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 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.

Estimations of primary production and export production in the South China Sea based on sediment trap experiments

1998 ◽  
Vol 43 (7) ◽  
pp. 583-586 ◽  
Author(s):  
Jianfang Chen ◽  
Lianfu Zheng ◽  
M. G. Wiesner ◽  
Ronghua Chen ◽  
Yulong Zheng ◽  
...  
Keyword(s):  
South China Sea ◽  
Primary Production ◽  
South China ◽  
Sediment Trap ◽  
The South China Sea ◽  
The South ◽  
Export Production ◽  
China Sea

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

A comparison study on primary production in typical low-latitude seas (South China Sea and Bay of Bengal)

2012 ◽  
Vol 32 (18) ◽  
pp. 5900-5906 ◽  
Author(s):  
刘华雪 LIU Huaxue ◽  
宋星宇 SONG Xingyu ◽  
黄洪辉 HUANG Honghui ◽  
谭烨辉 TAN Yehui ◽  
黄良民 HUANG Liangmin
Keyword(s):  
South China Sea ◽  
Primary Production ◽  
South China ◽  
Bay Of Bengal ◽  
Comparison Study ◽  
Low Latitude ◽  
China Sea

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 Distinct bacterial-production–DOC–primary-production relationships and implications for biogenic C cycling in the South China Sea shelf

2014 ◽  
Vol 11 (1) ◽  
pp. 147-156 ◽  
Author(s):  
C.-C. Lai ◽  
Y.-W. Fu ◽  
H.-B. Liu ◽  
H.-Y. Kuo ◽  
K.-W. Wang ◽  
...  
Keyword(s):  
South China Sea ◽  
Primary Production ◽  
South China ◽  
Bacterial Production ◽  
Northern South China Sea ◽  
Outer Shelf ◽  
Inorganic Nutrient ◽  
Shelf Area ◽  
China Sea ◽  
Spatio Temporal

Abstract. Based on two summer spatio-temporal data sets obtained from the northern South China Sea shelf and basin, this study reveals contrasting relationships among bacterial production (BP), dissolved organic (DOC) and primary production (PP) in the transition zone from the neritic to the oceanic regions. Inside the mid-shelf (bottom depth <100 m), where inorganic nutrient supplies from river discharge and internal waves were potentially abundant, BP, DOC and PP were positively intercorrelated, whereas these three measurements became uncorrelated in the oligotrophic outer shelf and slope. We suggest that the availability of limiting minerals could affect the couplings/decouplings between the source (i.e. phytoplankton) and sink (i.e. bacteria) of organic carbon, and thus DOC dynamics. DOC turnover times were homogeneously low (37–60 days) inside the mid-shelf area and then increased significantly to values >100 days in the outer shelf, indicating that riverine (Pearl River) DOC might be more labile. The actual mechanism for this is unknown, but might relate to higher inorganic nutrient supply from river/terrestrial sources. The positive correlation of the BP / PP ratios vs. phosphate (and nitrate) concentrations in the inner shelf implies that if anthropogenic mineral loading keeps increasing in the foreseeable future, the near-shore zone may become more heterotrophic, rendering the system a stronger source of CO2.

Sign in / Sign up

Export Citation Format

Share Document