An Expendable Microstructure Profiler for Deep Ocean Measurements

2017 ◽  
Vol 34 (1) ◽  
pp. 153-165 ◽  
Author(s):  
Xiaodong Shang ◽  
Yongfeng Qi ◽  
Guiying Chen ◽  
Changrong Liang ◽  
Rolf G. Lueck ◽  
...  
Keyword(s):  
Pacific Ocean ◽  
South China Sea ◽  
South China ◽  
Deep Ocean ◽  
Western Pacific ◽  
Western Pacific Ocean ◽  
Southern South China Sea ◽  
China Sea ◽  
Dissipation Rates ◽  
The Western Pacific

AbstractMeasurements of turbulence in the deep ocean, particularly close to the bottom, are extremely sparse because of the difficulty and operational risk of obtaining deep profiles near the seafloor. A newly developed expendable instrument—the VMP-X (Vertical Microstructure Profiler–Expendable)—carries two microstructure shear probes to measure the fluctuations of vertical shear into the dissipation range and can profile down to a depth of 6000 m. Data from nine VMP-X profiles in the western Pacific Ocean near 11.6°N over rough topography display bottom-intensified turbulence with dissipation rates increasing by two factors of 10 to 4 W kg−1 within 200 m above the bottom. In contrast, over smooth topography in the southern South China Sea near 11°N, three profiles show that turbulence in the bottom boundary layer increases only slightly, with dissipation rates reaching 1 W kg−1. The eddy diffusivity over rough topography reached to 5 m2 s−1. The average diffusivity over all depths was 0.3 and 0.9 m2 s−1 for the tests in the southern South China Sea and in the western Pacific Ocean, respectively, and these values are much larger than previous estimates of less than ≈0.1 m2 s−1 for the main thermocline.

scholarly journals Morphology and phylogenetic analysis of five deep-sea golden gorgonians (Cnidaria, Octocorallia, Chrysogorgiidae) in the Western Pacific Ocean, with the description of a new species

ZooKeys ◽  
2020 ◽  
Vol 989 ◽  
pp. 1-37
Author(s):  
Yu Xu ◽  
Zifeng Zhan ◽  
Kuidong Xu
Keyword(s):  
New Species ◽  
Pacific Ocean ◽  
South China Sea ◽  
South China ◽  
Body Wall ◽  
Original Description ◽  
Western Pacific ◽  
Western Pacific Ocean ◽  
China Sea ◽  
The Western Pacific

Explorations of seamounts in the Western Pacific Ocean and South China Sea resulted in collecting 18 specimens of golden gorgonians. Based on the morphology and the genetic analysis of mtMutS, they are described as one new species, Chrysogorgia carolinensissp. nov., and four known species, including Chrysogorgia dendritica Xu, Zhan & Xu, 2020, Metallogorgia melanotrichos (Wright & Studer, 1889), Metallogorgia macrospina Kükenthal, 1919, and Pseudochrysogorgia bellona Pante & France, 2010. Chrysogorgia carolinensis belongs to the Chrysogorgia “group A, Spiculosae” with rods or spindles distributed in the polyp-body wall and tentacles, and differs from all of its congeners except C. dendritica by the 1/3L branching sequence and amoeba-shaped sclerites at the basal polyp body. The mtMutS sequence of C. carolinensissp. nov. has six deletion mutations compared to those of its congeners, supporting the establishment of the new species. Although no genetic variability was observed between the closely related species C. dendritica and C. abludo Pante & Watling, 2012, the former is different from the latter by the apparently irregular sclerites in the polyp body wall. The two specimens of Metallogorgia melanotrichos match well with the original description except for relatively larger polyps, while the M. macrospina specimens have slightly smaller polyps than the holotype. The juvenile of Metallogorgia has an obvious morphological difference with the adults in the colony shape and branches, but they can be unified by the same polyps and sclerites as well as mitochondrial MutS sequences. Thus, the generic diagnosis of Metallogorgia is slightly extended to include the morphology of juveniles. The morphology of Pseudochrysogorgia bellona Pante & France, 2010, as a new record for the South China Sea, matches well with that of the original description. In the phylogenetic trees, the Chrysogorgia species are separated into two clades, and while Metallogorgia and Pseudochrysogorgia formed a sister clade.

scholarly journals Biogeographic variations of picophytoplankton in three contrasting seas: the Bay of Bengal, South China Sea and Western Pacific Ocean

2020 ◽  
Vol 84 ◽  
pp. 91-103 ◽  
Author(s):  
Y Wei ◽  
D Huang ◽  
G Zhang ◽  
Y Zhao ◽  
J Sun
Keyword(s):  
Pacific Ocean ◽  
South China Sea ◽  
South China ◽  
Bay Of Bengal ◽  
Western Pacific ◽  
Nutrient Concentrations ◽  
Small Scale ◽  
Western Pacific Ocean ◽  
China Sea ◽  
Geographical Patterns

Marine picophytoplankton are abundant in many oligotrophic oceans, but the known geographical patterns of picophytoplankton are primarily based on small-scale cruises or time-series observations. Here, we conducted a wider survey (5 cruises) in the Bay of Bengal (BOB), South China Sea (SCS) and Western Pacific Ocean (WPO) to better understand the biogeographic variations of picophytoplankton. Prochlorococcus (Pro) were the most abundant picophytoplankton (averaging [1.9-3.6] × 104 cells ml-1) across the 3 seas, while average abundances of Synechococcus (Syn) and picoeukaryotes (PEuks) were generally 1-2 orders of magnitude lower than Pro. Average abundances of total picophytoplankton were similar between the BOB and SCS (4.7 × 104 cells ml-1), but were close to 2-fold less abundant in the WPO (2.5 × 104 cells ml-1). Pro and Syn accounted for a substantial fraction of total picophytoplankton biomass (70-83%) in the 3 contrasting seas, indicating the ecological importance of Pro and Syn as primary producers. Pro were generally abundant in oligotrophic open waters; however, the exceptional presence of Pro near the SCS coast was potentially associated with the Kuroshio intrusion. Syn and PEuk abundances were higher near freshwater-dominated areas, which was likely due to dilution waters. Water temperature and cold eddies were also major drivers responsible for the biogeographic distributions of picophytoplankton. Although Pro, Syn and PEuks showed negative correlations with nutrient concentrations, their maximal abundances in vertical distribution showed positive correlations with the nutricline depth, indicating that nutrient availability plays a 2-faceted role in regulating the biogeographic variation in picophytoplankton.

Redescription of Sillago (Parasillago) indica McKay, Dutt & Sujatha, 1985 (Perciformes: Sillaginidae), with a reassignment to the subgenus Sillago

Zootaxa ◽  
2012 ◽  
Vol 3513 (1) ◽  
pp. 61 ◽  
Author(s):  
TATSUYA KAGA ◽  
HSUAN-CHING HO
Keyword(s):  
Pacific Ocean ◽  
South China Sea ◽  
South China ◽  
First Record ◽  
The South China Sea ◽  
Western Pacific ◽  
Western Pacific Ocean ◽  
The South ◽  
China Sea

The Indian sillago, Sillago indica McKay, Dutt & Sujatha, 1985, is redescribed on the basis of three paratypes and two newly collected specimens.  The presence of two posterior extensions of the swimbladder instead of one suggests that it belongs to the subgenus Sillago.  Comments on its subgeneric status and comparisons with members of Sillago (Sillago) are provided.  Two specimens collected from Vietnam represent the first record of the species from the South China Sea, western Pacific Ocean.

scholarly journals Prevalence of temperate viruses in deep South China Sea and western Pacific Ocean

2020 ◽  
Vol 166 ◽  
pp. 103403
Author(s):  
Min Jin ◽  
Lanlan Cai ◽  
Ruijie Ma ◽  
Runying Zeng ◽  
Nianzhi Jiao ◽  
...  
Keyword(s):  
Pacific Ocean ◽  
South China Sea ◽  
South China ◽  
Western Pacific ◽  
Deep South ◽  
Western Pacific Ocean ◽  
China Sea

Impacts of the Madden-Julian Oscillation on South China Sea Monsoon

2020 ◽  
Author(s):  
Qun Zhou ◽  
Lixin Wei
Keyword(s):  
South China Sea ◽  
South China ◽  
Meridional Circulation ◽  
East Asian ◽  
Winter Monsoon ◽  
Western Pacific ◽  
Madden Julian Oscillation ◽  
China Sea ◽  
The Western Pacific ◽  
Local Meridional Circulation

Abstract It is of great practical importance to understand the variability of the South China Sea (SCS) monsoon on intraseasonal time scales, since the anomalous enhancement of the SCS monsoon may exert serious impacts on the safety of offshore engineering and marine transportation. Our composite analysis shows that the SCS surface wind anomalies are considerably varying with the Madden-Julian Oscillation (MJO) eastward propagation. The SCS summer southwest monsoon tends to be stronger (weaker) in phases 5–8 (1–4) of MJO with the largest positive (negative) wind-speed anomalies when the MJO convection is centered in the western Pacific (far western Indian Ocean), suggesting the highest (lowest) probability of the gale over the SCS. The variation of the western Pacific Subtropical High (WPSH), induced by the variations of the local meridional circulation, is shown to play a crucial role in the MJO-SCS summer monsoon linkage. The SCS winter monsoon is also shown to be modulated by the MJO with strengthened (weakened) surface northeasterly in phases 5–6 (1–2). The extra-tropical East Asian trough and East Asian westerly jet associated with the local meridional circulation can well explain the changes of the MJO-SCS winter monsoon relationship. The opposite responses of the wind direction during the same phases of the MJO between summer and winter may be attributed to the discrepancy of meridional circulation related to the wintertime equatorward shift of the MJO convection. The present study indicates that the MJO could be taken into consideration when applying extended-range weather forecast over the SCS as the predictability of the MJO activity is up to 15–20 day currently.

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