Variation of Suspended Particles in the Bottom Layer of the East China Sea with Data from Seafloor Observatory

The in situ scattering and transmissometry laser (LISST-100X), equipped with an acoustic wave and current (AWAC) meter and conductivity, temperature, and depth (CTD) instruments over the seabed in the East China Sea, was used to monitor the variation in suspended particles in the bottom sea layer, including particle size distribution (PSD) and volume concentration. The power law approximation was tested to describe the variability in PSD based on the field data. The results show that the power law was robust in processing continuous data, accompanied with the same optimal reference particle size (~63 μm) and little change in the corresponding exponent (~3.4) in both periods. Suspended particles were divided into three types: macroflocs (>133 μm), microflocs (36–133 μm), and single grains (<36 μm). Particle sizes were coarse during the two seasons, with macroflocs representing more than 60% of all the suspended particles, especially in February, when the particle size spectra were usually open-ended. Results from the harmonic analysis method indicate that tidal-induced resuspension and advection are the major reasons for the diurnal dynamics of sediments. Due to the tidal asymmetry in the region, we only found one mode in volume concentration at the moment of maximum velocity. However, the ratios of macroflocs were bimodal, with maximum floods and ebbs in one tidal cycle in February, when the higher mode at the maximum ebbs may be contributed to by the flocculation of finer particles considering the decreasing ratios of finer particles. Due to the enhanced stratification and the clean barrier built up by the Taiwan Warm Current in the southeast corner, the significant daily variation in suspended particles observed in February weakened in September. The influence of waves was uncertain, although the correlation coefficient between significant wave height and volume concentration was about 64% in February.

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Variation of turbidity and particle transport in the bottom layer of the East China Sea

Deep Sea Research Part II Topical Studies in Oceanography ◽

10.1016/s0967-0645(02)00462-9 ◽

2003 ◽

Vol 50 (2) ◽

pp. 443-455 ◽

Cited By ~ 45

Author(s):

Akira Hoshika ◽

Terumi Tanimoto ◽

Yasufumi Mishima ◽

Kazuo Iseki ◽

Kazumaro Okamura

Keyword(s):

East China Sea ◽

Particle Transport ◽

Bottom Layer ◽

East China ◽

The East China Sea ◽

China Sea

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Water Exchange across Isobaths over the Continental Shelf of the East China Sea

Journal of Physical Oceanography ◽

10.1175/jpo-d-16-0231.1 ◽

2017 ◽

Vol 47 (5) ◽

pp. 1043-1060 ◽

Cited By ~ 14

Author(s):

Jing Zhang ◽

Xinyu Guo ◽

Liang Zhao ◽

Yasumasa Miyazawa ◽

Qun Sun

Keyword(s):

Continental Shelf ◽

East China Sea ◽

Water Exchange ◽

Bottom Layer ◽

Taiwan Strait ◽

East China ◽

The East China Sea ◽

China Sea ◽

The Taiwan Strait ◽

The Kuroshio

AbstractOnshore and offshore currents and the associated volume transport across three isobaths (50, 100, and 200 m) over the continental shelf of the East China Sea were examined using daily reanalysis data in 1993–2012. After being averaged along the isobaths, the velocities across 100 and 50 m are onshore in the bottom layer but offshore in the surface layer. In contrast, those across the 200-m isobath are onshore in the surface and bottom layers but without a clear direction in the midlayer, suggesting a three-layer structure. The surface offshore current across the 100-m isobath mainly arises from the Taiwan Strait Current, while the surface onshore current across the 200-m isobath mainly arises from the Kuroshio, both of which converge in the area between the 100- and 200-m isobaths and flow toward the Tsushima Strait. The control of bottom Ekman dynamics on the onshore bottom currents is important at the 100-m isobath, partly important at the 200-m isobath, and slightly important at the 50-m isobath. The seasonal variations of onshore and offshore currents in the surface layers across the three isobaths are likely caused by local winds, the Taiwan Strait Current, and the Changjiang discharge, while those in midlayer across the 200-m isobath demonstrate a strong geostrophic control and can be interpreted from a traditional viewpoint on the Kuroshio intrusion over the entire water column across the shelf slope. The close connection of bottom onshore currents across the three isobaths suggests that the bottom layer is an important pathway for water exchange of shelf water and the open sea.

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Vertical distribution of isoprenoid GDGTs in suspended particles from the East China Sea shelf and implications for sedimentary TEX86H records

Organic Geochemistry ◽

10.1016/j.orggeochem.2019.07.004 ◽

2019 ◽

Vol 136 ◽

pp. 103895 ◽

Cited By ~ 2

Author(s):

Yaoyao Wang ◽

Da-Wei Li ◽

Julian P. Sachs ◽

Jingwen Hu ◽

Yali Cao ◽

...

Keyword(s):

Vertical Distribution ◽

East China Sea ◽

Suspended Particles ◽

East China ◽

The East China Sea ◽

China Sea ◽

East China Sea Shelf

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Ontogenetic and inter-annual variation in the diet of Japanese jack mackerel (Trachurus japonicus) juveniles in the East China Sea

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315418000206 ◽

2018 ◽

Vol 99 (2) ◽

pp. 525-538 ◽

Cited By ~ 4

Author(s):

Chiyuki Sassa ◽

Satoshi Kitajima ◽

Kou Nishiuchi ◽

Motomitsu Takahashi

Keyword(s):

East China Sea ◽

Bottom Layer ◽

High Energy ◽

The Body ◽

East China ◽

The East China Sea ◽

Trachurus Japonicus ◽

China Sea ◽

Significant Difference ◽

Pelagic Juveniles

We examined the diet of pelagic juveniles ofTrachurus japonicusin the surface layer in April, and subsequent demersal juveniles in the near bottom layer during May to June of the East China Sea (ECS) in 2005, 2008 and 2009. Diet composition of the pelagic juveniles showed a significant difference between 2005 and the other two years. That is, they preyed mainly onParacalanus parvuss.l. and occasionally onCalanus sinicusin 2008 and 2009, while they fed mainly onCorycaeus affinisin 2005, partly corresponding with the between-year difference in prey densities. The demersal juveniles depended heavily on the fifth copepodites and females ofC. sinicuswhich store lipids in the body, i.e. high-energy food for the juveniles, without a significant inter-annual difference. The markedly low occurrence ofP. parvuss.l. andC. sinicus, which are considered to be energetically more favourable thanC. affinis, from the stomach of the pelagic juveniles in 2005 corresponded with the lowest growth rates of the pelagic juveniles in the three years. Potentially, this resulted in the lowest observed recruitment level of the demersal juveniles for the ECS in 2005 over these three years.

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