<sup>14</sup>C Measurements of Ice Samples from the Juvfonne Ice Tunnel, Jotunheimen, Southern Norway—Validation of a <sup>14</sup>C Dating Technique for Glacier Ice

Zapf, Alexander; Nesje, Atle; Szidat, Sönke; Wacker, Lukas; Schwikowski, M.

doi:10.1017/s0033822200057702

Cited by 5 publications

(1 citation statement)

References 21 publications

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“…Before using the f M values obtained for source apportionment of fossil and nonfossil contributions, several corrections are carried out. First, a mass dependent blank correction is applied to the measured f M following an isotopic mass balance approach [ Zapf et al ., ]:

{italicf}_{M, corr} = (m {italicC}_{normalsample} \times {italicf}_{M, sample} - m {italicC}_{normalblk} \times {italicf}_{M, blk}) / (m {italicC}_{normalsample} - m {italicC}_{normalblk})

where f M ,corr is the blank‐corrected f M , and f M,sample and f M ,blk are the f M measured for samples and blanks, respectively. The carbon mass in the samples and the blanks are denoted by mC sample and mC blk , respectively.…”

Section: Methodsmentioning

confidence: 99%

Diurnal cycle of fossil and nonfossil carbon using radiocarbon analyses during CalNex

et al. 2014

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Radiocarbon ( 14 C) analysis is a unique tool to distinguish fossil/nonfossil sources of carbonaceous aerosols. We present 14 C measurements of organic carbon (OC) and total carbon (TC) on highly time resolved filters (3-4 h, typically 12 h or longer have been reported) from 7 days collected during California Research at the Nexus of Air Quality and Climate Change (CalNex) 2010 in Pasadena. Average nonfossil contributions of 58% ± 15% and 51% ± 15% were found for OC and TC, respectively. Results indicate that nonfossil carbon is a major constituent of the background aerosol, evidenced by its nearly constant concentration (2-3 μgC m À3). Cooking is estimated to contribute at least 25% to nonfossil OC, underlining the importance of urban nonfossil OC sources. In contrast, fossil OC concentrations have prominent and consistent diurnal profiles, with significant afternoon enhancements (~3 μgC m À3 ), following the arrival of the western Los Angeles (LA) basin plume with the sea breeze. A corresponding increase in semivolatile oxygenated OC and organic vehicular emission markers and their photochemical reaction products occurs. This suggests that the increasing OC is mostly from fresh anthropogenic secondary OC (SOC) from mainly fossil precursors formed in the western LA basin plume. We note that in several European cities where the diesel passenger car fraction is higher, SOC is 20% less fossil, despite 2-3 times higher elemental carbon concentrations, suggesting that SOC formation from gasoline emissions most likely dominates over diesel in the LA basin. This would have significant implications for our understanding of the on-road vehicle contribution to ambient aerosols and merits further study.

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{italicf}_{M, corr} = (m {italicC}_{normalsample} \times {italicf}_{M, sample} - m {italicC}_{normalblk} \times {italicf}_{M, blk}) / (m {italicC}_{normalsample} - m {italicC}_{normalblk})

Section: Methodsmentioning

confidence: 99%

Diurnal cycle of fossil and nonfossil carbon using radiocarbon analyses during CalNex

et al. 2014

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Sources and contributions of wood smoke during winter in London: assessing local and regional influences

et al. 2015

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Abstract. Determining the contribution of wood smoke to air pollution in large cities such as London is becoming increasingly important due to the changing nature of domestic heating in urban areas. During winter, biomass burning emissions have been identified as a major cause of exceedances of European air quality limits. The aim of this work was to quantify the contribution of biomass burning in London to concentrations of PM2.5 and determine whether local emissions or regional contributions were the main source of biomass smoke. To achieve this, a number of biomass burning chemical tracers were analysed at a site within central London and two sites in surrounding rural areas. Concentrations of levoglucosan, elemental carbon (EC), organic carbon (OC) and K+ were generally well correlated across the three sites. At all the sites, biomass burning was found to be a source of OC and EC, with the largest contribution of EC from traffic emissions, while for OC the dominant fraction included contributions from secondary organic aerosols, primary biogenic and cooking sources. Source apportionment of the EC and OC was found to give reasonable estimation of the total carbon from non-fossil and fossil fuel sources based upon comparison with estimates derived from 14C analysis. Aethalometer-derived black carbon data were also apportioned into the contributions from biomass burning and traffic and showed trends similar to those observed for EC. Mean wood smoke mass at the sites was estimated to range from 0.78 to 1.0 μg m−3 during the campaign in January–February 2012. Measurements on a 160 m tower in London suggested a similar ratio of brown to black carbon (reflecting wood burning and traffic respectively) in regional and London air. Peaks in the levoglucosan and K+ concentrations were observed to coincide with low ambient temperature, consistent with domestic heating as a major contributing local source in London. Overall, the source of biomass smoke in London was concluded to be a background regional source overlaid by contributions from local domestic burning emissions. This could have implications when considering future emission control strategies during winter and may be the focus of future work in order to better determine the contributing local sources.

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Sources and contributions of wood smoke during winter in London: assessing local and regional influences

Crilley¹,

Bloss²,

Yin³

et al. 2014

Preprint

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Abstract. Determining the contribution of wood smoke to air pollution in large cities such as London is becoming increasingly important due to the changing nature of domestic heating in urban areas. During winter, biomass burning emissions can exceed the contributions from traffic emissions, and have been identified as a major cause of exceedences of European air quality limits. The aim of this work was to quantify the contribution of biomass burning in London to concentrations of PM2.5 and determine whether local emissions or regional contributions were the main source of biomass smoke. To achieve this, a number of biomass burning chemical tracers were analysed at a site within central London and two sites in surrounding rural areas. Concentrations of levoglucosan, elemental carbon (EC), organic carbon (OC) and K+ were generally well correlated across the three sites. At all the sites, biomass burning was found to be a source of OC and EC, with the largest contribution of EC from traffic emissions, while for OC the dominant fraction likely included contributions from secondary organic aerosols, primary biogenic and cooking sources. Source apportionment of the EC and OC using average source ratios from published data was found to give reasonable estimation of the total carbon from non-fossil and fossil fuel sources based upon comparison with estimates derived from 14C analysis. Black carbon (BC) data from 2 and 7 wavelength Aethalometers were also apportioned into the contributions from biomass burning and traffic, based upon the enhanced absorption of wood smoke at UV wavelengths compared to BC. While the source apportionment of BC using this approach found similar trends to that observed for EC, higher percentage contributions of wood burning to BC were estimated. Based on a wood smoke mass conversion factor for levoglucosan, mean wood smoke mass at the sites was found to range from 0.78–1.0 μg m−3 during the campaign in January–February 2012. Measurements on a 160 m tower in London suggested a similar ratio of brown to black carbon (reflecting wood burning and traffic respectively) in regional and London air. Peaks in the levoglucosan and K+ concentrations were observed to coincide with low ambient temperature, consistent with domestic heating as a major contributing local source in London. Overall, the source of biomass smoke in London was concluded to be a background regional source overlaid by contributions from local domestic burning emissions. This could have implications when considering future emission control strategies during winter and may be the focus of future work in order to better determine the contributing local sources.

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¹⁴C Measurements of Ice Samples from the Juvfonne Ice Tunnel, Jotunheimen, Southern Norway—Validation of a ¹⁴C Dating Technique for Glacier Ice

Cited by 5 publications

References 21 publications

Diurnal cycle of fossil and nonfossil carbon using radiocarbon analyses during CalNex

Diurnal cycle of fossil and nonfossil carbon using radiocarbon analyses during CalNex

Sources and contributions of wood smoke during winter in London: assessing local and regional influences

Sources and contributions of wood smoke during winter in London: assessing local and regional influences

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14C Measurements of Ice Samples from the Juvfonne Ice Tunnel, Jotunheimen, Southern Norway—Validation of a 14C Dating Technique for Glacier Ice

Cited by 5 publications

References 21 publications

Diurnal cycle of fossil and nonfossil carbon using radiocarbon analyses during CalNex

Diurnal cycle of fossil and nonfossil carbon using radiocarbon analyses during CalNex

Sources and contributions of wood smoke during winter in London: assessing local and regional influences

Sources and contributions of wood smoke during winter in London: assessing local and regional influences

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¹⁴C Measurements of Ice Samples from the Juvfonne Ice Tunnel, Jotunheimen, Southern Norway—Validation of a ¹⁴C Dating Technique for Glacier Ice