increases downward. Wave properties such as the period (5–60 days), wavelength (100–500 km), and vertical trapping scale (102–103 m) vary significantly depending on environmental parameters of the SCS. The TRW energy propagates along steep topography with phase propagation offshore. TRWs with high frequencies exhibit a stronger climbing effect than low-frequency ones and hence can move further upslope. For TRWs with a certain frequency, the wavelength and trapping scale are dominated by the topographic beta, whereas the group velocity is more sensitive to the internal Rossby deformation radius. Background circulation with horizontal shear can change the wavelength and direction of TRWs if the flow velocity is comparable to the group velocity, particularly in the central, southern, and eastern SCS. A case study suggests two possible energy sources for TRWs: mesoscale perturbation in the upper layer and large-scale background circulation in the deep layer. The former provides KE by pressure work, whereas the latter transfers the available potential energy (APE) through baroclinic instability.

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Differences in microbial communities between healthy and bleached coral Acropora solitaryensis from Xisha Islands, South China Sea

Marine Biology Research ◽

10.1080/17451000.2016.1236201 ◽

2016 ◽

Vol 12 (10) ◽

pp. 1101-1108

Author(s):

Zhuhong Liu ◽

Chang Chen ◽

Lei Gao ◽

Yuyang Zhang ◽

Jingjing Pei ◽

...

Keyword(s):

South China Sea ◽

Microbial Communities ◽

South China ◽

Xisha Islands ◽

China Sea ◽

Bleached Coral

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Significant Changes in Microbial Communities Associated With Reef Corals in the Southern South China Sea During the 2015/2016 Global‐Scale Coral Bleaching Event

Journal of Geophysical Research Oceans ◽

10.1029/2019jc015579 ◽

2020 ◽

Vol 125 (7) ◽

Author(s):

Zhenjun Qin ◽

Kefu Yu ◽

Jiayuan Liang ◽

Qiucui Yao ◽

Biao Chen

Keyword(s):

South China Sea ◽

Microbial Communities ◽

South China ◽

Coral Bleaching ◽

Global Scale ◽

Bleaching Event ◽

Southern South China Sea ◽

Reef Corals ◽

China Sea

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Eddy characteristics in the northern South China Sea as inferred from Lagrangian drifter data

Ocean Science ◽

10.5194/os-7-661-2011 ◽

2011 ◽

Vol 7 (5) ◽

pp. 661-669 ◽

Cited By ~ 26

Author(s):

◽

Keyword(s):

South China Sea ◽

South China ◽

Large Scale ◽

Northern South China Sea ◽

Temporal Distribution ◽

Height Anomaly ◽

Spatial And Temporal Patterns ◽

China Sea ◽

Eddy Characteristics ◽

Anticyclonic Eddies

Abstract. Cyclonic and anticyclonic eddies from large scale to submesoscale in the northern South China Sea (NSCS) have been statistically characterized based on the satellite-tracked Lagrangian drifters using our developed geometric eddy identification method. There are in total 2208 eddies identified, 70% of which are anticyclonic eddies. If the submesoscale eddies are eliminated, the other eddies in the NSCS will show a 1.2:1 ratio of the number of anticyclones (210) to the number of cyclones (171). The spatial distribution of the eddies is regional: in southwest of Taiwan, the number of anticyclones dominates the number of cyclones, and most of them are the submesoscale anticyclones with small radii; in contrast, the large and medium cyclonic eddies are a little more than the same scale anticyclonic eddies in northwest of Luzon. The temporal distribution of eddy number in the NSCS has a close relation with the Asian monsoon. The number of the large and medium eddies peaks during the winter monsoon, while the submesoscale eddies are apt to generate in the summer monsoon. The spatial and temporal patterns have a good agreement with the results of the sea surface height anomaly (SSHA). The maximum and mean tangential velocities of anticyclones (cyclones) are 40 (30) cm s−1 and 25 (15) cm s−1, respectively. The calculated normalized vorticities from drifters suggest that although the mesoscale eddies may be considered in geostrophic balance, ageostrophic dynamics and centrifugal effects may play an important role for the growth and decay of the mesoscale cores.

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Analysis of Severe Droughts in Taiwan and its Related Atmospheric and Oceanic Environments

Atmosphere ◽

10.3390/atmos10030159 ◽

2019 ◽

Vol 10 (3) ◽

pp. 159 ◽

Cited By ~ 1

Author(s):

Chih-wen Hung ◽

Ming-Fu Shih

Keyword(s):

South China Sea ◽

South China ◽

Large Scale ◽

Drought Index ◽

The South China Sea ◽

Severe Drought ◽

The South ◽

China Sea ◽

Dry Conditions ◽

Oceanic Environments

Drought is one of the important issues in climate studies. A drought index, Taiwan Meteorological Drought index (TMD index), was previously proposed and is applied here to identify historical severe droughts in Taiwan in order to clarify the corresponding large-scale backgrounds as a potential alert to the society in future. Through the TMD index, several historical severe drought cases in Taiwan are detected and characterized by significant seasonal variability in the annual cycle. Composites for large-scale atmospheric and oceanic environments over different periods within the dry season are conducted. From October to December, the colder sea surface temperature (SST) pattern of Pacific Meridional Mode (PMM) and the PMM-induced local anomalous anticyclones over the South China Sea are both in charge of the extremely dry conditions in Taiwan. From January to February, cold SST in the South China Sea and its adjacent oceans dominates local atmospheric conditions above these regions and creates an unfavorable environment for convection systems. From March to May, a massive anomalous anticyclonic circulation centering beside Alaska and extending its properties to East Asia and Taiwan generates a descending environment and in turn suppresses convection systems to develop. Therefore, the extremely dry conditions under this system are expected.

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Partitioning between strike-slip and orthogonal extension in the western South China Sea

10.5194/egusphere-egu2020-9137 ◽

2020 ◽

Author(s):

Pan Luo ◽

Jianye Ren ◽

Xi He ◽

Chao Lei ◽

Junjie Xu ◽

...

Keyword(s):

South China Sea ◽

Continental Crust ◽

South China ◽

Large Scale ◽

Strike Slip ◽

Fault System ◽

Relative Role ◽

China Sea ◽

Kinematic Evolution ◽

Mantle Exhumation

Our study focuses on the Zhongjianna (ZJN) (Phu Kham) Basin, located at the western termination of the South China Sea (SCS) and separated from the Indochina continent by the N-S striking East Vietnam Boundary Fault Zone, which is a large scale strike-slip fault system. The sedimentary infill history of the ZJN basin records the complete evolution and interaction of the Indochina-SCS system and allows the tectonic and kinematic evolution of the basin to be understood.. The discovery of hyper-extended continental crust and mantle exhumation in this basin leads to the question of what is the relative role of large-scale strike-slip and orthogonal faulting in controlling crustal thinning in the ZJN basin.&#160;&#160;&#160;&#160;Our preliminary results confirm the existence of hyperextended continental crust flooring the ZJN basin. Two different types of structures can be identified in this area: extension related deformation in the eastern part and strike-slip related deformation in the western part. The analysis of fault geometries and kinematics linked to timing and subsidence rates suggest that the N-S-orientated strike-slip structures dominated the continental shelf and slope area on the west side of the basin. In the basin, however, most faults strike NE-SW and are parallel to the mid-ocean ridge. Thus, it appears that the ZJN basin resulted from the partitioning between strike-slip and orthogonal extension.In our presentation we show the results of our seismic interpretation, strain and subsidence analysis and discuss the interaction between strike-slip and orthogonal extension in setting up the hyper-extended ZJN basin and its implications for the large scale tectonic and geodynamic framework.

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Formalin-Fixed Fish Larvae Could Be Effectively Identified by DNA Barcodes: A Case Study on Thousands of Specimens in South China Sea

Frontiers in Marine Science ◽

10.3389/fmars.2021.634575 ◽

2021 ◽

Vol 8 ◽

Author(s):

Gang Hou ◽

Yanying Chen ◽

Sijin Wang ◽

Jinrun Wang ◽

Weitao Chen ◽

...

Keyword(s):

South China Sea ◽

South China ◽

Large Scale ◽

Fish Larvae ◽

Morphological Characters ◽

Dna Barcodes ◽

High Quality ◽

China Sea ◽

Early Stages ◽

Formalin Fixed

Delimiting ichthyoplankton is fundamental work for monitoring the recruitment process and identifying the spawning and nursing grounds of fishes. Nevertheless, it is extremely difficult to identify the fish during the early stages at the species level based on morphological characters because of the paucity of diagnostic features. In this study, we investigated the fish larval community through large-scale ecosystemic sampling in South China Sea (SCS) during 2013 and 2017 using DNA barcodes. To maintain the morphologies of fish larvae, we preserved the larvae in formalin and developed a technique to recover their DNA. Among the 3,500 chosen larvae, we successfully extracted DNA from 2,787 larval samples and obtained 1,006 high-quality sequences. Blast searches showed that 408 larvae (i.e., 40.5%) could be unambiguously identified to species, 413 larvae (i.e., 41.1%) were ambiguously species delimitation, and 185 larvae (i.e., 18.4%) showed a low match similarity with target sequences. A total of 101 species were identified, among which 38 and 33 species corresponded to demersal and reef-associated species, whereas the remaining 30 species corresponded to benthopelagic, pelagic-oceanic, bathypelagic, and pelagic-neritic species. High-quality larval photographs of the 101 diagnosed species showed intact morphological characters and thus provided a reference for identifying fish species during the early stages based on morphological characters. Our study highlighted the possibility of recovering and amplifying DNA from formalin-fixed samples and provided new insight into the fish larval community in the SCS.

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Arctic and Antarctic Oscillation signatures in tropical coral proxies over the South China Sea

Annales Geophysicae ◽

10.5194/angeo-27-1979-2009 ◽

2009 ◽

Vol 27 (5) ◽

pp. 1979-1988 ◽

Cited By ~ 8

Author(s):

D.-Y. Gong ◽

S.-J. Kim ◽

C.-H. Ho

Keyword(s):

South China Sea ◽

South China ◽

Large Scale ◽

Horizontal Wind ◽

Time Lags ◽

Antarctic Oscillation ◽

Similar Time ◽

Sea Level Pressure ◽

Tropical Regions ◽

China Sea

Abstract. Arctic Oscillation (AO) and Antarctic Oscillation (AAO) are the leading modes of atmospheric circulation in mid-high latitudes. Previous studies have revealed that the climatic influences of the two modes are dominant in extra-tropical regions. This study finds that AO and AAO signals are also well recorded in coral proxies in the tropical South China Sea. There are significant interannual signals of AO and AAO in the strontium (Sr) content, which represents the sea surface temperature (SST). Among all the seasons, the most significant correlation occurs during winter in both hemispheres: the strongest AO-Sr and AAO-Sr coral correlations occur in January and August, respectively. This study also determined that the Sr content lags behind AO and AAO by 1–3 months. Large-scale anomalies in sea level pressure and horizontal wind at 850 hPa level support the strength of AO/AAO-coral teleconnections. In addition, a comparison with oxygen isotope records from two coral sites in neighboring oceans yields significant AO and AAO signatures with similar time lags. These results help to better understand monsoon climates and their teleconnection to high-latitude climate changes.

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