The Experts below are selected from a list of 3327 Experts worldwide ranked by ideXlab platform
Michael D Pluth - One of the best experts on this subject based on the ideXlab platform.
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cysteine activated hydrogen Sulfide h2s delivery through caged Carbonyl Sulfide cos donor motifs
Chemical Communications, 2018Co-Authors: Yu Zhao, Andrea K. Steiger, Michael D PluthAbstract:Hydrogen Sulfide (H2S) is an important biomolecule, and controllable H2S donors are needed to investigate H2S biological functions. Here we utilize cysteine-mediated addition/cyclization chemistry to unmask an acrylate-functionalized thiocarbamate and release Carbonyl Sulfide (COS), which is quickly converted to H2S by carbonic anhydrase (CA).
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Colorimetric Carbonyl Sulfide (COS)/Hydrogen Sulfide (H2S) Donation from γ-Ketothiocarbamate Donor Motifs
Angewandte Chemie - International Edition, 2018Co-Authors: Yu Zhao, Andrea K. Steiger, Michael D PluthAbstract:Hydrogen Sulfide (H 2 S) is a biologically active molecule that exhibits protective effects in a variety of physiological and pathological processes. Although several H 2 S-related biological effects have been discovered by using H 2 S donors, knowing how much H 2 S has been released from donors under different conditions remains challenging. Now, a series of g-ketothiocarbamate (g-KetoTCM) compounds that provide the first examples of colorimetric H 2 S donors and enable direct quantification of H 2 S release, were reported. These compounds are activated through a pH-dependent deprotonation/b-elimination sequence to release Carbonyl Sulfide (COS), which is quickly converted into H 2 S by carbonic anhydrase. The p-nitroaniline released upon donor activation provides an optical readout that correlates directly to COS/H 2 S release, thus enabling colorimetric measurement of H 2 S donation.
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kinetic insights into hydrogen Sulfide delivery from caged Carbonyl Sulfide isomeric donor platforms
Journal of the American Chemical Society, 2017Co-Authors: Yu Zhao, Hillary A Henthorn, Michael D PluthAbstract:Hydrogen Sulfide (H2S) is a biologically important small gaseous molecule that exhibits promising protective effects against a variety of physiological and pathological processes. To investigate the expanding roles of H2S in biology, researchers often use H2S donors to mimic enzymatic H2S synthesis or to provide increased H2S levels under specific circumstances. Aligned with the need for new broad and easily modifiable platforms for H2S donation, we report here the preparation and H2S release kinetics from a series of isomeric caged-Carbonyl Sulfide (COS) compounds, including thiocarbamates, thiocarbonates, and dithiocarbonates, all of which release COS that is quickly converted to H2S by the ubiquitous enzyme carbonic anhydrase. Each donor is designed to release COS/H2S after the activation of a trigger by activation by hydrogen peroxide (H2O2). In addition to providing a broad palette of new, H2O2-responsive donor motifs, we also demonstrate the H2O2 dose-dependent COS/H2S release from each donor core, ...
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kinetic insights into hydrogen Sulfide delivery from caged Carbonyl Sulfide isomeric donor platforms
Journal of the American Chemical Society, 2017Co-Authors: Yu Zhao, Hillary A Henthorn, Michael D PluthAbstract:Hydrogen Sulfide (H2S) is a biologically important small gaseous molecule that exhibits promising protective effects against a variety of physiological and pathological processes. To investigate the expanding roles of H2S in biology, researchers often use H2S donors to mimic enzymatic H2S synthesis or to provide increased H2S levels under specific circumstances. Aligned with the need for new broad and easily modifiable platforms for H2S donation, we report here the preparation and H2S release kinetics from a series of isomeric caged-Carbonyl Sulfide (COS) compounds, including thiocarbamates, thiocarbonates, and dithiocarbonates, all of which release COS that is quickly converted to H2S by the ubiquitous enzyme carbonic anhydrase. Each donor is designed to release COS/H2S after the activation of a trigger by activation by hydrogen peroxide (H2O2). In addition to providing a broad palette of new, H2O2-responsive donor motifs, we also demonstrate the H2O2 dose-dependent COS/H2S release from each donor core, establish that release profiles can be modified by structural modifications, and compare COS/H2S release rates and efficiencies from isomeric core structures. Supporting our experimental investigations, we also provide computational insights into the potential energy surfaces for COS/H2S release from each platform. In addition, we also report initial investigations into dithiocarbamate cores, which release H2S directly upon H2O2-mediated activation. As a whole, the insights on COS/H2S release gained from these investigations provide a foundation for the expansion of the emerging area of responsive COS/H2S donor systems.
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bio orthogonal click and release donation of caged Carbonyl Sulfide cos and hydrogen Sulfide h2s
Chemical Communications, 2017Co-Authors: Andrea K. Steiger, Yang Yang, Maksim Royzen, Michael D PluthAbstract:Hydrogen Sulfide (H2S) is an important biomolecule with high therapeutic potential. Here we leverage the inverse-electron demand Diels–Alder (IEDDA) click reaction between a thiocarbamate-functionalized trans-cyclooctene and a tetrazine to deliver Carbonyl Sulfide (COS), which is quickly converted to H2S by the uniquitous enzyme carbonic anhydrase (CA), thus providing a new strategy for bio-orthogonal COS/H2S donation.
Yu Zhao - One of the best experts on this subject based on the ideXlab platform.
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cysteine activated hydrogen Sulfide h2s delivery through caged Carbonyl Sulfide cos donor motifs
Chemical Communications, 2018Co-Authors: Yu Zhao, Andrea K. Steiger, Michael D PluthAbstract:Hydrogen Sulfide (H2S) is an important biomolecule, and controllable H2S donors are needed to investigate H2S biological functions. Here we utilize cysteine-mediated addition/cyclization chemistry to unmask an acrylate-functionalized thiocarbamate and release Carbonyl Sulfide (COS), which is quickly converted to H2S by carbonic anhydrase (CA).
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Colorimetric Carbonyl Sulfide (COS)/Hydrogen Sulfide (H2S) Donation from γ-Ketothiocarbamate Donor Motifs
Angewandte Chemie - International Edition, 2018Co-Authors: Yu Zhao, Andrea K. Steiger, Michael D PluthAbstract:Hydrogen Sulfide (H 2 S) is a biologically active molecule that exhibits protective effects in a variety of physiological and pathological processes. Although several H 2 S-related biological effects have been discovered by using H 2 S donors, knowing how much H 2 S has been released from donors under different conditions remains challenging. Now, a series of g-ketothiocarbamate (g-KetoTCM) compounds that provide the first examples of colorimetric H 2 S donors and enable direct quantification of H 2 S release, were reported. These compounds are activated through a pH-dependent deprotonation/b-elimination sequence to release Carbonyl Sulfide (COS), which is quickly converted into H 2 S by carbonic anhydrase. The p-nitroaniline released upon donor activation provides an optical readout that correlates directly to COS/H 2 S release, thus enabling colorimetric measurement of H 2 S donation.
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kinetic insights into hydrogen Sulfide delivery from caged Carbonyl Sulfide isomeric donor platforms
Journal of the American Chemical Society, 2017Co-Authors: Yu Zhao, Hillary A Henthorn, Michael D PluthAbstract:Hydrogen Sulfide (H2S) is a biologically important small gaseous molecule that exhibits promising protective effects against a variety of physiological and pathological processes. To investigate the expanding roles of H2S in biology, researchers often use H2S donors to mimic enzymatic H2S synthesis or to provide increased H2S levels under specific circumstances. Aligned with the need for new broad and easily modifiable platforms for H2S donation, we report here the preparation and H2S release kinetics from a series of isomeric caged-Carbonyl Sulfide (COS) compounds, including thiocarbamates, thiocarbonates, and dithiocarbonates, all of which release COS that is quickly converted to H2S by the ubiquitous enzyme carbonic anhydrase. Each donor is designed to release COS/H2S after the activation of a trigger by activation by hydrogen peroxide (H2O2). In addition to providing a broad palette of new, H2O2-responsive donor motifs, we also demonstrate the H2O2 dose-dependent COS/H2S release from each donor core, ...
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kinetic insights into hydrogen Sulfide delivery from caged Carbonyl Sulfide isomeric donor platforms
Journal of the American Chemical Society, 2017Co-Authors: Yu Zhao, Hillary A Henthorn, Michael D PluthAbstract:Hydrogen Sulfide (H2S) is a biologically important small gaseous molecule that exhibits promising protective effects against a variety of physiological and pathological processes. To investigate the expanding roles of H2S in biology, researchers often use H2S donors to mimic enzymatic H2S synthesis or to provide increased H2S levels under specific circumstances. Aligned with the need for new broad and easily modifiable platforms for H2S donation, we report here the preparation and H2S release kinetics from a series of isomeric caged-Carbonyl Sulfide (COS) compounds, including thiocarbamates, thiocarbonates, and dithiocarbonates, all of which release COS that is quickly converted to H2S by the ubiquitous enzyme carbonic anhydrase. Each donor is designed to release COS/H2S after the activation of a trigger by activation by hydrogen peroxide (H2O2). In addition to providing a broad palette of new, H2O2-responsive donor motifs, we also demonstrate the H2O2 dose-dependent COS/H2S release from each donor core, establish that release profiles can be modified by structural modifications, and compare COS/H2S release rates and efficiencies from isomeric core structures. Supporting our experimental investigations, we also provide computational insights into the potential energy surfaces for COS/H2S release from each platform. In addition, we also report initial investigations into dithiocarbamate cores, which release H2S directly upon H2O2-mediated activation. As a whole, the insights on COS/H2S release gained from these investigations provide a foundation for the expansion of the emerging area of responsive COS/H2S donor systems.
Ming Luo - One of the best experts on this subject based on the ideXlab platform.
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mechanistic study of regio defects in the copolymerization of propylene oxide Carbonyl Sulfide catalyzed by salen crx complexes
Macromolecules, 2017Co-Authors: Hanyi Duan, Xing-hong Zhang, Ming Luo, Yingying Zhang, Donald J DarensbourgAbstract:Small quantities of regio-defects in a regio-/stereoregular polymer weaken its tacticity and properties. This work clarified the origin of the regio-defect in the process of synthesizing poly(monothiocarbonate) through the copolymerization of propylene oxide (PO) and Carbonyl Sulfide (COS) catalyzed by a (salen)CrCl complex accompanied by bis(triphenylphosphoranylidene)ammonium chloride ([PPN]Cl). Quantitative characterization results from the MALDI-TOF-MS and 1H (13C) NMR spectroscopy suggested that the chain transfer reaction resulted in the regio-defect in the final copolymer, i.e., tail-to-tail (T–T) diad and dithiocarbonate (DTC) unit. The chain transferring to water in the reaction system led to the production of a (salen)Cr–OH intermediate, which initiated the copolymerization via either attacking PO first to result in formation of a T–T diad or first activating COS to produce mercapto (−SH) end-capped dormant chains via decarboxylation, thus generating a DTC unit in the final product through anoth...
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synthesis of cyclic monothiocarbonates via the coupling reaction of Carbonyl Sulfide cos with epoxides
Catalysis Science & Technology, 2016Co-Authors: Xiao Zhang, Ming Luo, Donald J DarensbourgAbstract:Two guanidine bases were used as organocatalysts for the synthesis of cyclic monothiocarbonates via the coupling reaction of Carbonyl Sulfide (COS) and epoxides. The systems proved to be efficient single-component, metal-free catalysts for the reaction of simple (propylene oxide, 1,3-butene oxide) or activated epoxides (epichlorohydrin, glycidyl phenyl ether) with COS under solvent-free and mild reaction conditions to selectively afford the corresponding cyclic monothiocarbonates. The yield of this reaction is generally high, thereby providing ready means for pure product isolation.
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highly regioselective and alternating copolymerization of Carbonyl Sulfide with phenyl glycidyl ether
Polymer Chemistry, 2015Co-Authors: Xiang Zhang, Ming Luo, Donald J DarensbourgAbstract:Polymer structures containing sulfur atoms can provide enhancement of important polymer properties compared to their oxygen-containing counterparts. In this regard, the copolymerization of phenyl glycidyl ether and Carbonyl Sulfide has been very effectively achieved employing (salen)CrCl in the presence of an onium salt at ambient temperature. The resulting copolymer is shown to be completely alternating and to possess extremely high regioselectivity in the epoxide ring-opening step. That is, the ring-opening step predominantly occurs at the less sterically hindered methylene carbon–oxygen bond leading to a tail-to-head structure (98%) in the copolymer. This observation was further confirmed when using the chiral epoxide monomer, (S)-PGE.
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An Examination of the Steric and Electronic Effects in the Copolymerization of Carbonyl Sulfide and Styrene Oxide
Macromolecules, 2015Co-Authors: Ming Luo, Xing-hong Zhang, Donald J DarensbourgAbstract:The completely alternating copolymerization of Carbonyl Sulfide (COS) and styrene oxide was found to occur under mild reaction conditions (0–30 °C and 1.5 MPa) in the presence of (salen)CrCl/onium salt catalyst systems to afford high molecular weight poly(monothiocarbonates) with narrow molecular weight distributions. Ring-opening of styrene oxide was shown to be 88% selective at the methylene carbon. That is the reaction is driven by steric hindrance, where ring-opening occurs preferentially at the less congested carbon center. Similar results were found upon utilizing the tetramethyltetraazaannulene (tmtaa)CrCl/onium salt catalyst. On the other hand, upon employing a zinc–cobalt double metal cyanide (Zn–Co DMCC) catalyst, where the ligands around the active zinc site are not sterically encumbering, ring-opening of styrene oxide occurs predominantly at the methine carbon site; i.e., the reaction is electronically driven.
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alternating copolymerization of Carbonyl Sulfide and cyclohexene oxide catalyzed by zinc cobalt double metal cyanide complex
Polymer, 2014Co-Authors: Ming Luo, Xing-hong Zhang, Qi Wang, Zhiqiang FanAbstract:Abstract This paper describes the first example of alternating copolymerization of Carbonyl Sulfide (COS) with cyclohexene oxide (CHO) via heterogenous catalysis of a nano-lamellar zinc–cobalt(III) double metal cyanide complex (Zn–Co(III) DMCC), providing an efficient method for converting COS to poly(cyclohexene monothiocarbonate) (PCHMTC) with an alternating degree up to 93%. The number-average molecular weight ( M n ) of PCHMTC was 6.5–25.0 kg/mol with polydispersities (PDIs) of 1.6–2.1. The productivity of the catalyst was up to 970 g polymer/g catalyst (5.0 h). The oxygen–sulfur exchange reaction (O/S ER) caused by Zn–Co(III) DMCC was largely suppressed when the reaction was performed at 100–110 °C in the presence of THF or CH 2 Cl 2 , and thus the selectivity of the monothiocarbonate over carbonate linkages was up to 98%. The mechanisms of the copolymerization and O/S ER were proposed based on the ESI-MS, GC–MS and FT-IR spectra. The obtained PCHMTC is highly transparent and exhibits good solubility in various organic solvents, high T g of 112 °C, initial decomposition temperature of 214 °C and high refractive index of 1.705.
M Whelan - One of the best experts on this subject based on the ideXlab platform.
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global gridded anthropogenic emissions inventory of Carbonyl Sulfide
Atmospheric Environment, 2018Co-Authors: Andrew Zumkehr, M Whelan, Timothy W Hilton, Le Kuai, J Worden, Steve Smith, Elliott J CampbellAbstract:Abstract Atmospheric Carbonyl Sulfide (COS or OCS) is the most abundant sulfur containing gas in the troposphere and is an atmospheric tracer for the carbon cycle. Gridded inventories of global anthropogenic COS are used for interpreting global COS measurements. However, previous gridded anthropogenic data are a climatological estimate based on input data that is over three decades old and are not representative of current conditions. Here we develop a new gridded data set of global anthropogenic COS sources that includes more source sectors than previously available and uses the most current emissions factors and industry activity data as input. Additionally, the inventory is provided as annually varying estimates from years 1980–2012 and employs a source specific spatial scaling procedure. We estimate a global source in year 2012 of 406 Gg S y−1 (range of 223–586 Gg S y−1), which is highly concentrated in China and is twice as large as the previous gridded inventory. Our large upward revision in the bottom-up estimate of the source is consistent with a recent top-down estimate based on air-monitoring and Antarctic firn data. Furthermore, our inventory time trends, including a decline in the 1990's and growth after the year 2000, are qualitatively consistent with trends in atmospheric data. Finally, similarities between the spatial distribution in this inventory and remote sensing data suggest that the anthropogenic source could potentially play a role in explaining a missing source in the global COS budget.
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plant uptake of atmospheric Carbonyl Sulfide in coast redwood forests
Journal of Geophysical Research, 2017Co-Authors: J E Campbell, M Whelan, Joseph A Berry, Timothy W Hilton, Andrew Zumkehr, Ulrike Seibt, J Stinecipher, Ari Kornfeld, Todd E DawsonAbstract:Author(s): Campbell, JE; Whelan, ME; Berry, JA; Hilton, TW; Zumkehr, A; Stinecipher, J; Lu, Y; Kornfeld, A; Seibt, U; Dawson, TE; Montzka, SA; Baker, IT; Kulkarni, S; Wang, Y; Herndon, SC; Zahniser, MS; Commane, R; Loik, ME | Abstract: The future resilience of coast redwoods (Sequoia sempervirens) is now of critical concern due to the detection of a 33% decline in California coastal fog over the 20th century. However, ecosystem-scale measurements of photosynthesis and stomatal conductance are challenging in coast redwood forests, making it difficult to anticipate the impacts of future changes in fog. To address this methodological problem, we explore coastal variations in atmospheric Carbonyl Sulfide (COS or OCS), which could potentially be used as a tracer of these ecosystem processes. We conducted atmospheric flask campaigns in coast redwood sites, sampling at surface heights and in the canopy (~70nm), at the University of California Landels-Hill Big Creek Reserve and Big Basin State Park. We simulated COS atmosphere-biosphere exchange with a high-resolution 3-D model to interpret these data. Flask measurements indicated a persistent daytime drawdown between the coast and the downwind forest (45n±n6nppt COS) that is consistent with the expected relationship between COS plant uptake, stomatal conductance, and gross primary production. Other sources and sinks of COS that could introduce noise to the COS tracer technique (soils, anthropogenic activity, nocturnal plant uptake, and surface hydrolysis on leaves) are likely to be small relative to daytime COS plant uptake. These results suggest that COS measurements may be useful for making ecosystem-scale estimates of carbon, water, and energy exchange in coast redwood forests.
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reviews and syntheses Carbonyl Sulfide as a multi scale tracer for carbon and water cycles
Biogeosciences, 2017Co-Authors: M Whelan, Timothy W Hilton, Georg Wohlfahrt, Linda M J Kooijmans, Sinikka T Lennartz, Teresa E Gimeno, Richard Wehr, Yuting Wang, Sauveur BelvisoAbstract:For the past decade, observations of Carbonyl Sulfide (OCS or COS) have been investigated as a proxy for carbon uptake by plants. OCS is destroyed by enzymes that interact with CO2 during photosynthesis, namely carbonic anhydrase (CA) and RuBisCO, where CA is the more important one. The majority of sources of OCS to the atmosphere are geographically separated from this large plant sink, whereas the sources and sinks of CO2 are co-located in ecosystems. The drawdown of OCS can therefore be related to the uptake of CO2 without the added complication of co-located emissions comparable in magnitude. Here we review the state of our understanding of the global OCS cycle and its applications to ecosystem carbon cycle science. OCS uptake is correlated well to plant carbon uptake, especially at the regional scale. OCS can be used in conjunction with other independent measures of ecosystem function, like solar-induced fluorescence and carbon and water isotope studies. More work needs to be done to generate global coverage for OCS observations and to link this powerful atmospheric tracer to systems where fundamental questions concerning the carbon and water cycle remain.
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Carbonyl Sulfide exchange in soils for better estimates of ecosystem carbon uptake
Atmospheric Chemistry and Physics, 2016Co-Authors: M Whelan, Joseph A Berry, Timothy W Hilton, Max Berkelhammer, Ankur R Desai, Elliott J CampbellAbstract:Abstract. Carbonyl Sulfide (COS) measurements are one of the emerging tools to better quantify gross primary production (GPP), the largest flux in the global carbon cycle. COS is a gas with a similar structure to CO2; COS uptake is thought to be a proxy for GPP. However, soils are a potential source or sink of COS. This study presents a framework for understanding soil–COS interactions. Excluding wetlands, most of the few observations of isolated soils that have been made show small uptake of atmospheric COS. Recently, a series of studies at an agricultural site in the central United States found soil COS production under hot conditions an order of magnitude greater than fluxes at other sites. To investigate the extent of this phenomenon, soils were collected from five new sites and incubated in a variety of soil moisture and temperature states. We found that soils from a desert, an oak savannah, a deciduous forest, and a rainforest exhibited small COS fluxes, behavior resembling previous studies. However, soil from an agricultural site in Illinois, > 800 km away from the initial central US study site, demonstrated comparably large soil fluxes under similar conditions. These new data suggest that, for the most part, soil COS interaction is negligible compared to plant uptake of COS. We present a model that anticipates the large agricultural soil fluxes so that they may be taken into account. While COS air-monitoring data are consistent with the dominance of plant uptake, improved interpretation of these data should incorporate the soil flux parameterizations suggested here.
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atmospheric Carbonyl Sulfide sources from anthropogenic activity implications for carbon cycle constraints
Geophysical Research Letters, 2015Co-Authors: J E Campbell, M Whelan, Ulli Seibt, Steven J Smith, Joseph A Berry, Timothy W HiltonAbstract:Carbonyl Sulfide (COS) has recently emerged as an atmospheric tracer of gross primary production. All modeling studies of COS air-monitoring data rely on a climatological anthropogenic inventory that does not reflect present conditions or support interpretation of ice core and firn trends. Here we develop a global anthropogenic inventory for the years 1850 to 2013 based on new emission measurements and material-specific data. By applying methods from a recent regional inventory to global data, we find that the anthropogenic source is similar in magnitude to the plant sink, confounding carbon cycle applications. However, a material-specific approach results in a current anthropogenic source that is only one third of plant uptake and is concentrated in Asia, supporting carbon cycle applications of global air-monitoring data. Furthermore, changes in the anthropogenic source alone cannot explain the century-scale mixing ratio growth, which suggests that ice and firn data may provide the first global history of gross primary production.
Joseph A Berry - One of the best experts on this subject based on the ideXlab platform.
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plant uptake of atmospheric Carbonyl Sulfide in coast redwood forests
Journal of Geophysical Research, 2017Co-Authors: J E Campbell, M Whelan, Joseph A Berry, Timothy W Hilton, Andrew Zumkehr, Ulrike Seibt, J Stinecipher, Ari Kornfeld, Todd E DawsonAbstract:Author(s): Campbell, JE; Whelan, ME; Berry, JA; Hilton, TW; Zumkehr, A; Stinecipher, J; Lu, Y; Kornfeld, A; Seibt, U; Dawson, TE; Montzka, SA; Baker, IT; Kulkarni, S; Wang, Y; Herndon, SC; Zahniser, MS; Commane, R; Loik, ME | Abstract: The future resilience of coast redwoods (Sequoia sempervirens) is now of critical concern due to the detection of a 33% decline in California coastal fog over the 20th century. However, ecosystem-scale measurements of photosynthesis and stomatal conductance are challenging in coast redwood forests, making it difficult to anticipate the impacts of future changes in fog. To address this methodological problem, we explore coastal variations in atmospheric Carbonyl Sulfide (COS or OCS), which could potentially be used as a tracer of these ecosystem processes. We conducted atmospheric flask campaigns in coast redwood sites, sampling at surface heights and in the canopy (~70nm), at the University of California Landels-Hill Big Creek Reserve and Big Basin State Park. We simulated COS atmosphere-biosphere exchange with a high-resolution 3-D model to interpret these data. Flask measurements indicated a persistent daytime drawdown between the coast and the downwind forest (45n±n6nppt COS) that is consistent with the expected relationship between COS plant uptake, stomatal conductance, and gross primary production. Other sources and sinks of COS that could introduce noise to the COS tracer technique (soils, anthropogenic activity, nocturnal plant uptake, and surface hydrolysis on leaves) are likely to be small relative to daytime COS plant uptake. These results suggest that COS measurements may be useful for making ecosystem-scale estimates of carbon, water, and energy exchange in coast redwood forests.
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Carbonyl Sulfide exchange in soils for better estimates of ecosystem carbon uptake
Atmospheric Chemistry and Physics, 2016Co-Authors: M Whelan, Joseph A Berry, Timothy W Hilton, Max Berkelhammer, Ankur R Desai, Elliott J CampbellAbstract:Abstract. Carbonyl Sulfide (COS) measurements are one of the emerging tools to better quantify gross primary production (GPP), the largest flux in the global carbon cycle. COS is a gas with a similar structure to CO2; COS uptake is thought to be a proxy for GPP. However, soils are a potential source or sink of COS. This study presents a framework for understanding soil–COS interactions. Excluding wetlands, most of the few observations of isolated soils that have been made show small uptake of atmospheric COS. Recently, a series of studies at an agricultural site in the central United States found soil COS production under hot conditions an order of magnitude greater than fluxes at other sites. To investigate the extent of this phenomenon, soils were collected from five new sites and incubated in a variety of soil moisture and temperature states. We found that soils from a desert, an oak savannah, a deciduous forest, and a rainforest exhibited small COS fluxes, behavior resembling previous studies. However, soil from an agricultural site in Illinois, > 800 km away from the initial central US study site, demonstrated comparably large soil fluxes under similar conditions. These new data suggest that, for the most part, soil COS interaction is negligible compared to plant uptake of COS. We present a model that anticipates the large agricultural soil fluxes so that they may be taken into account. While COS air-monitoring data are consistent with the dominance of plant uptake, improved interpretation of these data should incorporate the soil flux parameterizations suggested here.
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tropical sources and sinks of Carbonyl Sulfide observed from space
Geophysical Research Letters, 2015Co-Authors: N Glatthor, J E Campbell, Joseph A Berry, Ian Baker, M Hopfner, S R Kawa, Gisele Krysztofiak, A Leyser, Bjornmartin Sinnhuber, Gabriele StillerAbstract:According to current budget estimations the seasonal variation of Carbonyl Sulfide (COS) is governed by oceanic release and vegetation uptake. Its assimilation by plants is assumed to be similar to the photosynthetic uptake of CO 2 but, contrary to the latter process, to be irreversible. Therefore, COS has been suggested as cotracer of the carbon cycle. Observations of COS, however, are sparse, especially in tropical regions. We use the comprehensive data set of spaceborne measurements of the Michelson Interferometer for Passive Atmospheric Sounding to analyze its global distribution. Two major features are observed in the tropical upper troposphere around 250 hPa: enhanced amounts over the western Pacific and the Maritime Continent, peaking around 550 parts per trillion by volume (pptv) in boreal summer, and a seasonally varying depletion of COS extending from tropical South America to Africa. The large-scale COS depletion, which in austral summer amounts up to −40 pptv as compared to the rest of the respective latitude band, has not been observed before and reveals the seasonality of COS uptake through tropical vegetation. The observations can only be reproduced by global models, when a large vegetation uptake and a corresponding increase in oceanic emissions as proposed in several recent publications are assumed.
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seasonal fluxes of Carbonyl Sulfide in a midlatitude forest
Proceedings of the National Academy of Sciences of the United States of America, 2015Co-Authors: Roisin Commane, Joseph A Berry, Stephen A Montzka, Laura Meredith, Ian Baker, William J Munger, Pamela H Templer, Stephanie M Juice, Mark S Zahniser, Steven C WofsyAbstract:Carbonyl Sulfide (OCS), the most abundant sulfur gas in the atmosphere, has a summer minimum associated with uptake by vegetation and soils, closely correlated with CO2. We report the first direct measurements to our knowledge of the ecosystem flux of OCS throughout an annual cycle, at a mixed temperate forest. The forest took up OCS during most of the growing season with an overall uptake of 1.36 ± 0.01 mol OCS per ha (43.5 ± 0.5 g S per ha, 95% confidence intervals) for the year. Daytime fluxes accounted for 72% of total uptake. Both soils and incompletely closed stomata in the canopy contributed to nighttime fluxes. Unexpected net OCS emission occurred during the warmest weeks in summer. Many requirements necessary to use fluxes of OCS as a simple estimate of photosynthesis were not met because OCS fluxes did not have a constant relationship with photosynthesis throughout an entire day or over the entire year. However, OCS fluxes provide a direct measure of ecosystem-scale stomatal conductance and mesophyll function, without relying on measures of soil evaporation or leaf temperature, and reveal previously unseen heterogeneity of forest canopy processes. Observations of OCS flux provide powerful, independent means to test and refine land surface and carbon cycle models at the ecosystem scale.
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estimate of Carbonyl Sulfide tropical oceanic surface fluxes using aura tropospheric emission spectrometer observations
Journal of Geophysical Research, 2015Co-Authors: Le Kuai, Joseph A Berry, Stephen A Montzka, J Worden, S S Kulawik, Elliott J Campbell, Meemong Lee, Richard Weidner, Fred Moore, I T BakerAbstract:Author(s): Kuai, L; Worden, JR; Campbell, JE; Kulawik, SS; Li, KF; Lee, M; Weidner, RJ; Montzka, SA; Moore, FL; Berry, JA; Baker, I; Denning, AS; Bian, H; Bowman, KW; Liu, J; Yung, YL | Abstract: © 2015. American Geophysical Union. All Rights Reserved. Quantifying the Carbonyl Sulfide (OCS) land/ocean fluxes contributes to the understanding of both the sulfur and carbon cycles. The primary sources and sinks of OCS are very likely in a steady state because there is no significant observed trend or interannual variability in atmospheric OCS measurements. However, the magnitude and spatial distribution of the dominant ocean source are highly uncertain due to the lack of observations. In particular, estimates of the oceanic fluxes range from approximately 280 Gg S yr-1 to greater than 800 Gg S yr-1, with the larger flux needed to balance a similarly sized terrestrial sink that is inferred from NOAA continental sites. Here we estimate summer tropical oceanic fluxes of OCS in 2006 using a linear flux inversion algorithm and new OCS data acquired by the Aura Tropospheric Emissions Spectrometer (TES). Modeled OCS concentrations based on these updated fluxes are consistent with HIAPER Pole-to-Pole Observations during 4th airborne campaign and improve significantly over the a priori model concentrations. The TES tropical ocean estimate of 70±16GgS in June,when extrapolated over the whole year (about 840 ± 192 Gg S yr-1), supports the hypothesis proposed by Berry et al. (2013) that the ocean flux is in the higher range of approximately 800 Gg S yr-1.