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Evan S, Brioude J, Rosenlof KH, Gao RS, Portmann RW, Zhu Y, Volkamer R, Lee CF, Metzger JM, Lamy K, Walter P, Alvarez SL, Flynn JH, Asher E, Todt M, Davis SM, Thornberry T, Vömel H, Wienhold FG, Stauffer RM, Millán L, Santee ML, Froidevaux L, Read WG. Rapid ozone depletion after humidification of the stratosphere by the Hunga Tonga Eruption. Science 2023; 382:eadg2551. [PMID: 37856589 DOI: 10.1126/science.adg2551] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Accepted: 09/05/2023] [Indexed: 10/21/2023]
Abstract
The eruption of the Hunga Tonga-Hunga Ha'apai volcano on 15 January 2022 offered a good opportunity to explore the early impacts of tropical volcanic eruptions on stratospheric composition. Balloon-borne observations near Réunion Island revealed the unprecedented amount of water vapor injected by the volcano. The enhanced stratospheric humidity, radiative cooling, and expanded aerosol surface area in the volcanic plume created the ideal conditions for swift ozone depletion of 5% in the tropical stratosphere in just 1 week. The decrease in hydrogen chloride by 0.4 parts per million by volume (ppbv) and the increase in chlorine monoxide by 0.4 ppbv provided compelling evidence for chlorine activation within the volcanic plume. This study enhances our understanding of the effect of this unusual volcanic eruption on stratospheric chemistry and provides insights into possible chemistry changes that may occur in a changing climate.
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Affiliation(s)
- Stephanie Evan
- Laboratoire de l'Atmosphère et des Cyclones (LACy), UMR8105, CNRS, Université de La Réunion, Météo-France, Saint-Denis, France
| | - Jerome Brioude
- Laboratoire de l'Atmosphère et des Cyclones (LACy), UMR8105, CNRS, Université de La Réunion, Météo-France, Saint-Denis, France
| | | | - Ru-Shan Gao
- NOAA Chemical Sciences Laboratory, Boulder, CO, USA
| | | | - Yunqian Zhu
- NOAA Chemical Sciences Laboratory, Boulder, CO, USA
- Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO, USA
| | - Rainer Volkamer
- Department of Chemistry and Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO, USA
| | - Christopher F Lee
- Department of Chemistry and Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO, USA
| | - Jean-Marc Metzger
- Observatoire des Sciences de l'Univers de la Réunion, UAR 3365 (CNRS, Université de la Réunion, Météo-France), Saint-Denis, France
| | - Kevin Lamy
- Laboratoire de l'Atmosphère et des Cyclones (LACy), UMR8105, CNRS, Université de La Réunion, Météo-France, Saint-Denis, France
| | | | | | | | - Elizabeth Asher
- NOAA Chemical Sciences Laboratory, Boulder, CO, USA
- Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO, USA
| | - Michael Todt
- Finnish Meteorological Institute, Helsinki, Finland
| | - Sean M Davis
- NOAA Chemical Sciences Laboratory, Boulder, CO, USA
| | | | - Holger Vömel
- National Center for Atmospheric Research, Boulder, CO, USA
| | - Frank G Wienhold
- Swiss Federal Institute of Technology (ETH), Zurich, Switzerland
| | - Ryan M Stauffer
- Atmospheric Chemistry and Dynamics Laboratory, NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | - Luis Millán
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
| | - Michelle L Santee
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
| | - Lucien Froidevaux
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
| | - William G Read
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
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2
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Thapa HR, Agarwal V. Obligate Brominating Enzymes Underlie Bromoform Production by Marine Cyanobacteria. JOURNAL OF PHYCOLOGY 2021; 57:1131-1139. [PMID: 33556207 DOI: 10.1111/jpy.13142] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2020] [Revised: 01/02/2021] [Accepted: 01/14/2021] [Indexed: 06/12/2023]
Abstract
Marine algae are prolific producers of bromoform (CHBr3 ). This naturally produced molecule is a potent environmental pollutant as it volatilizes into the atmosphere and contributes to depletion of the ozone layer in a manner akin to, and in magnitude similar to, man-made chlorofluorocarbons. While phototrophs such as seaweeds, diatoms, and dinoflagellates are known sources of bromoform, additional as yet unknown biogenetic sources of bromoform exist in the oceans. Here, using halogenating enzymes as diagnostic genetic elements, we demonstrate that marine cyanobacteria also possess the enzymological potential for bromoform production. Using recombinantly purified vanadium-dependent bromoperoxidases from planktonic and bloom-forming marine cyanobacteria in in vitro biochemical assays, we reconstitute the enzymatic production of bromoform. We find cyanobacterial bromoform synthesizing enzymes to be obligate brominases possessing no chlorinating activities. These results expand the repertoire of marine biotic sources that introduce this pollutant in the atmosphere.
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Affiliation(s)
- Hem R Thapa
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA, USA
| | - Vinayak Agarwal
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA, USA
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, USA
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3
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Müller E, von Gunten U, Bouchet S, Droz B, Winkel LHE. Reaction of DMS and HOBr as a Sink for Marine DMS and an Inhibitor of Bromoform Formation. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:5547-5558. [PMID: 33788559 DOI: 10.1021/acs.est.0c08189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Recently, we suggested that hypobromous acid (HOBr) is a sink for the marine volatile organic sulfur compound dimethyl sulfide (DMS). However, HOBr is also known to react with reactive moieties of dissolved organic matter (DOM) such as phenolic compounds to form bromoform (CHBr3) and other brominated compounds. The reaction between HOBr and DMS may thus compete with the reaction between HOBr and DOM. To study this potential competition, kinetic batch and diffusion-reactor experiments with DMS, HOBr, and DOM were performed. Based on the reaction kinetics, we modeled concentrations of DMS, HOBr, and CHBr3 during typical algal bloom fluxes of DMS and HOBr (10-13 to 10-9 M s-1). For an intermediate to high HOBr flux (≥10-11 M s-1) and a DMS flux ≤10-11 M s-1, the model shows that the DMS degradation by HOBr was higher than for photochemical oxidation, biological consumption, and sea-air gas exchange combined. For HOBr fluxes ≤10-11 M s-1 and a DMS flux of 10-11 M s-1, our model shows that CHBr3 decreases by 86% compared to a lower DMS flux of 10-12 M s-1. Therefore, the reaction between HOBr and DMS likely not only presents a sink for DMS but also may lead to suppressed CHBr3 formation.
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Affiliation(s)
- Emanuel Müller
- Department of Water Resources and Drinking Water (W+T), Eawag, Swiss Federal Institute of Aquatic Science and Technology, Ueberlandstrasse 133, CH-8600 Duebendorf, Switzerland
- Department of Environment Systems (D-USYS), ETH Zurich, Swiss Federal Institute of Technology, Institute of Biogeochemistry and Pollutant Dynamics (IBP), Universitätsstrasse 16, 8092 Zürich, Switzerland
| | - Urs von Gunten
- Department of Water Resources and Drinking Water (W+T), Eawag, Swiss Federal Institute of Aquatic Science and Technology, Ueberlandstrasse 133, CH-8600 Duebendorf, Switzerland
- Department of Environment Systems (D-USYS), ETH Zurich, Swiss Federal Institute of Technology, Institute of Biogeochemistry and Pollutant Dynamics (IBP), Universitätsstrasse 16, 8092 Zürich, Switzerland
- School of Architecture, Civil and Environmental Engineering (ENAC), École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Sylvain Bouchet
- Department of Water Resources and Drinking Water (W+T), Eawag, Swiss Federal Institute of Aquatic Science and Technology, Ueberlandstrasse 133, CH-8600 Duebendorf, Switzerland
- Department of Environment Systems (D-USYS), ETH Zurich, Swiss Federal Institute of Technology, Institute of Biogeochemistry and Pollutant Dynamics (IBP), Universitätsstrasse 16, 8092 Zürich, Switzerland
| | - Boris Droz
- Department of Water Resources and Drinking Water (W+T), Eawag, Swiss Federal Institute of Aquatic Science and Technology, Ueberlandstrasse 133, CH-8600 Duebendorf, Switzerland
- Department of Environment Systems (D-USYS), ETH Zurich, Swiss Federal Institute of Technology, Institute of Biogeochemistry and Pollutant Dynamics (IBP), Universitätsstrasse 16, 8092 Zürich, Switzerland
| | - Lenny H E Winkel
- Department of Water Resources and Drinking Water (W+T), Eawag, Swiss Federal Institute of Aquatic Science and Technology, Ueberlandstrasse 133, CH-8600 Duebendorf, Switzerland
- Department of Environment Systems (D-USYS), ETH Zurich, Swiss Federal Institute of Technology, Institute of Biogeochemistry and Pollutant Dynamics (IBP), Universitätsstrasse 16, 8092 Zürich, Switzerland
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4
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Thapa HR, Lin Z, Yi D, Smith JE, Schmidt EW, Agarwal V. Genetic and Biochemical Reconstitution of Bromoform Biosynthesis in Asparagopsis Lends Insights into Seaweed Reactive Oxygen Species Enzymology. ACS Chem Biol 2020; 15:1662-1670. [PMID: 32453942 DOI: 10.1021/acschembio.0c00299] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Marine macroalgae, seaweeds, are exceptionally prolific producers of halogenated natural products. Biosynthesis of halogenated molecules in seaweeds is inextricably linked to reactive oxygen species (ROS) signaling as hydrogen peroxide serves as a substrate for haloperoxidase enzymes that participate in the construction these halogenated molecules. Here, using red macroalga Asparagopsis taxiformis, a prolific producer of the ozone depleting molecule bromoform, we provide the discovery and biochemical characterization of a ROS-producing NAD(P)H oxidase from seaweeds. This discovery was enabled by our sequencing of Asparagopsis genomes, in which we find the gene encoding the ROS-producing enzyme to be clustered with genes encoding bromoform-producing haloperoxidases. Biochemical reconstitution of haloperoxidase activities establishes that fatty acid biosynthesis can provide viable hydrocarbon substrates for bromoform production. The ROS production haloperoxidase enzymology that we describe here advances seaweed biology and biochemistry by providing the molecular basis for decades worth of physiological observations in ROS and halogenated natural product biosyntheses.
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Affiliation(s)
- Hem R. Thapa
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Zhenjian Lin
- Department of Medicinal Chemistry, University of Utah, Salt Lake City, Utah 84112, United States
| | - Dongqi Yi
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Jennifer E. Smith
- Center for Marine Biodiversity and Conservation, Scripps Institution of Oceanography, University of California, San Diego, La Jolla, California 92093, United States
| | - Eric W. Schmidt
- Department of Medicinal Chemistry, University of Utah, Salt Lake City, Utah 84112, United States
| | - Vinayak Agarwal
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
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5
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Suess E, Aemisegger F, Sonke JE, Sprenger M, Wernli H, Winkel LHE. Marine versus Continental Sources of Iodine and Selenium in Rainfall at Two European High-Altitude Locations. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:1905-1917. [PMID: 30658037 DOI: 10.1021/acs.est.8b05533] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The essential elements selenium (Se) and iodine (I) are often present in low levels in terrestrial diets, leading to potential deficiencies. Marine I and Se emissions and subsequent atmospheric wet deposition has been suggested to be an important source of I and Se to soils and terrestrial food chains. However, the contribution of recycled moisture of continental origin to I and Se to precipitation has never been analyzed. Here we report concentrations and speciation of I and Se, as well as of bromine (Br), sulfur (S), and DOC-δ13C signatures for weekly collected precipitation samples (in the period of April 2015 to September 2016) at two high altitude sites, i.e., Jungfraujoch (JFJ; Switzerland) and Pic du Midi (PDM; France). Analysis of precipitation chemistry and moisture sources indicate combined marine and continental sources of precipitation and Se, I, Br, and S at both sites. At JFJ, concentrations of I and Se were highest when continental moisture sources were dominant, indicating important terrestrial sources for these elements. Furthermore, correlations between investigated elements and DOC-δ13C, particularly when continental moisture source contributions were high, indicate a link between these elements and the source of dissolved organic matter, especially for I (JFJ and PDM) and Se (JFJ).
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Affiliation(s)
- Elke Suess
- Institute of Biogeochemistry and Pollutant Dynamics , ETH Zurich , 8092 Zurich , Switzerland
- Eawag , Swiss Federal Institute of Aquatic Science and Technology , 8600 Duebendorf Switzerland
| | - Franziska Aemisegger
- Institute for Atmospheric and Climate Science , ETH Zurich , 8092 Zurich , Switzerland
| | - Jeroen E Sonke
- Observatoire Midi-Pyrénées, CNRS-GET , Université de Toulouse , 31400 Toulouse , France
| | - Michael Sprenger
- Institute for Atmospheric and Climate Science , ETH Zurich , 8092 Zurich , Switzerland
| | - Heini Wernli
- Institute for Atmospheric and Climate Science , ETH Zurich , 8092 Zurich , Switzerland
| | - Lenny H E Winkel
- Institute of Biogeochemistry and Pollutant Dynamics , ETH Zurich , 8092 Zurich , Switzerland
- Eawag , Swiss Federal Institute of Aquatic Science and Technology , 8600 Duebendorf Switzerland
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6
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Abrahamsson K, Granfors A, Ahnoff M, Cuevas CA, Saiz-Lopez A. Organic bromine compounds produced in sea ice in Antarctic winter. Nat Commun 2018; 9:5291. [PMID: 30538229 PMCID: PMC6290016 DOI: 10.1038/s41467-018-07062-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Accepted: 10/08/2018] [Indexed: 11/09/2022] Open
Abstract
During polar springtime, active bromine drives ozone, a greenhouse gas, to near-zero levels. Bromine production and emission in the polar regions have so far been assumed to require sunlight. Here, we report measurements of bromocarbons in sea ice, snow, and air during the Antarctic winter that reveal an unexpected new source of organic bromine to the atmosphere during periods of no sunlight. The results show that Antarctic winter sea ice provides 10 times more bromocarbons to the atmosphere than Southern Ocean waters, and substantially more than summer sea ice. The inclusion of these measurements in a global climate model indicates that the emitted bromocarbons will disperse throughout the troposphere in the southern hemisphere and through photochemical degradation to bromine atoms, contribute ~ 10% to the tropospheric reactive bromine budget. Combined together, our results suggest that winter sea ice could potentially be an important source of atmospheric bromine with implications for atmospheric chemistry and climate at a hemispheric scale.
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Affiliation(s)
- Katarina Abrahamsson
- Department of Marine Sciences, University of Gothenburg, Carl Skottbergs gata 22B, SE-41319, Gothenburg, Sweden.
| | - Anna Granfors
- AstraZeneca, Product Technology and Development, SE-43183, Mölndal, Sweden
| | - Martin Ahnoff
- Department of Marine Sciences, University of Gothenburg, Carl Skottbergs gata 22B, SE-41319, Gothenburg, Sweden
| | - Carlos A Cuevas
- Department of Atmospheric Chemistry and Climate, Institute of Physical Chemistry Rocasolano, Serrano 119, 28006, Madrid, Spain
| | - Alfonso Saiz-Lopez
- Department of Atmospheric Chemistry and Climate, Institute of Physical Chemistry Rocasolano, Serrano 119, 28006, Madrid, Spain.
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7
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Punitha T, Phang SM, Juan JC, Beardall J. Environmental Control of Vanadium Haloperoxidases and Halocarbon Emissions in Macroalgae. MARINE BIOTECHNOLOGY (NEW YORK, N.Y.) 2018; 20:282-303. [PMID: 29691674 DOI: 10.1007/s10126-018-9820-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Accepted: 12/04/2017] [Indexed: 06/08/2023]
Abstract
Vanadium-dependent haloperoxidases (V-HPO), able to catalyze the reaction of halide ions (Cl-, Br-, I-) with hydrogen peroxide, have a great influence on the production of halocarbons, which in turn are involved in atmospheric ozone destruction and global warming. The production of these haloperoxidases in macroalgae is influenced by changes in the surrounding environment. The first reported vanadium bromoperoxidase was discovered 40 years ago in the brown alga Ascophyllum nodosum. Since that discovery, more studies have been conducted on the structure and mechanism of the enzyme, mainly focused on three types of V-HPO, the chloro- and bromoperoxidases and, more recently, the iodoperoxidase. Since aspects of environmental regulation of haloperoxidases are less well known, the present paper will focus on reviewing the factors which influence the production of these enzymes in macroalgae, particularly their interactions with reactive oxygen species (ROS).
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Affiliation(s)
- Thillai Punitha
- Institute of Ocean and Earth Sciences, University of Malaya, 50603, Kuala Lumpur, Malaysia
- Institute of Graduate Studies, University of Malaya, 50603, Kuala Lumpur, Malaysia
| | - Siew-Moi Phang
- Institute of Ocean and Earth Sciences, University of Malaya, 50603, Kuala Lumpur, Malaysia.
- Institute of Biological Sciences, University of Malaya, 50603, Kuala Lumpur, Malaysia.
| | - Joon Ching Juan
- Nanotechnology and Catalysis Research Centre (NANOCAT), University of Malaya, Level 3, IPS Building, Kuala Lumpur, Malaysia.
- School of Science, Monash University Malaysia Campus, Bandar Sunway, 46150, Subang Jaya, Malaysia.
| | - John Beardall
- School of Biological Sciences, Monash University, Clayton, VIC, 3800, Australia
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8
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Ward MKM, Rowley DM. Kinetics of the BrO + HO 2 reaction over the temperature range T = 246-314 K. Phys Chem Chem Phys 2017; 19:23345-23356. [PMID: 28825741 DOI: 10.1039/c7cp03854b] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The kinetics of the reaction between gas phase BrO and HO2 radicals, BrO + HO2 → HOBr + O2 (1), have been studied over the atmospherically relevant temperature range T = 246-314 K and at ambient pressure, p = 760 ± 20 Torr, using laser flash photolysis coupled with ultraviolet absorption spectroscopy. The reaction was initiated by the generation of bromine monoxide radicals following laser photolytic generation of Br atoms from Br2/Cl2 containing mixtures and their reaction with ozone. Subsequently, the addition of methanol vapour to the reaction mixture, in the presence of excess oxygen, afforded the efficient simultaneous post-photolysis formation of HO2 radicals using well-defined chemistry. The decay of BrO radicals, in the presence and absence of HO2, was interrogated to determine the rate coefficients for the BrO + BrO and the BrO + HO2 reactions. A detailed sensitivity analysis was performed to ensure that the BrO + HO2 reaction was unequivocally monitored. The rate coefficient for reaction (1) is described by the Arrhenius expression: where statistical errors are 1σ. The negative temperature dependence of this reaction is in general accord with those reported by previous studies of this reaction. However, the present work reports greater absolute values for k1 than those of several previous studies. An assessment of previous laboratory studies of k1 is presented. This work confirms that reaction (1) plays a significant role in HOBr formation throughout the atmosphere following both anthropogenic, biogenic and volcanic emissions of brominated species. Reaction (1) therefore contributes to an efficient ozone depleting process in the atmosphere, and further confirms the significance of interactions between two different families of reactive atmospheric trace species.
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Affiliation(s)
- Michael K M Ward
- Department of Chemistry, University College London, 20 Gordon Street, London, WC1H 0AJ, UK.
| | - David M Rowley
- Department of Chemistry, University College London, 20 Gordon Street, London, WC1H 0AJ, UK.
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9
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Agarwal V, Miles ZD, Winter JM, Eustáquio AS, El Gamal AA, Moore BS. Enzymatic Halogenation and Dehalogenation Reactions: Pervasive and Mechanistically Diverse. Chem Rev 2017; 117:5619-5674. [PMID: 28106994 PMCID: PMC5575885 DOI: 10.1021/acs.chemrev.6b00571] [Citation(s) in RCA: 235] [Impact Index Per Article: 33.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Naturally produced halogenated compounds are ubiquitous across all domains of life where they perform a multitude of biological functions and adopt a diversity of chemical structures. Accordingly, a diverse collection of enzyme catalysts to install and remove halogens from organic scaffolds has evolved in nature. Accounting for the different chemical properties of the four halogen atoms (fluorine, chlorine, bromine, and iodine) and the diversity and chemical reactivity of their organic substrates, enzymes performing biosynthetic and degradative halogenation chemistry utilize numerous mechanistic strategies involving oxidation, reduction, and substitution. Biosynthetic halogenation reactions range from simple aromatic substitutions to stereoselective C-H functionalizations on remote carbon centers and can initiate the formation of simple to complex ring structures. Dehalogenating enzymes, on the other hand, are best known for removing halogen atoms from man-made organohalogens, yet also function naturally, albeit rarely, in metabolic pathways. This review details the scope and mechanism of nature's halogenation and dehalogenation enzymatic strategies, highlights gaps in our understanding, and posits where new advances in the field might arise in the near future.
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Affiliation(s)
- Vinayak Agarwal
- Center for Oceans and Human Health, Scripps Institution of Oceanography, University of California, San Diego
| | - Zachary D. Miles
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California, San Diego
| | | | - Alessandra S. Eustáquio
- College of Pharmacy, Department of Medicinal Chemistry & Pharmacognosy and Center for Biomolecular Sciences, University of Illinois at Chicago
| | - Abrahim A. El Gamal
- Center for Oceans and Human Health, Scripps Institution of Oceanography, University of California, San Diego
| | - Bradley S. Moore
- Center for Oceans and Human Health, Scripps Institution of Oceanography, University of California, San Diego
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California, San Diego
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego
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10
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Thermochemistry of halogen-containing organic compounds with influence on atmospheric chemistry. COMPUT THEOR CHEM 2017. [DOI: 10.1016/j.comptc.2016.11.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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11
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de Souza GLC, Brown A. The ground and excited states of HBrO2 [HOOBr, HOBrO, and HBr(O)O] and HBrO3 (HOOOBr and HOOBrO) isomers. Theor Chem Acc 2016. [DOI: 10.1007/s00214-016-1931-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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12
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Hoehn RD, Yeole SD, Kais S, Francisco JS. Analytic ab initio-based molecular interaction potential for the BrO⋅H2O complex. J Chem Phys 2016; 144:204121. [PMID: 27250293 DOI: 10.1063/1.4950956] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Radical halogen oxide species play important roles within atmospheric processes, specifically those responsible for the removal of O3. To facilitate future investigations on this family of compounds, RCCSD(T)/aug-cc-pVQZ-level electronic structure calculations were employed to generate individual-molecule optimized geometries, as well as to determine the global minimum energy structure for the BrO⋅H2O complex. This information facilitated the generation of several one-dimensional potential energy surface (PES) scans for the BrO⋅H2O complex. Scans were performed for both the ground state and the first excited state; this inclusion is due to a low-lying first electronic excited-state energy. These rigid-geometry PES scans were used both to generate a novel analytic interaction potential by modifying the existing Thole-type model used for water and to the fitted potential function. This interaction potential features anisotropic atomic polarizabilities facilitating appropriate modeling of the physics regarding the unpaired electron residing within the p-orbitals of the oxygen atom of the bromine oxide radical. The intention of this work is to facilitate future molecular dynamics simulations involving the interaction between the BrO radical and water clusters as a first step in devising possible novel chemistries taking place at the water interface of clouds within the atmosphere.
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Affiliation(s)
- Ross D Hoehn
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, USA
| | - Sachin D Yeole
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, USA
| | - Sabre Kais
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, USA
| | - Joseph S Francisco
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, USA
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13
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Airborne measurements of organic bromine compounds in the Pacific tropical tropopause layer. Proc Natl Acad Sci U S A 2015; 112:13789-93. [PMID: 26504212 DOI: 10.1073/pnas.1511463112] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Very short-lived brominated substances (VSLBr) are an important source of stratospheric bromine, an effective ozone destruction catalyst. However, the accurate estimation of the organic and inorganic partitioning of bromine and the input to the stratosphere remains uncertain. Here, we report near-tropopause measurements of organic brominated substances found over the tropical Pacific during the NASA Airborne Tropical Tropopause Experiment campaigns. We combine aircraft observations and a chemistry-climate model to quantify the total bromine loading injected to the stratosphere. Surprisingly, despite differences in vertical transport between the Eastern and Western Pacific, VSLBr (organic + inorganic) contribute approximately similar amounts of bromine [∼6 (4-9) parts per trillion] [corrected] to the stratospheric input at the tropical tropopause. These levels of bromine cause substantial ozone depletion in the lower stratosphere, and any increases in future abundances (e.g., as a result of aquaculture) will lead to larger depletions.
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14
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Picoloto RS, Cruz SM, Mello PA, Muller EI, Smichowski P, Flores EM. Combining pyrohydrolysis and ICP-MS for bromine and iodine determination in airborne particulate matter. Microchem J 2014. [DOI: 10.1016/j.microc.2014.05.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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15
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Alves TV, Ornellas FR. Exploring the electronic states of iodocarbyne: a theoretical contribution. Phys Chem Chem Phys 2014; 16:9530-7. [DOI: 10.1039/c4cp00375f] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
By contrasting for the first time the non-relativistic and relativistic characterization of the electronic states of iodocarbyne, we provide a very reliable description of this species that we expect can motivate and guide the spectroscopist in its experimental investigation.
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Affiliation(s)
- Tiago Vinicius Alves
- Departamento de Química Fundamental
- Instituto de Química
- Universidade de São Paulo
- Av. Prof. Lineu Prestes
- São Paulo, Brazil
| | - Fernando R. Ornellas
- Departamento de Química Fundamental
- Instituto de Química
- Universidade de São Paulo
- Av. Prof. Lineu Prestes
- São Paulo, Brazil
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Wever R, van der Horst MA. The role of vanadium haloperoxidases in the formation of volatile brominated compounds and their impact on the environment. Dalton Trans 2013; 42:11778-86. [PMID: 23657250 DOI: 10.1039/c3dt50525a] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Vanadium haloperoxidases differ strongly from heme peroxidases in substrate specificity and stability and in contrast to a heme group they contain the bare metal oxide vanadate as a prosthetic group. These enzymes specifically oxidize halides in the presence of hydrogen peroxide into hypohalous acids. These reactive halogen intermediates will react rapidly and aspecifically with many organic molecules. Marine algae and diatoms containing these iodo- and bromoperoxidases produce short-lived brominated methanes (bromoform, CHBr3 and dibromomethane CH2Br2) or iodinated compounds. Some seas and oceans are supersaturated with these compounds and they form an important source of bromine to the troposphere and lower stratosphere and contribute significantly to the global budget of halogenated hydrocarbons. This perspective focuses, in particular, on the biosynthesis of these volatile compounds and the direct or indirect involvement of vanadium haloperoxidases in the production of huge amounts of bromoform and dibromomethane. Some of the global sources are discussed and from the literature a picture emerges in which oxidized brominated species generated by phytoplankton, seaweeds and cyanobacteria react with dissolved organic matter in seawater, resulting in the formation of intermediate brominated compounds. These compounds are unstable and decay via a haloform reaction to form an array of volatile brominated compounds of which bromoform is the major component followed by dibromomethane.
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Affiliation(s)
- Ron Wever
- University of Amsterdam, Van't Hoff Institute for Molecular Sciences, Science Park 904, 1098 XH Amsterdam, The Netherlands.
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Speciation analysis of iodine and bromine at picogram-per-gram levels in polar ice. Anal Bioanal Chem 2012; 405:647-54. [DOI: 10.1007/s00216-012-5806-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2011] [Revised: 01/28/2012] [Accepted: 01/28/2012] [Indexed: 10/28/2022]
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Aronson RB, Thatje S, McClintock JB, Hughes KA. Anthropogenic impacts on marine ecosystems in Antarctica. Ann N Y Acad Sci 2011; 1223:82-107. [PMID: 21449967 DOI: 10.1111/j.1749-6632.2010.05926.x] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Antarctica is the most isolated continent on Earth, but it has not escaped the negative impacts of human activity. The unique marine ecosystems of Antarctica and their endemic faunas are affected on local and regional scales by overharvesting, pollution, and the introduction of alien species. Global climate change is also having deleterious impacts: rising sea temperatures and ocean acidification already threaten benthic and pelagic food webs. The Antarctic Treaty System can address local- to regional-scale impacts, but it does not have purview over the global problems that impinge on Antarctica, such as emissions of greenhouse gases. Failure to address human impacts simultaneously at all scales will lead to the degradation of Antarctic marine ecosystems and the homogenization of their composition, structure, and processes with marine ecosystems elsewhere.
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Affiliation(s)
- Richard B Aronson
- Department of Biological Sciences, Florida Institute of Technology, Melbourne, Florida, USA.
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Andrady A, Aucamp PJ, Bais AF, Ballaré CL, Björn LO, Bornman JF, Caldwell M, Cullen AP, Erickson DJ, deGruijl FR, Häder DP, Ilyas M, Kulandaivelu G, Kumar HD, Longstreth J, McKenzie RL, Norval M, Paul N, Redhwi HH, Smith RC, Solomon KR, Sulzberger B, Takizawa Y, Tang X, Teramura AH, Torikai A, van der Leun JC, Wilson SR, Worrest RC, Zepp RG. Environmental effects of ozone depletion and its interactions with climate change: progress report, 2009. Photochem Photobiol Sci 2010; 9:275-94. [PMID: 20301813 DOI: 10.1039/b923342n] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The parties to the Montreal Protocol are informed by three panels of experts. One of these is the Environmental Effects Assessment Panel (EEAP), which deals with UV radiation and its effects on human health, animals, plants, biogeochemistry, air quality and materials. Since 2000, the analyses and interpretation of these effects have included interactions between UV radiation and global climate change. When considering the effects of climate change, it has become clear that processes resulting in changes in stratospheric ozone are more complex than believed previously. As a result of this, human health and environmental problems will likely be longer-lasting and more regionally variable. Like the other panels, the EEAP produces a detailed report every four years; the most recent was that for 2006 (Photochem. Photobiol. Sci., 2007, 6, 201-332). In the years in between, the EEAP produces a less detailed and shorter progress report, as is the case for this present one for 2009. A full quadrennial report will follow for 2010.
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Quack B, Peeken I, Petrick G, Nachtigall K. Oceanic distribution and sources of bromoform and dibromomethane in the Mauritanian upwelling. ACTA ACUST UNITED AC 2007. [DOI: 10.1029/2006jc003803] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Enami S, Vecitis CD, Cheng J, Hoffmann MR, Colussi AJ. Global Inorganic Source of Atmospheric Bromine. J Phys Chem A 2007; 111:8749-52. [PMID: 17713895 DOI: 10.1021/jp074903r] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A few bromine molecules per trillion (ppt) causes the complete destruction of ozone in the lower troposphere during polar spring and about half of the losses associated with the "ozone hole" in the stratosphere. Recent field and aerial measurements of the proxy BrO in the free troposphere suggest an even more pervasive global role for bromine. Models, which quantify ozone trends by assuming atmospheric inorganic bromine (Bry) stems exclusively from long-lived bromoalkane gases, significantly underpredict BrO measurements. This discrepancy effectively implies a ubiquitous tropospheric background level of approximately 4 ppt Bry of unknown origin. Here, we report that I- efficiently catalyzes the oxidation of Br- and Cl- in aqueous nanodroplets exposed to ozone, the everpresent atmospheric oxidizer, under conditions resembling those encountered in marine aerosols. Br- and Cl-, which are rather unreactive toward O3 and were previously deemed unlikely direct precursors of atmospheric halogens, are readily converted into IBr2- and ICl2- en route to Br2(g) and Cl2(g) in the presence of I-. Fine sea salt aerosol particles, which are predictably and demonstrably enriched in I- and Br-, are thus expected to globally release photoactive halogen compounds into the atmosphere, even in the absence of sunlight.
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Affiliation(s)
- S Enami
- W. M. Keck Laboratories, California Institute of Technology, Pasadena, California 91125, USA
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Liss PS. Trace gas emissions from the marine biosphere. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2007; 365:1697-704. [PMID: 17513265 DOI: 10.1098/rsta.2007.2039] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
A wide variety of trace gases (e.g. dimethyl sulphide, organohalogens, ammonia, non-methane and oxygenated hydrocarbons, volatile oxygenated organics and nitrous oxide) are formed in marine waters by biological and photochemical processes. This leads in many, but not all, cases to supersaturation of the water relative to marine air concentrations and a net flux of trace gas to the atmosphere. Since the gases are often in their reduced forms in the water, once in the atmosphere they are subject to oxidation by photolysis or radical attack to form chemically reactive species that can affect the oxidizing capacity of the air. They can also lead to the formation of new particles or the growth of existing ones that can then contribute to both direct and indirect (via the formation of cloud condensation nuclei) aerosol effects on climate. These cycles are discussed with respect to their impacts on the chemistry of the atmosphere, climate and human health. This whole topic was the subject of an extensive review (Nightingale & Liss 2003 In Treatise in geochemistry (eds H. D. Holland & K. K. Turekian), pp. 49-81) and what will be attempted here is a brief update of the earlier paper. There is no attempt to be comprehensive either in terms of gases covered or to give a complete review of all the recent literature. It is a personal view of recent advances both from my own research group as well as significant work from others. Questions raised at the meeting 'Trace gas biogeochemistry and global change' are dealt with at appropriate places in the text (rather than at the end of the piece). Discussion of each of the gases or group of gases is given in the following separate sections.
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Affiliation(s)
- Peter S Liss
- School of Environmental Sciences, University of East Anglia, Norwich, UK.
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Quack B, Atlas E, Petrick G, Wallace DWR. Bromoform and dibromomethane above the Mauritanian upwelling: Atmospheric distributions and oceanic emissions. ACTA ACUST UNITED AC 2007. [DOI: 10.1029/2006jd007614] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Enami S, Yamanaka T, Nakayama T, Hashimoto S, Kawasaki M, Shallcross DE, Nakano Y, Ishiwata T. A Gas-Phase Kinetic Study of the Reaction between Bromine Monoxide and Methylperoxy Radicals at Atmospheric Temperatures. J Phys Chem A 2007; 111:3342-8. [PMID: 17425290 DOI: 10.1021/jp068390k] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The rate constant of the reaction of BrO with CH(3)O(2) was determined to be k1 = (6.2 +/- 2.5) x 10(-12) cm3 molecule(-1) s(-1) at 298 K and 100-200 Torr of O2 diluent. Quoted uncertainty was two standard deviations. No significant pressure dependence of the rate constants was observed at 100-200 Torr total pressure of N2 or O2 diluents. Temperature dependence of the rate constants was further investigated over the range 233-333 K, and an Arrhenius type expression was obtained for k1 = 4.6 x 10(-13) exp[(798 +/- 76)/T] cm3 molecule(-1) s(-1). The product branching ratios were evaluated and the atmospheric implications were discussed.
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Affiliation(s)
- Shinichi Enami
- Department of Molecular Engineering, Kyoto University, Kyoto 615-8510, Japan
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Zepp RG, Erickson DJ, Paul ND, Sulzberger B. Interactive effects of solar UV radiation and climate change on biogeochemical cycling. Photochem Photobiol Sci 2007; 6:286-300. [PMID: 17344963 DOI: 10.1039/b700021a] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
This report assesses research on the interactions of UV radiation (280-400 nm) and global climate change with global biogeochemical cycles at the Earth's surface. The effects of UV-B (280-315 nm), which are dependent on the stratospheric ozone layer, on biogeochemical cycles are often linked to concurrent exposure to UV-A radiation (315-400 nm), which is influenced by global climate change. These interactions involving UV radiation (the combination of UV-B and UV-A) are central to the prediction and evaluation of future Earth environmental conditions. There is increasing evidence that elevated UV-B radiation has significant effects on the terrestrial biosphere with implications for the cycling of carbon, nitrogen and other elements. The cycling of carbon and inorganic nutrients such as nitrogen can be affected by UV-B-mediated changes in communities of soil organisms, probably due to the effects of UV-B radiation on plant root exudation and/or the chemistry of dead plant material falling to the soil. In arid environments direct photodegradation can play a major role in the decay of plant litter, and UV-B radiation is responsible for a significant part of this photodegradation. UV-B radiation strongly influences aquatic carbon, nitrogen, sulfur and metals cycling that affect a wide range of life processes. UV-B radiation changes the biological availability of dissolved organic matter to microorganisms, and accelerates its transformation into dissolved inorganic carbon and nitrogen, including carbon dioxide and ammonium. The coloured part of dissolved organic matter (CDOM) controls the penetration of UV radiation into water bodies, but CDOM is also photodegraded by solar UV radiation. Changes in CDOM influence the penetration of UV radiation into water bodies with major consequences for aquatic biogeochemical processes. Changes in aquatic primary productivity and decomposition due to climate-related changes in circulation and nutrient supply occur concurrently with exposure to increased UV-B radiation, and have synergistic effects on the penetration of light into aquatic ecosystems. Future changes in climate will enhance stratification of lakes and the ocean, which will intensify photodegradation of CDOM by UV radiation. The resultant increase in the transparency of water bodies may increase UV-B effects on aquatic biogeochemistry in the surface layer. Changing solar UV radiation and climate also interact to influence exchanges of trace gases, such as halocarbons (e.g., methyl bromide) which influence ozone depletion, and sulfur gases (e.g., dimethylsulfide) that oxidize to produce sulfate aerosols that cool the marine atmosphere. UV radiation affects the biological availability of iron, copper and other trace metals in aquatic environments thus potentially affecting metal toxicity and the growth of phytoplankton and other microorganisms that are involved in carbon and nitrogen cycling. Future changes in ecosystem distribution due to alterations in the physical and chemical climate interact with ozone-modulated changes in UV-B radiation. These interactions between the effects of climate change and UV-B radiation on biogeochemical cycles in terrestrial and aquatic systems may partially offset the beneficial effects of an ozone recovery.
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Affiliation(s)
- R G Zepp
- U.S. Environmental Protection Agency, National Exposure Research Laboratory, 960 College Station Road, Athens, Georgia 30605-2700, USA
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Gálvez O, Zoermer A, Grothe H. Theoretical Study on the Structure of the BrO Hydrates. J Phys Chem A 2006; 110:8818-25. [PMID: 16836445 DOI: 10.1021/jp062048q] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The hydrates of bromine monoxide, BrO(H2O)n, n = 1-4, have been studied by means of ab initio calculations at the B3LYP/aug-cc-pVTZ level of theory. These systems could be formed in the troposphere and participate in chemical reactions involved in the depletion of ozone. Several conformations are obtained and discussed for each of the hydrates mentioned. Two rather different intermolecular interactions are found, namely, conventional hydrogen bonding and Br...O associations. In contrast with a more traditional point of view in which hydrogen bonds could be assumed as the preferential interaction for the formation of these complexes, it is the Br...O association which yields the most stable conformations. Equilibrium geometries, harmonic frequencies, and relative energies have been calculated for the bromine monoxide hydrates for the first time. The theoretical binding energies indicate that the stabilization of the hydrates increases with the number of water molecules added. Cooperative effects are suggested to play a significant role in this stabilization. An analysis of relevant properties depending on the electron density in the bond critical points of the Br...O associations has been done for the first time, showing characteristic features of this interaction in comparison with the hydrogen bonds formed.
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Affiliation(s)
- O Gálvez
- Institut für Materialchemie, Technische Universität Wien, A-1210 Vienna, Austria.
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Sioris CE, Kovalenko LJ, McLinden CA, Salawitch RJ, Van Roozendael M, Goutail F, Dorf M, Pfeilsticker K, Chance K, von Savigny C, Liu X, Kurosu TP, Pommereau JP, Bösch H, Frerick J. Latitudinal and vertical distribution of bromine monoxide in the lower stratosphere from Scanning Imaging Absorption Spectrometer for Atmospheric Chartography limb scattering measurements. ACTA ACUST UNITED AC 2006. [DOI: 10.1029/2005jd006479] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Yang ES, Cunnold DM, Salawitch RJ, McCormick MP, Russell J, Zawodny JM, Oltmans S, Newchurch MJ. Attribution of recovery in lower-stratospheric ozone. ACTA ACUST UNITED AC 2006. [DOI: 10.1029/2005jd006371] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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