Reactive Halogen Species in the Mid-Latitude Troposphere — Recent Discoveries

2000 ◽  
pp. 229-244 ◽  
Author(s):  
U. Platt
Keyword(s):  
Reactive Halogen Species ◽  
Halogen Species

scholarly journals Chemical interactions between ship-originated air pollutants and ocean-emitted halogens

2021 ◽  
Author(s):  
Qinyi Li ◽  
Alba Badia ◽  
Rafael P. Fernandez ◽  
Anoop S. Mahajan ◽  
Ana Isabel López-Noreña ◽  
...  
Keyword(s):  
Air Pollutants ◽  
Atmospheric Composition ◽  
Chemical Transformations ◽  
Chemical Interactions ◽  
China Sea ◽  
Reactive Halogen Species ◽  
The Impact ◽  
Surface Increase ◽  
Halogen Species

<p>Ocean-going ships supply products from one region to another and contribute to the world’s economy. Ship exhaust contains many air pollutants and results in significant changes in marine atmospheric composition. The role of Reactive Halogen Species (RHS) in the troposphere has received increasing recognition and oceans are the largest contributors to their atmospheric burden. However, the impact of shipping emissions on RHS and that of RHS on ship-originated air pollutants have not been studied in detail. Here, an updated WRF-Chem model is utilized to explore the chemical interactions between ship emissions and oceanic RHS over the East Asia seas in summer. The emissions and resulting chemical transformations from shipping activities increase the level of NO and NO<sub>2</sub> at the surface, increase O<sub>3</sub> in the South China Sea, but decrease O<sub>3</sub> in the East China Sea. Such changes in pollutants result in remarkable changes in the levels of RHS as well as in their partitioning. The abundant RHS, in turn, reshape the loadings of air pollutants and those of the oxidants with marked patterns along the ship tracks. We, therefore, suggest that these important chemical interactions of ship-originated emissions with RHS should be considered in the environmental policy assessments of the role of shipping emissions in air quality and climate.</p>

scholarly journals A chemical probe technique for the determination of reactive halogen species in aqueous solution: Part 2 – chloride solutions and mixed bromide/chloride solutions

2006 ◽  
Vol 6 (1) ◽  
pp. 941-979 ◽  
Author(s):  
C. Anastasio ◽  
B. M. Matthew
Keyword(s):  
Aqueous Solution ◽  
Aqueous Solutions ◽  
Method Development ◽  
Companion Paper ◽  
Chemical Probe ◽  
Chloride Solutions ◽  
Reactive Halogen Species ◽  
A New Technique ◽  
Halogen Species

Abstract. Although reactive halogen species (X*=X●, ●X2−, X2 and HOX, where X=Br, Cl, or I) are important environmental oxidants, relatively little is known about their kinetics in condensed phases such as seawater and sea-salt particles. Here we describe a new technique to determine reactive chlorine and bromine species in aqueous solutions by using allyl alcohol (CH2=CHCH2OH) as a chemical probe. This probe is combined with competition kinetics in order to determine steady state concentrations of X*(aq). In some cases the technique also can be used to determine the rates of formation and lifetimes of X* in aqueous solution. In a companion paper we reported the results of our method development for aqueous solutions containing only bromide (Br−). In this paper, we discuss method development for solutions containing chloride (Cl−) alone, and for solutions containing both bromide and chloride.

scholarly journals Quantification of the depletion of ozone in the plume of Mount Etna

2014 ◽  
Vol 14 (16) ◽  
pp. 23639-23680 ◽  
Author(s):  
L. Surl ◽  
D. Donohoue ◽  
A. Aiuppa ◽  
N. Bobrowski ◽  
R. von Glasow
Keyword(s):  
Strong Dependence ◽  
Source Region ◽  
Mount Etna ◽  
Volcanic Plumes ◽  
Processing Times ◽  
Atmospheric Processing ◽  
Constant Rate ◽  
Halogen Chemistry ◽  
Reactive Halogen Species ◽  
Halogen Species

Abstract. Volcanoes are an important source of inorganic halogen species into the atmosphere. Chemical processing of these species generates oxidised, highly reactive, halogen species which catalyse considerable O3 destruction within volcanic plumes. A campaign of ground-based in situ O3, SO2 and meteorology measurements was undertaken at the summit of Mount Etna volcano in July–August 2012. At the same time, spectroscopic measurements were made of BrO and SO2 columns in the plume downwind. Depletions of O3 were seen at all in-plume measurement locations, with average O3 depletions ranging from 11–35 nmol mol−1 (15–45%). Atmospheric processing times of the plume were estimated to be between 1 and 4 min. A 1-D numerical model of early plume evolution was also used. It was found that in the early plume O3 was destroyed at an approximately constant rate relative to an inert plume tracer. This is ascribed to reactive halogen chemistry, and the data suggests the majority of the reactive halogen that destroys O3 in the early plume is generated within the crater, including a substantial proportion generated in a high-temperature "effective source region" immediately after emission. The model could approximately reproduce the main measured features of the O3 chemistry. Model results show a strong dependence of the near-vent bromine chemistry on the presence or absence of volcanic NOx emissions and suggest that near-vent O3 measurements can be used as a qualitative indicator of NOx emission.

scholarly journals Reactive bromine in the low troposphere of Antarctica: estimations at two research sites

2018 ◽  
Vol 18 (12) ◽  
pp. 8549-8570 ◽  
Author(s):  
Cristina Prados-Roman ◽  
Laura Gómez-Martín ◽  
Olga Puentedura ◽  
Mónica Navarro-Comas ◽  
Javier Iglesias ◽  
...  
Keyword(s):  
Arctic Region ◽  
The Arctic ◽  
Trace Gas ◽  
Optical Absorption Spectroscopy ◽  
Ancillary Data ◽  
Reactive Halogen Species ◽  
The Subject ◽  
The Antarctic ◽  
Halogen Species ◽  
The Arctic Region

Abstract. For decades, reactive halogen species (RHSs) have been the subject of detailed scientific research due to their influence on the oxidizing capacity of the atmosphere and on the climate. From the RHSs, those containing bromine are of particular interest in the polar troposphere as a result of their link to ozone-depletion events (ODEs) and to the perturbation of the cycle of toxic mercury, for example. Given its remoteness and related limited accessibility compared to the Arctic region, the RHSs in the Antarctic troposphere are still poorly characterized. This work presents ground-based observations of tropospheric BrO from two different Antarctic locations: Marambio Base (64∘13′ S, 56∘37′ W) and Belgrano II Base (77∘52′ S, 34∘7′ W) during the sunlit period of 2015. By means of MAX-DOAS (Multi-axis Differential Optical Absorption Spectroscopy) measurements of BrO performed from the two research sites, the seasonal variation in this reactive trace gas is described along with its vertical and geographical distribution in the Antarctic environment. Results show an overall vertical profile of BrO mixing ratio decreasing with altitude, with a median value of 1.6 pmol mol−1 in the lowest layers of the troposphere. Additionally, observations show that the polar sunrise triggers a geographical heterogeneous increase in bromine content in the Antarctic troposphere yielding a maximum BrO at Marambio (26 pmol mol−1), amounting to 3-fold the values observed at Belgrano at dawn. Data presented herein are combined with previous studies and ancillary data to update and expand our knowledge of the geographical and vertical distribution of BrO in the Antarctic troposphere, revealing Marambio as one of the locations with the highest BrO reported so far in Antarctica. Furthermore, the observations gathered during 2015 serve as a proxy to investigate the budget of reactive bromine (BrOx = Br + BrO) and the bromine-mediated ozone loss rate in the Antarctic troposphere.

Cross-Linking Methionine and Amine Residues with Reactive Halogen Species

2014 ◽  
Vol 76 ◽  
pp. S158
Author(s):  
Graziella Ronsein ◽  
Christine Winterbourn ◽  
Paolo Di Mascio ◽  
Anthony Kettle
Keyword(s):  
Cross Linking ◽  
Reactive Halogen Species ◽  
Halogen Species

Enzymatic and bactericidal activity of myeloperoxidase in conditions of halogenative stress

2018 ◽  
Vol 96 (5) ◽  
pp. 580-591 ◽  
Author(s):  
Tatyana V. Vakhrusheva ◽  
Daria V. Grigorieva ◽  
Irina V. Gorudko ◽  
Alexey V. Sokolov ◽  
Valeria A. Kostevich ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Bactericidal Activity ◽  
Linear Correlation ◽  
Secondary Products ◽  
Primary Products ◽  
Heme Degradation ◽  
Halogenative Stress ◽  
Negative Linear Correlation ◽  
Reactive Halogen Species ◽  
Halogen Species

Myeloperoxidase (MPO), found mainly in neutrophils, is released in inflammation. MPO produces reactive halogen species (RHS), which are bactericidal agents. However, RHS overproduction, i.e., halogenative stress, can also damage host biomolecules, and MPO itself may be targeted by RHS. Therefore, we examined the susceptibility of MPO to inactivation by its primary products (HOCl, HOBr, HOSCN) and secondary products such as taurine monochloramine (TauCl) and taurine monobromamine (TauBr). MPO was dose-dependently inhibited up to complete inactivity by treatment with HOCl or HOBr. TauBr diminished the activity but did not eliminate it. TauCl had no effect. MPO became inactivated when producing HOCl or HOBr but not HOSCN. Taurine protected MPO against inactivation when MPO was catalyzing oxidation of Cl− to HOCl, whereas taurine failed to prevent inactivation when MPO was working with Br−, either alone or in combination with Cl−. SCN− interfered with HOCl-mediated MPO inhibition. UV–vis spectra showed that heme degradation is involved in HOCl- and HOBr-mediated MPO inactivation. A negative linear correlation between the remaining chlorinating activity of HOCl- or HOBr-modified MPO and Escherichia coli survival upon incubation with MPO/H2O2/Cl− was found. This study elucidated the possibility of MPO downregulation by MPO-derived RHS, which could counteract halogenative stress.

scholarly journals Importance of reactive halogens in the tropical marine atmosphere: a regional modelling study using WRF-Chem

2019 ◽  
Vol 19 (5) ◽  
pp. 3161-3189 ◽  
Author(s):  
Alba Badia ◽  
Claire E. Reeves ◽  
Alex R. Baker ◽  
Alfonso Saiz-Lopez ◽  
Rainer Volkamer ◽  
...  
Keyword(s):  
Atmospheric Chemistry ◽  
Sea Salt ◽  
Heterogeneous Chemistry ◽  
Marine Atmosphere ◽  
Tropical Ocean ◽  
Mixing Ratios ◽  
Reactive Halogen Species ◽  
Inorganic Iodine ◽  
The Impact ◽  
Halogen Species

Abstract. This study investigates the impact of reactive halogen species (RHS, containing chlorine (Cl), bromine (Br) or iodine (I)) on atmospheric chemistry in the tropical troposphere and explores the sensitivity to uncertainties in the fluxes of RHS to the atmosphere and their chemical processing. To do this, the regional chemistry transport model WRF-Chem has been extended to include Br and I, as well as Cl chemistry for the first time, including heterogeneous recycling reactions involving sea-salt aerosol and other particles, reactions of Br and Cl with volatile organic compounds (VOCs), along with oceanic emissions of halocarbons, VOCs and inorganic iodine. The study focuses on the tropical east Pacific using field observations from the Tropical Ocean tRoposphere Exchange of Reactive halogen species and Oxygenated VOC (TORERO) campaign (January–February 2012) to evaluate the model performance. Including all the new processes, the model does a reasonable job reproducing the observed mixing ratios of bromine oxide (BrO) and iodine oxide (IO), albeit with some discrepancies, some of which can be attributed to difficulties in the model's ability to reproduce the observed halocarbons. This is somewhat expected given the large uncertainties in the air–sea fluxes of the halocarbons in a region where there are few observations of their seawater concentrations. We see a considerable impact on the inorganic bromine (Bry) partitioning when heterogeneous chemistry is included, with a greater proportion of the Bry in active forms such as BrO, HOBr and dihalogens. Including debromination of sea salt increases BrO slightly throughout the free troposphere, but in the tropical marine boundary layer, where the sea-salt particles are plentiful and relatively acidic, debromination leads to overestimation of the observed BrO. However, it should be noted that the modelled BrO was extremely sensitive to the inclusion of reactions between Br and the oxygenated VOCs (OVOCs), which convert Br to HBr, a far less reactive form of Bry. Excluding these reactions leads to modelled BrO mixing ratios greater than observed. The reactions between Br and aldehydes were found to be particularly important, despite the model underestimating the amount of aldehydes observed in the atmosphere. There are only small changes to the inorganic iodine (Iy) partitioning and IO when the heterogeneous reactions, primarily on sea salt, are included. Our model results show that tropospheric Ox loss due to halogens ranges between 25 % and 60 %. Uncertainties in the heterogeneous chemistry accounted for a small proportion of this range (25 % to 31 %). This range is in good agreement with other estimates from state-of-the-art atmospheric chemistry models. The upper bound is found when reactions between Br and Cl with VOCs are not included and, consequently, Ox loss by BrOx, ClOx and IOx cycles is high (60 %). With the inclusion of halogens in the troposphere, O3 is reduced by 7 ppbv on average. However, when reactions between Br and Cl with VOCs are not included, O3 is much lower than observed. Therefore, the tropospheric Ox budget is highly sensitive to the inclusion of halogen reactions with VOCs and to the uncertainties in current understanding of these reactions and the abundance of VOCs in the remote marine atmosphere.

scholarly journals A box model study on photochemical interactions between VOCs and reactive halogen species in the marine boundary layer

2004 ◽  
Vol 4 (7) ◽  
pp. 1961-1987 ◽  
Author(s):  
K. Toyota ◽  
Y. Kanaya ◽  
M. Takahashi ◽  
H. Akimoto
Keyword(s):  
Boundary Layer ◽  
Marine Boundary Layer ◽  
Box Model ◽  
Chemical Mechanism ◽  
Oh Radicals ◽  
Halogen Chemistry ◽  
Reactive Halogen Species ◽  
Oceanic Emissions ◽  
Chemical Scheme ◽  
Halogen Species

Abstract. A new chemical scheme is developed for the multiphase photochemical box model SEAMAC (size-SEgregated Aerosol model for Marine Air Chemistry) to investigate photochemical interactions between volatile organic compounds (VOCs) and reactive halogen species in the marine boundary layer (MBL). Based primarily on critically evaluated kinetic and photochemical rate parameters as well as a protocol for chemical mechanism development, the new scheme has achieved a near-explicit description of oxidative degradation of up to C3-hydrocarbons (CH4, C2H6, C3H8, C2H4, C3H6, and C2H2) initiated by reactions with OH radicals, Cl- and Br-atoms, and O3. Rate constants and product yields for reactions involving halogen species are taken from the literature where available, but the majority of them need to be estimated. In particular, addition reactions of halogen atoms with alkenes will result in forming halogenated organic intermediates, whose photochemical loss rates are carefully evaluated in the present work. Model calculations with the new chemical scheme reveal that the oceanic emissions of acetaldehyde (CH3CHO) and alkenes (especially C3H6) are important factors for regulating reactive halogen chemistry in the MBL by promoting the conversion of Br atoms into HBr or more stable brominated intermediates in the organic form. The latter include brominated hydroperoxides, bromoacetaldehyde, and bromoacetone, which sequester bromine from a reactive inorganic pool. The total mixing ratio of brominated organic species thus produced is likely to reach 10-20% or more of that of inorganic gaseous bromine species over wide regions over the ocean. The reaction between Br atoms and C2H2 is shown to be unimportant for determining the degree of bromine activation in the remote MBL. These results imply that reactive halogen chemistry can mediate a link between the oceanic emissions of VOCs and the behaviors of compounds that are sensitive to halogen chemistry such as dimethyl sulfide, NOx, and O3 in the MBL.

Sign in / Sign up

Export Citation Format

Share Document