Bubbleology Research International (BRI), Solvang, CA 93463, United States.
Bubbleology Research International (BRI), Solvang, CA 93463, United States.
Environ Pollut. 2017 Feb;221:37-51. doi: 10.1016/j.envpol.2016.09.083. Epub 2016 Dec 16.
Methane (CH) and ammonia (NH) directly and indirectly affect the atmospheric radiative balance with the latter leading to aerosol generation. Both have important spectral features in the Thermal InfraRed (TIR) that can be studied by remote sensing, with NH allowing discrimination of husbandry from other CH sources. Airborne hyperspectral imagery was collected for the Chino Dairy Complex in the Los Angeles Basin as well as in situ CH, carbon dioxide (CO) and NH data. TIR data showed good spatial agreement with in situ measurements and showed significant emissions heterogeneity between dairies. Airborne remote sensing mapped plume transport for ∼20 km downwind, documenting topographic effects on plume advection. Repeated multiple gas in situ measurements showed that emissions were persistent on half-year timescales. Inversion of one dairy plume found annual emissions of 4.1 × 10 kg CH, 2.2 × 10 kg NH, and 2.3 × 10 kg CO, suggesting 2300, 4000, and 2100 head of cattle, respectively, and Chino Dairy Complex emissions of 42 Gg CH and 8.4 Gg NH implying ∼200k cows, ∼30% more than Peischl et al. (2013) estimated for June 2010. Far-field data showed chemical conversion and/or deposition of Chino NH occurs within the confines of the Los Angeles Basin on a four to six h timescale, faster than most published rates, and likely from higher Los Angeles oxidant loads. Satellite observations from 2011 to 2014 confirmed that observed in situ transport patterns were representative and suggests much of the Chino Dairy Complex emissions are driven towards eastern Orange County, with a lesser amount transported to Palm Springs, CA. Given interest in mitigating husbandry health impacts from air pollution emissions, this study highlights how satellite observations can be leveraged to understand exposure and how multiple gas in situ emissions studies can inform on best practices given that emissions reduction of one gas could increase those of others.
甲烷 (CH) 和氨 (NH) 直接和间接影响大气辐射平衡，后者导致气溶胶生成。两者在热红外 (TIR) 中都有重要的光谱特征，可以通过遥感进行研究，而 NH 则可以区分畜牧业与其他 CH 源。在洛杉矶盆地的奇诺奶牛场综合体以及现场 CH、二氧化碳 (CO) 和 NH 数据中收集了航空高光谱图像。TIR 数据与现场测量具有良好的空间一致性，并显示出奶牛场之间存在显著的排放异质性。航空遥感绘制了下风方向约 20 公里的羽流传输图，记录了地形对羽流平流的影响。多次重复的气体现场测量表明，排放物在半年的时间尺度上持续存在。对一个奶牛场羽流的反演发现，其年排放量为 4.1×10kg CH、2.2×10kg NH 和 2.3×10kg CO，分别相当于 2300 头、4000 头和 2100 头牛，奇诺奶牛场综合体的排放量为 42Gg CH 和 8.4Gg NH，这意味着大约有 20 万头牛，比 Peischl 等人（2013 年）估计的 2010 年 6 月多 30%。远场数据表明，奇诺 NH 在洛杉矶盆地范围内，在四到六个小时的时间尺度内发生化学转化和/或沉积，比大多数已发表的速率都快，可能是由于洛杉矶的氧化剂负荷较高。2011 年至 2014 年的卫星观测证实，观察到的现场传输模式具有代表性，并表明奇诺奶牛场综合体的大部分排放物都被推向了奥兰治县东部，而较少的排放物被输送到加利福尼亚州的棕榈泉。鉴于人们对减轻畜牧业空气污染排放对健康的影响感兴趣，本研究强调了如何利用卫星观测来了解暴露情况，以及如何利用多个气体现场排放研究来告知最佳实践，因为一种气体的减排可能会增加其他气体的排放。
