Eastwood Michael L, Thompson David R, Green Robert O, Fahlen Jay E, Adams Taylor J, Brandt Adam R, Brodrick Philip G, Chlus Adam, Kort Eric A, Reuland Frances, Thorpe Andrew K
Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109.
Climate and Space Sciences and Engineering, University of Michigan, Ann Arbor, MI 48109.
Proc Natl Acad Sci U S A. 2025 Sep 9;122(36):e2507350122. doi: 10.1073/pnas.2507350122. Epub 2025 Sep 2.
An explosion of recent research uses remote imaging spectroscopy from aircraft and spacecraft to detect and quantify methane point source emissions. These instruments first map the methane enhancement field and then combine this information with the effective wind speed to estimate the source emission rate. This wind speed is typically the largest uncertainty in derived emission rates. It is often, by necessity, inferred from coarse-resolution meteorological reanalysis products which do not match the spatial or temporal extent of wind experienced by the gas plume. Here, we circumvent this problem by simultaneously measuring plume velocity using the same spectrometer that maps the methane plume. Our approach acquires multiple consecutive views of the same point source, with visual tracking of the plume's features to estimate its ground velocity. This resolves the representational mismatch between reanalysis and effective wind speeds. It provides data with exact spatiotemporal coincidence to the plume being measured. The approach facilitates dramatic improvement in the precision of remote methane point source quantification.
最近大量的研究利用来自飞机和航天器的遥感成像光谱技术来检测和量化甲烷点源排放。这些仪器首先绘制甲烷增强场图，然后将此信息与有效风速相结合，以估算源排放率。这种风速通常是推导排放率中最大的不确定因素。由于需要，它通常是从粗分辨率气象再分析产品中推断出来的，而这些产品与气团所经历的风的空间或时间范围不匹配。在此，我们通过使用绘制甲烷羽流的同一光谱仪同时测量羽流速度来规避这个问题。我们的方法获取同一点源的多个连续视图，通过对羽流特征的视觉跟踪来估算其地面速度。这解决了再分析风速与有效风速之间的代表性不匹配问题。它提供了与被测羽流在时空上精确重合的数据。该方法有助于显著提高远程甲烷点源量化的精度。
