Quantifying the loss of processed natural gas within California's South Coast Air Basin using long-term measurements of ethane and methane
Methane emissions inventories for Southern California's South Coast Air Basin (SoCAB) have underestimated emissions from atmospheric measurements. To provide insight into the sources of the discrepancy, we analyze records of atmospheric trace gas total column abundances in the SoCAB starting...
| الحاوية / القاعدة: | Atmospheric Chemistry and Physics |
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| المؤلفون الرئيسيون: | , , , , , , , , |
| التنسيق: | مقال |
| اللغة: | الإنجليزية |
| منشور في: |
Copernicus Publications
2016-11-01
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| الوصول للمادة أونلاين: | https://www.atmos-chem-phys.net/16/14091/2016/acp-16-14091-2016.pdf |
| الملخص: | Methane emissions inventories for Southern California's South Coast Air Basin (SoCAB)
have underestimated emissions from atmospheric measurements. To provide
insight into the sources of the discrepancy, we analyze records of
atmospheric trace gas total column abundances in the SoCAB starting in the
late 1980s to produce annual estimates of the ethane emissions from
1989 to 2015 and methane emissions from 2007 to 2015. The first decade of
measurements shows a rapid decline in ethane emissions coincident with
decreasing natural gas and crude oil production in the basin. Between 2010
and 2015, however, ethane emissions have grown gradually from about
13 ± 5 to about 23 ± 3 Gg yr<sup>−1</sup>, despite the steady
production of natural gas and oil over that time period. The methane
emissions record begins with 1 year of measurements in 2007 and continuous
measurements from 2011 to 2016 and shows little trend over time, with an
average emission rate of 413 ± 86 Gg yr<sup>−1</sup>. Since 2012, ethane to
methane ratios in the natural gas withdrawn from a storage facility within
the SoCAB have been increasing by 0.62 ± 0.05 % yr<sup>−1</sup>,
consistent with the ratios measured in the delivered gas. Our atmospheric
measurements also show an increase in these ratios but with a slope of
0.36 ± 0.08 % yr<sup>−1</sup>, or 58 ± 13 % of the slope
calculated from the withdrawn gas. From this, we infer that more than half of
the excess methane in the SoCAB between 2012 and 2015 is attributable to losses
from the natural gas infrastructure. |
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| تدمد: | 1680-7316 1680-7324 |