scholarly journals What’s the Average Methane Isotope Signature in Arctic Wetlands?

Eos ◽  
2017 ◽  
Author(s):  
Terri Cook
Keyword(s):  
Ground Level ◽  
Methane Emissions ◽  
Isotopic Signature ◽  
Aircraft Measurements ◽  
Isotope Signature ◽  
Carbon Isotopic ◽  
Northern European ◽  
Arctic Wetlands

Aircraft measurements confirm that methane emissions from northern European wetlands exhibit a uniform regional carbon isotopic signature, despite considerable ground-level heterogeneity.

UK landfill methane emissions: Use of mobile plume measurements and carbon isotopic characterisation to reassess oxidation rates for open and closed sites 

2021 ◽  
Author(s):  
Semra Bakkaloglu ◽  
Dave Lowry ◽  
Rebecca Fisher ◽  
James France ◽  
Euan Nisbet
Keyword(s):  
Methane Oxidation ◽  
Mole Fraction ◽  
Oxidation Rate ◽  
Methane Emissions ◽  
Isotopic Signature ◽  
Oxidation Rates ◽  
Landfill Cover ◽  
Carbon Isotopic ◽  
Landfill Sites ◽  
The Impact

<p>Biological methane oxidation in landfill cover material can be characterised using stable isotopes. Methane oxidation fraction is calculated from the carbon isotopic signature of emitted CH<sub>4</sub>, with enhanced microbial consumption of methane in the aerobic portion of the landfill cover indicated by a shift to less depleted isotopic values in the residual methane emitted to air. This study was performed at four southwest England landfill sites. Mobile mole fraction measurement at the four sites was coupled with Flexfoil bag sampling of air for high-precision isotope analysis. Gas well samples collected from the pipeline systems and downwind plume air samples were utilized to estimate methane oxidation rate for whole sites. This work was designed to assess the impact on carbon isotopic signature and oxidation rate as UK landfill practice and waste streams have changed in recent years.</p><p>The landfill status such as closed and active, seasonal variation, cap stripping and site closure impact on landfill isotopic signature and oxidation rate were evaluated. The isotopic signature of <sup>13</sup>C-CH<sub>4</sub> values of emissions varied between -60 and -54‰, with an averaged value of -57 +- 2‰ for methane from closed and active landfill sites. Methane emissions from older, closed landfill sites were typically more enriched in <sup>13</sup>C than emissions from active sites. This study found that the isotopic signature of <sup>13</sup>C-CH<sub>4</sub> of fugitive methane did not show a seasonal trend, and there was no plume observed from a partial cap stripping process to assess changes in <sup>13</sup>C-CH<sub>4</sub>  isotopic signatures of emitted methane. Also, the closure of an active landfill cell caused a significant decrease in mole fraction of measured CH<sub>4</sub>, which was less depleted <sup>13</sup>C in the emitted plume due to a higher oxidation rate. Methane oxidation, estimated from the isotope fractionation, ranged from 3 to 27%, with mean values of 7% and 15% for active and closed landfills, respectively. These results indicate that the oxidation rate is highly site specific.</p><p> </p>

scholarly journals Measurement of the 13 C isotopic signature of methane emissions from northern European wetlands

2017 ◽  
Vol 31 (3) ◽  
pp. 605-623 ◽  
Author(s):  
Rebecca E. Fisher ◽  
James L. France ◽  
David Lowry ◽  
Mathias Lanoisellé ◽  
Rebecca Brownlow ◽  
...  
Keyword(s):  
Methane Emissions ◽  
Isotopic Signature ◽  
Northern European

scholarly journals Carbon isotopic signature of coal-derived methane emissions to atmosphere: from coalification to alteration

2016 ◽  
Author(s):  
Giulia Zazzeri ◽  
Dave Lowry ◽  
Rebecca E. Fisher ◽  
James France ◽  
Mathias Lanoisellé ◽  
...  
Keyword(s):  
Coalbed Methane ◽  
Bituminous Coal ◽  
Methane Emissions ◽  
Isotopic Signature ◽  
Atmospheric Methane ◽  
Isotopic Signatures ◽  
Carbon Isotopic ◽  
The Uk ◽  
Open Cast ◽  
Fossil Fuel Emissions

Abstract. Currently, the atmospheric methane burden is rising rapidly, but the extent to which shifts in coal production contribute to this rise is not known. Coalbed methane emissions into the atmosphere are poorly characterised, and this study provides representative δ13CCH4 signatures to be used in regional and global models in order to allow better apportionment of fossil fuel emissions. Integrated methane emissions from both underground and opencast coal mines in the UK, Australia and Poland were sampled and isotopically characterised. Progression in coal rank and secondary biogenic production of methane due to incursion of water are suggested as the processes affecting the isotopic composition of coal-derived methane. An averaged value of −65 ‰ has been assigned to bituminous coal exploited in open cast mines and of −55 ‰ in deep mines, whereas values of −40 ‰ and −30 ‰ can be allocated to anthracite opencast and deep mines respectively. However, the isotopic signatures that are included in global atmospheric modelling of coal emissions should be region or nation specific, as greater detail is needed, given the wide global variation in coal type.

scholarly journals Carbon isotopic signature of coal-derived methane emissions to the atmosphere: from coalification to alteration

2016 ◽  
Vol 16 (21) ◽  
pp. 13669-13680 ◽  
Author(s):  
Giulia Zazzeri ◽  
Dave Lowry ◽  
Rebecca E. Fisher ◽  
James L. France ◽  
Mathias Lanoisellé ◽  
...  
Keyword(s):  
Coalbed Methane ◽  
Bituminous Coal ◽  
Methane Emissions ◽  
Isotopic Signature ◽  
Atmospheric Methane ◽  
Isotopic Signatures ◽  
Carbon Isotopic ◽  
The Uk ◽  
Open Cast ◽  
Coal Type

Abstract. Currently, the atmospheric methane burden is rising rapidly, but the extent to which shifts in coal production contribute to this rise is not known. Coalbed methane emissions into the atmosphere are poorly characterised, and this study provides representative δ13CCH4 signatures of methane emissions from specific coalfields. Integrated methane emissions from both underground and opencast coal mines in the UK, Australia and Poland were sampled and isotopically characterised. Progression in coal rank and secondary biogenic production of methane due to incursion of water are suggested as the processes affecting the isotopic composition of coal-derived methane. An averaged value of −65 ‰ has been assigned to bituminous coal exploited in open cast mines and of −55 ‰ in deep mines, whereas values of −40 and −30 ‰ can be allocated to anthracite opencast and deep mines respectively. However, the isotopic signatures that are included in global atmospheric modelling of coal emissions should be region- or nation-specific, as greater detail is needed, given the wide global variation in coal type.

Seasonal variations in the stable carbon isotopic signature of biogenic methane in a coastal sediment

Science ◽  
1986 ◽  
Vol 233 (4770) ◽  
pp. 1300-1303 ◽  
Author(s):  
C. Martens ◽  
N. Blair ◽  
C. Green ◽  
D. Des Marais
Keyword(s):  
Seasonal Variations ◽  
Isotopic Signature ◽  
Coastal Sediment ◽  
Stable Carbon ◽  
Biogenic Methane ◽  
Carbon Isotopic

scholarly journals An Optimized Snowmelt Lysimeter System for Monitoring Melt Rates and Collecting Samples for Stable Water Isotope Analysis

2019 ◽  
Vol 67 (1) ◽  
pp. 20-31 ◽  
Author(s):  
Andrea Rücker ◽  
Massimiliano Zappa ◽  
Stefan Boss ◽  
Jana von Freyberg
Keyword(s):  
Isotopic Composition ◽  
Isotope Analysis ◽  
Ground Level ◽  
Isotopic Signature ◽  
Small Scale ◽  
Spatial And Temporal Variability ◽  
Environmental Tracers ◽  
Hydrograph Separation ◽  
Stable Water Isotopes ◽  
Restricted Volume

Abstract The contribution of snow meltwater to catchment streamflow can be quantified through hydrograph separation analyses for which stable water isotopes (18O, 2H) are used as environmental tracers. For this, the spatial and temporal variability of the isotopic composition of meltwater needs to be captured by the sampling method. This study compares an optimized snowmelt lysimeter system and an unheated precipitation collector with focus on their ability to capture snowmelt rates and the isotopic composition of snowmelt. The snowmelt lysimeter system consists of three individual unenclosed lysimeters at ground level with a surface of 0.14 m2 each. The unheated precipitation collector consists of a 30 cm-long, extended funnel with its orifice at 2.3 m above ground. Daily snowmelt samples were collected with both systems during two snowfall-snowmelt periods in 2016. The snowmelt lysimeter system provided more accurate measurements of natural melt rates and allowed for capturing the small-scale variability of snowmelt process at the plot scale, such as lateral meltwater flow from the surrounding snowpack. Because of the restricted volume of the extended funnel, daily melt rates from the unheated precipitation collector were up to 43% smaller compared to the snowmelt lysimeter system. Overall, both snowmelt collection methods captured the general temporal evolution of the isotopic signature in snowmelt.

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