标题： 利用 Sentinel-5P 卫星对加拿大奶牛场甲烷排放进行季节性指纹识别 显示英文标题

标题： Satellite-Based Seasonal Fingerprinting of Methane Emissions from Canadian Dairy Farms Using Sentinel-5P

摘要： 甲烷 (CH4) 排放是乳品农业中一个显著但未被充分量化的主要温室气体组成部分。 本研究利用高分辨率 Sentinel-5P TROPOMI 数据，基于卫星评估了加拿大乳品业特有的甲烷排放情况。 通过整合 1,701 家乳品农场和加工企业的空间聚类分析、与非乳品参考区域配对的准实验设计以及季节性模式分解，我们分析了全国及区域层面的时空排放趋势。 结果显示，乳品区的甲烷水平持续较高（平均差异：16.99 ppb），并且有明显的秋季-冬季峰值。 值得注意的是，从 2019 年到 2024 年，定义为乳品区与非乳品区浓度差异的乳品特定甲烷异常值下降了 62.25%，其中在 2022-2023 年间急剧下降（-41.11%）。 同时，全国甲烷水平上升了 3.83%，各省之间的空间异质性增加。 基线甲烷水平与增长率之间的反向关系表明存在收敛效应。 季节性分析显示普遍春季最小值和秋季-冬季最大值，为源归因提供了独特的时序特征。 本研究展示了基于卫星监测对于政策相关的甲烷评估的价值，并引入了一种可扩展到其他地区的框架。 观察到的乳品甲烷异常值收窄表明排放动态正在演变，可能反映出基线甲烷水平上升而非乳品源排放的明确减少。 这突显了综合卫星和地面方法以增强理解和指导缓解努力的必要性。 显示英文摘要

摘要： Methane (CH4) emissions from dairy farming are a significant but under-quantified component of agricultural greenhouse gases. This study provides a satellite-based assessment of dairy-specific methane emissions across Canada using high-resolution Sentinel-5P TROPOMI data. By integrating spatial clustering of 1,701 dairy farms and processors, a quasi-experimental design with paired non-dairy reference regions, and seasonal pattern decomposition, we analyzed national and regional spatiotemporal emission trends. Results show persistently higher methane levels in dairy regions (mean difference: 16.99 ppb), with consistent fall-winter peaks. Notably, the dairy-specific methane anomaly, defined as the concentration difference between dairy and non-dairy regions declined by 62.25% from 2019 to 2024, with a sharp drop during 2022-2023 (-41.11%). Meanwhile, national methane levels rose by 3.83%, with increasing spatial heterogeneity across provinces. An inverse relationship between baseline methane levels and growth rates suggests a convergence effect. Seasonal analysis revealed universal spring minima and fall-winter maxima, offering distinct temporal signatures for source attribution. This study demonstrates the value of satellite-based monitoring for policy-relevant methane assessments and introduces a scalable framework applicable to other regions. The observed narrowing of dairy methane anomaly indicates evolving emission dynamics, potentially reflecting rising baseline methane rather than a definitive reduction in dairy source emissions. This highlights the need for integrated satellite and ground-based approaches to enhance understanding and guide mitigation efforts.