Humic acid in ice: Photo-enhanced conversion of nitrogen dioxide into nitrous acid

Bartels-Rausch, Thorsten; Brigante, Marcello; Elshorbany, Yasin; Ammann, Markus; D’Anna, Barbara; George, Christian; Stemmler, Konrad; Ndour, Marième; Kleffmann, Jörg

doi:10.1016/j.atmosenv.2009.12.025

Cited by 59 publications

(49 citation statements)

References 28 publications

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“…tion since they were done with chemically pure air and, when placing the cut-off filter at 385 nm, we suppress the primary source of HONO as well as NO 2 that is needed for secondary HONO production. Among possible secondary productions it is generally accepted that the reduction of NO 2 on photo-sensitized organic material like humic acid (George et al, 2005;Bartels-Rausch et al, 2010) would proceed more efficiently than the disproportionation reaction of NO 2 (2 NO 2 + H 2 O → HONO + HNO 3 ) (Finlayson-Pitts et al, 2003). As discussed by Grannas et al (2007), the relevance of this secondary production was supported even for Antarctica by the significant presence of dissolved fulvic acid reported for Antarctic snow (26-46 ppb C) by Calace et al (2005).…”

Section: Hono Observations At Concordiamentioning

confidence: 61%

Large mixing ratios of atmospheric nitrous acid (HONO) at Concordia (East Antarctic Plateau) in summer: a strong source from surface snow?

et al. 2014

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Abstract. During the austral summer 2011/2012 atmospheric nitrous acid (HONO) was investigated for the second time at the Concordia site (75 • 06 S, 123 • 33 E), located on the East Antarctic Plateau, by deploying a long-path absorption photometer (LOPAP). Hourly mixing ratios of HONO measured in December 2011/January 2012 (35 ± 5.0 pptv) were similar to those measured in December 2010/January 2011 (30.4 ± 3.5 pptv). The large value of the HONO mixing ratio at the remote Concordia site suggests a local source of HONO in addition to weak production from oxidation of NO by the OH radical. Laboratory experiments demonstrate that surface snow removed from Concordia can produce gasphase HONO at mixing ratios half that of the NO x mixing ratio produced in the same experiment at typical temperatures encountered at Concordia in summer. Using these lab data and the emission flux of NO x from snow estimated from the vertical gradient of atmospheric concentrations measured during the campaign, a mean diurnal HONO snow emission ranging between 0.5 and 0.8 × 10 9 molecules cm −2 s −1 is calculated. Model calculations indicate that, in addition to around 1.2 pptv of HONO produced by the NO oxidation, these HONO snow emissions can only explain 6.5 to 10.5 pptv of HONO in the atmosphere at Concordia. To explain the difference between observed and simulated HONO mixing ratios, tests were done both in the field and at lab to explore the possibility that the presence of HNO 4 had biased the measurements of HONO.

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Section: Hono Observations At Concordiamentioning

confidence: 61%

Large mixing ratios of atmospheric nitrous acid (HONO) at Concordia (East Antarctic Plateau) in summer: a strong source from surface snow?

et al. 2014

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“…The reaction showed a linear production of HONO for increasing irradiation intensity and humic acid surface concentration, but no temperature dependence from 260 down to 215 K (Bartels-Rausch, 2010). Similarly, Beine et al (2008) observed an increase in HONO production from illuminated natural snow doped with humic acid between 260 and 273 K. The photoreduction of mercuric ions in a thin ice film is also enhanced in the presence of organics such as benzophenone and oxalic acid (Bartels-Rausch et al, 2011). The reaction showed a linear temperature trend from 240 K up to a liquid solution at 273 K.…”

Section: Electron Transfer Processes In Icementioning

confidence: 82%

Organics in environmental ices: sources, chemistry, and impacts

et al. 2012

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Abstract. The physical, chemical, and biological processes involving organics in ice in the environment impact a number of atmospheric and biogeochemical cycles. Organic material in snow or ice may be biological in origin, deposited from aerosols or atmospheric gases, or formed chemically in situ. In this manuscript, we review the current state of knowledge regarding the sources, properties, and chemistry of organic materials in environmental ices. Several outstanding questions remain to be resolved and fundamental data gathered before an accurate model of transformations and transport of organic species in the cryosphere will be possible. For example, more information is needed regarding the quantitative impacts of chemical and biological processes, ice morphology, and snow formation on the fate of organic material in cold regions. Interdisciplinary work at the interfaces of chemistry, physics and biology is needed in order to fully characterize the nature and evolution of organics in the cryosphere and predict the effects of climate change on the Earth's carbon cycle.

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“…The heterogeneous photosensitised reduction of inorganic species such as NO 2 has been investigated in the presence of humic substances and proxies for these species. These reactions are likely due to energy transfer from the humic substance to the reagent on the ice surface (Bartels-Rausch et al, 2010). The last study found that the reaction rate depends linearly on the concentration of the organic compounds for low total concentrations in the ice sample.…”

Section: Physical Environmentsmentioning

confidence: 89%

“…For example, organic chromophores act as photosensitisers that promote photochemical reactions (Bartels-Rausch et al, 2010, 2011, and produce reactive species such as OH radicals (Grannas et al, 2007b;Dolinová et al, 2006). They also suppress photochemical reactions by acting as a filter of light and by scavenging reactive species (Grannas et al, 2007b).…”

Section: Chemical Environmentsmentioning

confidence: 99%

A review of air–ice chemical and physical interactions (AICI): liquids, quasi-liquids, and solids in snow

et al. 2014

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Abstract. Snow in the environment acts as a host to rich chemistry and provides a matrix for physical exchange of contaminants within the ecosystem. The goal of this review is to summarise the current state of knowledge of physical processes and chemical reactivity in surface snow with relevance to polar regions. It focuses on a description of impurities in distinct compartments present in surface snow, such as snow crystals, grain boundaries, crystal surfaces, and liquid parts. It emphasises the microscopic description of the ice surface and its link with the environment. Distinct differences between the disordered air–ice interface, often termed quasi-liquid layer, and a liquid phase are highlighted. The reactivity in these different compartments of surface snow is discussed using many experimental studies, simulations, and selected snow models from the molecular to the macro-scale. Although new experimental techniques have extended our knowledge of the surface properties of ice and their impact on some single reactions and processes, others occurring on, at or within snow grains remain unquantified. The presence of liquid or liquid-like compartments either due to the formation of brine or disorder at surfaces of snow crystals below the freezing point may strongly modify reaction rates. Therefore, future experiments should include a detailed characterisation of the surface properties of the ice matrices. A further point that remains largely unresolved is the distribution of impurities between the different domains of the condensed phase inside the snowpack, i.e. in the bulk solid, in liquid at the surface or trapped in confined pockets within or between grains, or at the surface. While surface-sensitive laboratory techniques may in the future help to resolve this point for equilibrium conditions, additional uncertainty for the environmental snowpack may be caused by the highly dynamic nature of the snowpack due to the fast metamorphism occurring under certain environmental conditions. Due to these gaps in knowledge the first snow chemistry models have attempted to reproduce certain processes like the long-term incorporation of volatile compounds in snow and firn or the release of reactive species from the snowpack. Although so far none of the models offers a coupled approach of physical and chemical processes or a detailed representation of the different compartments, they have successfully been used to reproduce some field experiments. A fully coupled snow chemistry and physics model remains to be developed.

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Humic acid in ice: Photo-enhanced conversion of nitrogen dioxide into nitrous acid

Cited by 59 publications

References 28 publications

Large mixing ratios of atmospheric nitrous acid (HONO) at Concordia (East Antarctic Plateau) in summer: a strong source from surface snow?

Large mixing ratios of atmospheric nitrous acid (HONO) at Concordia (East Antarctic Plateau) in summer: a strong source from surface snow?

Organics in environmental ices: sources, chemistry, and impacts

A review of air–ice chemical and physical interactions (AICI): liquids, quasi-liquids, and solids in snow

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