scholarly journals Оптические свойства растворенного органического вещества поверхностного слоя воды моря Лаптевых

2019 ◽  
Vol 126 (3) ◽  
pp. 383
Author(s):  
А.Н. Дроздова
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Continental Slope ◽  
Riverine Water ◽  
Lena River ◽  
Humic Compounds ◽  
Fluorescence Maximum ◽  
Autochthonous Organic Matter ◽  
Main Component ◽  
Lena River Delta

AbstractFeatures of fluorescence of humic compounds transported by the Lena River runoff in September 2015 are considered. The change in optical properties of dissolved organic matter, namely, fluorescence spectra and absorption coefficients at a wavelength of 350 nm, on the transect from the Lena River delta to the continental slope is demonstrated. For humic compounds of terrigenous origin, the position of the fluorescence maximum has been determined at excitation wavelengths of 270, 310, and 355 nm. It has been shown that fresh riverine waters of Lena River propagate throughout the entire shelf and humic compounds are the main component of the colored fraction of dissolved organic matter. In samples collected near the continental slope, the presence of labile autochthonous organic matter has been revealed. The content of dissolved organic matter in riverine water in 2015 is comparable with results of previous investigations and amounts to 548 μM/L.

scholarly journals From Fresh to Marine Waters: Characterization and Fate of Dissolved Organic Matter in the Lena River Delta Region, Siberia

2015 ◽  
Vol 2 ◽  
Author(s):  
Rafael Gonçalves-Araujo ◽  
Colin A. Stedmon ◽  
Birgit Heim ◽  
Ivan Dubinenkov ◽  
Alexandra Kraberg ◽  
...  
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
River Delta ◽  
Delta Region ◽  
Marine Waters ◽  
Lena River ◽  
Lena River Delta

scholarly journals Coloured dissolved organic matter in aquatic ecosystems of three representative regions of the Arctic according to the data obtained in year 2019

2020 ◽  
Vol 163 ◽  
pp. 04006
Author(s):  
Anastasiia Pashovkina ◽  
Irina Fedorova
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Kola Peninsula ◽  
Aquatic Ecosystems ◽  
River Delta ◽  
The Arctic ◽  
Yamal Peninsula ◽  
Lena River ◽  
Lena River Delta ◽  
The Yamal Peninsula

In this study the laboratory analysis of water samples from three representative regions of the Arctic for content of coloured dissolved organic matter (CDOM) – the important component of natural waters, which has a direct impact on state of aquatic ecosystems, was made. Samples were collected from water objects from the Kola Peninsula, the Yamal Peninsula and the Lena River Delta. The results of the analysis made it possible to determine CDOM concentrations in water. According to the average values, the highest values were obtained for the Yamal Peninsula and lowest – for the Kola Peninsula. The predominance of allochthonous CDOM in the water objects from all three regions was revealed. Moreover, the complete absence of photodegradation processes was determined. For the lakes and rivers from the Kola Peninsula it was also possible to follow seasonal dynamic of CDOM concentration in water and to compare it with earlier obtained data concerning seasonal CDOM dynamic in the Lena River Delta. Results are actual due to the currently existing tendency of climate change which leads to intensification of thermal denudation and thermal erosion processes in the cryolithozone, which are consequently increasing income of allochthonous CDOM in water objects.

scholarly journals Trace metal distribution in pristine permafrost-affected soils of the Lena River Delta and its Hinterland, Northern Siberia, Russia

2013 ◽  
Vol 10 (2) ◽  
pp. 2205-2244 ◽  
Author(s):  
I. Antcibor ◽  
S. Zubrzycki ◽  
A. Eschenbach ◽  
L. Kutzbach ◽  
D. Bol'shiyanov ◽  
...  
Keyword(s):  
Trace Elements ◽  
Organic Matter ◽  
Trace Metal ◽  
Climatic Changes ◽  
River Delta ◽  
Metal Distribution ◽  
Background Concentrations ◽  
Lena River ◽  
Trace Metal Distribution ◽  
Lena River Delta

Abstract. Soils are an important compartment of ecosystems and have the ability to immobilize chemicals preventing their movement to other environment compartments. Predicted climatic changes together with other anthropogenic influences on Arctic terrestrial environments may affect biogeochemical processes enhancing leaching and migration of trace elements in permafrost-affected soils. This is especially important since the Arctic ecosystems are considered to be very sensitive to climatic changes as well as to chemical contamination. This study characterizes background levels of trace metals in permafrost-affected soils of the Lena River Delta and its hinterland in northern Siberia (73.5° N–69.5° N) representing a remote region far from evident anthropogenic trace metal sources. Investigations on total element contents of iron (Fe), arsenic (As), manganese (Mn), zinc (Zn), nickel (Ni), copper (Cu), lead (Pb), cadmium (Cd), cobalt (Co) and mercury (Hg) in different soil types developed in different geological parent materials have been carried out. The highest concentrations of the majority of the measured elements were observed in soils belonging to ice-rich permafrost sediments formed during the Pleistocene (ice-complex) in the Lena River Delta region. Correlation analyses of trace metal concentrations and soil chemical and physical properties at a Holocene estuarine terrace and two modern floodplain levels in the southern-central Lena River Delta (Samoylov Island) showed that the main factors controlling the trace metal distribution in these soils are organic matter content, soil texture and contents of iron and manganese-oxides. Principal Component Analysis (PCA) revealed that soil oxides play a significant role in trace metal distribution in both top and bottom horizons. Occurrence of organic matter contributes to Cd binding in top soils and Cu binding in bottom horizons. Observed ranges of the background concentrations of the majority of trace elements were similar to background levels reported for other pristine arctic areas and did not exceed mean global background concentrations examined for the continental crust as well as for the world's soils.

Seasonality in Lena River biogeochemistry and dissolved organic matter

2020 ◽  
Author(s):  
Bennet Juhls ◽  
Pier Paul Overduin ◽  
Colin Andrew Stedmon ◽  
Anne Morgenstern ◽  
Hanno Meyer ◽  
...  
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Arctic Ocean ◽  
The Arctic ◽  
Research Station ◽  
Lena River ◽  
Continuous Sampling ◽  
The Arctic Ocean ◽  
Frequency Sampling ◽  
Sampling Program

<p>The carbon export by rivers to the Arctic Ocean is expected to increase in response to the rapidly changing climate in the Arctic (Camill, 2005; Freeman et al., 2001; Frey and Smith, 2005). This is in part due to thawing permafrost and mobilization of particulate and dissolved organic matter (DOM). The Lena River delivers approximately one fifth of the total river discharge to the Arctic Ocean and is the main source of DOM in the Laptev Sea shelf (Thibodeau et al., 2014). To date river fluxes of DOM have been based on sparse coverage of sample across the hydrograph about 700 km upstream (Cooper et al 2005; Raymond et al 2007; Stedmon et al 2011; Amon et al 2012). The effects of low frequency sampling on load estimates are unknown and potentially large for systems such as these where there are considerable changes across the hydrograph.   Here we present results from a unique high frequency sampling program and evaluate its viability to monitor export fluxes of DOM and its biogeochemistry in the Lena River. The sampling takes place close to the river mouth at the research station Samoylov in the central Lena River Delta. The Samoylov research station allows a unique chance for continuous sampling since it operates throughout the year. The sampling program includes measurements of several water parameters, such as temperature, electric conductivity, dissolved organic carbon (DOC), spectral CDOM absorption (aCDOM), fluorescent dissolved organic matter (FDOM) and water stable isotopes.<br>The data facilitated the identification of the main drivers behind the seasonality of DOM concentration and biogeochemistry of the Lena River. Three main water sources could be identified (1) (snow) melt water, (2) rain water and (3) subsurface water. Melt and rain water are found to be the prevailing water sources that combined transport 5.8 Tg C dissolved organic matter (~ 85 % of annual flux (6.8 Tg C)) into the Lena River. The high number of samples throughout the whole year allowed flux calculations that are independently from load models that likely lead to a large variation of earlier studies.<br>The absorption properties of DOM revealed changing composition and sources of DOM throughout the year. Decreasing SUVA values during the summer point towards an increasing fraction of old DOM which potentially originates from degrading permafrost. In contrast, during the spring freshet, high SUVA indicate mostly fresh organic matter with high molecular weight and high aromaticity.<br>This dataset represents the first year of a planned long-term monitoring program at the Research Station Samoylov Island and provides a baseline data set against which future change of this large integrative system may be measured. A continuous sampling of Arctic River water will facilitate to identify intra and inter-annual trends with ongoing climate change.</p>

scholarly journals Hydrological and hydrochemical investigation in the Lena River Delta in winter 2015–2016

2017 ◽  
pp. 107-114
Author(s):  
I. V. Fedorova ◽  
A. A. Chetverova ◽  
N. K. Alekseeva ◽  
T. V. Skorospekhova ◽  
S. G. Romanov ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Organic Matter ◽  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Water Color ◽  
Lena River ◽  
Bodies Of Water ◽  
Available Information ◽  
Lena River Delta ◽  
Permanganate Oxidability

The results of hydrological and hydrochemical research of on bodies of water: ducts and lakes of the delta of the Lena River are reported here. Studies were performed during the 2015/16 summer (July-August) and winter (April) expeditionary seasons. The present work also introduces the results of field hydrochemical analyzes made immediately after sampling. The values of hydrochemical and hydrophysical indicators of ducts and lakes such as electrical conductivity, pH, permanganate oxidability, concentration of dissolved organic carbon, water color and absorption of colored organic matter were received. This obtained values supplemented significantly the available information on the delta water bodies in winter.

scholarly journals Identifying Drivers of Seasonality in Lena River Biogeochemistry and Dissolved Organic Matter Fluxes

2020 ◽  
Vol 8 ◽  
Author(s):  
Bennet Juhls ◽  
Colin A. Stedmon ◽  
Anne Morgenstern ◽  
Hanno Meyer ◽  
Jens Hölemann ◽  
...  
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Lena River

Dissolved organic matter and nutrients in the Lena River, Siberian Arctic: Characteristics and distribution

1998 ◽  
Vol 59 (3-4) ◽  
pp. 301-309 ◽  
Author(s):  
Rubén J Lara ◽  
Volker Rachold ◽  
Gerhard Kattner ◽  
Hans W Hubberten ◽  
Georg Guggenberger ◽  
...  
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Lena River ◽  
Siberian Arctic

scholarly journals Assessments of Organic Carbon Stabilization Using the Spectroscopic Characteristics of Humic Acids Separated from Soils of the Lena River Delta

Separations ◽  
2021 ◽  
Vol 8 (6) ◽  
pp. 87
Author(s):  
Vyacheslav Polyakov ◽  
Evgeny Abakumov
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Organic Carbon ◽  
Humic Acids ◽  
Terrestrial Ecosystems ◽  
River Delta ◽  
The Arctic ◽  
Lena River ◽  
Organic Matter Stabilization ◽  
Lena River Delta

In the Arctic zone, where up to 1024 × 1013 kg of organic matter is stored in permafrost-affected soils, soil organic matter consists of about 50% humic substances. Based on the analysis of the molecular composition of humic acids, we assessed the processes of accumulation of the key structural fragments, their transformations and the stabilization rates of carbon pools in soils in general. The landscape of the Lena River delta is the largest storage of stabilized organic matter in the Arctic. There is active accumulation and deposition of a significant amount of soil organic carbon from terrestrial ecosystems in a permafrost state. Under ongoing climate change, carbon emission fluxes into the atmosphere are estimated to be higher than the sequestration and storing of carbon compounds. Thus, investigation of soil organic matter stabilization mechanisms and rates is quite an urgent topic regarding polar soils. For study of molecular elemental composition, humic acids were separated from the soils of the Lena River delta. Key structural fragments of humic matter were identified and quantified by CP/MAS 13C NMR spectroscopy: carboxyl (–COOR); carbonyl (–C=O); CH3–; CH2–; CH-aliphatic; –C-OR alcohols, esters and carbohydrates; and the phenolic (Ar-OH), quinone (Ar = O) and aromatic (Ar–) groups as benchmark Cryosols of the Lena delta river terrestrial ecosystem. Under the conditions of thermodynamic evolutionary selection, during the change between the dry and wet seasons, up to 41% of aromatic and carboxyl fragments accumulated in humic acids. Data obtained showed that three main groups of carbon played the most important role in soil organic matter stabilization, namely C, H-alkyls ((CH2)n/CH/C and CH3), aromatic compounds (C-C/C-H, C-O) and an OCH group (OCH/OCq). The variations of these carbon species’ content in separated humics, with special reference to soil–permafrost organic profiles’ recalcitrance in the current environment, is discussed.

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