scholarly journals Spatiotemporal Variation in Particulate Organic Carbon Based on Long-Term MODIS Observations in Taihu Lake, China

2017 ◽  
Vol 9 (6) ◽  
pp. 624 ◽  
Author(s):  
Changchun Huang ◽  
Quanliang Jiang ◽  
Ling Yao ◽  
Yunmei Li ◽  
Hao Yang ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Particulate Organic Carbon ◽  
Taihu Lake ◽  
Spatiotemporal Variation ◽  
Carbon Based

scholarly journals Estimation of the Particulate Organic Carbon to Chlorophyll-a Ratio Using MODIS-Aqua in the East/Japan Sea, South Korea

2020 ◽  
Vol 12 (5) ◽  
pp. 840 ◽  
Author(s):  
Dabin Lee ◽  
SeungHyun Son ◽  
HuiTae Joo ◽  
Kwanwoo Kim ◽  
Myung Joon Kim ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Particulate Organic Carbon ◽  
Chlorophyll A ◽  
Primary Productivity ◽  
Seasonal Variability ◽  
Japan Sea ◽  
Global Ocean ◽  
Phytoplankton Communities

In recent years, the change of marine environment due to climate change and declining primary productivity have been big concerns in the East/Japan Sea, Korea. However, the main causes for the recent changes are still not revealed clearly. The particulate organic carbon (POC) to chlorophyll-a (chl-a) ratio (POC:chl-a) could be a useful indicator for ecological and physiological conditions of phytoplankton communities and thus help us to understand the recent reduction of primary productivity in the East/Japan Sea. To derive the POC in the East/Japan Sea from a satellite dataset, the new regional POC algorithm was empirically derived with in-situ measured POC concentrations. A strong positive linear relationship (R2 = 0.6579) was observed between the estimated and in-situ measured POC concentrations. Our new POC algorithm proved a better performance in the East/Japan Sea compared to the previous one for the global ocean. Based on the new algorithm, long-term POC:chl-a ratios were obtained in the entire East/Japan Sea from 2003 to 2018. The POC:chl-a showed a strong seasonal variability in the East/Japan Sea. The spring and fall blooms of phytoplankton mainly driven by the growth of large diatoms seem to be a major factor for the seasonal variability in the POC:chl-a. Our new regional POC algorithm modified for the East/Japan Sea could potentially contribute to long-term monitoring for the climate-associated ecosystem changes in the East/Japan Sea. Although the new regional POC algorithm shows a good correspondence with in-situ observed POC concentrations, the algorithm should be further improved with continuous field surveys.

scholarly journals Quantitative estimates of sinking sea ice particulate organic carbon based on the biomarker IP25

2016 ◽  
Vol 546 ◽  
pp. 17-29 ◽  
Author(s):  
TA Brown ◽  
ST Belt ◽  
M Gosselin ◽  
M Levasseur ◽  
M Poulin ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Sea Ice ◽  
Particulate Organic Carbon ◽  
Quantitative Estimates ◽  
Carbon Based

Rates of carbon fixation, organic carbon release and translocation in a reef-building foraminifer, Marginopora vertebralis

1977 ◽  
Vol 28 (3) ◽  
pp. 311 ◽  
Author(s):  
DF Smith ◽  
WJ Wiebe
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Particulate Organic Carbon ◽  
Carbon Fixation ◽  
Turnover Time ◽  
In Situ Incubation ◽  
Carbon Release ◽  
Hermatypic Corals ◽  
Shell Carbonate

Rate measurements obtained in this study and the population densities of foraminifera reported elsewhere suggest that such organisms may well exceed the hermatypic corals in their contribution to reef biogensis and energy fluxes. The average rates at which M. vertebralis photosynthetically fixes carbon into particulate organic carbon, dissolved organic carbon, and shell carbonate, per square centimetre of organism, were estimated to be 50, 1 .5, and 26 ng C min-1 respectively. Exogenously supplied dissolved organic carbon was taken up by M. vertebralis at a rate of 0.05 ng C min-1 in the light, and 0.09 ng C min-1 in the dark per square centimetre of organism. The turnover time of particulate organic carbon (91 h) was measured in a long-term in situ incubation during which 19% of the radioactivity lost from the particulate organic carbon entered the calcareous foraminiferal shell.

Long-Term Effects of Inorganic and Organic Amendments on Organic Carbon in a Paddy Soil of the Taihu Lake Region, China

Pedosphere ◽  
2011 ◽  
Vol 21 (2) ◽  
pp. 186-196 ◽  
Author(s):  
Li MA ◽  
Lin-Zhang YANG ◽  
Li-Zhong XIA ◽  
Ming-Xing SHEN ◽  
Shi-Xue YIN ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Paddy Soil ◽  
Taihu Lake ◽  
Organic Amendments ◽  
Long Term Effects ◽  
Lake Region ◽  
Inorganic And Organic

Event-driven dynamics of the total mobile inventory in soils - Results from a comparative multi-year lysimeter study

2021 ◽  
Author(s):  
Katharina Lehmann ◽  
Robert Lehmann ◽  
Kai U. Totsche
Keyword(s):  
Organic Carbon ◽  
Particulate Organic Carbon ◽  
Winter Season ◽  
Critical Zone ◽  
Field Scale ◽  
Undisturbed Soil ◽  
Event Scale ◽  
Event Driven ◽  
Sampling Procedures

<p>A diverse size- and matter spectrum of inorganic, organo-mineral and organic substances, and dissolved, colloidal, but also larger particulate matter, including microbiota, is mobile in soil and potentially involved in matter interchange between surface and subsurface ecosystems. Specifically including the widely neglected particulate fractions, conditions and field-scale factors controlling the long-term seasonal and episodic dynamics of the “total mobile inventory” (Lehmann et al., 2021), in undisturbed soil and its translocation through the subsurface of the Critical Zone is almost unknown. To overcome this knowledge gap, we established long-term soil monitoring plots in the Hainich Critical Zone Exploratory (HCZE; NW-Thuringia, central Germany). Soil seepage from 22 tension-controlled lysimeters in topsoil and subsoil, covering different land use (forest, pasture, cropland) in the topographic recharge area of the HCZE, was collected and analyzed by a variety of analytical methods (physico-/chemical and spectroscopic) on a regular (biweekly) and event-scale cycle. Atmospheric forcing was found to be the major factor triggering the translocation of the mobile inventory, mainly causing considerable seasonality in the solute signature (e.g., sulphate) and seepage pH. However, episodic high-flow (infiltration) events rather than seasonality caused mobilization of significant amounts of particulates, for instance, after snow melts or rainstorms. Noteworthy, particulate organic carbon translocated during the winter-season infiltration events, accounted for up to 80% of annual fluxes. On average, 21% of the total OC of the seepage was particulate (>0.45 µm). Our study provides field-scale evidence for the importance of the mobile inventory fraction >0.45 µm for soil elemental dynamics and budgets. We, thus, suggest involving suspended fractions in environmental monitoring programs, although requiring adapted sampling procedures.</p><p> </p><p>References:</p><p>Lehmann, K., Lehmann, R., & Totsche, K. U. (2021). Event-driven dynamics of the total mobile inventory in undisturbed soil account for significant fluxes of particulate organic carbon. Science of The Total Environment, 143774.</p>

Remote sensing of particulate organic carbon dynamics in a eutrophic lake (Taihu Lake, China)

2015 ◽  
Vol 532 ◽  
pp. 245-254 ◽  
Author(s):  
Guangjia Jiang ◽  
Ronghua Ma ◽  
Steven A. Loiselle ◽  
Hongtao Duan ◽  
Wen Su ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Organic Carbon ◽  
Particulate Organic Carbon ◽  
Taihu Lake ◽  
Lake Taihu ◽  
Carbon Dynamics ◽  
Eutrophic Lake

The Carbon:²³⁴Thorium ratios of sinking particles in the California Current Ecosystem 2: Examination of a thorium sorption, desorption, and particle transport model

2019 ◽  
Author(s):  
Michael Stukel ◽  
Thomas Kelly
Keyword(s):  
Organic Carbon ◽  
Water Column ◽  
Particulate Organic Carbon ◽  
Transport Model ◽  
California Current ◽  
In Situ Measurements ◽  
Power Law Distribution ◽  
Sinking Particles ◽  
Organic Carbon Concentration

Thorium-234 (234Th) is a powerful tracer of particle dynamics and the biological pump in the surface ocean; however, variability in carbon:thorium ratios of sinking particles adds substantial uncertainty to estimates of organic carbon export. We coupled a mechanistic thorium sorption and desorption model to a one-dimensional particle sinking model that uses realistic particle settling velocity spectra. The model generates estimates of 238U-234Th disequilibrium, particulate organic carbon concentration, and the C:234Th ratio of sinking particles, which are then compared to in situ measurements from quasi-Lagrangian studies conducted on six cruises in the California Current Ecosystem. Broad patterns observed in in situ measurements, including decreasing C:234Th ratios with depth and a strong correlation between sinking C:234Th and the ratio of vertically-integrated particulate organic carbon (POC) to vertically-integrated total water column 234Th, were accurately recovered by models assuming either a power law distribution of sinking speeds or a double log normal distribution of sinking speeds. Simulations suggested that the observed decrease in C:234Th with depth may be driven by preferential remineralization of carbon by particle-attached microbes. However, an alternate model structure featuring complete consumption and/or disaggregation of particles by mesozooplankton (e.g. no preferential remineralization of carbon) was also able to simulate decreasing C:234Th with depth (although the decrease was weaker), driven by 234Th adsorption onto slowly sinking particles. Model results also suggest that during bloom decays C:234Th ratios of sinking particles should be higher than expected (based on contemporaneous water column POC), because high settling velocities minimize carbon remineralization during sinking.

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