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1. Importance of reactive halogens in the tropical marine atmosphere: a regional modelling study using WRF-Chem [2019]

  • Badia, Alba, Reeves, Claire E., Baker, Alex R., Saiz-Lopez, Alfonso, Volkamer, Rainer, Koenig, Theodore K., Apel, Eric C., Hornbrook, Rebecca S., Carpenter, Lucy J., Andrews, Stephen J., Sherwen, Tomás, and von Glasow, Roland
  • Atmospheric Chemistry and Physics. March 12, 2019, Vol. 19 Issue 5, p3161.

2. The influence of meteorological factors and biomass burning on surface ozone concentrations at Tanah Rata, Malaysia [2013]

  • Toh, Ying Ying, Lim, Sze Fook, and von Glasow, Roland
  • In Atmospheric Environment May 2013 70:435-446

3. Megacities and Large Urban Agglomerations in the Coastal Zone: Interactions Between Atmosphere, Land, and Marine Ecosystems [2013]

  • Glasow, Roland, Jickells, Tim D., Baklanov, Alexander, Carmichael, Gregory R., Church, Tom M., Gallardo, Laura, Hughes, Claire, Kanakidou, Maria, Liss, Peter S., Mee, Laurence, Raine, Robin, Ramachandran, Purvaja, Ramesh, R., Sundseth, Kyrre, Tsunogai, Urumu, Uematsu, Mitsuo, and Zhu, Tong
  • Ambio. Feb, 2013, Vol. 42 Issue 1, p13, 16 p.

4. 1980―2010 Variability in U.K. Surface Wind Climate [2013]

  • EARL, Nick, DORLING, Steve, HEWSTON, Richard, and VON GLASOW, Roland
  • Journal of climate. 26(4):1172-1191
Subjects
Ecology, Ecologie, Glaciology, Glaciologie, Geology, Géologie, Geophysics, Géophysique, Climatology, meteorology, Climatologie, météorologie, Sciences exactes et technologie, Exact sciences and technology, Terre, ocean, espace, Earth, ocean, space, Geophysique externe, External geophysics, Météorologie, Meteorology, Vents et leurs effets, Winds and their effects, Climatologie, Climatology, Climatología, Distribution vent, Wind field, Distribución viento, Rafale, Gust, Ráfaga, Valeur extrême, extreme value, Variation annuelle, annual variations, Variación anual, Variation interannuelle, Interannual variation, Variación interanual, Vent surface, Surface wind, Viento superficial, Vitesse vent, Wind velocity, and Velocidad viento
Abstract
The climate of the northeast Atlantic region comprises substantial decadal variability in storminess. It also exhibits strong inter- and intra-annual variability in extreme high and low wind speed episodes. Here the authors quantify and discuss causes of the variability seen in the U.K. wind climate over the recent period 1980-2010. Variations in U.K. hourly mean (HM) wind speeds, in daily maximum gust speeds and in associated wind direction measurements, made at standard 10-m height and recorded across a network of 40 stations, are considered. The Weibull distribution is shown to generally provide a good fit to the hourly wind data, albeit with the shape parameter k spatially varying from 1.4 to 2.1, highlighting that the commonly assumed k = 2 Rayleigh distribution is not universal. It is found that the 10th and 50th percentile HM wind speeds have declined significantly over this specific period, while still incorporating a peak in the early 1990s. The authors' analyses place the particularly low wind year of 2010 into longer-term context and their findings are compared with other recent international studies. Wind variability is also quantified and discussed in terms of variations in the exceedance of key wind speed thresholds of relevance to the insurance and wind energy industries. Associated interannual variability in energy density and potential wind power output of the order of ±20% around the mean is revealed. While 40% of network average winds are in the southwest quadrant, 51 % of energy in the wind is associated with this sector. The findings are discussed in the context of current existing challenges to improve predictability in the Euro-Atlantic sector over all time scales.

5. Megacities and Large Urban Agglomerations in the Coastal Zone: Interactions Between Atmosphere, Land, and Marine Ecosystems [2013]

  • VON GLASOW, Roland, JICKELLS, Tim D, RAINE, Robin, RAMACHANDRAN, Purvaja, RAMESH, R, SUNDSETH, Kyrre, TSUNOGAI, Urumu, UEMATSU, Mitsuo, TONG ZHU, BAKLANOV, Alexander, CARMICHAEL, Gregory R, CHURCH, Tom M, GALLARDO, Laura, HUGHES, Claire, KANAKIDOU, Maria, LISS, Peter S, and MEE, Laurence
  • Ambio. 42(1):13-28
Subjects
Environment, Environnement, Multidisciplinary, Multidisciplinaire, Sciences biologiques et medicales, Biological and medical sciences, Sciences biologiques fondamentales et appliquees. Psychologie, Fundamental and applied biological sciences. Psychology, Ecologie animale, vegetale et microbienne, Animal, plant and microbial ecology, Ecologie appliquée, Applied ecology, Ecotoxicologie, effets biologiques de la pollution, Ecotoxicology, biological effects of pollution, Ecosystèmes marins et saumâtres, Marine and brackish environment, Algae, Algue nuisible, Harmful alga, Alga nociva, Atmosphère, Atmosphere, Atmósfera, Bloom, Dépôt, Deposition, Depósito, Ecosystème, Ecosystem, Ecosistema, Interaction, Interacción, Milieu marin, Marine environment, Medio marino, Ozone, Ozono, Pollution air, Air pollution, Contaminación aire, Pollution eau, Water pollution, Contaminación agua, Zone côtière, Coastal zone, Zona costera, Zone urbaine, Urban area, Zona urbana, Mégapole, Megacity, Megaciudad, Coastal zone management, Harmful algal blooms, and Marine pollution
Abstract
Megacities are not only important drivers for socio-economic development but also sources of environmental challenges. Many megacities and large urban agglomerations are located in the coastal zone where land, atmosphere, and ocean meet, posing multiple environmental challenges which we consider here. The atmospheric flow around megacities is complicated by urban heat island effects and topographic flows and sea breezes and influences air pollution and human health. The outflow of polluted air over the ocean perturbs biogeochemical processes. Contaminant inputs can damage downstream coastal zone ecosystem function and resources including fisheries, induce harmful algal blooms and feedback to the atmosphere via marine emissions. The scale of influence of megacities in the coastal zone is hundreds to thousands of kilometers in the atmosphere and tens to hundreds of kilometers in the ocean. We list research needs to further our understanding of coastal megacities with the ultimate aim to improve their environmental management.

6. Multiphase Halogen Chemistry in the Tropical Atlantic Ocean : Marine Boundary Layer Focus [2012]

  • SOMMARIVA, Roberto and VON GLASOW, Roland
  • Environmental science & technology. 46(19):10429-10437
Subjects
Biotechnology, Biotechnologies, Ecology, Ecologie, Energy, Énergie, Environment, Environnement, Pollution, Sciences exactes et technologie, Exact sciences and technology, Terre, ocean, espace, Earth, ocean, space, Geophysique externe, External geophysics, Météorologie, Meteorology, Convection, turbulence, diffusion. Structure et dynamique de la couche limite atmosphérique, Convection, turbulence, diffusion. Boundary layer structure and dynamics, Composition et réactions chimiques. Interactions et processus ioniques, Chemical composition and interactions. Ionic interactions and processes, Atmosphère marine, Marine atmosphere, Atmósfera marina, Chimie atmosphérique, Atmospheric chemistry, Couche limite atmosphérique, Atmospheric boundary layer, Capa límite atmosférico, Halogène Composé, halogens compounds, Halógeno, Interface air mer, air-sea interface, Interfase aire mar, Masse air, Air mass, Masa aire, Modèle 1 dimension, one-dimensional models, Modelo 1 dimensión, Relation source puits, Source sink relationship, Relación fuente sumidero, Simulation numérique, digital simulation, and Simulación numérica
Abstract
We used a one-dimensional model to simulate the chemical evolution of air masses in the tropical Atlantic Ocean, with a focus on halogen chemistry. The model results were compared to the observations of inorganic halogen species made in this region. The model could largely reproduce the measurements of most chlorine species, especially under unpolluted conditions, but overestimated sea salt chloride, BrCl, and bromine species. Agreement with the measurements could be improved by taking into account the reactivity with aldehydes and the effects of dimethyl sulfide (DMS) and Saharan dust on aerosol pH; a hypothetical HOX → X― aqueous-phase reaction could also improve the agreement with measured Cl2 and HOCl, especially under semipolluted conditions. The results also showed that halogens speciation and concentrations are very sensitive to cloud processing. The model was used to calculate the impact of the observed levels of halogens: Cl atoms accounted for 5.4―11.6% of total methane sinks and halogens (mostly bromine and iodine) accounted for 35―40% of total ozone destruction.

7. Importance of reactive halogens in the tropical marine atmosphere : A regional modelling study using WRF-Chem [2019]

  • Badia, Alba, Reeves, Claire E., Baker, Alex R., Saiz-Lopez, Alfonso, Volkamer, Rainer, Koenig, Theodore K., Apel, Eric C., Hornbrook, Rebecca S., Carpenter, Lucy J., Andrews, Stephen J., Sherwen, Tomás, and Von Glasow, Roland
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 (Br y ) partitioning when heterogeneous chemistry is included, with a greater proportion of the Br y 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 Br y . 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, O 3 is reduced by 7ppbv on average. However, when reactions between Br and Cl with VOCs are not included, O 3 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.

8. Modelling the multiphase near-surface chemistry related to ozone depletions in polar spring [2009]

  • PIOT, Matthias and VON GLASOW, Roland
  • Journal of atmospheric chemistry (Print). 64(2-3):77-105
Subjects
Environment, Environnement, Climatology, meteorology, Climatologie, météorologie, Pollution, Sciences exactes et technologie, Exact sciences and technology, Terre, ocean, espace, Earth, ocean, space, Geophysique externe, External geophysics, Météorologie, Meteorology, Composition et réactions chimiques. Interactions et processus ioniques, Chemical composition and interactions. Ionic interactions and processes, Analyse sensibilité, sensitivity analysis, Aérosol, aerosols, Aerosol, Chimie atmosphérique, Atmospheric chemistry, Couche limite atmosphérique, Atmospheric boundary layer, Capa límite atmosférico, Déplétion, Depletion, Depleción, Modèle boîte, Box model, Modelo caja, Modèle chimique, Chemical model, Modelo químico, Mécanisme réaction, Reaction mechanism, Mecanismo reacción, Neige, snow, Nieve, Ozone, ozone, Ozono, Printemps, Spring(season), Primavera, Réaction hétérogène, Heterogeneous reaction, Reacción heterogénea, Système multiphase, Multiphase system, Sistema multifase, Zone polaire, Polar region, Zona polar, Chemical processes, Ozone depletion events, Polar spring, and Sensitivity studies
Abstract
Near-total depletions of ozone have been observed in the Arctic spring since the mid 1980s. The autocatalytic reaction cycles involving reactive halogens are now recognized to be of main importance for ozone depletion events in the polar boundary layer. We present sensitivity studies using the model MISTRA in the box-model mode on the influence of chemical species on these ozone depletion processes. In order to test the sensitivity of the chemistry under polar conditions, we compared base runs undergoing fluxes of either Br2, BrCl, or C12 to induce ozone depletions, with similar runs including a modification of the chemical conditions. The role of HCHO, H2O2, DMS, C12, C2H6, HONO, NO2, and RONO2 was investigated. Cases with elevated mixing ratios of HCHO, H202, DMS, C12, and HONO induced a shift in bromine speciation from Br/BrO to HOBr/HBr, while high mixing ratios of C2H6 induced a shift from HOBr/HBr to Br/BrO. The shifts from Br/BrO to HOBr/HBr accelerated the aerosol debromination, but also increased the total amount of deposited bromine at the surface (mainly via increased deposition of HOBr). For all NOy species studied (HONO, N02, RONO2) the chemistry is characterized by an increased bromine deposition on snow reducing the amount of reactive bromine in the air. Ozone is less depleted under conditions of high mixing ratios of NOx. The production of HNO3 led to the acid displacement of HCl, and the release of chlorine out of salt aerosol (C12 or BrCl) increased.

9. Climate-induced change in biogenic bromine emissions from the Antarctic marine biosphere [2012]

  • HUGHES, Claire, JOHNSON, Martin, TURNER, Suzanne M, MALIN, Gill, LISS, Peter S, VON GLASOW, Roland, CHANCE, Rosie, ATKINSON, Helen, SOUSTER, Terri, LEE, Gareth A, CLARKE, Andrew, MEREDITH, Michael, and VENABLES, Hugh J
  • Global biogeochemical cycles. 26(3)
Subjects
Geology, Géologie, Climatology, meteorology, Climatologie, météorologie, Oceanography, Océanographie, Sciences exactes et technologie, Exact sciences and technology, Terre, ocean, espace, Earth, ocean, space, Sciences de la terre, Earth sciences, Géochimie, Geochemistry, Sciences biologiques et medicales, Biological and medical sciences, Sciences biologiques fondamentales et appliquees. Psychologie, Fundamental and applied biological sciences. Psychology, Ecologie animale, vegetale et microbienne, Animal, plant and microbial ecology, Ecologie animale et végétale, Animal and plant ecology, Synécologie, Synecology, Généralités, General aspects, Algae, Heterokontophyta, Plancton, plankton, Action anthropique, human activity, Acción hombre, Activité humaine, Human activity, Actividad humana, Air, air, Bacillariophyta, Biosphère, biosphere, Biosfera, Bloom, Brome, bromine, Bromo, Changement climatique, climate change, Chlorophylle, chlorophyll, Clorofila, Climat, climate, Clima, Concentration, concentration, Concentración, Cycle biogéochimique, biogeochemical cycle, Durée, duration, Dynamique, dynamics, Dinámica, Eau mer, sea water, Agua mar, Ecosystème, ecosystems, Ecosistema, Facteur anthropique, Anthropogenic factor, Factor antrópico, Facteur biogène, Biogenic factor, Factor biógeno, Glace marine, sea ice, Hielo marino, Groupement végétal, Plant community, Comunidad vegetal, Milieu marin, marine environment, Medio marino, Phytoplancton, phytoplankton, Fitoplancton, Structure communauté, Community structure, Estructura comunidad, Variation annuelle, annual variations, Variación anual, Zone côtière, coastal zone, and Méthyle sulfure
Abstract
[1] Climate change and human activities are expected to have a major impact on the structure and functioning of marine ecosystems and the biogeochemical cycles they mediate in the coming years. Here we describe time series measurements of biogenic bromocarbons (CHBr3 and CH2Br2) collected in coastal waters of the western Antarctic Peninsula which is one of the world's most rapidly changing marine environments. Our measurements spanned a period of changing sea-ice dynamics and phytoplankton community structure driven by climatic forcing. Specifically, the occurrence of high chlorophyll a concentrations (>5 μg L―1) and dominance of the largest phytoplankton size fraction (≥20 μm) indicating diatom bloom conditions was reduced following winter periods with a relatively short winter sea-ice duration (<50 days). While large inter-annual variability in seawater CHBr3 concentrations was observed alongside these changes the same was not found for CH2Br2 which is surprising given their proposed common source. Seawater CHBr3 concentrations were found to be significantly higher (122 [14.7-580] pmol L―1, P < 0.0001, Mann-Whitney) in samples collected in diatom bloom compared to non-bloom waters (42.9 [12.0-126] pmol L―1). A comparison of sea-to-air flux rates suggests that a switch from diatom bloom to non-bloom conditions results in a factor of 3―4 decrease in average CHBr3 sea-to-air emission rates which will reduce the supply of biogenic bromine to the atmosphere. Our calculations suggest that this will drive a decrease in inorganic bromine levels in the troposphere by a factor of 2-3 outside of ozone depletion events with potentially important implications for ozone cycling and dimethyl sulphide oxidation. This work has captured and crucially quantified the impact of a climate-induced change in a marine ecosystem on ocean-atmosphere biogeochemistry.

10. Atmospheric chemistry in volcanic plumes [2010]

  • von Glasow Roland and Finlayson-Pitts Barbara J.
  • Proceedings of the National Academy of Sciences of the United States of America. 107(15):6594-6599

11. Variation of sea salt aerosol pH with relative humidity [2001]

  • VON GLASOW, Roland and SANDER, Rolf
  • Geophysical research letters. 28(2):247-250
Subjects
Astronomy earth cosmic environment, Astronomie et environnement cosmique terrestre, Geophysics, Géophysique, Climatology, meteorology, Climatologie, météorologie, Oceanography, Océanographie, Sciences exactes et technologie, Exact sciences and technology, Terre, ocean, espace, Earth, ocean, space, Geophysique externe, External geophysics, Météorologie, Meteorology, Particules et aérosols, Particles and aerosols, Acidité, Acidity, Acidez, Atmosphère marine, Marine atmosphere, Atmósfera marina, Aérosol, Aerosols, Aerosol, Chlorure, Chlorides, Cloruro, Concentration, Concentración, Couche limite atmosphérique, Atmospheric boundary layer, Capa límite atmosférico, Humidité relative, Relative humidity, Humedad relativa, Hydrogène Chlorure, Hydrogen Chlorides, Hidrógeno Cloruro, Partage phase, Phase partition, Repartición fase, Sel marin, Sea salt, Sal marina, Solution analytique, Analytical solution, Teneur eau, Water content, Dosis agua, and pH
Abstract
Calculations of the pH of sea salt aerosol particles show that the pH decreases with increasing relative humidity and therefore increasing liquid water content of the particles. We show that this puzzling effect is a result of the high concentration of chloride in the particles and the phase partitioning of HCl between the gas and aqueous phase, that makes the gas phase act as a reservoir for acidity for the sea salt particles. Implications for the marine boundary layer are briefly discussed.

12. The effects of volcanic eruptions on atmospheric chemistry [2009]

  • von Glasow, Roland, Bobrowski, Nicole, and Kern, Christoph
  • In Halogens in Volcanic Systems and Their Environmental Impacts, Chemical Geology 2009 263(1):131-142

13. Ozone depletion in tropospheric volcanic plumes [2010]

  • VANCE, Alan, MCGONIGLE, Andrew J. S, AIUPPA, Alessandro, STITH, Jeffrey L, TURNBULL, Kate, and VON GLASOW, Roland
  • Geophysical research letters. 37(22)
Subjects
Astronomy earth cosmic environment, Astronomie et environnement cosmique terrestre, Geophysics, Géophysique, Climatology, meteorology, Climatologie, météorologie, Oceanography, Océanographie, Sciences exactes et technologie, Exact sciences and technology, Terre, ocean, espace, Earth, ocean, space, Sciences de la terre, Earth sciences, Amérique du Nord, North America, America del norte, Age, age, Edad, Appauvrissement, depletion, Brome, bromine, Bromo, Cendre, ash, Ceniza, Concentration, concentration, Concentración, Cratère, craters, Cráter, Destruction, destruction, Déplétion, Depletion, Depleción, Modèle, models, Modelo, Ozone, ozone, Ozono, Panache, plumes, Penacho, Troposphère, and troposphere
Abstract
[1] We measured ozone (03) concentrations in the atmospheric plumes of the volcanoes St. Augustine (1976), Mt. Etna (2004, 2009) and Eyjafjallajökull (2010) and found 03 to be strongly depleted compared to the background at each volcano. At Mt. Etna 03 was depleted within tens of seconds from the crater, the age of the St. Augustine plumes was on the order of hours, whereas the O3 destruction in the plume of Eyjafjallajökull was maintained in 1-9 day old plumes. The most likely cause for this 03 destruction are catalytic bromine reactions as suggested by a model that manages to reproduce the very early destruction of O3 but also shows that 03 destruction is ongoing for several days. Given the observed rapid and sustained destruction of O3, heterogeneous loss of O3 on ash is unlikely to be important.

14. Quantifying the contribution of marine organic gases to atmospheric iodine [2010]

  • JONES, Charlotte E, HORNSBY, Karen E, SOMMARIVA, Roberto, DUNK, Rachel M, VON GLASOW, Roland, MCFIGGANS, Gordon, and CARPENTER, Lucy J
  • Geophysical research letters. 37(18)
Subjects
Astronomy earth cosmic environment, Astronomie et environnement cosmique terrestre, Geophysics, Géophysique, Climatology, meteorology, Climatologie, météorologie, Oceanography, Océanographie, Sciences exactes et technologie, Exact sciences and technology, Terre, ocean, espace, Earth, ocean, space, Sciences de la terre, Earth sciences, Air, air, Cap, capes, Cabo, Chimie atmosphérique, Atmospheric chemistry, Climat, climate, Clima, Eau mer, sea water, Agua mar, Gaz, gases, Gas, Incertitude, uncertainties, Io, Iode, iodine, Iodo, Matière volatile, volatiles, Materia volátil, Modèle atmosphère, Atmosphere model, Modelo atmósfera, Monde, global, Mundo, Phénomène précurseur, precursors, Fenómeno precursor, Précurseur, Precursor, Zone tropicale, tropical zone, and Zona tropical
Abstract
[1] Oceanic emissions of gaseous organic iodine-atom precursors have the potential to significantly affect atmospheric chemistry and climate, however there is currently considerable uncertainty associated with quantifying their sources. We present sea-air fluxes calculated from simultaneous air and seawater measurements of a comprehensive range of volatile organic iodine compounds (VOICs), including CH3I and the less commonly reported dihalomethanes CH2ICl, CH2IBr and CH2I2, made during two cruises in the Atlantic Ocean between 15-58°N. The combined dihalomethane flux provides a global iodine source (∼0.33 ± 0.19 Tg I y-1 ) comparable to that of CH3I, and a surface iodine atom source 3-4 times higher. However, a 1 D atmospheric model reveals that, in the tropical east Atlantic Ocean in the vicinity of Cape Verde, even these combined VOIC fluxes are capable of supporting only ∼10-25% of the observed IO levels, and suggests that a substantial (340-640 nmol I m-2 d-1) additional photochemical source of iodine is required.

15. Tropospheric halogen chemistry: sources, cycling, and impacts [2015]

  • Simpson, William R., Brown, Steven S., Saiz-Lopez, Alfonso, Thornton, Joel A., and Glasow, Roland von
  • Chemical Reviews. May 27, 2015, Vol. 115 Issue 10, 4035-4062

16. Inorganic chlorine and bromine in coastal New England air during summer : International Consortium for Atmospheric Research Transport and Transformation: North America to Europe, Part II [2007]

  • KEENE, William C, STUTZ, Jochen, PSZENNY, Alexander A. P, MABEN, John R, FISCHER, Emily V, SMITH, Allen M, VON GLASOW, Roland, PECHTL, Susanne, SIVE, Barkley C, and VARNER, Ruth K
  • Journal of geophysical research. 112(D10)
Subjects
Astronomy earth cosmic environment, Astronomie et environnement cosmique terrestre, Geology, Géologie, Geophysics, Géophysique, Climatology, meteorology, Climatologie, météorologie, Oceanography, Océanographie, Sciences exactes et technologie, Exact sciences and technology, Terre, ocean, espace, Earth, ocean, space, Sciences de la terre, Earth sciences, Amérique du Nord, North America, America del norte, Acide, acids, Acido, Air, air, Aérosol, aerosols, Aerosol, Brome, bromine, Bromo, Chlore, chlorine, Cloro, Composé trace, Trace compound, Compuesto huella, Concentration, concentration, Concentración, Diamètre, Diameter, Diámetro, Déplacement, displacements, Echantillonnage, sampling, Muestreo, Eté, Summer, Verano, Evolution chimique, Chemical evolution, Evolución química, Halogène, halogens, Halógeno, Hydrocarbure, hydrocarbons, Hidrocarburo, Ile, islands, Isla, Océan Atlantique, Atlantic Ocean, Océano Atlántico, Ozone, ozone, Ozono, Photolyse, Photolysis, Fotolisis, Phénomène précurseur, precursors, Fenómeno precursor, Précurseur, Precursor, Rapport mélange, Mixing ratio, Relación mezcla, Sel marin, Sea salt, Sal marina, Transformation, transformations, Transformación, Transport, transport, and Transporte
Abstract
During summer 2004, a comprehensive suite of reactive trace gases (including halogen radicals and precursors, ozone, reactive N, soluble acids, and hydrocarbons), the chemical and physical characteristics of size-resolved aerosols, actinic flux, and related physical conditions were measured at Appledore Island, Maine, as part of the International Consortium for Atmospheric Research on Transport and Transformation (ICARTT). Sea-salt mass averaged 4 to 8 times lower than that over the open North Atlantic Ocean. Production in association with sea salt was the primary source for inorganic Cl and Br. Acid displacement of sea-salt Cl- primarily by HNO3 sustained high HCl mixing ratios (often >2000 pptv) during daytime. Median pHs for the larger sea-salt size fractions (geometric mean diameters, GMDs > 2.9 μm) ranged from 3.1 to 3.4; median pHs for sub-μm size fractions were < 1.6. Cl* (including HOCl and Cl2) ranged from <20 to 421 pptv Cl but was less than the detection limit (DL) during most sampling intervals. Periods during which Cl* was consistently detectable corresponded to relatively clean conditions, multiday transport over water, and relatively low actinic flux. At high HCl mixing ratios (>1000 pptv), HCl + OH sustained steady state Cl-atom concentrations in the range of 104 cm-3. When detectable, photolysis of Cl* was generally the dominant source of atomic Cl; steady state concentrations of Cl atoms were frequently in the range of 104 to 105 cm-3. At these concentrations, Cl played an important role in the chemical evolution of polluted coastal air. Br radical chemistry was relatively unimportant.

17. Wider role for airborne chlorine [2010]

  • von Glasow, Roland
  • Nature. Mar 11, 2010 464(7286):168-169

18. ATMOSPHERIC CHEMISTRY: Sun, sea and ozone destruction [2008]

  • von Glasow, Roland
  • Nature. Jun 26, 2008 453(7199):1195-1196

19. Sun, sea and ozone destruction: halogens are known to decrease the levels of stratospheric ozone. The latest measurements show that something similar occurs in the lower atmosphere over tropical oceans--and probably above most other oceans, too [2008]

  • von Glasow, Roland
  • Nature. June 26, 2008, Vol. 453 Issue 7199, p1195, 2 p.

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