scholarly journals Data on dissolved metals in Terengganu waters of South China Sea during pre-, post-, and Northeast Monsoon season

Data in Brief ◽  
2019 ◽  
Vol 27 ◽  
pp. 104806
Author(s):  
Marinah Mohd Ariffin ◽  
Ghazali Adiana ◽  
Joseph Bidai ◽  
Lee Siang Hing ◽  
Mohd Yusoff Nurulnadia ◽  
...  
Keyword(s):  
South China Sea ◽  
South China ◽  
Monsoon Season ◽  
Northeast Monsoon ◽  
Dissolved Metals ◽  
China Sea

scholarly journals Primary productivity and its variability in the equatorial South China Sea during the northeast monsoon

2013 ◽  
Vol 13 (8) ◽  
pp. 21573-21608 ◽  
Author(s):  
S. H. Ooi ◽  
A. A. Samah ◽  
P. Braesicke
Keyword(s):  
South China Sea ◽  
Chlorophyll A ◽  
South China ◽  
Primary Productivity ◽  
Monsoon Season ◽  
Winter Monsoon ◽  
Phytoplankton Growth ◽  
Northeast Monsoon ◽  
Cold Surge ◽  
China Sea

Abstract. Near coastal areas of the equatorial South China Sea (SCS) are one of the world's regions with highest primary productivity (phytoplankton growth). Concentrations of phytoplankton in the SCS depend significantly on atmospheric forcings and the oceanic state, in particular during the northeast (winter) monsoon season from November to March. Aided by new ocean-observing satellite data, we present a climatological overview of recent surface atmospheric and oceanic features in the equatorial SCS during the northeast monsoon to identify the dominant air-sea processes influencing and modulating the primary productivity of the region. Measured chlorophyll a concentrations are used as a proxy for phytoplankton amounts and the spatial and temporal variations are characterized according to meteorological conditions. Converging northeasterly surface winds support high chlorophyll a concentrations along East Malaysia's coastline in conjunction with a continual nutrient supply from the bottom of the continental shelf by vertical mixing. The mixing can be enhanced due to increased turbulence by wind-generated high waves when they approach shallow water from the deep basin during strong cold surges and monsoon disturbances. Intraseasonal variability during the winter monsoon is characterized by a coastal increase of chlorophyll a starting in November and peaking in January. A general decrease is observed in March. Interannual variability of chlorophyll a concentrations is influenced by ENSO (due to the known modulation of cold surge occurrences), with decreases during El Niño and increases during La Niña in early winter along the shore of East Malaysia. As an example, we discuss an enhanced phytoplankton growth event that occurred due to a typical cold surge-induced Borneo vortex event in January 2010.

scholarly journals New constraints on biological production and mixing processes in the South China Sea from triple isotope composition of dissolved oxygen

2021 ◽  
Author(s):  
Hana Jurikova ◽  
Osamu Abe ◽  
Fuh-Kwo Shiah ◽  
Mao-Chang Liang
Keyword(s):  
South China Sea ◽  
Primary Production ◽  
South China ◽  
Isotope Composition ◽  
Gross Primary Production ◽  
Northeast Monsoon ◽  
Production Rates ◽  
Mixing Processes ◽  
China Sea ◽  
Net Heterotrophy

Abstract. South China Sea (SCS), world’s largest marginal sea, plays an important role in the global as well as regional biogeochemical cycling of carbon and oxygen. However, its overall metabolic balance, primary production rates, and their link to East Asian Monsoon forcing still remain poorly constrained. Here, we report seasonal trends in triple oxygen isotope composition (17Δ) of dissolved O2, a tracer for biological O2, gross primary production (GP; inferred from δ17O and δ18O values), and net community production (NP; evaluated from oxygen–argon ratios) from the SouthEast Asian Time-series Study (SEATS) in SCS. Our results suggest stable mixed-layer GP rates of 1.8 g C m−2 d−1 and NP of −0.02 g C m−2 d−1 during the summer southwest monsoon, indicating the prevalence of net heterotrophy. During winter months characterised by stronger northeast monsoon forcing, the system is more dynamic with variable production rates, which may shift the metabolism from net heterotrophy to net autotrophy (NP up to ~0.15 g C  m−2 d−1). These findings underscore the importance of monsoon intensity on tilting the carbon balance from source to sink in a warm oligotrophic sea, and on driving the regional circulation pattern. Finally, our data from the deeper regions show that SCS circulation is strongly affected by monsoon wind forcing, with a larger part of the water column down to at least 400 m depth fully exchanged during a winter, suggesting the 17Δ of deep O2 as a valuable novel conservative tracer for probing mixing processes from a new perspective.

scholarly journals On The Simulation of Northeast Monsoon Rainfall Over Southern Peninsular India in CMIP5 Models

2021 ◽  
Author(s):  
P.P. Sree ◽  
C. A. Babu ◽  
S. Vijaya Bhaskara Rao
Keyword(s):  
Pacific Ocean ◽  
Indian Ocean ◽  
South China Sea ◽  
South China ◽  
Cmip5 Models ◽  
Northeast Monsoon ◽  
Peninsular India ◽  
China Sea ◽  
Sst Bias ◽  
The Mean

Abstract The skill of 34 CMIP5 models to simulate the mean state and interannual variability of Northeast Monsoon Rainfall (NEMR) is studied here. The mean (1979-2005) NEMR over southern Peninsular India (SPIRF), Indian Ocean and Maritime continents (10°S-30°N,40°E- 120°E) is simulated reasonably well by CMIP5 models with pattern correlation ranges from 0.6 to 0.93. Diverse behaviour in the simulation of Indian and Pacific Ocean SST is observed in the CMIP5 models. A set of models (high skill models: HSM), which shows a Negative Indian Ocean Dipole (NIOD) like mean (1979-2005) SST bias in Indian Ocean and strong La Nina like mean SST bias in the Pacific Ocean, are able to simulate the mean NEMR more realistically. Another set of models (low skill models: LSM) which shows a Positive IOD (PIOD) like mean SST bias in the Indian Ocean and weak La Nina like mean SST bias in the Pacific Ocean are not able to simulate the observed equatorial Indian Ocean westerlies, which leads to an abnormal ascending motion and unrealistic wet bias over the western Indian Ocean and dry bias over the southern Peninsular India, southeast Asia and southeast Indian Ocean. The observation analysis reveals that the establishment of South China Sea anticyclone and Bay of Bengal anticyclone during El Nino and PIOD are strongly related with the ascending motion over south peninsular India and enhances the south Peninsular Indian rainfall during NEM season. Around 70% of the CMIP5 models were not able to capture the observed positive correlation that exist between SPIRF and Nino3.4 SST as well as SPIRF and DMI. Unrealistic westward extension of South China Sea anticyclone and Bay of Bengal anticyclone (up to 70°E) in the low skill models (LSM-IAV) manifested as the abnormal descending anomalies and unrealistic dry bias over the southern Peninsular India. This leads to a negative Correlation coefficient (CC) between SPIRF and Nino 3.4 SST as well as SPIRF and DMI in the low skill models. The descending anomalies over South China Sea and ascending anomalies over the western Indian Ocean and southern Peninsular India (50°E-80°E) is well captured but with lower intensity in the high skill models (HSM-IAV) and hence it captures the observed positive CC between SPIRF and Nino3.4 SST as well as SPIRF and DMI.

scholarly journals Seasonal changes in gaseous elemental mercury in relation to monsoon cycling over the northern South China Sea

2012 ◽  
Vol 12 (16) ◽  
pp. 7341-7350 ◽  
Author(s):  
C. M. Tseng ◽  
C. S. Liu ◽  
C. Lamborg
Keyword(s):  
South China Sea ◽  
South China ◽  
Northern South China Sea ◽  
Elemental Mercury ◽  
Source Tracking ◽  
Northeast Monsoon ◽  
Air Masses ◽  
Gaseous Elemental Mercury ◽  
China Sea ◽  
The Impact

Abstract. The distribution of gaseous elemental mercury (GEM) was determined in the surface atmosphere of the northern South China Sea (SCS) during 12 SEATS cruises between May 2003 and December 2005. The sampling and analysis of GEM were performed on board ship by using an on-line mercury analyzer (GEMA). Distinct annual patterns were observed for the GEM with a winter maximum of 5.7 ± 0.2 ng m−3 (n = 3) and minimum in summer (2.8 ± 0.2; n = 3), with concentrations elevated 2–3 times global background values. Source tracking through backward air trajectory analysis demonstrated that during the northeast monsoon (winter), air masses came from Eurasia, bringing continental- and industrial-derived GEM to the SCS. In contrast, during summer southwest monsoon and inter-monsoon, air masses were from the Indochina Peninsula and Indian Ocean and west Pacific Ocean. This demonstrates the impact that long-range transport, as controlled by seasonal monsoons, has on the Hg atmospheric distribution and cycling in the SCS.

scholarly journals Statistical Characteristics of Raindrop Size Distribution in Monsoon Season over South China Sea

2021 ◽  
Vol 13 (15) ◽  
pp. 2878
Author(s):  
Chaoying Huang ◽  
Sheng Chen ◽  
Asi Zhang ◽  
Ying Pang
Keyword(s):  
South China Sea ◽  
Size Distribution ◽  
Summer Monsoon ◽  
South China ◽  
Southern China ◽  
Monsoon Season ◽  
Statistical Characteristics ◽  
China Sea ◽  
Raindrop Size Distribution ◽  
Raindrop Size

The South China Sea (SCS) is the largest and southernmost sea in China. Water vapor from the SCS is the primary source of precipitation over coastal areas during the summer monsoon season and may cause the uneven distribution of rainfall in southern China. Deep insight into the spatial variability of raindrop size distribution (DSD) is essential for understanding precipitation microphysics, since DSD contains abundant information about rainfall microphysics processes. However, compared to the studies of DSDs over mainland China, very little is known about DSDs over Chinese ocean areas, especially over the South China Sea (SCS). This study investigated the statistical characteristics of the DSD in summer monsoon seasons using the second-generation Particle Size and Velocity (Parsivel2) installed on the scientific research vessel that measured the size and velocity of raindrops over the SCS. In this study, the characteristics of precipitation over the SCS for daytime and nighttime rains were analyzed for different precipitation systems and upon different rain rates. It was found that: 1) rain events were more frequent during the late evening to early morning; 2) more than 78.2% of the raindrops’ diameters were less than 2 mm, and the average value of mass-weighted mean diameter (1.46 mm) of the SCS is similar to that over land in the southern China; 3) the stratiform precipitation features a relatively high concentration of medium to large-sized rain drops compared to other regions; 4) the DSD in the SCS agreed with a three-parameter gamma distribution for the small raindrop diameter. Furthermore, a possible factor for significant DSD variability in the ocean compared with the coast and large islands is also discussed.

scholarly journals SURFACE SALINITIES IN THE STRAIT OF MALACCA

2008 ◽  
Vol 2 ◽  
pp. 27-55 ◽  
Author(s):  
Raden E. Soeriaatmadja
Keyword(s):  
South China Sea ◽  
South China ◽  
Saline Water ◽  
Southwest Monsoon ◽  
The South China Sea ◽  
Northeast Monsoon ◽  
The South ◽  
Surface Salinity ◽  
China Sea ◽  
Strait Of Malacca

A continuous northwest-going current prevails in the Strait of Malacca throughout the year, except June and August, when the currents are very weak and sometimes reversed  in the .southern part. The southern part of the Strait of Malacca is influenced by the currents. These currents transport low saline water into the Strait during the southwest monsoon and high saline water from the South China Sea during the northeast monsoon. In the northern part, the rainfall is of greater importance for the variations of the surface salinity and a strong correlation between rainfall and surface salinities is found in this region. It is unlikely that Indian Ocean water penetrates the South China Sea.

scholarly journals Inter-shelf nutrient transport from the East China Sea as a major nutrient source supporting winter primary production on the northeast South China Sea shelf

2013 ◽  
Vol 10 (12) ◽  
pp. 8159-8170 ◽  
Author(s):  
A. Q. Han ◽  
M. H. Dai ◽  
J. P. Gan ◽  
S.-J. Kao ◽  
X. Z. Zhao ◽  
...  
Keyword(s):  
South China Sea ◽  
Primary Production ◽  
East China Sea ◽  
South China ◽  
East China ◽  
Lower Latitude ◽  
Coastal Current ◽  
Northeast Monsoon ◽  
The East China Sea ◽  
China Sea

Abstract. The East China Sea (ECS) and the South China Sea (SCS) are two major marginal seas of the North Pacific with distinct seasonal variations of primary productivity. Based upon field observations covering both the ECS and the northern SCS (NSCS) during December 2008–January 2009, we examined southward long-range transport of nutrients from the ECS to the northeastern SCS (NESCS) carried by the China Coastal Current (CCC) driven by the prevailing northeast monsoon in wintertime. These escaped nutrients from the ECS shelf, where primary production (PP) was limited in winter, might however refuel the PP on the NESCS shelf at lower latitude, where the water temperature remained favorable, but river-sourced nutrients were limited. By combining the field observation of nitrate+nitrite (NO3+NO2, DIN) with our best estimate of volume transport of the CCC, we derived a first-order estimate for DIN flux of 1430 ± 1024 mol s−1. Under the assumption that DIN was the limiting nutrient, such southward DIN transport would have stimulated 8.84 ± 6.33 × 1011 gC of new production (NP), accounting for 33–74% of the NP or 14–22% of PP in winter on the NESCS shelf shallower than 100 m.

scholarly journals Impacts of Sea Temperature Rise on Rastrelliger kanagurta Potential Fishing Grounds in the Exclusive Economic Zone (EEZ) Off South China Sea

2021 ◽  
Vol 50 (12) ◽  
pp. 3467-3479
Author(s):  
Kamaruzzaman Y.N. ◽  
Mustapha M.A. ◽  
Ghaffar M.A.
Keyword(s):  
Elevated Temperature ◽  
South China Sea ◽  
South China ◽  
Temperature Rise ◽  
Exclusive Economic Zone ◽  
Northeast Monsoon ◽  
China Sea ◽  
Rastrelliger Kanagurta ◽  
Economic Zone ◽  
The Impact

The Indian mackerel (Rastrelliger kanagurta) is one of the most commercially crucial epipelagic scombrid where it is caught in the Exclusive Economic Zone (EEZ) off the South China Sea (SCS). High demand for fisheries resources is a challenge for fishers to achieve optimal fish landing targets. By using R. kanagurta catch data, and high resolution satellite data of chl-a and SST (MODIS-Aqua) and SSH (AVISO) from 2018 together with boosted regression tree (BRT) model, this study aims to determine the impact of sea surface temperature (SST) increase on the potential catch of R. kanagurta based on temperature projection of IPCC-AR5-RCPs scenarios. BRT modelling result indicated that during the northeast monsoon (NEM), at elevated temperature of 1.80 and 2.60 ℃ showed that the potential fishing grounds of R. kanagurta increase in the area especially in the northern part of the EEZ. However, at elevated temperature of 3.30 ℃, the potential fishing areas was found to decrease along the coast of Peninsular Malaysia. Meanwhile, during southwest monsoon (SWM) and inter-monsoon transition, at temperature rise of 1.80, 2.60 and 3.30 °C showed a significant reduction in the potential fishing area of the R. kanagurta potential fishing grounds especially along the coast of the EEZ off SCS. Results indicated that changes in SST influenced suitability of habitat which affected the distribution of R. kanagurta. Understanding the impacts of temperature increase would contribute towards future sustainable fisheries resource management strategies.

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