†Atmospheric, Oceanic, and Space Sciences, University of Michigan, Ann Arbor, Michigan 48109, United States.
‡CIRES, University of Colorado, Boulder, Colorado 80309, United States.
Environ Sci Technol. 2015 Jul 7;49(13):8158-66. doi: 10.1021/acs.est.5b00219.
We present high time resolution airborne ethane (C2H6) and methane (CH4) measurements made in March and October 2013 as part of the Barnett Coordinated Campaign over the Barnett Shale formation in Texas. Ethane fluxes are quantified using a downwind flight strategy, a first demonstration of this approach for C2H6. Additionally, ethane-to-methane emissions ratios (C2H6:CH4) of point sources were observationally determined from simultaneous airborne C2H6 and CH4 measurements during a survey flight over the source region. Distinct C2H6:CH4 × 100% molar ratios of 0.0%, 1.8%, and 9.6%, indicative of microbial, low-C2H6 fossil, and high-C2H6 fossil sources, respectively, emerged in observations over the emissions source region of the Barnett Shale. Ethane-to-methane correlations were used in conjunction with C2H6 and CH4 fluxes to quantify the fraction of CH4 emissions derived from fossil and microbial sources. On the basis of two analyses, we find 71-85% of the observed methane emissions quantified in the Barnett Shale are derived from fossil sources. The average ethane flux observed from the studied region of the Barnett Shale was 6.6 ± 0.2 × 10(3) kg hr(-1) and consistent across six days in spring and fall of 2013.
我们呈现了 2013 年 3 月和 10 月在德克萨斯州 Barnett Shale 地区进行的高时间分辨率机载乙烷（C2H6）和甲烷（CH4）测量结果，这是 Barnett 协调行动的一部分。乙烷通量是使用下风飞行策略定量的，这是首次对此方法进行 C2H6 的演示。此外，在对源区进行的一次调查飞行中，通过同时进行机载 C2H6 和 CH4 测量，从点源观测到了乙烷与甲烷排放比（C2H6:CH4）。在 Barnett Shale 的排放源区上空的观测中，出现了分别指示微生物、低 C2H6 化石和高 C2H6 化石源的独特 C2H6:CH4×100%摩尔比 0.0%、1.8%和 9.6%。乙烷-甲烷相关性与 C2H6 和 CH4 通量结合使用，以量化来自化石和微生物源的 CH4 排放的分数。基于两种分析，我们发现 Barnett Shale 中定量的甲烷排放中有 71-85%源自化石源。从 Barnett Shale 研究区域观测到的平均乙烷通量为 6.6±0.2×10(3)kg hr(-1)，在 2013 年春季和秋季的六天内是一致的。
