scholarly journals Isotopic Signatures of Methane Emissions from Dairy Farms in California's San Joaquin Valley

Author(s):  
Valerie Carranza ◽  
Brenna Biggs ◽  
Deanne Meyer ◽  
Amy Townsend‐Small ◽  
Ranga Rajan Thiruvenkatachari ◽  
...  
2021 ◽  
Author(s):  
Valerie Carranza ◽  
Brenna Biggs ◽  
Deanne Meyer ◽  
Amy Townsend-Small ◽  
Ranga Rajan Thiruvenkatachari ◽  
...  

2014 ◽  
Vol 194 ◽  
pp. 259-267 ◽  
Author(s):  
A.C. VanderZaag ◽  
T.K. Flesch ◽  
R.L. Desjardins ◽  
H. Baldé ◽  
T. Wright

2013 ◽  
Vol 13 (10) ◽  
pp. 28225-28278 ◽  
Author(s):  
D. R. Gentner ◽  
T. B. Ford ◽  
A. Guha ◽  
K. Boulanger ◽  
J. Brioude ◽  
...  

Abstract. Petroleum and dairy operations are prominent sources of gas-phase organic compounds in California's San Joaquin Valley. Ground site measurements in Bakersfield and aircraft measurements of reactive gas-phase organic compounds were made in this region as part of the CalNex (California Research at the Nexus of Air Quality and Climate Change) project to determine the sources contributing to regional gas-phase organic carbon emissions. Using a combination of near-source and downwind data, we assess the composition and magnitude of emissions from these prominent sources that are relatively understudied compared to motor vehicles We also developed a statistical modeling method with the FLEXPART-WRF transport and meteorological model using ground-based data to assess the spatial distribution of emissions in the San Joaquin Valley. We present evidence for large sources of paraffinic hydrocarbons from petroleum extraction/processing operations and oxygenated compounds from dairy (and other cattle) operations. In addition to the small straight-chain alkanes typically associated with petroleum operations, we observed a wide range of branched and cyclic alkanes that have limited previous in situ measurements or characterization in emissions from petroleum operations. Observed dairy emissions were dominated by ethanol, methanol, and acetic acid, and methane. Dairy operations were responsible for the vast majority of methane emissions in the San Joaquin Valley; observations of methane were well-correlated with non-vehicular ethanol, and multiple assessments of the spatial distribution of emissions in the San Joaquin Valley highlight the dominance of dairy operations for methane emissions. The good agreement of the observed petroleum operations source profile with the measured composition of non-methane hydrocarbons in unrefined natural gas associated with crude oil suggests a fugitive emissions pathway during petroleum extraction, storage, or processing with negligible coincident methane emissions Aircraft observations of emission hotspots from operations at oil wells and dairies are consistent with the statistical source footprint determined via transport modeling and ground-based data. At Bakersfield, petroleum and dairy operations each comprised 22–23% of anthropogenic non-methane organic carbon and were each responsible for ~12% of potential precursors to ozone, but their direct impacts as potential SOA precursors were estimated to be minor. A comparison with the California Air Resources Board emission inventory supports the current relative emission rates of reactive organic gases from these sources in the region.


2017 ◽  
Vol 122 (6) ◽  
pp. 3686-3699 ◽  
Author(s):  
Yu Yan Cui ◽  
Jerome Brioude ◽  
Wayne M. Angevine ◽  
Jeff Peischl ◽  
Stuart A. McKeen ◽  
...  

2008 ◽  
Author(s):  
Dawn Sedorovich Chianese ◽  
C Alan Rotz ◽  
Tom L Richard

2014 ◽  
Vol 14 (10) ◽  
pp. 4955-4978 ◽  
Author(s):  
D. R. Gentner ◽  
T. B. Ford ◽  
A. Guha ◽  
K. Boulanger ◽  
J. Brioude ◽  
...  

Abstract. Petroleum and dairy operations are prominent sources of gas-phase organic compounds in California's San Joaquin Valley. It is essential to understand the emissions and air quality impacts of these relatively understudied sources, especially for oil/gas operations in light of increasing US production. Ground site measurements in Bakersfield and regional aircraft measurements of reactive gas-phase organic compounds and methane were part of the CalNex (California Research at the Nexus of Air Quality and Climate Change) project to determine the sources contributing to regional gas-phase organic carbon emissions. Using a combination of near-source and downwind data, we assess the composition and magnitude of emissions, and provide average source profiles. To examine the spatial distribution of emissions in the San Joaquin Valley, we developed a statistical modeling method using ground-based data and the FLEXPART-WRF transport and meteorological model. We present evidence for large sources of paraffinic hydrocarbons from petroleum operations and oxygenated compounds from dairy (and other cattle) operations. In addition to the small straight-chain alkanes typically associated with petroleum operations, we observed a wide range of branched and cyclic alkanes, most of which have limited previous in situ measurements or characterization in petroleum operation emissions. Observed dairy emissions were dominated by ethanol, methanol, acetic acid, and methane. Dairy operations were responsible for the vast majority of methane emissions in the San Joaquin Valley; observations of methane were well correlated with non-vehicular ethanol, and multiple assessments of the spatial distribution of emissions in the San Joaquin Valley highlight the dominance of dairy operations for methane emissions. The petroleum operations source profile was developed using the composition of non-methane hydrocarbons in unrefined natural gas associated with crude oil. The observed source profile is consistent with fugitive emissions of condensate during storage or processing of associated gas following extraction and methane separation. Aircraft observations of concentration hotspots near oil wells and dairies are consistent with the statistical source footprint determined via our FLEXPART-WRF-based modeling method and ground-based data. We quantitatively compared our observations at Bakersfield to the California Air Resources Board emission inventory and find consistency for relative emission rates of reactive organic gases between the aforementioned sources and motor vehicles in the region. We estimate that petroleum and dairy operations each comprised 22% of anthropogenic non-methane organic carbon at Bakersfield and were each responsible for 8–13% of potential precursors to ozone. Yet, their direct impacts as potential secondary organic aerosol (SOA) precursors were estimated to be minor for the source profiles observed in the San Joaquin Valley.


2016 ◽  
Author(s):  
Giulia Zazzeri ◽  
Dave Lowry ◽  
Rebecca E. Fisher ◽  
James France ◽  
Mathias Lanoisellé ◽  
...  

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.


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