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Concentration And C13 Content Of Molecular Size Fractions Of The Dissolved Organic Matter In Estuarine And Marine Waters
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Book Synopsis Concentration and C13 Content of Molecular Size Fractions of the Dissolved Organic Matter in Estuarine and Marine Waters by : Fie Kearsley
Download or read book Concentration and C13 Content of Molecular Size Fractions of the Dissolved Organic Matter in Estuarine and Marine Waters written by Fie Kearsley and published by . This book was released on 1973 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Special Publication written by and published by . This book was released on 1995 with total page 310 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Linking Optical and Chemical Properties of Dissolved Organic Matter in Natural Waters by : Christopher L. Osburn
Download or read book Linking Optical and Chemical Properties of Dissolved Organic Matter in Natural Waters written by Christopher L. Osburn and published by Frontiers Media SA. This book was released on 2017-01-17 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt: A substantial increase in the number of studies using the optical properties (absorbance and fluorescence) of dissolved organic matter (DOM) as a proxy for its chemical properties in estuaries and the coastal and open ocean has occurred during the last decade. We are making progress on finding the actual chemical compounds or phenomena responsible for DOM’s optical properties. Ultrahigh resolution mass spectrometry, in particular, has made important progress in making the key connections between optics and chemistry. But serious questions remain and the last major special issue on DOM optics and chemistry occurred nearly 10 years ago. Controversies remain from the non-specific optical properties of DOM that are not linked to discrete sources, and sometimes provide conflicting information. The use of optics, which is relatively easier to employ in synoptic and high resolution sampling to determine chemistry, is a critical connection to make and can lead to major advances in our understanding of organic matter cycling in all aquatic ecosystems. The contentions and controversies raised by our poor understanding of the linkages between optics and chemistry of DOM are bottlenecks that need to be addressed and overcome.
Book Synopsis Treatise on Estuarine and Coastal Science by :
Download or read book Treatise on Estuarine and Coastal Science written by and published by Academic Press. This book was released on 2012-03-06 with total page 4604 pages. Available in PDF, EPUB and Kindle. Book excerpt: The study of estuaries and coasts has seen enormous growth in recent years, since changes in these areas have a large effect on the food chain, as well as on the physics and chemistry of the ocean. As the coasts and river banks around the world become more densely populated, the pressure on these ecosystems intensifies, putting a new focus on environmental, socio-economic and policy issues. Written by a team of international expert scientists, under the guidance of Chief Editors Eric Wolanski and Donald McClusky, the Treatise on Estuarine and Coastal Science, Ten Volume Set examines topics in depth, and aims to provide a comprehensive scientific resource for all professionals and students in the area of estuarine and coastal science Most up-to-date reference for system-based coastal and estuarine science and management, from the inland watershed to the ocean shelf Chief editors have assembled a world-class team of volume editors and contributing authors Approach focuses on the physical, biological, chemistry, ecosystem, human, ecological and economics processes, to show how to best use multidisciplinary science to ensure earth's sustainability Provides a comprehensive scientific resource for all professionals and students in the area of estuarine and coastal science Features up-to-date chapters covering a full range of topics
Book Synopsis Biogeochemistry of Marine Dissolved Organic Matter by : Dennis A. Hansell
Download or read book Biogeochemistry of Marine Dissolved Organic Matter written by Dennis A. Hansell and published by Academic Press. This book was released on 2014-10-02 with total page 712 pages. Available in PDF, EPUB and Kindle. Book excerpt: Marine dissolved organic matter (DOM) is a complex mixture of molecules found throughout the world's oceans. It plays a key role in the export, distribution, and sequestration of carbon in the oceanic water column, posited to be a source of atmospheric climate regulation. Biogeochemistry of Marine Dissolved Organic Matter, Second Edition, focuses on the chemical constituents of DOM and its biogeochemical, biological, and ecological significance in the global ocean, and provides a single, unique source for the references, information, and informed judgments of the community of marine biogeochemists. Presented by some of the world's leading scientists, this revised edition reports on the major advances in this area and includes new chapters covering the role of DOM in ancient ocean carbon cycles, the long term stability of marine DOM, the biophysical dynamics of DOM, fluvial DOM qualities and fate, and the Mediterranean Sea. Biogeochemistry of Marine Dissolved Organic Matter, Second Edition, is an extremely useful resource that helps people interested in the largest pool of active carbon on the planet (DOC) get a firm grounding on the general paradigms and many of the relevant references on this topic. Features up-to-date knowledge of DOM, including five new chapters The only published work to synthesize recent research on dissolved organic carbon in the Mediterranean Sea Includes chapters that address inputs from freshwater terrestrial DOM
Book Synopsis Dynamics and Characterization of Marine Organic Matter by : N. Handa
Download or read book Dynamics and Characterization of Marine Organic Matter written by N. Handa and published by Springer Science & Business Media. This book was released on 2013-03-09 with total page 561 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over the past decade the scientific activities of the Joint Global Ocean Flux Study (JGOFS), which focuses on the role of the oceans in controlling climate change via the transport and storage of greenhouse gases and organic matter, have led to an increased interest in the study of the biogeochemistry of organic matter. There is also a growing interest in global climate fluctuations. This, and the need for a precise assessment of the dynamics of carbon and other bio-elements, has led to a demand for an improved understanding of biogeochemical processes and the chemical characteristics of both particulate and dissolved organic matter in the ocean. A large amount of proxy data has been published describing the changes of the oceanic environment, but qualitative and quantitative estimates of the vertical flux of (proxy) organic compounds have not been well documented. There is thus an urgent need to pursue this line of study and, to this end, this book starts with several papers dealing with the primary production of organic matter in the upper ocean. Thereafter, the book goes on to follow the flux and characterization of particulate organic matter, discussed in relation to the primary production in the euphotic zone and resuspension in the deep waters, including the vertical flux of proxy organic compounds. It goes on to explain the decomposition and transformation of organic matter in the ocean environment due to photochemical and biological agents, and the reactivity of bulk and specific organic compounds, including the air-sea interaction of biogenic gases. The 22 papers in the book reflect the interests of JGOFS and will thus serve as a valuable reference source for future biogeochemical investigations of both bio-elements and organic matter in seawater, clarifying the role of the ocean in global climate change.
Book Synopsis Spectral Shape as an Indicator of Molecular Weight in Chromophoric Dissolved Organic Matter by : John Robert Helms
Download or read book Spectral Shape as an Indicator of Molecular Weight in Chromophoric Dissolved Organic Matter written by John Robert Helms and published by . This book was released on 2006 with total page 78 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis dissolved organic carbon concentrations and compositions, and trihalomethane formation potentials in waters from agricultural peat soils, sacramento-san joaquin delta, california: implications for drinking-water quality by :
Download or read book dissolved organic carbon concentrations and compositions, and trihalomethane formation potentials in waters from agricultural peat soils, sacramento-san joaquin delta, california: implications for drinking-water quality written by and published by DIANE Publishing. This book was released on with total page 81 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Bibliography and Index of Geology by :
Download or read book Bibliography and Index of Geology written by and published by . This book was released on 1987 with total page 1440 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis High Molecular Weight (HMW) Dissolved Organic Matter (DOM) in Seawater by : Lihini I. Aluwihare
Download or read book High Molecular Weight (HMW) Dissolved Organic Matter (DOM) in Seawater written by Lihini I. Aluwihare and published by . This book was released on 1999 with total page 436 pages. Available in PDF, EPUB and Kindle. Book excerpt: The goal of this thesis was to use high resolution analytical techniques coupled with molecular level analyses to chemically characterize high molecular weight (> 1 k Da (HMW)) dissolved organic matter (DOM) isolated from seawater in an attempt to provide new insights in to the cycling of DOM in the ocean. While a variety of sites spanning different environments (fluvial, coastal and oceanic) and ocean basins were examined, the chemical structure of the isolated HMW DOM varied little at both the polymer and monomer levels. All samples show similar ratios of carbohydrate:acetate:lipid carbon (80±4:10±2:9±4) indicating that these biochemicals are present within a family of related polymers. The carbohydrate fraction shows a characteristic distribution of seven major neutral monosaccharides: rhamnose, fucose, arabinose, xylose, mannose, glucose and galactose; and additionally contains Nacetylated amino sugars as seen by Nuclear Magnetic Resonance Spectroscopy (NMR). This family of compounds, consisting of a specifically linked polysaccharide backbone that is acylated at several positions, has been termed acylated polysaccharides (APS) by our laboratory. APS accounts for 50% of the carbon in HMW DOM isolated from the surface ocean and 20% of the carbon in HMW DOM isolated from the deep ocean. In order to identify a possible source for APS three species of phytoplankton, Thalassiossira weissflogii, Emiliania huxleyi and Phaeocystis, were cultured in seawater and their HMW DOM exudates examined by variety of analytical techniques. Both the T. weissflogii and E. huxleyi exudates contain compounds that resemble APS indicating that phytoplankton are indeed a source of APS to the marine environment. Furthermore, the degradation of the T. weissflogii exudate by a natural assemblage of microorganisms indicates that the component resembling APS is more resistant to microbial degradation compared to other polysaccharides present in the culture. Molecular level analyses show the distribution of monosaccharides to be conservative in surface and deep waters suggesting that APS is present throughout the water column. In order to determine the mechanism by which APS is delivered to the deep ocean the [delta]14C value of APS in the deep ocean was compared to the A14C value of the dissolved inorganic carbon (DIC) at the same depth. If the formation of deep water is the dominant mode of transport then both the DIC and APS will have similar [delta]14C values. However, if APS is injected into the deep ocean from particles or marine snow then the [delta]14C value of APS will be higher than the DIC at the same depth. Our results indicate that APS in the deep Pacific Ocean carries a modem [delta]14C value and is substantially enriched in 14C relative to the total HMW DOM and the DIC at that depth. Thus, particle dissolution appears to be the most important pathway for the delivery of APS to the deep ocean.
Download or read book 1998 Ocean Sciences Meeting written by and published by . This book was released on 1998 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Chemical Controls on the Cycling and Reactivity of Marine Dissolved Organic Matter by : Benjamin Nash Granzow
Download or read book Chemical Controls on the Cycling and Reactivity of Marine Dissolved Organic Matter written by Benjamin Nash Granzow and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Marine dissolved organic matter (DOM) is an actively cycling reservoir of carbon containing thousands of unique compounds. To describe the complex dynamics that govern the biological transformation and decomposition of compounds in this molecular black box, models of DOM reactivity use chemical characteristics, as well as environmental parameters, to describe trends in the turnover time of classes of DOM. In this thesis, I describe two projects that examine hypotheses regarding the turnover of two classes of DOM. In the 1st project, I test the assumption made by the size-reactivity continuum hypothesis that high molecular weight (> 1 kDa) DOM (HMWDOM) represents a diagenetic intermediate between large labile material and small recalcitrant compounds. Size-fractions of HMWDOM were collected using size-exclusion chromatography, and the changes in MW and chemical composition of the fractions were studied using diffusion-ordered spectroscopy. The size fraction carbon isotopic values were correlated with the proportion of humic substances in the fractions. Through linear modeling, the apparent radiocarbon ages of the two major components of HMWDOM were determined to be 1-3 yrs and 2-4 kyrs, respectively. Combined with the measurements of MW distribution this work demonstrates that HMWDOM is composed of two components that have contrasting decomposition pathways in the ocean. HMWDOM cannot be treated as a single DOM pool when incorporated into models of DOM diagenesis. The 2nd project in this dissertation examines the remineralization of phosphonates, compounds with a direct C-P bond, in the lower euphotic zone using a newly developed fluorescent assay, which measures the activity of carbon-phosphorus lyase. C-P lyase activity (CLA) profiles from the North Pacific Subtropical Gyre (NPSG) showed a sharp activity maximum near the deep-chlorophyll maximum (DCM). High-resolution nutrient measurements suggest that this subsurface CLA maximum is the result of a high nitrate flux at the top of the nitracline. The composition of particulate-P through the euphotic zone was also examined. While phosphonates were not detected in suspended particles, a significant amount of aminoethylphosphonate was measured in sinking material, suggesting eukaryotic material may be an important source of phosphonates to the ocean.
Book Synopsis Biogeochemistry of Marine Dissolved Organic Matter by : Oliver J. Lechtenfeld
Download or read book Biogeochemistry of Marine Dissolved Organic Matter written by Oliver J. Lechtenfeld and published by . This book was released on 2012 with total page 304 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Biogeochemistry of Marine Dissolved Organic Matter by : Oliver J. Lechtenfeld
Download or read book Biogeochemistry of Marine Dissolved Organic Matter written by Oliver J. Lechtenfeld and published by . This book was released on 2012 with total page 304 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Molecular and Optical Characterization of Dissolved Organic Matter in the Central Arctic Ocean by : Xianyu Kong
Download or read book Molecular and Optical Characterization of Dissolved Organic Matter in the Central Arctic Ocean written by Xianyu Kong and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dissolved organic matter (DOM) in the ocean is a complex mixture of molecules derived from autochthonous (marine) or allochthonous (terrestrial) origins. DOM plays an important role in marine biogeochemical cycles by attenuating light available for primary production, serving as an energy and nutrient source for heterotrophic communities, regulating the ultraviolet and visible light absorption, undergoing photochemical processing, and acting as a trace metal ligand. DOM in the Central Arctic Ocean (CAO) is influenced by increased freshwater input and associated terrestrial materials in recent decades due to rapid climate change. The quantification of DOM sources (terrestrial versus marine) in the water column of the CAO is not well constrained. Few studies have systematically investigated the seasonality and spatial variability of DOM by combining optical and molecular-level analytical techniques in the CAO, especially during winter. State of the art chemical characterization of DOM is subject to major challenges: Solid phase extraction (SPE) that is often used to desalt and pre-concentrate marine DOM introduces chemical fractionation effects, which limits the comparability between analytical results for original samples and those carried out for SPE-DOM. There is no specific method to quantify fractionation effects, nor specific guidelines to avoid fractionation. Using mass spectrometry, quantitative DOM analyses is challenged by selective ionization of molecules and the large number of unresolved structural isomers that prevent classical external calibration. In the first part of this thesis, a method was developed to quantitatively track optical or chemical fractionation during SPE and investigate the potential mechanisms. We found a decrease in extraction efficiency of dissolved organic carbon (DOC), fluorescence and absorbance, and polar organic substances with increasing carbon loading on the SPE column. As the surface loading of the solid-phase increased, the dominant extraction mechanism shifted from PPL physisorption to increased DOM self-assembly, resulting in optical and chemical fractionation. The relative DOC loading (DOCload) was used to assess the carbon loading during SPE, and a double sigmoid model was applied to our online permeate fluorescence data as a function of DOCload, which allowed us to assess the degree of variability induced by DOCload. This finding has ample implications for the future processing and previous interpretation of chemical characteristics in SPE-DOM of aquatic organic matter. For the second part of the thesis, original water samples were acquired from the “Multidisciplinary Drifting Observatory for the Study of Arctic Climate” (MOSAiC) expedition. The water column samples covered a full year (2019 / 2020) and included the regions Amundsen Basin, western Nansen Basin and Yermak Plateau and Fram Strait. Samples were analyzed using optical spectroscopy to determine chromophoric DOM (CDOM) and fluorescent DOM (FDOM). In addition, a new method was applied that used Fourier transform ion cyclotron resonance mass spectrometry hyphenated to high performance liquid chromatography (LC-FTMS). The method allowed DOM analysis in original filtered water and thus avoided the chemical fractionation introduced by SPE. During the MOSAiC expedition, DOC concentrations and CDOM characteristics in the water column were primarily influenced by regional differences. These differences were largely dependent on terrestrially-derived DOM (tDOM) input by the transpolar drift (TPD) as indicative of average 136% and 45% higher aCDOM(350) and DOC concentration, respectively, in the Amundsen compared to the western Nansen Basin and Yermak Plateau, and slightly modified by seasonal changes. Despite the convenient identification of tDOM, optical spectroscopy was not suitable to quantify the contribution of tDOM to bulk DOC or to track sea ice derived DOM in the water column. In contrast, using LC-FTMS, we found quantitative linear correlation between the summed mass peak magnitudes for each sample (intsum) and DOC concentration. By combing LC-FTMS and source identification with optical parameters, we were able to quantify DOM sources (terrestrial versus marine) in the water column: 83% of the summed peak magnitude of all samples could be related to marine or terrestrial sources. tDOM contributed ∼17% (or 8 μmol kg-1) to deep DOC (~2000 m) in the CAO and was more refractory and had a higher state of unsaturation compared to marine DOM. The quantitative characterization of DOM in original seawater from different origin is a major step in the field of research. It provides a unique and new insight into the molecular changes in marine DOM composition and an improved understanding of the terrestrial DOM distribution in the CAO.
Download or read book Geographical Abstracts written by and published by . This book was released on 1975 with total page 1050 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Characterization of High Molecular Weight Dissolved Organic Matter in Estuaries by : Julie Callahan
Download or read book Characterization of High Molecular Weight Dissolved Organic Matter in Estuaries written by Julie Callahan and published by . This book was released on 2004 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt:
