Quantification of CH4 coal mining emissions in Upper Silesia by passive airborne remote sensing observations with the MAMAP instrument during CoMet
Quantification of CH4 coal mining emissions in Upper Silesia by passive airborne remote sensing observations with the MAMAP instrument during CoMet
复制标题
DOI：
10.5194/acp-2020-1014
复制
发表时间：
2021-01
影响因子：
6.3
通讯作者：
S. Krautwurst;K. Gerilowski;J. Borchardt;N. Wildmann;Michał Gałkowski;J. Swolkień;J. Marshall;A. Fiehn;A. Roiger;T. Ruhtz;C. Gerbig;J. Nęcki;J. Burrows;A. Fix;H. Bovensmann
中科院分区：
文献类型：
--
作者：
S. Krautwurst;K. Gerilowski;J. Borchardt;N. Wildmann;Michał Gałkowski;J. Swolkień;J. Marshall;A. Fiehn;A. Roiger;T. Ruhtz;C. Gerbig;J. Nęcki;J. Burrows;A. Fix;H. Bovensmann
抽象的。甲烷（CH 4）是第二重要的人为温室气体，其大气浓度受人类活动的影响，具有比二氧化碳（CO2）更大的全球变暖潜力。由于甲烷在大气中的寿命相对于CO2而言较短，因此减少甲烷在大气中的丰度是短期气候缓解战略的一个有吸引力的目标。然而，要降低大气中的甲烷浓度，就必须减少其排放量，因此，了解其来源至关重要。因此，2018年初夏启动了CO2和甲烷（CoMet）活动，其主要目标是使用自上而下的方法和清单数据评估欧洲最大的CH 4排放热点之一，波兰南部的上西里西亚煤炭盆地（USCB）的排放。在这场运动中，使用了各种仪器（现场和遥感）和平台（例如，地面和空中），并辅之以支持飞行规划和解释观测结果的建模活动。因此，可以在不同的尺度上对分布在60 × 40 km 2面积上的约54个煤矿通风井的CH 4排放进行调查，范围从单个通风井到较小的通风井群到整个流域。在这项研究中，我们将专注于从光谱辐射观测，这是由一维的天底被动遥感甲烷机载MAPper（MAMAP）仪器，使用加权函数修正差分光学吸收光谱（WFM-DOAS）方法获得的CH 4柱异常。柱异常结合风激光雷达测量和反演横截面通量不同的飞行轨迹，利用质量平衡的方法。这些通量随后被用来评估报告的排放量的小集群的通风井。MAMAP CH 4柱观测允许将观测到的通量准确分配给通风井的小集群。估算了4个组群的甲烷通量，共包括23个通风井，约占目标区域采矿甲烷排放总量的40%。所使用的观察结果是在2018年5月28日至6月7日的不同日期多次飞越期间进行的。在活动期间，单个集群（或子集群）的最终平均CH 4通量范围约为1至9 t CH 4 hr-1。在不同的飞越过程中，在一个集群处观测到的通量范围可以变化多达各自平均值的50%。相关误差（1-σ）通常在平均通量的15%和59%之间，主要取决于盛行风条件、飞行轨迹的数量和通量本身的大小。比较已知的每小时排放量，在可用的情况下，显示出良好的协议与计算通量的不确定性。如果只有年度报告的排放量可供与观测值进行比较，则需要谨慎，因为一年内甚至数小时内的排放量可能会波动。为了更精确地测量排放量，并进一步将其分解，以分配给美国CB中遇到的复杂源区中的各个竖井，建议使用成像遥感仪器。
Abstract. Methane (CH4) is the second most important anthropogenic greenhouse gas, whose atmospheric concentration is modulated by human-induced activities, and it has a larger global warming potential than carbon dioxide (CO2). Because of its short atmospheric lifetime relative to that of CO2, the reduction of the atmospheric abundance of CH4 is an attractive target for short term climate mitigation strategies. However, reducing the atmospheric CH4 concentration requires a reduction of its emissions and, therefore, knowledge of its sources is essential. For this reason, the CO2 and Methane (CoMet) campaign in early summer of 2018 was initiated with the primary goal of assessing emissions of one of the largest CH4 emission hot spots in Europe, the Upper Silesian Coal Basin (USCB) in southern Poland, using top-down approaches and inventory data. In this campaign, a variety of instruments (both in situ and remote sensing) and platforms (e.g., ground-based and airborne) were deployed, which were supplemented by modeling activities supporting the flight planning and the interpretation of the observations. Consequently, CH4 emissions originating from ~54 coal mine ventilation shafts distributed over an area of around 60 × 40 km2 could be investigated on different scales, ranging from single shafts over smaller clusters up to the entire basin. In this study, we will focus on CH4 column anomalies retrieved from spectral radiance observations, which were acquired by the 1D nadir-looking passive remote sensing Methane Airborne MAPper (MAMAP) instrument, using the Weighting Function Modified Differential Optical Absorption Spectroscopy (WFM-DOAS) method. The column anomalies are combined with wind lidar measurements and inverted to cross-sectional fluxes for different flight tracks making use of a mass balance approach. These fluxes are subsequently used to assess the reported emissions of small clusters of ventilation shafts. The MAMAP CH4 column observations allow for accurate assignment of observed fluxes to small clusters of ventilation shafts. CH4 fluxes are estimated for 4 clusters comprising 23 ventilation shafts in total, which are responsible for about 40 % of the total CH4 emissions from mining in the target area. The observations used were made during multiple overflights on different days between 28 May and 7 June 2018. The final averaged CH4 fluxes for the single clusters (or sub-clusters) range from about 1 to 9 t CH4 hr−1 at the time of the campaign. The range of fluxes observed at one cluster during different overflights can vary by as much as 50 % of the respective averaged value. Associated errors (1-σ) are usually between 15 % and 59 % of the averaged flux, mainly depending on the prevailing wind conditions, the number of flight tracks, and the magnitude of the flux itself. Comparison to known hourly emissions, where available, shows good agreement with the computed fluxes within the uncertainties. In the case that only annually reported emissions are available for comparison with the observations, caution is required due to potential fluctuations of the emissions during one year or even within hours. To measure emissions even more precisely and to further unravel them for allocation to individual shafts in a complex source region as encountered in the USCB, imaging remote sensing instruments are recommended.