Influence of dissolved organic matter on carbonyl sulfide and carbon disulfide formation from cysteine during sunlight photolysis

2020 ◽  
Vol 22 (9) ◽  
pp. 1852-1864
Author(s):  
Mahsa Modiri Gharehveran ◽  
Ethan Hain ◽  
Lee Blaney ◽  
Amisha D. Shah
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Carbon Disulfide ◽  
Carbonyl Sulfide ◽  
Water Sources ◽  
Open Ocean ◽  
Ocean Water ◽  
Disulfide Formation

Sunlight photolysis of cysteine and dissolved organic matter (DOM) from freshwater to open ocean water sources generates carbonyl sulfide (COS) but not carbon disulfide (CS2).

scholarly journals The influence of dissolved organic matter on the marine production of carbonyl sulfide (OCS) and carbon disulfide (CS<sub>2</sub>) in the Peruvian upwelling

Ocean Science ◽  
2019 ◽  
Vol 15 (4) ◽  
pp. 1071-1090 ◽  
Author(s):  
Sinikka T. Lennartz ◽  
Marc von Hobe ◽  
Dennis Booge ◽  
Henry C. Bittig ◽  
Tim Fischer ◽  
...  
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Carbon Disulfide ◽  
Solid Phase ◽  
Carbonyl Sulfide ◽  
Limiting Factors ◽  
Biogeochemical Model ◽  
Fluorescent Dissolved Organic Matter ◽  
Process Understanding ◽  
Future Emission

Abstract. Oceanic emissions of the climate-relevant trace gases carbonyl sulfide (OCS) and carbon disulfide (CS2) are a major source to their atmospheric budget. Their current and future emission estimates are still uncertain due to incomplete process understanding and therefore inexact quantification across different biogeochemical regimes. Here we present the first concurrent measurements of both gases together with related fractions of the dissolved organic matter (DOM) pool, i.e., solid-phase extractable dissolved organic sulfur (DOSSPE, n=24, 0.16±0.04 µmol L−1), chromophoric (CDOM, n=76, 0.152±0.03), and fluorescent dissolved organic matter (FDOM, n=35), from the Peruvian upwelling region (Guayaquil, Ecuador to Antofagasta, Chile, October 2015). OCS was measured continuously with an equilibrator connected to an off-axis integrated cavity output spectrometer at the surface (29.8±19.8 pmol L−1) and at four profiles ranging down to 136 m. CS2 was measured at the surface (n=143, 17.8±9.0 pmol L−1) and below, ranging down to 1000 m (24 profiles). These observations were used to estimate in situ production rates and identify their drivers. We find different limiting factors of marine photoproduction: while OCS production is limited by the humic-like DOM fraction that can act as a photosensitizer, high CS2 production coincides with high DOSSPE concentration. Quantifying OCS photoproduction using a specific humic-like FDOM component as proxy, together with an updated parameterization for dark production, improves agreement with observations in a 1-D biogeochemical model. Our results will help to better predict oceanic concentrations and emissions of both gases on regional and, potentially, global scales.

scholarly journals The influence of dissolved organic matter on the marine production of carbonyl sulfide (OCS) and carbon disulfide (CS<sub>2</sub>) in the Eastern Tropical South Pacific

2019 ◽  
Author(s):  
Sinikka T. Lennartz ◽  
Marc von Hobe ◽  
Dennis Booge ◽  
Henry Bittig ◽  
Tim Fischer ◽  
...  
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Carbon Disulfide ◽  
Solid Phase ◽  
Carbonyl Sulfide ◽  
South Pacific ◽  
Limiting Factors ◽  
Fluorescent Dissolved Organic Matter ◽  
Process Understanding ◽  
The Indian Ocean

Abstract. Oceanic emissions of the climate relevant trace gases carbonyl sulfide (OCS) and carbon disulfide (CS2) are a major source to their atmospheric budget. Their current and future emission estimates are still uncertain due to incomplete process understanding and, therefore, inexact quantification across different biogeochemical regimes. Here we present the first concurrent measurements of both gases together with related fractions of the dissolved organic matter (DOM) pool, i.e. solid-phase extractable dissolved organic sulfur (DOSSPE), chromophoric (CDOM) and fluorescent dissolved organic matter (FDOM) from the Eastern Tropical South Pacific (ETSP). These observations are used to estimate in-situ production rates and identify their drivers. We find different limiting factors of marine photoproduction: while OCS production is limited by the humic-like DOM fraction that can act as a photosensitizer, high CS2 production coincides with high DOSSPE concentration. The lack of correlation between OCS production and DOSSPE may be explained by the active cycling of sulfur between OCS and dissolved inorganic sulfide via OCS photoproduction and hydrolysis. In addition, the only existing parameterization for OCS dark production is validated and updated with new rates from the ETSP and the Indian Ocean. Our results will help to predict oceanic concentrations and emissions of both gases on regional and, potentially, global scales.

scholarly journals Photobleaching as a factor controlling spectral characteristics of chromophoric dissolved organic matter in open ocean

2013 ◽  
Vol 10 (11) ◽  
pp. 7207-7217 ◽  
Author(s):  
Y. Yamashita ◽  
Y. Nosaka ◽  
K. Suzuki ◽  
H. Ogawa ◽  
K. Takahashi ◽  
...  
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Surface Waters ◽  
Spectral Characteristics ◽  
Open Ocean ◽  
Global Ocean ◽  
Chromophoric Dissolved Organic Matter ◽  
Spectral Slope ◽  
Subtropical Region ◽  
Subarctic Region

Abstract. Chromophoric dissolved organic matter (CDOM) ubiquitously occurs in marine environments and plays a significant role in the marine biogeochemical cycles. Basin scale distributions of CDOM have recently been surveyed in the global ocean and indicate that quantity and quality of oceanic CDOM are mainly controlled by in situ production and photobleaching. However, factors controlling the spectral parameters of CDOM in the UV region, i.e., spectral slope of CDOM determined at 275–295 nm (S275–295) and the ratio of two spectral slope parameters (SR); the ratio of S275–295 to S350–400, have not been well documented. To evaluate the factor controlling the spectral characteristics of CDOM in the UV region in the open ocean, we determined the quantitative and qualitative characteristics of CDOM in the subarctic and subtropical surface waters (5–300 m) of the western North Pacific. Absorption coefficients at 320 nm in the subarctic region were higher than those in the subtropical region throughout surface waters, suggesting that magnitudes of photobleaching were different between the two regions. The values of S275–295 and SR were also higher in the subtropical region than the subarctic region. The dark microbial incubation showed biodegradation of DOM little affected S275–295, but slightly decreased SR. On the other hand, increases in S275–295 and relative stableness of SR were observed during photo-irradiation incubations respectively. These experimental results indicated that photobleaching of CDOM mainly induced qualitative differences in CDOM at UV region between the subarctic and subtropical surface waters. The results of this study imply that S275–295 can be used as a tracer of photochemical history of CDOM in the open ocean.

scholarly journals A new model for the global biogeochemical cycle of carbonyl sulfide – Part 1: Assessment of direct marine emissions with an oceanic general circulation and biogeochemistry model

2015 ◽  
Vol 15 (5) ◽  
pp. 2295-2312 ◽  
Author(s):  
T. Launois ◽  
S. Belviso ◽  
L. Bopp ◽  
C. G. Fichot ◽  
P. Peylin
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
General Circulation ◽  
Carbonyl Sulfide ◽  
Chromophoric Dissolved Organic Matter ◽  
Quantum Yields ◽  
Global Budget ◽  
Ecosystem Studies ◽  
Color Data ◽  
Photo Production

Abstract. The global budget of tropospheric carbonyl sulfide (OCS) is believed to be at equilibrium because background air concentrations have remained roughly stable over at least the last decade. Since the uptake of OCS by leaves (associated with photosynthesis) and soils have been revised significantly upwards recently, an equilibrated budget can only be obtained with a compensatory source of OCS. It has been assumed that the missing source of OCS comes from the low-latitude ocean, following the incident solar flux. The present work uses parameterizations of major production and removal processes of organic compounds in the NEMO-PISCES (Nucleus for European Modelling of the Ocean, Pelagic Interaction Scheme for Carbon and Ecosystem Studies) ocean general circulation and biogeochemistry model to assess the marine source of OCS. In addition, the OCS photo-production rates computed with the NEMO-PISCES model~were evaluated independently using the UV absorption coefficient of chromophoric dissolved organic matter (derived from satellite ocean color data) and apparent quantum yields available in the literature. Our simulations show global direct marine emissions of OCS in the range of 573–3997 GgS yr−1, depending mostly on the quantification of the absorption rate of chromophoric dissolved organic matter. The high estimates of that range are unlikely, as they correspond to a formulation that most likely overestimate photo-production process. Low and medium (813 GgS yr−1) estimates derived from the NEMO-PISCES model are however consistent spatially and temporally~with the suggested missing source of Berry et al. (2013), allowing us thus to close the global budget of OCS given the recent estimates of leaf and soil OCS uptake.

scholarly journals Effects of nitrate and phosphate supply on chromophoric and fluorescent dissolved organic matter in the Eastern Tropical North Atlantic: a mesocosm study

2015 ◽  
Vol 12 (10) ◽  
pp. 7209-7255
Author(s):  
A. N. Loginova ◽  
C. Borchard ◽  
J. Meyer ◽  
H. Hauss ◽  
R. Kiko ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Organic Matter ◽  
Optical Properties ◽  
Amino Acid ◽  
Dissolved Organic Matter ◽  
North Atlantic ◽  
Phytoplankton Biomass ◽  
Open Ocean ◽  
Nutrient Concentrations ◽  
Tropical North Atlantic

Abstract. The Eastern Tropical North Atlantic (ETNA) is an open ocean region with little input of terrestrial dissolved organic matter (DOM), suggesting that pelagic production has to be the main source of DOM. Inorganic nitrogen (DIN) and phosphorus (DIP) concentrations affect pelagic production, leading to DOM modifications. The quantitative and qualitative changes in DOM are often estimated by its optical properties. Colored DOM (CDOM) is often used to estimate dissolved organic carbon (DOC) concentrations by applied techniques, e.g. through remote sensing, whereas DOM properties, such as molecular weight, can be estimated from the slopes of the CDOM absorption spectra (S). Fluorescence properties of CDOM (FDOM) allow discriminating between different structural CDOM properties. The investigation of distribution and cycling of CDOM and FDOM was recognized to be important for understanding of physical and biogeochemical processes, influencing DOM. However, little information is available about effects of nutrient variability on CDOM and FDOM dynamics. Here we present results from two mesocosm experiments conducted with a natural plankton community of the ETNA, where effects of DIP ("Varied P") and DIN ("Varied N") supply on optical properties of DOM were studied. CDOM accumulated proportionally to phytoplankton biomass during the experiments. S decreased over time indicating accumulation of high molecular weight DOM. In Varied N, an additional CDOM portion, as a result of bacterial DOM reworking, was determined. It increased the CDOM fraction in DOC proportionally to the supplied DIN. The humic-like FDOM component (Comp.1) was derived by bacteria proportionally to DIN supply. The bound-to-protein amino acid-like FDOM component (Comp.2) was released irrespectively to phytoplankton biomass, but depending on DIP and DIN concentrations, as a part of an overflow mechanism. Under high DIN supply, Comp.2 was removed by bacterial reworking processes, leading to an accumulation of humic-like Comp.1. No influence of nutrient availability on amino acid-like FDOM component in peptide form (Comp.3) was observed. Comp.3 potentially acted as an intermediate product during formation or degradation Comp.2. Our findings suggest that changes in nutrient concentrations may lead to substantial responses in the quantity and "quality" of optically active DOM and, therefore, might bias results of the applied techniques for an estimation of DOC concentrations in open ocean regions.

Extraction kinetics of solid phase extraction of dissolved organic matter in environmental samples from various aquatic system

2020 ◽  
Author(s):  
Yun-Hsuan Ho ◽  
Jie Yinn Lee ◽  
Chia-Ying Chuang
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Solid Phase Extraction ◽  
Solid Phase ◽  
Open Ocean ◽  
Phase Extraction ◽  
Extraction Kinetics ◽  
Deep Ocean Water ◽  
Kinetics Of ◽  
Extraction Selectivity

&lt;p&gt;Progress has been made towards optimizing extracting dissolved organic matter (DOM) using a styrene-divinylbenzene copolymer (PPL) sorbent, which is a widely used solid phase extraction (SPE) method to separate DOM from different aquatic samples. To establish the suitable extraction conditions, the effects of critical SPE variables such as loading mass, concentration, flow rate, as well as the extraction selectivity of the PPL sorbent have been systematically studied. Tens liters of water samples were collected from various aquatic environments, including headwater, downstream river water, coastal seawater, surface seawater from open ocean, seawater from open ocean at the depth of fluorescence maximum, and deep ocean water. 5g-Bond Elut PPL columns were used and the extraction kinetics of DOM were monitored liter-by-liter while extraction. Fluorescence spectrum were decomposed into their underlying chemical components resolved by PARAllel FACtor analysis (PARAFAC). Extraction selectivity of the PPL sorbent among different types of waters was verified through those fluorescence excitation emission matrices (EEMs) and chromophoric dissolved organic matter (CDOM) measurements.&lt;/p&gt;

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