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Full-Text Articles in Physical Sciences and Mathematics

Dissolved Organic Matter Composition And Bioavailability Reflect Ecosystem Productivity In The Western Arctic Ocean, Yuan Shen, Cedric Fichot, Ronald Benner Dec 2012

Dissolved Organic Matter Composition And Bioavailability Reflect Ecosystem Productivity In The Western Arctic Ocean, Yuan Shen, Cedric Fichot, Ronald Benner

Faculty Publications

Dissolved organic carbon (DOC) and total dissolved amino acids (TDAA) were measured in high (Chukchi Sea) and low (Beaufort Sea) productivity regions of the western Arctic Ocean to investigate the composition and bioavailability of dissolved organic matter (DOM). Concentrations and DOC-normalized yields of TDAA in Chukchi surface waters were relatively high, indicating an accumulation of bioavailable DOM. High concentrations and yields of TDAA were also observed in the upper halocline of slope and basin waters, indicating off-shelf transport of bioavailable DOM from the Chukchi Sea. In contrast, concentrations and yields of TDAA in Beaufort surface waters were relatively low, indicting …


Spectroscopic Characterization Of Dissolved Organic Matter: Insights Into Composition, Photochemical Transformation And Carbon Cycling, John Robert Helms Jul 2012

Spectroscopic Characterization Of Dissolved Organic Matter: Insights Into Composition, Photochemical Transformation And Carbon Cycling, John Robert Helms

Chemistry & Biochemistry Theses & Dissertations

This dissertation explores processes affecting the composition of dissolved organic matter (DOM) and how DOM composition changes in sunlit surface waters and in the dark interior ocean. Simulated solar irradiations were used to investigate the impact of photochemistry on terrestrial waters and deep ocean DOM. The photochemically mediated processes observed in Dismal Swamp samples included (i) light induced flocculation of up to 12% of the organic matter and 84% of the dissolved iron originally present; (ii) 74-88% mineralization of dissolved organic carbon (DOC) and 95-99% bleaching of chromophoric DOM (CDOM) during 110 days of irradiation; and (iii) nearly complete loss …


Evolution Of The Optical Properties Of Seawater Influenced By The Deepwater Horizon Oil Spill In The Gulf Of Mexico, Zhengzhen Zhou, Laodong Guo Apr 2012

Evolution Of The Optical Properties Of Seawater Influenced By The Deepwater Horizon Oil Spill In The Gulf Of Mexico, Zhengzhen Zhou, Laodong Guo

Faculty Publications

The fluorescence excitation-emission matrix (EEM) technique coupled with parallel factor (PARAFAC) modeling and measurements of bulk organic carbon and other optical properties were used to characterize the oil components released from the Deepwater Horizon oil spill in the Gulf of Mexico and to examine the chemical evolution and transformation of oil in the water column. Seawater samples were collected from the Gulf of Mexico during October 2010 and October 2011, three months and fifteen months, respectively, after the oil spill was stopped. Together with previous results from samples collected during the oil spill in May/June 2010, these time series samples …


Tracing The Transport Of Colored Dissolved Organic Matter In Water Masses Of The Southern Beaufort Sea: Relationship With Hydrographic Characteristics, A. Matsuoka, A. Bricaud, Ronald Benner, J. Para, R. Sempéré, L. Prieur, S. Bélanger, M. Babin Mar 2012

Tracing The Transport Of Colored Dissolved Organic Matter In Water Masses Of The Southern Beaufort Sea: Relationship With Hydrographic Characteristics, A. Matsuoka, A. Bricaud, Ronald Benner, J. Para, R. Sempéré, L. Prieur, S. Bélanger, M. Babin

Faculty Publications

Light absorption by colored dissolved organic matter (CDOM) [aCDOM(λ)] plays an important role in the heat budget of the Arctic Ocean, contributing to the recent decline in sea ice, as well as in biogeochemical processes. We investigated aCDOM(λ) in the Southern Beaufort Sea where a significant amount of CDOM is delivered by the Mackenzie River. In the surface layer, aCDOM(440) showed a strong and negative correlation with salinity, indicating strong river influence and conservative transport in the river plume. Below the mixed layer, a weak but positive correlation between aCDOM(440) and salinity was observed above the upper halocline, resulting from …


A Molecular Perspective On The Ageing Of Marine Dissolved Organic Matter, R. Flerus, O. J. Lechtenfeld, B. P. Koch, S. L. Mccallister, P. Schmitt-Kopplin, Ronald Benner, G. Kattner Jan 2012

A Molecular Perspective On The Ageing Of Marine Dissolved Organic Matter, R. Flerus, O. J. Lechtenfeld, B. P. Koch, S. L. Mccallister, P. Schmitt-Kopplin, Ronald Benner, G. Kattner

Faculty Publications

Dissolved organic matter (DOM) was extracted by solid-phase extraction (SPE) from 137 water samples from different climate zones and different depths along an eastern Atlantic Ocean transect. The extracts were analyzed with Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) with electrospray ionization (ESI). Δ14C analyses were performed on subsamples of the SPE-DOM. In addition, the amount of dissolved organic carbon was determined for all water and SPE-DOM samples as well as the yield of amino sugars for selected samples. Linear correlations were observed between the magnitudes of 43 % of the FT-ICR mass peaks and the extract Δ14C …