scholarly journals Using rare earth elements to constrain particulate organic carbon flux in the East China Sea

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Chin-Chang Hung ◽  
Ya-Feng Chen ◽  
Shih-Chieh Hsu ◽  
Kui Wang ◽  
Jianfang Chen ◽  
...  
Keyword(s):  
Rare Earth ◽  
Organic Carbon ◽  
Rare Earth Elements ◽  
Continental Shelf ◽  
Particulate Organic Carbon ◽  
East China Sea ◽  
Sediment Resuspension ◽  
East China ◽  
The East China Sea ◽  
Marginal Seas

Abstract Fluxes of particulate organic carbon (POC) in the East China Sea (ECS) have been reported to decrease from the inner continental shelf towards the outer continental shelf. Recent research has shown that POC fluxes in the ECS may be overestimated due to active sediment resuspension. To better characterize the effect of sediment resuspension on particle fluxes in the ECS, rare earth elements (REEs) and organic carbon (OC) were used in separate two-member mixing models to evaluate trap-collected POC fluxes. The ratio of resuspended particles from sediments to total trap-collected particles in the ECS ranged from 82–94% using the OC mixing model, and 30–80% using the REEs mixing model, respectively. These results suggest that REEs may be better proxies for sediment resuspension than OC in high turbidity marginal seas because REEs do not appear to undergo degradation during particle sinking as compared to organic carbon. Our results suggest that REEs can be used as tracers to provide quantitative estimates of POC fluxes in marginal seas.

scholarly journals Behavior and fluxes of particulate organic carbon in the East China Sea

2013 ◽  
Vol 10 (3) ◽  
pp. 4271-4302 ◽  
Author(s):  
C.-C. Hung ◽  
C.-W. Tseng ◽  
G.-C. Gong ◽  
K.-S. Chen ◽  
M.-H. Chen ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Particulate Organic Carbon ◽  
East China Sea ◽  
Sediment Resuspension ◽  
Vertical Mixing ◽  
Mixing Model ◽  
Outer Shelf ◽  
East China ◽  
The East China Sea ◽  
Inner Shelf

Abstract. To better understand carbon cycling in marginal seas, particulate organic carbon (POC) concentrations, POC fluxes and primary production (PP) were measured in the East China Sea (ECS) in summer 2007. Higher concentrations of POC were observed in the inner shelf and lower POC values were found in the outer shelf. Similar to POC concentrations, elevated uncorrected POC fluxes (720–7300 mg C m−2 d−1) were found in the inner shelf and lower POC fluxes (80–150 mg C m−2 d−1) were in the outer shelf, respectively. PP values (~340–3380 mg C m−2 d−1) had analogous distribution patterns to POC fluxes, while some of PP values were significantly lower than POC fluxes, suggesting that contributions of resuspended particles to POC fluxes need to be appropriately corrected. A vertical mixing model was used to correct effects of bottom sediment resuspension and the corrected POC fluxes ranging from 41 ± 20 to 956 ± 443 mg C m−2 d−1, which were indeed lower than PP values. The results suggest that 49–93% of the POC flux in the ECS might be from the contribution of resuspension of bottom sediments rather than from the actual biogenic carbon sinking flux. While the vertical mixing model is not a perfect model to solve sediment resuspension because it ignores biological degradation of sinking particles, Changjinag plume (or terrestrial) inputs and lateral transport, it makes significant progress in both correcting resuspension problem and in assessing a reasonable quantitative estimate in a marginal sea.

scholarly journals Fluxes of particulate organic carbon in the East China Sea in summer

2013 ◽  
Vol 10 (10) ◽  
pp. 6469-6484 ◽  
Author(s):  
C.-C. Hung ◽  
C.-W. Tseng ◽  
G.-C. Gong ◽  
K.-S. Chen ◽  
M.-H. Chen ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Particulate Organic Carbon ◽  
East China Sea ◽  
Sediment Resuspension ◽  
Vertical Mixing ◽  
Outer Shelf ◽  
East China ◽  
The East China Sea ◽  
Inner Shelf ◽  
Poc Flux

Abstract. To understand carbon cycling in marginal seas better, particulate organic carbon (POC) concentrations, POC fluxes and primary production (PP) were measured in the East China Sea (ECS) in summer 2007. Higher concentrations of POC were observed in the inner shelf, and lower POC values were found in the outer shelf. Similar to POC concentrations, elevated uncorrected POC fluxes (720–7300 mg C m−2 d−1) were found in the inner shelf, and lower POC fluxes (80–150 mg C m−2 d−1) were in the outer shelf, respectively. PP values (~ 340–3380 mg C m−2 d−1) had analogous distribution patterns to POC fluxes, while some of PP values were significantly lower than POC fluxes, suggesting that contributions of resuspended particles to POC fluxes need to be appropriately corrected. A vertical mixing model was used to correct effects of bottom sediment resuspension, and the lowest and highest corrected POC fluxes were in the outer shelf (58 ± 33 mg C m−2 d−1) and the inner shelf (785 ± 438 mg C m−2 d−1), respectively. The corrected POC fluxes (486 to 785 mg C m−2 d−1) in the inner shelf could be the minimum value because we could not exactly distinguish the effect of POC flux from Changjiang influence with turbid waters. The results suggest that 27–93% of the POC flux in the ECS might be from the contribution of resuspension of bottom sediments rather than from the actual biogenic carbon sinking flux. While the vertical mixing model is not a perfect model to solve sediment resuspension because it ignores biological degradation of sinking particles, Changjiang plume (or terrestrial) inputs and lateral transport, it makes significant progress in both correcting the resuspension problem and in assessing a reasonable quantitative estimate of POC flux in a marginal sea.

scholarly journals Variability of the nutrient stream near Kuroshio's origin

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Chen-Tung Arthur Chen ◽  
Ting-Hsuan Huang ◽  
Chi-Hsuan Wu ◽  
Haiyan Yang ◽  
Xinyu Guo
Keyword(s):  
Pacific Ocean ◽  
Continental Shelf ◽  
East China Sea ◽  
Kuroshio Extension ◽  
Subsurface Water ◽  
East China ◽  
The East China Sea ◽  
High Productivity ◽  
China Sea ◽  
The Kuroshio

AbstractThe Kuroshio—literally “the Black Stream”—is the most substantial current in the Pacific Ocean. It was called the Black Stream because this oligotrophic current is so nutrient-poor in its euphotic zone that the water appears black without the influence of phytoplankton and the associated, often colored dissolved organic matter. Yet, below the euphotic layer, nutrient concentrations increase with depth while current speed declines. Consequently, a core of maximum nutrient flux, the so-called nutrient stream, develops at a depth of roughly between 200 and 800 m. This poorly studied nutrient stream transports nutrients to and supports high productivity and fisheries on the East China Sea continental shelf; it also transports nutrients to and promotes increased productivity and fisheries in the Kuroshio Extension and the subarctic Pacific Ocean. Three modes of the Kuroshio nutrient stream are detected off SE Taiwan for the first time: one has a single-core; one has two cores that are apparently separated by the ridge at 120.6–122° E, and one has two cores that are separated by a southward flow above the ridge. More importantly, northward nutrient transports seem to have been increasing since 2015 as a result of a 30% increase in subsurface water transport, which began in 2013. Such a nutrient stream supports the Kuroshio's high productivity, such as on the East China Sea continental shelf and in the Kuroshio Extension SE of Japan.

Spatial variations in dissolved rare earth element concentrations in the East China Sea water column

2018 ◽  
Vol 205 ◽  
pp. 1-15 ◽  
Author(s):  
Le Duc Luong ◽  
Ryuichi Shinjo ◽  
Nguyen Hoang ◽  
Renat B. Shakirov ◽  
Nadezhda Syrbu
Keyword(s):  
Rare Earth ◽  
Water Column ◽  
East China Sea ◽  
Rare Earth Element ◽  
Earth Element ◽  
Sea Water ◽  
Spatial Variations ◽  
East China ◽  
The East China Sea ◽  
Element Concentrations
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