Vertically stratified water source characteristics and associated driving mechanisms of particulate organic carbon in a large floodplain lake system

2021 ◽  
pp. 117963
Author(s):  
Shuoyue Wang ◽  
Yang Gao ◽  
Junjie Jia ◽  
Yao Lu ◽  
Kun Sun ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Particulate Organic Carbon ◽  
Water Source ◽  
Floodplain Lake ◽  
Source Characteristics ◽  
Lake System ◽  
Driving Mechanisms

A depositional history of particulate organic carbon in a floodplain lake from the lower Ob’ River, Siberia

2011 ◽  
Vol 75 (17) ◽  
pp. 4796-4815 ◽  
Author(s):  
Angela F. Dickens ◽  
Jeff Baldock ◽  
Timothy C. Kenna ◽  
Timothy I. Eglinton
Keyword(s):  
Organic Carbon ◽  
Particulate Organic Carbon ◽  
Floodplain Lake ◽  
Depositional History ◽  
Ob River ◽  
History Of

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.

Interaction between Solvatochromic Dyes and Water Sampled from a Natural Source Treated with High Dilutions of Phosphorus

Homeopathy ◽  
2020 ◽  
Vol 109 (03) ◽  
pp. 126-132
Author(s):  
Ana Carla C. Aparicio ◽  
Larissa Helen S. de Oliveira ◽  
Jefferson S. Silva ◽  
Cideli P. Coelho ◽  
Sonia Regina Pinheiro ◽  
...  
Keyword(s):  
Water Source ◽  
Chemical Monitoring ◽  
Lake System ◽  
Solvatochromic Dyes ◽  
Physico Chemical ◽  
Untreated Water ◽  
Before And After ◽  
High Dilutions ◽  
Methylene Violet ◽  
Solvatochromic Dye

Abstract Background Highly diluted and succussed solutions interact with solvatochromic dyes, indicating that changes in solvent and solute polarity could be related to their mechanism of action. It is not known, however, how the activity associated with succussed high dilutions is transferred to untreated water and what the limits of this process are. Aims The aims of the present study were to ascertain whether a succussed high dilution of phosphorus (1.5 × 1−59 M; Phos 30cH) seeded into a natural water source that fed a fjord and two connected lakes could propagate itself through the lake system (total volume 2200 m3) and, moreover, whether the process could be tracked using solvatochromic dyes. Methods Samples of water were collected before and after seeding, at different times and places throughout the lake system. Controls comprised water taken from an untreated and adjacent, but independent, lake (1385 m3). Results Water samples taken up to 72 hours after the source treatment produced significant increases (p ≤ 0.03) in the absorbance of the solvatochromic dye methylene violet (MV), while samples from the control lake produced no changes. Conclusions The study indicates that activity associated with Phos 30c can propagate itself through large volumes of water, causing changes throughout a whole connected lake system, and that these changes can be tracked using the solvatochromic dye MV. This in turn means the use of homeopathic medicines in large volumes of drinking water, in farming and ecological contexts, now has the potential to be assessed with physico-chemical monitoring.

Particulate organic carbon in Atlantic surface waters

Nature ◽  
1977 ◽  
Vol 266 (5604) ◽  
pp. 713-716 ◽  
Author(s):  
S. KRISHNASWAMI ◽  
D. LAL
Keyword(s):  
Organic Carbon ◽  
Particulate Organic Carbon ◽  
Surface Waters
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