Halogens and their role in polar boundary-layer ozone depletion

During springtime in the polar regions, unique photochemistry converts inert halide salt ions (e.g. Br − ) into reactive halogen species (e.g. Br atoms and BrO) that deplete ozone in the boundary layer to near zero levels. Since their discovery in the late 1980s, research on ozone depletion events (ODEs) has made great advances; however many key processes remain poorly understood. In this article we review the history, chemistry, dependence on environmental conditions, and impacts of ODEs. This research has shown the central role of bromine photochemistry, but how salts are transported from the ocean and are oxidized to become reactive halogen species in the air is still not fully understood. Halogens other than bromine (chlorine and iodine) are also activated through incompletely understood mechanisms that are probably coupled to bromine chemistry. The main consequence of halogen activation is chemical destruction of ozone, which removes the primary precursor of atmospheric oxidation, and generation of reactive halogen atoms/oxides that become the primary oxidizing species. The different reactivity of halogens as compared to OH and ozone has broad impacts on atmospheric chemistry, including near complete removal and deposition of mercury, alteration of oxidation fates for organic gases, and export of bromine into the free troposphere. Recent changes in the climate of the Arctic and state of the Arctic sea ice cover are likely to have strong effects on halogen activation and ODEs; however, more research is needed to make meaningful predictions of these changes.

[1]  Luria,et al.  DOAS measurements of tropospheric bromine oxide in mid-latitudes , 1999, Science.

[2]  P. Shepson,et al.  Measurements of photolyzable chlorine and bromine during the Polar Sunrise Experiment 1995 , 1997 .

[3]  P. Ariya,et al.  Reactions of Gaseous Mercury with Atomic and Molecular Halogens: Kinetics, Product Studies, and Atmospheric Implications , 2002 .

[4]  Measurements of halogen oxides by GOME , 1998 .

[5]  T. Berntsen,et al.  A global three‐dimensional chemical transport model: 2. Nitrogen oxides and nonmethane hydrocarbon results , 1997 .

[6]  D. R. Hastie,et al.  The sensitivity of the radical amplifier to ambient water vapour , 1998 .

[7]  Roger G. Barry,et al.  A record minimum arctic sea ice extent and area in 2002 , 2003 .

[8]  K. Pfeilsticker,et al.  Spectroscopic measurements of tropospheric iodine oxide at Neumayer Station, Antarctica , 2001 .

[9]  J. Kahl,et al.  Theoretical heights of buoyant convection above open leads in the winter Arctic pack ice cover , 1992 .

[10]  K. Tung,et al.  A Closer Comparison of Early and Late-Winter Atmospheric Trends in the Northern Hemisphere , 2005 .

[11]  L. Barrie,et al.  Arctic springtime depletion of mercury , 1998, Nature.

[12]  S. Bekki,et al.  Climate and CCN , 1995, Nature.

[13]  M. Legrand,et al.  Methane sulfonic acid to non-sea-salt sulfate ratio in coastal Antarctic aerosol and surface snow , 1998 .

[14]  M. Hausmann,et al.  Spectroscopic measurement of bromine oxide and ozone in the high Arctic during Polar Sunrise Experiment 1992 , 1994 .

[15]  Eric W. Wolff,et al.  A year-long record of size-segregated aerosol composition at Halley, Antarctica , 2003 .

[16]  O. Lønne.  On Productivity in Ice-Covered Polar Oceans , 1999 .

[17]  Carlo Barbante,et al.  Eight glacial cycles from an Antarctic ice core , 2004, Nature.

[18]  Ulrich Platt,et al.  Observations of BrO and its vertical distribution during surface ozone depletion at Alert , 2002 .

[19]  L. Avallone,et al.  Frost flower influence on springtime boundary‐layer ozone depletion events and atmospheric bromine levels , 2006 .

[20]  Paul J. Crutzen,et al.  Iodine Chemistry and its Role in Halogen Activation and Ozone Loss in the Marine Boundary Layer: A Model Study , 1999 .

[21]  P. Crutzen,et al.  On the global distribution of the halogen oxides from observations by GOME (Global Ozone Monitoring Experiment) on ERS-2 , 1998 .

[22]  E. Wolff.  Understanding the past-climate history from Antarctica , 2005, Antarctic Science.

[23]  Hacene Boudries,et al.  A study of photochemical and physical processes affecting carbonyl compounds in the Arctic atmospheric boundary layer , 2002 .

[24]  Ulrich Platt,et al.  Heterogeneous and Homogeneous Chemistry of Reactive Halogen Compounds in the Lower Troposphere , 1999 .

[25]  川村 宏,et al.  "Space at the Service of our Environment"シンポジウム報告 , 1993 .

[26]  Sarit Kraus,et al.  Year-to-year variations of spring time polar tropospheric BrO as seen by GOME , 2004 .

[27]  P. Crutzen,et al.  Are CH2O measurements in the marine boundary layer suitable for testing the current understanding of CH4 photooxidation , 2002 .

[28]  P. Ariya,et al.  Product study of the gas-phase BrO-initiated oxidation of Hg0: evidence for stable Hg1+ compounds. , 2004, Environmental science & technology.

[29]  Paul B. Shepson,et al.  Air-Snow Interactions and Atmospheric Chemistry , 2002, Science.

[30]  R. N. Schindler,et al.  Experimental verification of gas phase bromine enrichment in reactions of HOBr with sea salt doped ice surfaces , 1997 .

[31]  P. Crutzen,et al.  Modeling the chemistry of ozone , halogen compounds , and hydrocarbons in the arctic troposphere during spring , 2009 .

[32]  U. Platt,et al.  The role of halogen species in the troposphere. , 2003, Chemosphere.

[33]  A. Jones,et al.  Speciation and rate of photochemical NO and NO2 production in Antarctic snow , 2000 .

[34]  J. Farman,et al.  LARGE LOSSES OF TOTAL OZONE IN ANTARCTICA , 1985 .

[35]  B. Jobson,et al.  Measurements of C2-C7 hydrocarbons during the Polar Sunrise Experiment 1994: Further evidence for halogen chemistry in the troposphere , 1998 .

[36]  P. Shepson,et al.  Atmospheric chemistry of formaldehyde in the Arctic troposphere at Polar Sunrise, and the influence of the snowpack , 2002 .

[37]  J. Crowley,et al.  The Measurement of Active Chlorine in the Atmosphere by Chemical Amplification , 1999 .

[38]  S. C. Gerlach,et al.  Arctic system on trajectory to new, seasonally ice‐free state , 2005 .

[39]  P. Crutzen,et al.  Impact of reactive bromine chemistry in the troposphere , 2004 .

[40]  Sheldon Landsberger,et al.  Anthropogenic aerosols and gases in the lower troposphere at Alert Canada in April 1986 , 1989 .

[41]  S. Oltmans.  Surface ozone measurements in clean air , 1981 .

[42]  H. Bovensmann,et al.  Measurements of iodine monoxide (IO) above Spitsbergen , 2000 .

[43]  U. Platt,et al.  A one dimensional model study of the mechanism of halogen liberation and vertical transport in the polar troposphere , 2004 .

[44]  M. Goodsite,et al.  Environmental costs of mercury pollution. , 2006, The Science of the total environment.

[45]  K. Anlauf,et al.  Measurement of ozone during Polar Sunrise Experiment 1992 , 1994 .

[46]  W. Evans,et al.  Boundary layer ozone depletion during AGASP-II , 1989 .

[47]  R. Kwok,et al.  A Laboratory Study of the Effect of Frost Flowers on C Band Radar Backscatter from Sea Ice , 1997 .

[48]  J. Plane,et al.  The absorption cross-section and photochemistry of OIO , 2005 .

[49]  J. Burrows,et al.  SO2, OClO, BrO, and other minor trace gases from the Global Ozone Monitoring Experiment (GOME) , 1997 .

[50]  R. Toumi.  BrO as a sink for dimethylsulphide in the marine atmosphere , 1994 .

[51]  J. Bottenheim,et al.  A trajectory study into the origin of spring time Arctic boundary layer ozone depletion , 2005 .

[52]  J. Plane,et al.  High resolution spectroscopy of the OIO radical: Implications for the ozone‐depleting potential of iodine , 2002 .

[53]  U. Platt,et al.  Observation and role of the free radicals NO3, ClO, BrO and IO in the troposphere , 1995 .

[54]  M. D. Angelis,et al.  Limited dechlorination of sea salt aerosols during the last glacial period , 2003 .

[55]  R. Rasmussen,et al.  Composition of Br-containing aerosols and gases related to boundary layer ozone destruction in the arctic , 1993 .

[56]  R. Gersonde,et al.  Sea-surface temperature and sea ice distribution of the Southern Ocean at the EPILOG Last Glacial Maximum—a circum-Antarctic view based on siliceous microfossil records , 2005 .

[57]  J. Abbatt,et al.  Heterogeneous reaction of HOBr with HBr and HCl on ice surfaces at 228 k , 1994 .

[58]  R. Ebinghaus,et al.  Summary report: first international Arctic atmospheric mercury research workshop , 2003 .

[59]  Florence Fetterer,et al.  Tracking the Arctic's shrinking ice cover: Another extreme September minimum in 2004 , 2005 .

[60]  R. Glasow,et al.  The potential importance of frost flowers , recycling on snow , and open leads for ozone depletion events , 2008 .

[61]  Marika M. Holland,et al.  Future abrupt reductions in the summer Arctic sea ice , 2006 .

[62]  B. Finlayson‐Pitts,et al.  Chemistry of the Upper and Lower Atmosphere , 2000 .

[63]  D. Tobias,et al.  Chloride Anion on Aqueous Clusters, at the Air−Water Interface, and in Liquid Water: Solvent Effects on Cl- Polarizability , 2002 .

[64]  D. Orihel,et al.  Relationship between the loading rate of inorganic mercury to aquatic ecosystems and dissolved gaseous mercury production and evasion. , 2006, Chemosphere.

[65]  A. Minikin,et al.  Sea‐salt aerosol in coastal Antarctic regions , 1998 .

[66]  R. Koppmann,et al.  Hydrocarbon measurements during tropospheric ozone depletion events : Evidence for halogen atom chemistry , 1999 .

[67]  D. Jacob,et al.  Surface ozone depletion in Arctic spring sustained by bromine reactions on aerosols , 1992, Nature.

[68]  C. N. Hewitt,et al.  Dimethyl sulfide, methane sulfonic acid and physicochemical aerosol properties in Atlantic air from the United Kingdom to Halley Bay , 1996 .

[69]  M. Molina,et al.  Phase transitions of sea-salt/water mixtures at low temperatures: Implications for ozone chemistry in the polar marine boundary layer , 2000 .

[70]  W. Neff,et al.  A study of boundary layer behavior associated with high NO concentrations at the South Pole using a minisodar, tethered balloon, and sonic anemometer , 2008 .

[71]  W. Sturges.  Excess particulate and gaseous bromine at a remote coastal location , 1990 .

[72]  Y. Yokouchi,et al.  Serial gas chromatographic/mass spectrometric measurements of some volatile organic compounds in the Arctic atmosphere during the 1992 Polar Sunrise Experiment , 1994 .

[73]  P. Shepson,et al.  Molecular halogens before and during ozone depletion events in the Arctic at polar sunrise: concentrations and sources , 2002 .

[74]  P. Shepson,et al.  Impacts of snowpack emissions on deduced levels of OH and peroxy radicals at Summit, Greenland , 2002 .

[75]  P. Crutzen,et al.  Global distribution of atmospheric bromine‐monoxide from GOME on Earth Observing Satellite ERS‐2 , 1998 .

[76]  J. Burrows,et al.  Antarctic springtime depletion of atmospheric mercury. , 2002, Environmental science & technology.

[77]  D. Jacob,et al.  Uncertainty in preindustrial abundance of tropospheric ozone: Implications for radiative forcing calculations , 2001 .

[78]  M. Molina,et al.  Stratospheric sink for chlorofluoromethanes: chlorine atomc-atalysed destruction of ozone , 1974, Nature.

[79]  A. Grund,et al.  Observation of BrO in the atmosphere by remote sensing and its significance for the global budget of bromine , 1998 .

[80]  N. Schmidbauer,et al.  Boundary-layer ozone depletion as seen in the Norwegian Arctic in spring , 1996 .

[81]  H. Skov,et al.  A synthesis of atmospheric mercury depletion event chemistry linking atmosphere, snow and water , 2007 .

[82]  Michael Eisinger,et al.  GOME observations of tropospheric BrO in northern hemispheric spring and summer 1997 , 1998 .

[83]  K. Kreher,et al.  Ground‐based measurements of OClO and HCl in austral spring 1993 at Arrival Heights, Antarctica , 1996 .

[84]  Y. Yokouchi,et al.  Measurements of C2‐C6 hydrocarbons during the Polar Sunrise1992 Experiment: Evidence for Cl atom and Br atom chemistry , 1994 .

[85]  J. McConnell,et al.  Overview of Recent Field Experiments for the Study of the Air-Snow Transfer of H2O2 and HCHO , 1996 .

[86]  A. Laskin,et al.  Reactions at Interfaces As a Source of Sulfate Formation in Sea-Salt Particles , 2003, Science.

[87]  D. Lenschow,et al.  Formaldehyde and hydrogen peroxide in air, snow and interstitial air at South Pole , 2004 .

[88]  A. Ianniello,et al.  The origin of sea salt in snow on Arctic sea ice and in coastal regions , 2004 .

[89]  H. Chan.  A database for environmental contaminants in traditional foods in northern and Arctic Canada: development and applications. , 1998, Food additives and contaminants.

[90]  Douglas J. Tobias,et al.  Molecular Structure of Salt Solutions: A New View of the Interface with Implications for Heterogeneous Atmospheric Chemistry , 2001 .

[91]  U. Platt,et al.  First-year sea-ice contact predicts bromine monoxide (BrO) levels at Barrow, Alaska better than potential frost flower contact , 2007 .

[92]  John Munthe,et al.  Atmospheric mercury—An overview , 1998 .

[93]  W. Simpson,et al.  Specific surface area, density and microstructure of frost flowers , 2005 .

[94]  J. Bottenheim,et al.  Cl and Br atom concentrations during a surface boundary layer ozone depletion event in the Canadian High Arctic , 2000 .

[95]  R. Garcia,et al.  On the role of iodine in ozone depletion , 1994 .

[96]  J. Burrows,et al.  Carbonate precipitation in brine – the trigger for tropospheric ozone depletion events , 2006 .

[97]  J. Hollwedel.  Observations of Tropospheric and Stratospheric Bromine Monoxide from Satellite : Analysis of Satellite Data derived from GOME for 1996-2001 , 2004 .

[98]  P. Shepson,et al.  Measurement Technique for the Determination of Photolyzable Chlorine and Bromine in the Atmosphere , 1997 .

[99]  J. Crowley,et al.  Activation of Br2 and BrCl via uptake of HOBr onto aqueous salt solutions , 1999 .

[100]  D. Blake,et al.  Ozone depletion events observed in the high latitude surface layer during the TOPSE aircraft program , 2003 .

[101]  P. Shepson,et al.  Airborne observations related to ozone depletion at polar sunrise , 1994 .

[102]  A. Richter,et al.  Dynamic oxidation of gaseous mercury in the Arctic troposphere at polar sunrise. , 2002, Environmental science & technology.

[103]  P. Shepson,et al.  Snowpack photochemical production of HONO: A major source of OH in the Arctic boundary layer in springtime , 2001 .

[104]  J. Abbatt,et al.  Gas-Phase Br2 Production in Heterogeneous Reactions of Cl2, HOCl, and BrCl with Halide−Ice Surfaces , 2000 .

[105]  P. Shepson,et al.  An introduction to the ALERT 2000 and SUMMIT 2000 Arctic research studies , 2002 .

[106]  Shalina,et al.  Satellite Evidence for an Arctic Sea Ice Cover in Transformation. , 1999, Science.

[107]  L. Barrie,et al.  Photochemical bromine production implicated in Arctic boundary-layer ozone depletion , 1992, Nature.

[108]  J. Crowley,et al.  Photodissociation of IO (355 nm) and OIO (532 nm): Quantum yields for O(3P) and I(2PJ) production , 2000 .

[109]  S. Warren,et al.  Oceanic phytoplankton, atmospheric sulphur, cloud albedo and climate , 1987, Nature.

[110]  G. Marion.  Carbonate mineral solubility at low temperatures in the Na-K-Mg-Ca-H-Cl-SO , 2001 .

[111]  J. Rudolph,et al.  Halogen atom concentrations in the Arctic Troposphere derived from hydrocarbon measurements: Impact on the budget of formaldehyde , 1999 .

[112]  G. Shaw.  The Arctic Haze Phenomenon , 1995 .

[113]  Robert Sausen,et al.  European scientific assessment of the atmospheric effects of aircraft emissions , 1998 .

[114]  Seelye Martin,et al.  A laboratory study of frost flower growth on the surface of young sea ice , 1995 .

[115]  P. Shepson,et al.  Snowpack processing of acetaldehyde and acetone in the Arctic atmospheric boundary layer , 2002 .

[116]  P. Shepson,et al.  Chemical and meteorological observations at ice camp SWAN during Polar Sunrise Experiment 1992 , 1994 .

[117]  R. Bargagli,et al.  Enhanced deposition and bioaccumulation of mercury in Antarctic terrestrial ecosystems facing a coastal polynya. , 2005, Environmental science & technology.

[118]  P. Crutzen,et al.  Ozone destruction and photochemical reactions at polar sunrise in the lower Arctic atmosphere , 1988, Nature.

[119]  S. Solomon,et al.  On the depletion of Antarctic ozone , 1986, Nature.

[120]  T. Wagner,et al.  Satellite mapping of enhanced BrO concentrations in the troposphere , 1998, Nature.

[121]  W. Cleveland,et al.  Regression by local fitting: Methods, properties, and computational algorithms , 1988 .

[122]  B. Finlayson‐Pitts.  The tropospheric chemistry of sea salt: a molecular-level view of the chemistry of NaCl and NaBr. , 2003, Chemical reviews.

[123]  J. Crowley,et al.  The reactions of IO with HO2, NO and CH3SCH3: Flow tube studies of kinetics and product formation , 2001 .

[124]  U. Platt,et al.  A possible mechanism for combined chlorine and bromine catalyzed destruction of tropospheric ozone in the Arctic , 1995 .

[125]  P. Shepson,et al.  Ocean‐atmosphere‐sea ice‐snowpack interactions in the Arctic, and global change , 2003 .

[126]  W. Sturges,et al.  Chemistry of the Antarctic Boundary Layer and the Interface with Snow: an overview of the CHABLIS campaign , 2008 .

[127]  A. Lewis,et al.  Abiotic source of reactive organic halogens in the sub-arctic atmosphere? , 2005, Environmental science & technology.

[128]  D. R. Blakea,et al.  Photochemically induced production of CH 3 Br, CH 3 I, C 2 H 5 I, ethene, and propene within surface snow at Summit, Greenland , 2002 .

[129]  C. Serves.  Gas phase formaldehyde and peroxide measurements in the Arctic atmosphere , 1994 .

[130]  H. Coe,et al.  Measurements and Modelling of I 2 , Io, Oio, Bro and No 3 in the Mid-latitude Marine Boundary Layer , 2022 .

[131]  J. Haarpaintner,et al.  SSM/I Sea Ice Remote Sensing for Mesoscale Ocean-Atmosphere Interaction Analysis , 2001 .

[132]  James D. Lee,et al.  On the vertical distribution of boundary layer halogens over coastal Antarctica: implications for O 3 , HO x , NO x and the Hg lifetime , 2007 .

[133]  Tomohisa Yukawa,et al.  Strong emission of methyl chloride from tropical plants , 2002, Nature.

[134]  K. Pfeilsticker,et al.  Spatial and temporal distribution of enhanced boundary layer BrO concentrations measured by the GOME instrument aboard ERS‐2 , 2001 .

[135]  R. Röthlisberger,et al.  Southern Ocean sea-ice extent, productivity and iron flux over the past eight glacial cycles , 2006 .

[136]  L. Barrie,et al.  The Arctic: a sink for mercury , 2004 .

[137]  P. Shepson,et al.  Peroxyacetyl nitrate photochemistry and interactions with the Arctic surface , 2004 .

[138]  L. Barrie,et al.  Chemical composition of snowfall in the high Arctic: 1990–1994 , 2002 .

[139]  F. Slemr,et al.  Worldwide trend of atmospheric mercury since 1977 , 2003 .

[140]  Y. Nojiri,et al.  Measurements of ozone concentrations on a commercial vessel in the marine boundary layer over the northern North Pacific Ocean , 2005 .

[141]  P. Zieger,et al.  Multi axis differential optical absorption spectroscopy (MAX-DOAS) , 2003 .

[142]  O. Schrems,et al.  Discrepancies between formaldehyde measurements and methane oxidation model predictions in the Antarctic troposphere: An assessment of other possible formaldehyde sources , 2005 .

[143]  Brian A. Michalowski,et al.  A computer model study of multiphase chemistry in the Arctic boundary layer during polar sunrise , 2000 .

[144]  J. Farman,et al.  Large losses of total ozone in Antarctica reveal seasonal ClOx/NOx interaction , 1985, Nature.

[145]  S. Lindberg,et al.  Potential influence of iodine-containing compounds on the chemistry of the troposphere in the polar spring. I. Ozone depletion , 2004 .

[146]  R. A. Cox,et al.  Evaluated kinetic and photochemical data for atmospheric chemistry: Volume II – reactions of organic species , 2005 .

[147]  J. Abbatt,et al.  Interactions of atmospheric trace gases with ice surfaces: adsorption and reaction. , 2003, Chemical reviews.

[148]  K. Heumann,et al.  Bromo- and bromochloromethanes in the Antarctic atmosphere and the south polar sea , 1992 .

[149]  M. Lizotte,et al.  The Contributions of Sea Ice Algae to Antarctic Marine Primary Production , 2001 .

[150]  G. König‐Langlo,et al.  Dynamics and chemistry of tropospheric bromine explosion events in the Antarctic coastal region , 2004 .

[151]  H. Skov,et al.  A theoretical study of the oxidation of Hg0 to HgBr2 in the troposphere. , 2004, Environmental science & technology.

[152]  A. Richter,et al.  Magnification of atmospheric mercury deposition to polar regions in springtime: The link to tropospheric ozone depletion chemistry , 2001 .

[153]  P. Crutzen,et al.  A mechanism for halogen release from sea-salt aerosol in the remote marine boundary layer , 1996, Nature.

[154]  D. Blake,et al.  Unexplained enhancements of CH3Br in the Arctic and sub‐Arctic lower troposphere during TOPSE spring 2000 , 2003 .

[155]  A. Stohl.  Characteristics of atmospheric transport into the Arctic troposphere , 2006 .

[156]  J. Nowak,et al.  Heterogeneous Interactions of HBr and HOCl with Cold Sulfuric Acid Solutions: Implications for Arctic Boundary Layer Bromine Chemistry , 1997 .

[157]  J. Burrows,et al.  Carbonate precipitation in brine – a potential trigger for tropospheric ozone depletion events , 2006 .

[158]  J. Curry,et al.  Lead-induced atmospheric circulations , 1995 .

[159]  P. Shepson,et al.  Chlorine and bromine atom ratios in the springtime Arctic troposphere as determined from measurements of halogenated volatile organic compounds , 2006 .

[160]  P. Ariya,et al.  A Theoretical Study on the Reactions of Hg with Halogens: Atmospheric Implications. , 2003 .

[161]  P. Quinn,et al.  Variations in the methanesulfonate to sulfate molar ratio in submicrometer marine aerosol particles over the south Pacific Ocean , 1992 .

[162]  N. Holmes,et al.  Uptake and reaction of HOBr on frozen and dry NaCl/NaBr surfaces between 253 and 233 K , 2002 .

[163]  B. Shepler,et al.  Mercury Monoxide: A Systematic Investigation of Its Ground Electronic State , 2003 .

[164]  P. Shepson,et al.  Formaldehyde in Arctic snow. Incorporation into ice particles and evolution in the snowpack , 2002 .

[165]  Kelly Chance,et al.  Analysis of BrO measurements from the Global Ozone Monitoring Experiment , 1998 .

[166]  J. Burrows,et al.  Observation of a fast ozone loss in the marginal ice zone of the Arctic Ocean , 2006 .

[167]  P. Crutzen,et al.  Modelling the chemistry of ozone, halogen compounds, and hydrocarbons in the arctic troposphere during spring , 1993 .

[168]  William F. Fitzgerald,et al.  The biogeochemical cycling of elemental mercury: Anthropogenic influences☆ , 1994 .

[169]  J. Jimenez,et al.  Chemical and physical processes controlling the distribution of aerosols in the Lower Fraser Valley, Canada, during the Pacific 2001 field campaign , 2004 .

[170]  L. Barrie,et al.  Fine and coarse modes of dicarboxylic acids in the Arctic aerosols collected during the Polar Sunrise Experiment 1997 , 2003 .

[171]  Roger Atkinson,et al.  Evaluated kinetic and photochemical data for atmospheric chemistry: Volume I - gas phase reaxtions of Ox, HOx, NOx and SOx species , 2004 .

[172]  D. Wardle,et al.  Changes in the vertical distribution of ozone over Canada from ozonesondes: 1980-2001 , 2005 .

[173]  D. Tarasick,et al.  Surface ozone depletion episodes in the Arctic and Antarctic from historical ozonesonde records , 2002 .

[174]  Seelye Martin,et al.  Frost flowers: Implications for tropospheric chemistry and ice core interpretation , 2002 .

[175]  P. Shepson,et al.  A study of the vertical scale of halogen chemistry in the Arctic troposphere during Polar Sunrise at Barrow, Alaska , 2007 .

[176]  Mark New,et al.  Surface air temperature and its changes over the past 150 years , 1999 .

[177]  J. Fuentes,et al.  Denuder measurements of gas and aerosol species above Arctic snow surfaces at Alert 2000 , 2002 .

[178]  T. Stocker,et al.  Stable Carbon Cycle–Climate Relationship During the Late Pleistocene , 2005, Science.

[179]  Paul B. Shepson,et al.  Measurements of Photolyzable Halogen Compounds and Bromine Radicals During the Polar Sunrise Experiment 1997 , 1999 .

[180]  P. Wennberg.  Atmospheric chemistry: Bromine explosion , 1999, Nature.

[181]  G. C. Tiao,et al.  A Course in Time Series Analysis , 2000 .

[182]  G. Hartog,et al.  Aerosol size distributions in Arctic haze during the Polar Sunrise Experiment 1992 , 1994 .

[183]  J. McConnell,et al.  Autocatalytic release of bromine from Arctic snow pack during polar sunrise , 1996 .

[184]  John M. C. Plane,et al.  Boundary Layer Halogens in Coastal Antarctica , 2007, Science.

[185]  Solving the Aerosol Puzzle , 1999, Science.

[186]  K. Kreher,et al.  Ozone loss episodes in the free Antarctic troposphere, suggesting a possible climate feedback , 2001 .

[187]  Miguel Ángel Martínez,et al.  The role of bromine and chlorine chemistry for arctic ozone depletion events in Ny-Ålesund and comparison with model calculations , 1999 .

[188]  M. Gauß,et al.  Impact of H2O emissions from cryoplanes and kerosene aircraft on the atmosphere , 2003 .

[189]  J. Abbatt,et al.  Kinetics and Product Yields in the Heterogeneous Reactions of HOBr with Ice Surfaces Containing NaBr and NaCl , 2002 .

[190]  S. Oltmans,et al.  Surface ozone distributions and variations from 1973–1984: Measurements at the NOAA Geophysical Monitoring for Climatic Change Baseline Observatories , 1986 .

[191]  Peter V. Hobbs,et al.  Airborne observations of Arctic aerosols. I: Characteristics of Arctic haze , 1984 .

[192]  Donald J. Wuebbles,et al.  Radiative Forcing of Climate Changes in the Vertical Distribution of Ozone , 1990 .

[193]  H. Kennedy,et al.  Experimental evidence for carbonate precipitation and CO2 degassing during sea ice formation , 2004 .

[194]  Nicola Pirrone,et al.  Measurements of atmospheric mercury species during an international study of mercury depletion events at Ny-Ålesund, Svalbard, spring 2003. How reproducible are our present methods? , 2005 .

[195]  C. Davidson,et al.  Introduction: The special issue of Atmospheric environment on arctic air, snow, and ice chemistry , 1993 .

[196]  T. Platt,et al.  An estimate of global primary production in the ocean from satellite radiometer data , 1995 .

[197]  T. Peter,et al.  The uptake of acidic gases on ice. , 2006, Chemical reviews.

[198]  K. Kreher,et al.  Ground‐based measurements of tropospheric and stratospheric BrO at Arrival Heights, Antarctica , 1997 .

[199]  C. Davidson,et al.  Arctic air, snow and ice chemistry , 1993 .

[200]  M. Molina,et al.  Chemical kinetics and photochemical data for use in stratospheric modeling , 1985 .

[201]  C. T. McElroy,et al.  Evidence for bromine monoxide in the free troposphere during the Arctic polar sunrise , 1999, Nature.

[202]  W. Simpson,et al.  Halogens in the coastal snow pack near Barrow, Alaska: Evidence for active bromine air‐snow chemistry during springtime , 2005 .

[203]  P. Shepson,et al.  An overview of snow photochemistry: evidence, mechanisms and impacts , 2007 .

[204]  C. Barbante,et al.  Southern Ocean sea-ice extent, productivity and iron flux over the past eight glacial cycles , 2006, Nature.

[205]  L. Barrie,et al.  Arctic air pollution: An overview of current knowledge , 1986 .

[206]  W. Simpson,et al.  Elevated mercury measured in snow and frost flowers near Arctic sea ice leads , 2005 .

[207]  G. Mcfiggans,et al.  A modeling study of iodine chemistry in the marine boundary layer , 2000 .

[208]  T. Berntsen,et al.  A global three‐dimensional chemical transport model for the troposphere: 1. Model description and CO and ozone results , 1997 .

[209]  W. Sturges,et al.  Bromoform emission from Arctic ice algae , 1992, Nature.

[210]  M. Legrand.  Ice-core records of atmospheric sulphur , 1997 .

[211]  D. Hölscher,et al.  Absorption cross section and photolysis of OIO. , 2006, Physical chemistry chemical physics : PCCP.

[212]  R. Honrath,et al.  Observations of rapid photochemical destruction of ozone in snowpack interstitial air , 2001 .

[213]  K. Chance,et al.  DEVELOPMENT OF A BROMINE OXIDE PRODUCT FROM GOME , 1999 .

[214]  U. Platt,et al.  Arctic tropospheric chemistry: an overview , 1997 .

[215]  T. Wagner,et al.  Enhanced tropospheric BrO over Antarctic sea ice in mid winter observed by MAX-DOAS on board the research vessel Polarstern , 2007 .

[216]  M. Chipperfield,et al.  Total and tropospheric BrO derived from GOME and SCIAMACHY as part of the temis project , 2005 .

[217]  D. Jacob,et al.  Coupled evolution of BrOx-ClOx-HOx-NOx chemistry during bromine- catalyzed ozone depletion events in the arctic boundary layer , 2003 .

[218]  T. Hoffmann,et al.  Coastal New Particle Formation: A Review of the Current State-Of-The-Art , 2005 .

[219]  A. Richter,et al.  Circumpolar transport and air-surface exchange of atmospheric mercury at Ny-Ålesund ( 79 ◦ N ) , Svalbard , spring 2002 , 2008 .

[220]  S. Lindberg,et al.  A modeling study of the mechanism of the halogen-ozone-mercury homogeneous reactions in the troposphere during the polar spring , 2003 .

[221]  E. Atlas,et al.  The Tropospheric Ozone Production about the Spring Equinox (TOPSE) experiment: Introduction : Tropospheric Ozone Production about the Spring Equinox (TOPSE) , 2003 .

[222]  W. Cleveland,et al.  Locally Weighted Regression: An Approach to Regression Analysis by Local Fitting , 1988 .

[223]  D. Toohey,et al.  In situ measurements of bromine oxide at two high‐latitude boundary layer sites: Implications of variability , 2003 .

[224]  K. Heumann,et al.  GC determination of volatile organoiodine and organobromine compounds in Arctic seawater and air samples , 1993 .

[225]  T. Sideris,et al.  Spring 1989 observations of lower tropospheric chemistry in the Canadian high arctic , 1993 .

[226]  P. Mayewski,et al.  Glaciochemistry of polar ice cores: A review , 1997 .

[227]  J. Hemminger,et al.  Surface segregation of bromine in bromide doped NaCl: Implications for the seasonal variations in Arctic ozone , 2000 .

[228]  R. Salawitch.  Atmospheric chemistry: Biogenic bromine , 2006, Nature.

[229]  Seelye Martin,et al.  The temperature dependence of frost flower growth on laboratory sea ice and the effect of the flowers on infrared observations of the surface , 1996 .

[230]  J. Dibb,et al.  Release of NOx from sunlight‐irradiated midlatitude snow , 2000 .

[231]  L. Barrie,et al.  Atmospheric reactive chlorine and bromine at the Great Salt Lake, Utah , 2002 .

[232]  K. Rahn,et al.  Atmospheric bromine in the Arctic , 1983 .

[233]  R. Ebinghaus,et al.  Springtime accumulation of atmospheric mercury in polar ecosystems , 2004 .

[234]  J. Burrows,et al.  Intercomparison of BrO measurements from ERS-2 GOME, ground-based and balloon platforms , 2002 .

[235]  John P. Burrows,et al.  GOME MEASUREMENTS OF STRATOSPHERIC AND TROPOSPHERIC BrO , 2002 .

[236]  S. Ackley,et al.  Ecology of sea ice biota , 1992, Polar Biology.

[237]  D. Etheridge,et al.  Natural and anthropogenic changes in atmospheric CO2 over the last 1000 years from air in Antarctic ice and firn , 1996 .

[238]  D. Blake,et al.  Photochemically induced production of CH3Br, CH3I, C2H5I, ethene, and propene within surface snow at Summit, Greenland , 2002 .

[239]  H. Jacobi,et al.  A mechanism for the photochemical transformation of nitrate in snow , 2007 .

[240]  U. Platt,et al.  DOAS-observation of halogen radical-catalysed arctic boundary layer ozone destruction during the ARCTOC-campaigns 1995 and 1996 in Ny-Ålesund, Spitsbergen , 1997 .

[241]  C. Richardson.  Phase Relationships in Sea Ice as a Function of Temperature , 1976 .

[242]  K. Chance,et al.  Widespread persistent near‐surface ozone depletion at northern high latitudes in spring , 2003 .

[243]  W. Sturges,et al.  Halogens in aerosols in Central Alaska , 1993 .

[244]  M. Lizotte,et al.  The Contributions of Sea Ice Algae to Antarctic Marine Primary Production1 , 2001 .

[245]  G. Poulet,et al.  The BrO + Ch3O2 reaction: Kinetics and role in the atmospheric ozone budget , 1997 .

[246]  Donald K. Perovich,et al.  Surface characteristics of lead ice , 1994 .

[247]  P. Crutzen,et al.  Inorganic bromine in the marine boundary layer: a critical review , 2003 .

[248]  R. Davisa,et al.  Thermodynamic attributes of Arctic boundary layer ozone depletion , 2002 .

[249]  R. N. Schindler,et al.  Halogen oxides: Radicals, sources and reservoirs in the laboratory and in the atmosphere , 1995 .

[250]  W. Schroeder,et al.  Vertical distribution of gaseous elemental mercury in Canada , 2003 .

[251]  D. Tobias,et al.  Experiments and simulations of ion-enhanced interfacial chemistry on aqueous NaCl aerosols , 2000, Science.

[252]  P. Shepson,et al.  Depletion of lower tropospheric ozone during arctic spring : the Polar Sunrise Experiment 1988 , 1990 .

[253]  M. Hayashi,et al.  Chemistry of sea-salt particles and inorganic halogen species in Antarctic regions: Compositional differences between coastal and inland stations , 2004 .

[254]  U. Lohmann,et al.  Summertime pollution events in the Arctic and potential implications , 2006 .

[255]  W. Sturges,et al.  Spring measurements of tropospheric bromine at Barrow, Alaska , 1993 .

[256]  S. Niven,et al.  Ocean‐atmosphere exchange of methyl chloride: Results from NW Atlantic and Pacific Ocean studies , 1996 .

[257]  W. Neff,et al.  Boundary layer physics over snow and ice - reply , 2008 .

[258]  H. Roscoe,et al.  Polar tropospheric ozone depletion events observed in the International Geophysical Year of 1958 , 2006 .

[259]  P. Shepson,et al.  Relationships between organic nitrates and surface ozone destruction during Polar Sunrise Experiment 1992 , 1994 .

[260]  G. Hönninger.  Halogen Oxide Studies in the Boundary Layer by Multi Axis Differential Optical Absorption Spectroscopy and Active Longpath-DOAS , 2002 .

[261]  Yuk L. Yung,et al.  Atmospheric Bromine and Ozone Perturbations in the Lower Stratosphere , 1980 .

[262]  J. Bottenheim,et al.  Measurements of NO Y species and O 3 at 82° N latitude , 1986 .

[263]  P. Shepson,et al.  Henry's Law Constants and Removal Processes for Several Atmospheric β-Hydroxy Alkyl Nitrates , 1996 .

[264]  M. Chipperfield,et al.  Climatology of the stratospheric BrO vertical distribution by balloon‐borne UV–visible spectrometry , 2002 .

[265]  G. Huey,et al.  Measurements of OH, HO2+RO2, H2SO4, and MSA at the South Pole during ISCAT 2000 , 2004 .

[266]  F. Laturnus,et al.  Biogenic volatile organoiodine and organobromine compounds released from polar macroalgae , 1994 .

[267]  Nicola J. Blake,et al.  Halogen‐driven low‐altitude O3 and hydrocarbon losses in spring at northern high latitudes , 2006 .

[268]  U. Platt,et al.  Reactive bromine and sulfur emissions at Salar de Uyuni, Bolivia , 2004 .

[269]  S. O'Doherty,et al.  Atmospheric bromoform at Mace Head, Ireland: Evidence for a peatland source , 2005 .

[270]  R. A. Cox,et al.  Tropospheric bromine chemistry and its impacts on ozone: A model study , 2005 .

[271]  P. Shepson,et al.  The role of Br2 and BrCl in surface ozone destruction at polar sunrise. , 2001, Science.

[272]  U. Platt,et al.  Ground‐based measurements of halogen oxides at the Hudson Bay by active longpath DOAS and passive MAX‐DOAS , 2004 .

[273]  O. Schrems,et al.  Tropospheric ozone depletion in polar regions A comparison of observations in the Arctic and Antarctic , 1998 .

[274]  L. Barrie,et al.  Polar Sunrise Experiment 1992 (PSE 1992): Preface , 1994 .

[275]  T. Stocker,et al.  Atmospheric Methane and Nitrous Oxide of the Late Pleistocene from Antarctic Ice Cores , 2005, Science.

[276]  F. E. Livingston,et al.  Ozone destruction and bromine photochemistry at ground level in the Arctic spring , 1990, Nature.

[277]  L. Barrie,et al.  Ozone and meteorology during the 1994 Polar Sunrise Experiment , 1998 .

[278]  R. Röthlisberger,et al.  Atmosphere‐to‐snow‐to‐firn transfer studies of HCHO at Summit, Greenland , 1999 .

[279]  W. Simpson,et al.  Atmospheric photolysis rate coefficients during the Polar Sunrise Experiment ALERT2000 , 2002 .

[280]  R. Röthlisberger,et al.  An ice core indicator of Antarctic sea ice production? , 2003 .

[281]  J. Sodeau,et al.  Freezing halide ion solutions and the release of interhalogens to the atmosphere. , 2006, The journal of physical chemistry. A.

[282]  Xiong Liu,et al.  First observations of iodine oxide from space , 2007 .

[283]  R. Hillamo,et al.  Fluxes of nitrates between snow surfaces and the atmosphere in the European high Arctic , 2003 .

[284]  J. Francis,et al.  The Arctic Amplification Debate , 2006 .

[285]  A. Marjani,et al.  Brominating activity of the seaweed Ascophyllum nodosum: impact on the biosphere , 1991 .

[286]  J. Peischl,et al.  Observations of hydroxyl and the sum of peroxy radicals at Summit, Greenland during summer 2003 , 2007 .

[287]  J. W. Winchester,et al.  Seasonal surface ozone and filterable bromine relationship in the high arctic , 1989 .

[288]  Jean-Pierre Blanchet,et al.  Modeling sea-salt aerosols in the atmosphere 1. Model development , 1997 .

[289]  Y. Yokouchi,et al.  The seasonal variation of selected natural and anthropogenic halocarbons in the arctic troposphere , 1996 .

[290]  R. Bales,et al.  Chemical exchange between the atmosphere and polar snow , 1996 .

[291]  Michael Eisinger,et al.  The Global Ozone Monitoring Experiment (GOME): Mission Concept and First Scientific Results , 1999 .

[292]  O. Boucher,et al.  DMS atmospheric concentrations and sulphate aerosol indirect radiative forcing: a sensitivity study to the DMS source representation and oxidation , 2002 .

[293]  J. Turner,et al.  A role for newly forming sea ice in springtime polar tropospheric ozone loss? Observational evidence from Halley station, Antarctica , 2006 .

[294]  M. Salmeron,et al.  In situ study of water-induced segregation of bromide in bromide-doped sodium chloride by scanning polarization force microscopy. , 2005, The journal of physical chemistry. A.

[295]  J. Plane,et al.  Novel iodine chemistry in the marine boundary layer , 2004 .

[296]  P. Shepson,et al.  An investigation of the interaction of carbonyl compounds with the snowpack , 2000 .

[297]  G. Moortgat,et al.  Temperature Dependence (256–296K) of the Absorption Cross-Sections of Bromoform in the Wavelength Range 285–360 nm , 1993 .

[298]  O. Boucher,et al.  Sensitivity study of dimethylsulphide (DMS) atmospheric concentrations and sulphate aerosol indirect radiative forcing to the DMS source representation and oxidation , 2002 .

[299]  J. Burrows,et al.  Frost flowers on sea ice as a source of sea salt and their influence on tropospheric halogen chemistry , 2004 .

[300]  K. Heumann,et al.  Determinations of methyl iodide in the Antarctic atmosphere and the South Polar Sea , 1992 .

[301]  R. Boers,et al.  Ozone in the Marine Boundary Layer at Cape Grim: Model Simulation , 1997 .

[302]  S. O'Doherty,et al.  Atmospheric bromoform at Mace Head, Ireland: seasonality and evidence for a peatland source , 2005 .

[303]  P. Shepson,et al.  Organic and inorganic bromine compounds and their composition in the Arctic troposphere during polar sunrise , 1994 .

[304]  Paul J. Crutzen,et al.  Model study of multiphase DMS oxidation with a focus on halogens , 2003 .

[305]  P. Shepson,et al.  Snowpack production of formaldehyde and its effect on the Arctic troposphere , 1999, Nature.

[306]  S. Morin,et al.  A high time resolution study of boundary layer ozone chemistry and dynamics over the Arctic Ocean near Alert, Nunavut , 2005 .

[307]  P. Shepson,et al.  Evidence of NOx production within or upon ice particles in the Greenland snowpack , 1999 .

[308]  R. Schnell.  Arctic haze and the Arctic Gas and Aerosol Sampling Program (AGASP) , 1984 .