Ozone destruction and bromine photochemistry at ground level in the Arctic spring

Finlayson-Pitts, Barbara J.; Livingston, Frank E.; Berko, H.

doi:10.1038/343622a0

Cited by 198 publications

(120 citation statements)

References 20 publications

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“…Following the polar sunrise, episodic ozone losses have been routinely observed at places close to the Arctic and Antarctic Oceans. The identified mechanism responsible for ozone depletion is the reaction of ozone with halogens, principally with bromine atoms of marine origin which are formed and released by photochemical heterogeneous ice chemistry (Oltmans et al, 1989;Finlayson-Pitts et al, 1990;Fan and Jacob, 1992;Foster et al, 2001;Bottenheim et al, 2002). This depletion of ozone in the boundary layer has been consistently observed at Northern Hemisphere (NH) polar coastal sites including Barrow, Alert, and Spitzbergen.…”

Section: Ozone Uptake To Snowmentioning

confidence: 99%

The role of ozone atmosphere-snow gas exchange on polar, boundary-layer tropospheric ozone – a review and sensitivity analysis

et al. 2007

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Abstract. Recent research on snowpack processes and atmosphere-snow gas exchange has demonstrated that chemical and physical interactions between the snowpack and the overlaying atmosphere have a substantial impact on the composition of the lower troposphere. These observations also imply that ozone deposition to the snowpack possibly depends on parameters including the quantity and composition of deposited trace gases, solar irradiance, snow temperature and the substrate below the snowpack. Current literature spans a remarkably wide range of ozone deposition velocities (v dO3 ); several studies even reported positive ozone fluxes out of the snow. Overall, published values range from ∼-3

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Section: Ozone Uptake To Snowmentioning

confidence: 99%

The role of ozone atmosphere-snow gas exchange on polar, boundary-layer tropospheric ozone – a review and sensitivity analysis

et al. 2007

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“…Oxidation of condensed phase bromides or HBr to gas phase bromine could solve this inconsistency (McConnell et al, 1992;Tang and McConnell, 1996). Finlayson-Pitts et al (1990) proposed the surface oxidation of Br À by dinitrogenpentoxide, while Fan and Jacob (1992) propagated the heterogeneous oxidation of HBr by hypobromous acid, HOBr (Eigen and Kustin, 1962), on ice or aerosol surfaces see Eq. (13).…”

Section: Oclo Hm 3 O Clo 12mentioning

confidence: 99%

The role of bromine and chlorine chemistry for arctic ozone depletion events in Ny-Ålesund and comparison with model calculations

1999

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Abstract. During the Arctic Tropospheric Ozone Chemistry (ARCTOC) campaigns at Ny-A Ê lesund, Spitsbergen, the role of halogens in the depletion of boundary layer ozone was investigated. In spring 1995 and 1996 up to 30 ppt bromine monoxide were found whenever ozone decreased from normal levels of about 40 ppb. Those main trace gases and others were speci®cally followed in the UV-VIS spectral region by dierential optical absorption spectroscopy (DOAS) along light paths running between 20 and 475 m a.s.l.. The daily variation of peroxy radicals closely followed the ozone photolysis rate J(O 3 (O 1 D)) in the absence of ozone depletion most of the time. However, during low ozone events this close correlation was no longer found because the measurement of radicals by chemical ampli®cation (CA) turned out to be sensitive to peroxy radicals and ClO x . Large CA signals at night can sometimes de®nitely be assigned to ClO x and reached up to 2 ppt. Total bromine and iodine were both stripped quantitatively from air by active charcoal traps and measured after neutron activation of the samples. Total bromine increased from background levels of about 15 ppt to a maximum of 90 ppt during an event of complete ozone depletion. For the spring season a strong source of bromine is identi®ed in the pack ice region according to back trajectories. Though biogenic emission sources cannot be completely ruled out, a primary activation of halogenides by various oxidants seems to initiate an ecient autocatalytic process, mainly driven by ozone and light, on ice and perhaps on aerosols. Halogenides residing on pack ice surfaces are continuously oxidised by hypohalogenous acids releasing bromine and chlorine into the air. During transport and especially above open water this air mixes with upper layer pristine air. As large quantities of bromine, often in the form of BrO, have been observed at polar sunrise also around Antarctica, its release seems to be a natural phenomenon. The source strength of bromine from halogen activation on the pack ice, as based on the measured inorganic bromine levels, averages about 1012 Br-atoms m À2 s À1 during sunlit periods in Arctic spring. The total source strength of inorganic bromine from sunlit polar regions may therefore amount to 30 kt y À1 .

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“…[1][2][3][4][5][6][7] Molecular dynamics 8,9 and Monte Carlo 10 simulations on alkali halide solutions have shown that there is a propensity of the large anions to segregate to the water-air surface. Ex-situ atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS) have revealed Br -segregation in NaBr in NaBr/NaCl crystals grown from aqueous solutions.…”

Section: Introductionmentioning

confidence: 99%

Ion Segregation and Deliquescence of Alkali Halide Nanocrystals on SiO₂

et al. 2009

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The adsorption of water on alkali halide (KBr, KCl, KF, NaCl) nanocrystals on SiO 2and their deliquescence was investigated as a function of relative humidity (RH) from 8%to near saturation by scanning polarization force microscopy. At low humidity water adsorption solvates ions at the surface of the crystals and increases their mobility. This results in a large increase in the dielectric constant, which is manifested in an increase in the electrostatic force and in an increase in the apparent height of the nanocrystals. Above 58% RH the diffusion of ions leads to Ostwald ripening, where larger nanocrystals grow at the expense of the smaller ones. At the deliquescence point droplets were formed. For KBr, KCl and NaCl, the droplets exhibit a negative surface potential relative to the surrounding region, indicative of the preferential segregation of anions to the air-solution interface.

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Ozone destruction and bromine photochemistry at ground level in the Arctic spring

Cited by 198 publications

References 20 publications

The role of ozone atmosphere-snow gas exchange on polar, boundary-layer tropospheric ozone – a review and sensitivity analysis

The role of ozone atmosphere-snow gas exchange on polar, boundary-layer tropospheric ozone – a review and sensitivity analysis

The role of bromine and chlorine chemistry for arctic ozone depletion events in Ny-Ålesund and comparison with model calculations

Ion Segregation and Deliquescence of Alkali Halide Nanocrystals on SiO₂

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Ozone destruction and bromine photochemistry at ground level in the Arctic spring

Cited by 198 publications

References 20 publications

The role of ozone atmosphere-snow gas exchange on polar, boundary-layer tropospheric ozone – a review and sensitivity analysis

The role of ozone atmosphere-snow gas exchange on polar, boundary-layer tropospheric ozone – a review and sensitivity analysis

The role of bromine and chlorine chemistry for arctic ozone depletion events in Ny-Ålesund and comparison with model calculations

Ion Segregation and Deliquescence of Alkali Halide Nanocrystals on SiO2

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Ion Segregation and Deliquescence of Alkali Halide Nanocrystals on SiO₂