scholarly journals Spatial and temporal distribution of coloured dissolved organic matter in a hypertrophic freshwater lagoon

2015 ◽  
Author(s):  
Diana Vaičiūtė ◽  
Mariano Bresciani ◽  
Marco Bartoli ◽  
Claudia Giardino ◽  
Martynas Bučas
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Temporal Distribution ◽  
Late Summer ◽  
Temporal Variations ◽  
Curonian Lagoon ◽  
Imaging Spectrometer ◽  
Lagoon Water ◽  
Medium Resolution ◽  
Relevant Role

<p>A dataset of 224 Medium Resolution Imaging Spectrometer (MERIS) full resolution satellite images were processed to retrieve the concentration of coloured dissolved organic matter (CDOM) in a hypertrophic estuary (Curonian Lagoon, Lithuania and Russia). Images covered a period of 7 months, spanning from the ice melting (March) to the late summer (September) of 7 consecutive years (2005-2011). The aim of the study was to analyse the spatial and temporal variations of CDOM, by focusing on the main regulating factors (riverine discharge, sea-lagoon water exchange, water temperature, chlorophyll <em>a</em>, wind) in a large estuary. The working hypothesis is that CDOM distribution may reveal distinct, site specific seasonal patterns. Our results demonstrated that CDOM concentrations at the whole lagoon level were elevated (1.5-4 m<sup>-1</sup>) and slightly but significantly higher in spring (1.50 m<sup>-1</sup> on average) compared to the summer (1.45 m<sup>-1</sup> on average). This is due to very different flow of CDOM-rich freshwater from the main lagoon tributary in spring compared to summer. They also highlight macroscopic differences among areas within the lagoon, depending on season, suggesting a complex regulation of CDOM in this system. Significant factors explaining observed differences are the dilution of lagoon water with CDOM-poor brackish water, regeneration of large amounts of dissolved organic matter from sediments and combinations of uptake/release from phytoplankton. CDOM and its variations are understudied due to inherent methodological and analytical difficulties. However, this pool has a demonstrated relevant role in the biogeochemistry of aquatic environments. We speculate that the dissolved organic pool in the Curonian Lagoon has a mainly allochthonous origin in the high discharge period and an autochthonous origin in the summer, algal bloom period. Both positive and negative relationships between CDOM and phytoplankton suggest that pelagic microalgae may act as a source or as a sink of this pool, in particular when inorganic nutrients are limiting. </p>

Spatio-temporal Variations of Dissolved Organic Matter in a German Forested Mountainous Headwater Catchment

2015 ◽  
Vol 14 (4) ◽  
pp. vzj2015.01.0005 ◽  
Author(s):  
Roland Bol ◽  
Andreas Lücke ◽  
Wolfgang Tappe ◽  
Sirgit Kummer ◽  
Martina Krause ◽  
...  
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Temporal Variations ◽  
Spatio Temporal ◽  
Headwater Catchment

scholarly journals Origin and fate of dissolved organic matter in four shallow Baltic Sea estuaries

2020 ◽  
Author(s):  
Maren Voss ◽  
Eero Asmala ◽  
Ines Bartl ◽  
Jacob Carstensen ◽  
Daniel J. Conley ◽  
...  
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Baltic Sea ◽  
Residence Time ◽  
Nutrient Concentrations ◽  
Curonian Lagoon ◽  
Published Data ◽  
Coastal Systems ◽  
Catchment Areas ◽  
The Baltic

Abstract Coastal waters have strong gradients in dissolved organic matter (DOM) quantity and characteristics, originating from terrestrial inputs and autochthonous production. Enclosed seas with high freshwater input therefore experience high DOM concentrations and gradients from freshwater sources to more saline waters. The brackish Baltic Sea experiences such salinity gradients from east to west and from river mouths to the open sea. Furthermore, the catchment areas of the Baltic Sea are very diverse and vary from sparsely populated northern areas to densely populated southern zones. Coastal systems vary from enclosed or open bays, estuaries, fjords, archipelagos and lagoons where the residence time of DOM at these sites varies and may control the extent to which organic matter is biologically, chemically or physically modified or simply diluted with transport off-shore. Data of DOM with simultaneous measurements of dissolved organic (DO) nitrogen (N), carbon (C) and phosphorus (P) across a range of contrasting coastal systems are scarce. Here we present data from the Roskilde Fjord, Vistula and Öre estuaries and Curonian Lagoon; four coastal systems with large differences in salinity, nutrient concentrations, freshwater inflow and catchment characteristics. The C:N:P ratios of DOM of our data, despite high variability, show site specific significant differences resulting largely from differences residence time. Microbial processes seemed to have minor effects, and only in spring did uptake of DON in the Vistula and Öre estuaries take place and not at the other sites or seasons. Resuspension from sediments impacts bottom waters and the entire shallow water column in the Curonian Lagoon. Finally, our data combined with published data show that land use in the catchments seems to impact the DOC:DON and DOC:DOP ratios of the tributaries most.

scholarly journals Characteristics and Source of Dissolved Organic Matter in Lake Hulun, A Large Shallow Eutrophic Steppe Lake in Northern China

Water ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 953
Author(s):  
Wenwen Wang ◽  
Binghui Zheng ◽  
Xia Jiang ◽  
Junyi Chen ◽  
Shuhang Wang
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Temporal Distribution ◽  
Northern China ◽  
High Concentration ◽  
Excitation Emission Matrix ◽  
Occurrence Characteristics ◽  
Parallel Factor ◽  
The Difference ◽  
High Degree

Lake Hulun, the fifth largest lake in China, is a typical eutrophic steppe lake located in the Hulun Buir Prairie. The dissolved organic matter (DOM) in the water of Lake Hulun has a high concentration. However, little is known about the occurrence characteristics and source of the DOM in Lake Hulun. The spatial and temporal distribution characteristics of DOM concentration in Lake Hulun were thoroughly surveyed, and the optical characteristics, fluorescence components and sources of DOM were analyzed by excitation emission matrix (EMM) and parallel factor analysis (PARAFAC) technology. The DOM concentration was 6.46–42.87 mg C/L, and was highest in summer and lowest in winter. The difference in the spatial distribution of DOM in winter was significant due to the ice over, and showed a trend where the concentration near the shore was higher than that in the center of the lake. Three humic-like components and one component consisting of a mixture of humic-like and protein-like substances of DOM were identified, with the former being prevalent. The humification index of DOM was 2.22–9.92, indicating that the DOM has a high degree of humification. The DOM is mainly derived from terrestrial sources, with the highest proportion (91.0% ± 8.1%) found in winter and the lowest (66.2% ± 7.7%) in summer. Given that the DOM in Lake Hulun is mainly dominated by humic-like components with a high degree humification, the DOM may have low bioactivity. However, this is just a preliminary analysis and judgment, and it is necessary to conduct other experiments such as biodegradation experiments to further study the bioavailability of DOM in Lake Hulun.

scholarly journals Using remote sensing to enhance modelling of fine sediment dynamics in the Dutch coastal zone

2013 ◽  
Vol 16 (2) ◽  
pp. 458-476 ◽  
Author(s):  
A. M. Y. Kamel ◽  
G. Y. El Serafy ◽  
B. Bhattacharya ◽  
T. van Kessel ◽  
D. P. Solomatine
Keyword(s):  
Remote Sensing ◽  
Temporal Distribution ◽  
Fine Sediment ◽  
In Situ Measurements ◽  
Sediment Dynamics ◽  
Model Parameters ◽  
Imaging Spectrometer ◽  
Suspended Particulate ◽  
Medium Resolution

Modelling fine sediment dynamics, including transport, deposition and re-suspension, is very complex. This led to studies that validate the modelled suspended particulate matter (SPM) based on in-situ measurements. While in-situ measurements are often sparse in time and space, satellite measurements provide us with higher spatial and temporal resolution. This information can be used to validate and enhance the model's capability of predicting the spatial and temporal distribution of SPM. In this paper, the SPM retrieved from the MEdium Resolution Imaging Spectrometer (MERIS) on board European Space Agency's ENVISAT spacecraft is used to carry out a thorough calibration and validation of the SPM description provided by the Delft3DWAQ model of the Southern North Sea for the year 2007. In an uncertainty analysis framework, the key model parameters affecting the SPM distributions were first identified in predefined physical regions. The sensitivity of the model to slight changes in those parameters is tested and the spatial and temporal errors compared to remote sensing images were identified and a new set of parameters has been suggested and further subjected to uncertainty to define prediction intervals of the SPM distribution at a number of locations. The so-called adapted model has been validated against independent data and has shown a decrease in errors, particularly along the Dutch coast.

Spatio-temporal variations of fluorescence properties of dissolved organic matter along the River Têt (Pyrénées-Orientales, France)

2009 ◽  
Vol 25 (6) ◽  
pp. 435-452 ◽  
Author(s):  
Florence Vouvé ◽  
Leticia Cotrim da Cunha ◽  
Léon Serve ◽  
Jean Vigo ◽  
Jean-Marie Salmon
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Temporal Variations ◽  
Fluorescence Properties ◽  
Spatio Temporal
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