Hemispheric average Cl atom concentration from &amp;lt;sup&amp;gt;13&amp;lt;/sup&amp;gt;C/&amp;lt;sup&amp;gt;12&amp;lt;/sup&amp;gt;C ratios in atmospheric methane

Platt, U.; Allan, W.; Lowe, DM

doi:10.5194/acp-4-2393-2004

Cited by 86 publications

(67 citation statements)

References 42 publications

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“…Allan, personal communication, 2006). Without the chlorine sink the bottom-up estimate for ε total would be −5.4±0.8‰, while for an intermediate chlorine strength of 10 ± 9 Tg yr −1 consistent with Platt et al (2004), that estimate would be −6.3 ± 1.2‰, an estimate close to that adopted elsewhere Ferretti et al, 2007). Thus a weaker chlorine sink would exacerbate the discrepancy between apparent ε and bottom-up ε total by up to ∼2.4‰.…”

Section: Forward Modelled 13 Chmentioning

confidence: 66%

“…Although the chlorine sink in Table 2 is of minor and uncertain magnitude, it discriminates strongly between isotopologues and therefore exerts large "isotope leverage" on ε total : in its absence, the bottom-up estimate for ε total in Table 2 would be −5.4±0.8‰. The chlorine sink has been invoked to explain the large δ 13 C seasonal amplitude observed in the SW Pacific region (Allan et al, 2001a, b;Platt et al, 2004), and a varying chlorine sink to explain inter-annual variability in those amplitudes . However, while this approach estimates the seasonal amplitude in the putative chlorine sink that can account for the "seasonal KIE" (Allan et al, 2001b), it only weakly constrains the annualmean chlorine sink ; W. Allan, personal communication, 2006).…”

Section: The Evolving 13 Ch 4 Sinkmentioning

confidence: 99%

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Centennial evolution of the atmospheric methane budget: what do the carbon isotopes tell us?

et al. 2007

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Abstract.Little is known about how the methane source inventory and sinks have evolved over recent centuries. New and detailed records of methane mixing ratio and isotopic composition ( 12 CH 4 , 13 CH 4 and 14 CH 4 ) from analyses of air trapped in polar ice and firn can enhance this knowledge. We use existing bottom-up constructions of the source history, including "EDGAR"-based constructions, as inputs to a model of the evolving global budget for methane and for its carbon isotope composition through the 20th century. By matching such budgets to atmospheric data, we examine the constraints imposed by isotope information on those budget evolutions. Reconciling both 12 CH 4 and 13 CH 4 budgets with EDGAR-based source histories requires a combination of: a greater proportion of emissions from biomass burning and/or of fossil methane than EDGAR constructions suggest; a greater contribution from natural such emissions than is commonly supposed; and/or a significant role for active chlorine or other highly-fractionating tropospheric sink as has been independently proposed. Examining a companion budget evolution for 14 CH 4 exposes uncertainties in inferring the fossil-methane source from atmospheric 14 CH 4 data. Specifically, methane evolution during the nuclear era is sensitive to the cycling dynamics of "bomb 14 C" (originating from atmospheric weapons tests) through the biosphere. In addition, since ca. 1970, direct production and release of 14 CH 4 from nuclear-power facilities is influential but poorly quantified. Atmospheric 14 CH 4 determinations in the nuclear era have the potential to better characterize both biospheric carbon cycling, from photosynthesis to methane synthesis, and the nuclear-power source.

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Section: Forward Modelled 13 Chmentioning

confidence: 66%

Section: The Evolving 13 Ch 4 Sinkmentioning

confidence: 99%

Centennial evolution of the atmospheric methane budget: what do the carbon isotopes tell us?

et al. 2007

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“…FeCl 3 has an acidic pH from the beginning because it hydrolyzes in accordance with Eq. (4) (Platt et al, 2004) to 4.3 % (Allan et al, 2007). According to the results of Wittmer et al (2015a), at a Cl − / Fe(III) molar ratio of 101, this amount would rise 4-fold from 13 to 17 %.…”

Section: Active Inhibition Of Methane Emissions Frommentioning

confidence: 99%

Climate engineering by mimicking natural dust climate control: the iron salt aerosol method

et al. 2017

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Abstract. Power stations, ships and air traffic are among the most potent greenhouse gas emitters and are primarily responsible for global warming. Iron salt aerosols (ISAs), composed partly of iron and chloride, exert a cooling effect on climate in several ways. This article aims firstly to examine all direct and indirect natural climate cooling mechanisms driven by ISA tropospheric aerosol particles, showing their cooperation and interaction within the different environmental compartments. Secondly, it looks at a proposal to enhance the cooling effects of ISA in order to reach the optimistic target of the Paris climate agreement to limit the global temperature increase between 1.5 and 2 • C.Mineral dust played an important role during the glacial periods; by using mineral dust as a natural analogue tool and by mimicking the same method used in nature, the proposed ISA method might be able to reduce and stop climate warming. The first estimations made in this article show that by doubling the current natural iron emissions by ISA into the troposphere, i.e., by about 0.3 Tg Fe yr −1 , artificial ISA would enable the prevention or even reversal of global warming. The ISA method proposed integrates technical and economically feasible tools.

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“…The correspondence of these two trends suggests that the less neutralized nss SO = 4 aerosol yields an increase in the HCl displacement from the sea salt aerosol. The consequent increase in concentration of Cl atoms, even at low concentrations, can reduce the lifetime of volatile organic compounds (VOCs) including CH 4 (Platt et al, 2004), a potent greenhouse gas, and impact reactions that destroy or produce O 3 (Knipping et al, 2003). In addition to HCl, there is evidence that highly reactive gases such as Cl 2 , HOCl, and ClNO 2 may also volatilize from sea salt aerosol (e.g.…”

Section: − Deficit At Barrowmentioning

confidence: 99%

Decadal trends in aerosol chemical composition at Barrow, Alaska: 1976–2008

et al. 2009

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Abstract. Aerosol measurements at Barrow, Alaska during the past 30 years have identified the long range transport of pollution associated with Arctic Haze as well as ocean-derived aerosols of more local origin. Here, we focus on measurements of aerosol chemical composition to assess (1) trends in Arctic Haze aerosol and implications for source regions, (2) the interaction between pollution-derived and ocean-derived aerosols and the resulting impacts on the chemistry of the Arctic boundary layer, and (3) the response of aerosols to a changing climate. Aerosol chemical composition measured at Barrow, AK during the Arctic haze season is compared for the years 1976-1977 and 1997-2008. Based on these two data sets, concentrations of non-sea salt (nss) sulfate (SO = 4 ) and non-crustal (nc) vanadium (V) have decreased by about 60% over this 30 year period. Consistency in the ratios of nss SO = 4 /ncV and nc manganese (Mn)/ncV between the two data sets indicates that, although emissions have decreased in the source regions, the source regions have remained the same over this time period. The measurements from 1997-2008 indicate that, during the haze season, the nss SO = 4 aerosol at Barrow is becoming less neutralized by ammonium (NH + 4 ) yielding an increasing sea salt aerosol chloride (Cl − ) deficit. The expected consequence is an increase in the release of Cl atoms to the atmosphere and a change in the lifetime of volatile organic compounds (VOCs) including methane. In addition, summertime concentrations of biogenically-derived methanesulfonate (MSA − ) andCorrespondence to: P. K. Quinn (patricia.k.quinn@noaa.gov) nss SO = 4 are increasing at a rate of 12 and 8% per year, respectively. Further research is required to assess the environmental factors behind the increasing concentrations of biogenic aerosol.

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Hemispheric average Cl atom concentration from <sup>13</sup>C/<sup>12</sup>C ratios in atmospheric methane

Cited by 86 publications

References 42 publications

Centennial evolution of the atmospheric methane budget: what do the carbon isotopes tell us?

Centennial evolution of the atmospheric methane budget: what do the carbon isotopes tell us?

Climate engineering by mimicking natural dust climate control: the iron salt aerosol method

Decadal trends in aerosol chemical composition at Barrow, Alaska: 1976–2008

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